Merge pull request #1 from google/beta-3

Beta 3

170 files changed, 15284 insertions, 5896 deletions

diff --git a/java/core/generate-sources-build.xml b/java/core/generate-sources-build.xml
new file mode 100644
index 00000000..0996e5ff
--- /dev/null
+++ b/java/core/generate-sources-build.xml
@@ -0,0 +1,20 @@
+<project name="generate-sources">
+    <echo message="Running protoc ..."/>
+    <mkdir dir="${generated.sources.dir}"/>
+    <exec executable="${protoc}">
+        <arg value="--java_out=${generated.sources.dir}"/>
+        <arg value="--proto_path=${protobuf.source.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/any.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/api.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/descriptor.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/duration.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/empty.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/field_mask.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/source_context.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/struct.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/timestamp.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/type.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/wrappers.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/compiler/plugin.proto"/>
+    </exec>
+</project>
\ No newline at end of file
diff --git a/java/core/generate-test-sources-build.xml b/java/core/generate-test-sources-build.xml
new file mode 100644
index 00000000..ab415db6
--- /dev/null
+++ b/java/core/generate-test-sources-build.xml
@@ -0,0 +1,43 @@
+<project name="generate-test-sources">
+    <mkdir dir="${generated.testsources.dir}"/>
+    <exec executable="${protoc}">
+        <arg value="--java_out=${generated.testsources.dir}"/>
+        <arg value="--proto_path=${protobuf.source.dir}"/>
+        <arg value="--proto_path=${test.proto.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_public.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_mset.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_mset_wire_format.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_optimize_for.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_custom_options.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_public_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_lite_imports_nonlite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_enormous_descriptor.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_no_generic_services.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_well_known_types.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/lazy_fields_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/lite_equals_and_hash.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/multiple_files_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_builders_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_extension.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_extension_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/non_nested_extension.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/non_nested_extension_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test2.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test3.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_bad_identifiers.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_check_utf8.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_check_utf8_size.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_custom_options.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/any_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/field_presence_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_for_proto2_lite_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_for_proto2_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_initialization_order_test.proto"/>
+    </exec>
+</project>
\ No newline at end of file
diff --git a/java/core/pom.xml b/java/core/pom.xml
new file mode 100644
index 00000000..0d4c5c75
--- /dev/null
+++ b/java/core/pom.xml
@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-parent</artifactId>
+    <version>3.0.0-beta-3</version>
+  </parent>
+
+  <artifactId>protobuf-java</artifactId>
+  <packaging>bundle</packaging>
+
+  <name>Protocol Buffers [Core]</name>
+  <description>
+    Core Protocol Buffers library. Protocol Buffers are a way of encoding structured data in an
+    efficient yet extensible format.
+  </description>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymock</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymockclassextension</artifactId>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <!-- Include core protos in the bundle as resources -->
+    <resources>
+      <resource>
+        <directory>${protobuf.source.dir}</directory>
+        <includes>
+          <include>google/protobuf/any.proto</include>
+          <include>google/protobuf/api.proto</include>
+          <include>google/protobuf/descriptor.proto</include>
+          <include>google/protobuf/duration.proto</include>
+          <include>google/protobuf/empty.proto</include>
+          <include>google/protobuf/field_mask.proto</include>
+          <include>google/protobuf/source_context.proto</include>
+          <include>google/protobuf/struct.proto</include>
+          <include>google/protobuf/timestamp.proto</include>
+          <include>google/protobuf/type.proto</include>
+          <include>google/protobuf/wrappers.proto</include>
+          <include>google/protobuf/compiler/plugin.proto</include>
+        </includes>
+      </resource>
+    </resources>
+
+    <plugins>
+      <!-- Use Antrun plugin to generate sources with protoc -->
+      <plugin>
+        <artifactId>maven-antrun-plugin</artifactId>
+        <executions>
+          <!-- Generate core protos -->
+          <execution>
+            <id>generate-sources</id>
+            <phase>generate-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="generate-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+
+          <!-- Generate the test protos -->
+          <execution>
+            <id>generate-test-sources</id>
+            <phase>generate-test-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="generate-test-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+
+      <!-- Add the generated sources to the build -->
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <generatedSourcesDirectory>${generated.sources.dir}</generatedSourcesDirectory>
+          <generatedTestSourcesDirectory>${generated.testsources.dir}</generatedTestSourcesDirectory>
+        </configuration>
+      </plugin>
+
+      <!-- OSGI bundle configuration -->
+      <plugin>
+        <groupId>org.apache.felix</groupId>
+        <artifactId>maven-bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <instructions>
+            <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
+            <Bundle-SymbolicName>com.google.protobuf</Bundle-SymbolicName>
+            <Export-Package>com.google.protobuf;version=${project.version}</Export-Package>
+          </instructions>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>
diff --git a/java/src/main/java/com/google/protobuf/AbstractMessage.java b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
index cc89173a..03c0d579 100644
--- a/java/src/main/java/com/google/protobuf/AbstractMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
@@ -30,6 +30,7 @@
 
 package com.google.protobuf;
 
+import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
 import com.google.protobuf.Internal.EnumLite;
@@ -49,17 +50,23 @@ import java.util.Map;
  *
  * @author kenton@google.com Kenton Varda
  */
-public abstract class AbstractMessage extends AbstractMessageLite
-                                      implements Message {
+public abstract class AbstractMessage
+    // TODO(dweis): Update GeneratedMessage to parameterize with MessageType and BuilderType.
+    extends AbstractMessageLite
+    implements Message {
+  
+  @Override
   public boolean isInitialized() {
     return MessageReflection.isInitialized(this);
   }
 
 
+  @Override
   public List<String> findInitializationErrors() {
     return MessageReflection.findMissingFields(this);
   }
 
+  @Override
   public String getInitializationErrorString() {
     return MessageReflection.delimitWithCommas(findInitializationErrors());
   }
@@ -82,12 +89,14 @@ public abstract class AbstractMessage extends AbstractMessageLite
     return TextFormat.printToString(this);
   }
 
+  @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
     MessageReflection.writeMessageTo(this, getAllFields(), output, false);
   }
 
   protected int memoizedSize = -1;
 
+  @Override
   public int getSerializedSize() {
     int size = memoizedSize;
     if (size != -1) {
@@ -161,10 +170,18 @@ public abstract class AbstractMessage extends AbstractMessageLite
     Descriptors.Descriptor descriptor = entry.getDescriptorForType();
     Descriptors.FieldDescriptor key = descriptor.findFieldByName("key");
     Descriptors.FieldDescriptor value = descriptor.findFieldByName("value");
-    result.put(entry.getField(key), entry.getField(value));
+    Object fieldValue = entry.getField(value);
+    if (fieldValue instanceof EnumValueDescriptor) {
+      fieldValue = ((EnumValueDescriptor) fieldValue).getNumber();
+    }
+    result.put(entry.getField(key), fieldValue);
     while (iterator.hasNext()) {
       entry = (Message) iterator.next();
-      result.put(entry.getField(key), entry.getField(value));
+      fieldValue = entry.getField(value);
+      if (fieldValue instanceof EnumValueDescriptor) {
+        fieldValue = ((EnumValueDescriptor) fieldValue).getNumber();
+      }
+      result.put(entry.getField(key), fieldValue);
     }
     return result;
   }
@@ -279,8 +296,8 @@ public abstract class AbstractMessage extends AbstractMessageLite
    * other methods.
    */
   @SuppressWarnings("unchecked")
-  public static abstract class Builder<BuilderType extends Builder>
-      extends AbstractMessageLite.Builder<BuilderType>
+  public static abstract class Builder<BuilderType extends Builder<BuilderType>>
+      extends AbstractMessageLite.Builder
       implements Message.Builder {
     // The compiler produces an error if this is not declared explicitly.
     @Override
@@ -305,6 +322,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
       throw new UnsupportedOperationException("clearOneof() is not implemented.");
     }
 
+    @Override
     public BuilderType clear() {
       for (final Map.Entry<FieldDescriptor, Object> entry :
            getAllFields().entrySet()) {
@@ -313,14 +331,22 @@ public abstract class AbstractMessage extends AbstractMessageLite
       return (BuilderType) this;
     }
 
+    @Override
     public List<String> findInitializationErrors() {
       return MessageReflection.findMissingFields(this);
     }
 
+    @Override
     public String getInitializationErrorString() {
       return MessageReflection.delimitWithCommas(findInitializationErrors());
     }
+    
+    @Override
+    protected BuilderType internalMergeFrom(AbstractMessageLite other) {
+      return mergeFrom((Message) other);
+    }
 
+    @Override
     public BuilderType mergeFrom(final Message other) {
       if (other.getDescriptorForType() != getDescriptorForType()) {
         throw new IllegalArgumentException(
@@ -398,6 +424,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
       return (BuilderType) this;
     }
 
+    @Override
     public BuilderType mergeUnknownFields(final UnknownFieldSet unknownFields) {
       setUnknownFields(
         UnknownFieldSet.newBuilder(getUnknownFields())
@@ -406,17 +433,19 @@ public abstract class AbstractMessage extends AbstractMessageLite
       return (BuilderType) this;
     }
 
+    @Override
     public Message.Builder getFieldBuilder(final FieldDescriptor field) {
       throw new UnsupportedOperationException(
           "getFieldBuilder() called on an unsupported message type.");
     }
 
-    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field,
-        int index) {
+    @Override
+    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field, int index) {
       throw new UnsupportedOperationException(
           "getRepeatedFieldBuilder() called on an unsupported message type.");
     }
 
+    @Override
     public String toString() {
       return TextFormat.printToString(this);
     }
@@ -453,7 +482,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
     @Override
     public BuilderType mergeFrom(final ByteString data)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data);
+      return (BuilderType) super.mergeFrom(data);
     }
 
     @Override
@@ -461,20 +490,20 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final ByteString data,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, extensionRegistry);
+      return (BuilderType) super.mergeFrom(data, extensionRegistry);
     }
 
     @Override
     public BuilderType mergeFrom(final byte[] data)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data);
+      return (BuilderType) super.mergeFrom(data);
     }
 
     @Override
     public BuilderType mergeFrom(
         final byte[] data, final int off, final int len)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, off, len);
+      return (BuilderType) super.mergeFrom(data, off, len);
     }
 
     @Override
@@ -482,7 +511,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final byte[] data,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, extensionRegistry);
+      return (BuilderType) super.mergeFrom(data, extensionRegistry);
     }
 
     @Override
@@ -490,13 +519,13 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final byte[] data, final int off, final int len,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, off, len, extensionRegistry);
+      return (BuilderType) super.mergeFrom(data, off, len, extensionRegistry);
     }
 
     @Override
     public BuilderType mergeFrom(final InputStream input)
         throws IOException {
-      return super.mergeFrom(input);
+      return (BuilderType) super.mergeFrom(input);
     }
 
     @Override
@@ -504,7 +533,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final InputStream input,
         final ExtensionRegistryLite extensionRegistry)
         throws IOException {
-      return super.mergeFrom(input, extensionRegistry);
+      return (BuilderType) super.mergeFrom(input, extensionRegistry);
     }
 
     @Override
diff --git a/java/src/main/java/com/google/protobuf/AbstractMessageLite.java b/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
index 12384983..43736dd1 100644
--- a/java/src/main/java/com/google/protobuf/AbstractMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
@@ -43,9 +43,13 @@ import java.util.Collection;
  *
  * @author kenton@google.com Kenton Varda
  */
-public abstract class AbstractMessageLite implements MessageLite {
+public abstract class AbstractMessageLite<
+    MessageType extends AbstractMessageLite<MessageType, BuilderType>,
+    BuilderType extends AbstractMessageLite.Builder<MessageType, BuilderType>> 
+        implements MessageLite {
   protected int memoizedHashCode = 0;
-
+  
+  @Override
   public ByteString toByteString() {
     try {
       final ByteString.CodedBuilder out =
@@ -59,6 +63,7 @@ public abstract class AbstractMessageLite implements MessageLite {
     }
   }
 
+  @Override
   public byte[] toByteArray() {
     try {
       final byte[] result = new byte[getSerializedSize()];
@@ -73,6 +78,7 @@ public abstract class AbstractMessageLite implements MessageLite {
     }
   }
 
+  @Override
   public void writeTo(final OutputStream output) throws IOException {
     final int bufferSize =
         CodedOutputStream.computePreferredBufferSize(getSerializedSize());
@@ -82,6 +88,7 @@ public abstract class AbstractMessageLite implements MessageLite {
     codedOutput.flush();
   }
 
+  @Override
   public void writeDelimitedTo(final OutputStream output) throws IOException {
     final int serialized = getSerializedSize();
     final int bufferSize = CodedOutputStream.computePreferredBufferSize(
@@ -120,25 +127,27 @@ public abstract class AbstractMessageLite implements MessageLite {
    * other methods.
    */
   @SuppressWarnings("unchecked")
-  public static abstract class Builder<BuilderType extends Builder>
+  public abstract static class Builder<
+      MessageType extends AbstractMessageLite<MessageType, BuilderType>,
+      BuilderType extends Builder<MessageType, BuilderType>>
       implements MessageLite.Builder {
     // The compiler produces an error if this is not declared explicitly.
     @Override
     public abstract BuilderType clone();
 
-    public BuilderType mergeFrom(final CodedInputStream input)
-                                 throws IOException {
+    @Override
+    public BuilderType mergeFrom(final CodedInputStream input) throws IOException {
       return mergeFrom(input, ExtensionRegistryLite.getEmptyRegistry());
     }
 
     // Re-defined here for return type covariance.
+    @Override
     public abstract BuilderType mergeFrom(
-        final CodedInputStream input,
-        final ExtensionRegistryLite extensionRegistry)
+        final CodedInputStream input, final ExtensionRegistryLite extensionRegistry)
         throws IOException;
 
-    public BuilderType mergeFrom(final ByteString data)
-        throws InvalidProtocolBufferException {
+    @Override
+    public BuilderType mergeFrom(final ByteString data) throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input = data.newCodedInput();
         mergeFrom(input);
@@ -153,9 +162,9 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
+    @Override
     public BuilderType mergeFrom(
-        final ByteString data,
-        final ExtensionRegistryLite extensionRegistry)
+        final ByteString data, final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input = data.newCodedInput();
@@ -171,14 +180,14 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
-    public BuilderType mergeFrom(final byte[] data)
-        throws InvalidProtocolBufferException {
+    @Override
+    public BuilderType mergeFrom(final byte[] data) throws InvalidProtocolBufferException {
       return mergeFrom(data, 0, data.length);
     }
 
-    public BuilderType mergeFrom(final byte[] data, final int off,
-                                 final int len)
-                                 throws InvalidProtocolBufferException {
+    @Override
+    public BuilderType mergeFrom(final byte[] data, final int off, final int len)
+        throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input =
             CodedInputStream.newInstance(data, off, len);
@@ -194,15 +203,17 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
-    public BuilderType mergeFrom(
-        final byte[] data,
-        final ExtensionRegistryLite extensionRegistry)
+    @Override
+    public BuilderType mergeFrom(final byte[] data, final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       return mergeFrom(data, 0, data.length, extensionRegistry);
     }
 
+    @Override
     public BuilderType mergeFrom(
-        final byte[] data, final int off, final int len,
+        final byte[] data,
+        final int off,
+        final int len,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       try {
@@ -220,6 +231,7 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
+    @Override
     public BuilderType mergeFrom(final InputStream input) throws IOException {
       final CodedInputStream codedInput = CodedInputStream.newInstance(input);
       mergeFrom(codedInput);
@@ -227,10 +239,9 @@ public abstract class AbstractMessageLite implements MessageLite {
       return (BuilderType) this;
     }
 
+    @Override
     public BuilderType mergeFrom(
-        final InputStream input,
-        final ExtensionRegistryLite extensionRegistry)
-        throws IOException {
+        final InputStream input, final ExtensionRegistryLite extensionRegistry) throws IOException {
       final CodedInputStream codedInput = CodedInputStream.newInstance(input);
       mergeFrom(codedInput, extensionRegistry);
       codedInput.checkLastTagWas(0);
@@ -292,10 +303,9 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
+    @Override
     public boolean mergeDelimitedFrom(
-        final InputStream input,
-        final ExtensionRegistryLite extensionRegistry)
-        throws IOException {
+        final InputStream input, final ExtensionRegistryLite extensionRegistry) throws IOException {
       final int firstByte = input.read();
       if (firstByte == -1) {
         return false;
@@ -306,11 +316,24 @@ public abstract class AbstractMessageLite implements MessageLite {
       return true;
     }
 
-    public boolean mergeDelimitedFrom(final InputStream input)
-        throws IOException {
+    @Override
+    public boolean mergeDelimitedFrom(final InputStream input) throws IOException {
       return mergeDelimitedFrom(input,
           ExtensionRegistryLite.getEmptyRegistry());
     }
+    
+    @Override
+    @SuppressWarnings("unchecked") // isInstance takes care of this
+    public BuilderType mergeFrom(final MessageLite other) {
+      if (!getDefaultInstanceForType().getClass().isInstance(other)) {
+        throw new IllegalArgumentException(
+            "mergeFrom(MessageLite) can only merge messages of the same type.");
+      }
+        
+      return internalMergeFrom((MessageType) other);
+    }
+    
+    protected abstract BuilderType internalMergeFrom(MessageType message);
 
     /**
      * Construct an UninitializedMessageException reporting missing fields in
diff --git a/java/src/main/java/com/google/protobuf/AbstractParser.java b/java/core/src/main/java/com/google/protobuf/AbstractParser.java
index 1a4c6311..66b0ee3b 100644
--- a/java/src/main/java/com/google/protobuf/AbstractParser.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractParser.java
@@ -78,26 +78,27 @@ public abstract class AbstractParser<MessageType extends MessageLite>
   private static final ExtensionRegistryLite EMPTY_REGISTRY
       = ExtensionRegistryLite.getEmptyRegistry();
 
+  @Override
   public MessageType parsePartialFrom(CodedInputStream input)
       throws InvalidProtocolBufferException {
     return parsePartialFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(CodedInputStream input,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialFrom(input, extensionRegistry));
   }
 
-  public MessageType parseFrom(CodedInputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(CodedInputStream input) throws InvalidProtocolBufferException {
     return parseFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(ByteString data,
-                                      ExtensionRegistryLite extensionRegistry)
-    throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
     MessageType message;
     try {
       CodedInputStream input = data.newCodedInput();
@@ -113,24 +114,25 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     }
   }
 
-  public MessageType parsePartialFrom(ByteString data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(ByteString data) throws InvalidProtocolBufferException {
     return parsePartialFrom(data, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(ByteString data,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(parsePartialFrom(data, extensionRegistry));
   }
 
-  public MessageType parseFrom(ByteString data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(ByteString data) throws InvalidProtocolBufferException {
     return parseFrom(data, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(byte[] data, int off, int len,
-                                      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parsePartialFrom(
+      byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     try {
       CodedInputStream input = CodedInputStream.newInstance(data, off, len);
@@ -146,47 +148,50 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     }
   }
 
+  @Override
   public MessageType parsePartialFrom(byte[] data, int off, int len)
       throws InvalidProtocolBufferException {
     return parsePartialFrom(data, off, len, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(byte[] data,
-                                      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parsePartialFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return parsePartialFrom(data, 0, data.length, extensionRegistry);
   }
 
-  public MessageType parsePartialFrom(byte[] data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(byte[] data) throws InvalidProtocolBufferException {
     return parsePartialFrom(data, 0, data.length, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(byte[] data, int off, int len,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(
+      byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialFrom(data, off, len, extensionRegistry));
   }
 
+  @Override
   public MessageType parseFrom(byte[] data, int off, int len)
       throws InvalidProtocolBufferException {
     return parseFrom(data, off, len, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(byte[] data,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return parseFrom(data, 0, data.length, extensionRegistry);
   }
 
-  public MessageType parseFrom(byte[] data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(byte[] data) throws InvalidProtocolBufferException {
     return parseFrom(data, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(InputStream input,
-                                      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parsePartialFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     CodedInputStream codedInput = CodedInputStream.newInstance(input);
     MessageType message = parsePartialFrom(codedInput, extensionRegistry);
@@ -198,26 +203,26 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     return message;
   }
 
-  public MessageType parsePartialFrom(InputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(InputStream input) throws InvalidProtocolBufferException {
     return parsePartialFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(InputStream input,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialFrom(input, extensionRegistry));
   }
 
-  public MessageType parseFrom(InputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(InputStream input) throws InvalidProtocolBufferException {
     return parseFrom(input, EMPTY_REGISTRY);
   }
 
+  @Override
   public MessageType parsePartialDelimitedFrom(
-      InputStream input,
-      ExtensionRegistryLite extensionRegistry)
+      InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     int size;
     try {
@@ -233,21 +238,21 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     return parsePartialFrom(limitedInput, extensionRegistry);
   }
 
+  @Override
   public MessageType parsePartialDelimitedFrom(InputStream input)
       throws InvalidProtocolBufferException {
     return parsePartialDelimitedFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parseDelimitedFrom(
-      InputStream input,
-      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseDelimitedFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialDelimitedFrom(input, extensionRegistry));
   }
 
-  public MessageType parseDelimitedFrom(InputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseDelimitedFrom(InputStream input) throws InvalidProtocolBufferException {
     return parseDelimitedFrom(input, EMPTY_REGISTRY);
   }
 }
diff --git a/java/src/main/java/com/google/protobuf/AbstractProtobufList.java b/java/core/src/main/java/com/google/protobuf/AbstractProtobufList.java
index bb6446b2..b17db6e0 100644
--- a/java/src/main/java/com/google/protobuf/AbstractProtobufList.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractProtobufList.java
@@ -34,19 +34,25 @@ import com.google.protobuf.Internal.ProtobufList;
 
 import java.util.AbstractList;
 import java.util.Collection;
+import java.util.List;
+import java.util.RandomAccess;
 
 /**
  * An abstract implementation of {@link ProtobufList} which manages mutability semantics. All mutate
- * methods are check if the list is mutable before proceeding. Subclasses must invoke
+ * methods must check if the list is mutable before proceeding. Subclasses must invoke
  * {@link #ensureIsMutable()} manually when overriding those methods.
+ * <p>
+ * This implementation assumes all subclasses are array based, supporting random access.
  */
 abstract class AbstractProtobufList<E> extends AbstractList<E> implements ProtobufList<E> {
 
+  protected static final int DEFAULT_CAPACITY = 10;
+
   /**
    * Whether or not this list is modifiable.
    */
   private boolean isMutable;
-  
+
   /**
    * Constructs a mutable list by default.
    */
@@ -55,6 +61,44 @@ abstract class AbstractProtobufList<E> extends AbstractList<E> implements Protob
   }
 
   @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof List)) {
+      return false;
+    }
+    // Handle lists that do not support RandomAccess as efficiently as possible by using an iterator
+    // based approach in our super class. Otherwise our index based approach will avoid those
+    // allocations.
+    if (!(o instanceof RandomAccess)) {
+      return super.equals(o);
+    }
+
+    List<?> other = (List<?>) o;
+    final int size = size();
+    if (size != other.size()) {
+      return false;
+    }
+    for (int i = 0; i < size; i++) {
+      if (!get(i).equals(other.get(i))) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    final int size = size();
+    int hashCode = 1;
+    for (int i = 0; i < size; i++) {
+      hashCode = (31 * hashCode) + get(i).hashCode();
+    }
+    return hashCode;
+  }
+
+  @Override
   public boolean add(E e) {
     ensureIsMutable();
     return super.add(e);
diff --git a/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java b/java/core/src/main/java/com/google/protobuf/BlockingRpcChannel.java
index d535efb9..d535efb9 100644
--- a/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java
+++ b/java/core/src/main/java/com/google/protobuf/BlockingRpcChannel.java
diff --git a/java/src/main/java/com/google/protobuf/BlockingService.java b/java/core/src/main/java/com/google/protobuf/BlockingService.java
index d01f0b8f..d01f0b8f 100644
--- a/java/src/main/java/com/google/protobuf/BlockingService.java
+++ b/java/core/src/main/java/com/google/protobuf/BlockingService.java
diff --git a/java/src/main/java/com/google/protobuf/BooleanArrayList.java b/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
index 45492d2f..8b2820b6 100644
--- a/java/src/main/java/com/google/protobuf/BooleanArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.BooleanList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -45,8 +44,6 @@ import java.util.RandomAccess;
 final class BooleanArrayList
     extends AbstractProtobufList<Boolean> implements BooleanList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final BooleanArrayList EMPTY_LIST = new BooleanArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -60,7 +57,7 @@ final class BooleanArrayList
    * The backing store for the list.
    */
   private boolean[] array;
-  
+
   /**
    * The size of the list distinct from the length of the array. That is, it is the number of
    * elements set in the list.
@@ -68,31 +65,60 @@ final class BooleanArrayList
   private int size;
 
   /**
-   * Constructs a new mutable {@code BooleanArrayList}.
+   * Constructs a new mutable {@code BooleanArrayList} with default capacity.
    */
   BooleanArrayList() {
-    array = new boolean[DEFAULT_CAPACITY];
-    size = 0;
+    this(new boolean[DEFAULT_CAPACITY], 0);
   }
 
   /**
-   * Constructs a new mutable {@code BooleanArrayList} containing the same elements as
-   * {@code other}.
+   * Constructs a new mutable {@code BooleanArrayList}.
    */
-  BooleanArrayList(List<Boolean> other) {
-    if (other instanceof BooleanArrayList) {
-      BooleanArrayList list = (BooleanArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new boolean[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private BooleanArrayList(boolean[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof BooleanArrayList)) {
+      return super.equals(o);
+    }
+    BooleanArrayList other = (BooleanArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final boolean[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
   }
-  
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + Internal.hashBoolean(array[i]);
+    }
+    return result;
+  }
+
+  @Override
+  public BooleanList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new BooleanArrayList(Arrays.copyOf(array, capacity), size);
+  }
+
   @Override
   public Boolean get(int index) {
     return getBoolean(index);
diff --git a/java/core/src/main/java/com/google/protobuf/ByteBufferWriter.java b/java/core/src/main/java/com/google/protobuf/ByteBufferWriter.java
new file mode 100644
index 00000000..0cc38175
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/ByteBufferWriter.java
@@ -0,0 +1,145 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.lang.Math.max;
+import static java.lang.Math.min;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.ref.SoftReference;
+import java.nio.ByteBuffer;
+
+/**
+ * Utility class to provide efficient writing of {@link ByteBuffer}s to {@link OutputStream}s.
+ */
+final class ByteBufferWriter {
+  private ByteBufferWriter() {}
+
+  /**
+   * Minimum size for a cached buffer. This prevents us from allocating buffers that are too
+   * small to be easily reused.
+   */
+  // TODO(nathanmittler): tune this property or allow configuration?
+  private static final int MIN_CACHED_BUFFER_SIZE = 1024;
+
+  /**
+   * Maximum size for a cached buffer. If a larger buffer is required, it will be allocated
+   * but not cached.
+   */
+  // TODO(nathanmittler): tune this property or allow configuration?
+  private static final int MAX_CACHED_BUFFER_SIZE = 16 * 1024;
+
+  /**
+   * The fraction of the requested buffer size under which the buffer will be reallocated.
+   */
+  // TODO(nathanmittler): tune this property or allow configuration?
+  private static final float BUFFER_REALLOCATION_THRESHOLD = 0.5f;
+
+  /**
+   * Keeping a soft reference to a thread-local buffer. This buffer is used for writing a
+   * {@link ByteBuffer} to an {@link OutputStream} when no zero-copy alternative was available.
+   * Using a "soft" reference since VMs may keep this reference around longer than "weak"
+   * (e.g. HotSpot will maintain soft references until memory pressure warrants collection).
+   */
+  private static final ThreadLocal<SoftReference<byte[]>> BUFFER =
+      new ThreadLocal<SoftReference<byte[]>>();
+
+  /**
+   * For testing purposes only. Clears the cached buffer to force a new allocation on the next
+   * invocation.
+   */
+  static void clearCachedBuffer() {
+    BUFFER.set(null);
+  }
+
+  /**
+   * Writes the remaining content of the buffer to the given stream. The buffer {@code position}
+   * will remain unchanged by this method.
+   */
+  static void write(ByteBuffer buffer, OutputStream output) throws IOException {
+    final int initialPos = buffer.position();
+    try {
+      if (buffer.hasArray()) {
+        // Optimized write for array-backed buffers.
+        // Note that we're taking the risk that a malicious OutputStream could modify the array.
+        output.write(buffer.array(), buffer.arrayOffset() + buffer.position(), buffer.remaining());
+      } else if (output instanceof FileOutputStream) {
+        // Use a channel to write out the ByteBuffer. This will automatically empty the buffer.
+        ((FileOutputStream) output).getChannel().write(buffer);
+      } else {
+        // Read all of the data from the buffer to an array.
+        // TODO(nathanmittler): Consider performance improvements for other "known" stream types.
+        final byte[] array = getOrCreateBuffer(buffer.remaining());
+        while (buffer.hasRemaining()) {
+          int length = min(buffer.remaining(), array.length);
+          buffer.get(array, 0, length);
+          output.write(array, 0, length);
+        }
+      }
+    } finally {
+      // Restore the initial position.
+      buffer.position(initialPos);
+    }
+  }
+
+  private static byte[] getOrCreateBuffer(int requestedSize) {
+    requestedSize = max(requestedSize, MIN_CACHED_BUFFER_SIZE);
+
+    byte[] buffer = getBuffer();
+    // Only allocate if we need to.
+    if (buffer == null || needToReallocate(requestedSize, buffer.length)) {
+      buffer = new byte[requestedSize];
+
+      // Only cache the buffer if it's not too big.
+      if (requestedSize <= MAX_CACHED_BUFFER_SIZE) {
+        setBuffer(buffer);
+      }
+    }
+    return buffer;
+  }
+
+  private static boolean needToReallocate(int requestedSize, int bufferLength) {
+    // First check against just the requested length to avoid the multiply.
+    return bufferLength < requestedSize
+        && bufferLength < requestedSize * BUFFER_REALLOCATION_THRESHOLD;
+  }
+
+  private static byte[] getBuffer() {
+    SoftReference<byte[]> sr = BUFFER.get();
+    return sr == null ? null : sr.get();
+  }
+
+  private static void setBuffer(byte[] value) {
+    BUFFER.set(new SoftReference<byte[]>(value));
+  }
+}
diff --git a/java/core/src/main/java/com/google/protobuf/ByteOutput.java b/java/core/src/main/java/com/google/protobuf/ByteOutput.java
new file mode 100644
index 00000000..8b7b04c8
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/ByteOutput.java
@@ -0,0 +1,116 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * An output target for raw bytes. This interface provides semantics that support two types of
+ * writing:
+ *
+ * <p/><b>Traditional write operations:</b>
+ * (as defined by {@link java.io.OutputStream}) where the target method is responsible for either
+ * copying the data or completing the write before returning from the method call.
+ *
+ * <p/><b>Lazy write operations:</b> where the caller guarantees that it will never modify the
+ * provided buffer and it can therefore be considered immutable. The target method is free to
+ * maintain a reference to the buffer beyond the scope of the method call (e.g. until the write
+ * operation completes).
+ */
+@ExperimentalApi
+public abstract class ByteOutput {
+  /**
+   * Writes a single byte.
+   *
+   * @param value the byte to be written
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void write(byte value) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} must copy {@code value} if it will
+   * not be processed prior to the return of this method call, since {@code value} may be
+   * reused/altered by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written
+   * @param offset the offset of the start of the writable range
+   * @param length the number of bytes to write starting from {@code offset}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void write(byte[] value, int offset, int length) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} is free to retain a reference to the value
+   * beyond the scope of this method call (e.g. write later) since it is considered immutable and is
+   * guaranteed not to change by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written
+   * @param offset the offset of the start of the writable range
+   * @param length the number of bytes to write starting from {@code offset}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void writeLazy(byte[] value, int offset, int length) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} must copy {@code value} if it will
+   * not be processed prior to the return of this method call, since {@code value} may be
+   * reused/altered by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written. Upon returning from this call, the {@code position} of
+   * this buffer will be set to the {@code limit}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void write(ByteBuffer value) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} is free to retain a reference to the value
+   * beyond the scope of this method call (e.g. write later) since it is considered immutable and is
+   * guaranteed not to change by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written. Upon returning from this call, the {@code position} of
+   * this buffer will be set to the {@code limit}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void writeLazy(ByteBuffer value) throws IOException;
+}
diff --git a/java/src/main/java/com/google/protobuf/ByteString.java b/java/core/src/main/java/com/google/protobuf/ByteString.java
index b092bc36..62c94508 100644
--- a/java/src/main/java/com/google/protobuf/ByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/ByteString.java
@@ -30,9 +30,12 @@
 
 package com.google.protobuf;
 
+import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.io.UnsupportedEncodingException;
@@ -40,7 +43,9 @@ import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.nio.charset.UnsupportedCharsetException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.NoSuchElementException;
@@ -81,7 +86,62 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
   /**
    * Empty {@code ByteString}.
    */
-  public static final ByteString EMPTY = new LiteralByteString(new byte[0]);
+  public static final ByteString EMPTY = new LiteralByteString(Internal.EMPTY_BYTE_ARRAY);
+  
+  /** 
+   * An interface to efficiently copy {@code byte[]}.
+   * 
+   * <p>One of the noticable costs of copying a byte[] into a new array using 
+   * {@code System.arraycopy} is nullification of a new buffer before the copy. It has been shown 
+   * the Hotspot VM is capable to intrisicfy {@code Arrays.copyOfRange} operation to avoid this
+   * expensive nullification and provide substantial performance gain. Unfortunately this does not
+   * hold on Android runtimes and could make the copy slightly slower due to additional code in
+   * the {@code Arrays.copyOfRange}. Thus we provide two different implementation for array copier
+   * for Hotspot and Android runtimes. 
+   */
+  private interface ByteArrayCopier {
+    /**
+     * Copies the specified range of the specified array into a new array
+     */
+    byte[] copyFrom(byte[] bytes, int offset, int size);
+  }
+  
+  /** Implementation of {@code ByteArrayCopier} which uses {@link System#arraycopy}. */
+  private static final class SystemByteArrayCopier implements ByteArrayCopier {
+    @Override
+    public byte[] copyFrom(byte[] bytes, int offset, int size) {
+      byte[] copy = new byte[size];
+      System.arraycopy(bytes, offset, copy, 0, size);
+      return copy;
+    }
+  }
+  
+  /** Implementation of {@code ByteArrayCopier} which uses {@link Arrays#copyOfRange}. */
+  private static final class ArraysByteArrayCopier implements ByteArrayCopier {
+    @Override
+    public byte[] copyFrom(byte[] bytes, int offset, int size) {
+      return Arrays.copyOfRange(bytes, offset, offset + size);
+    }
+  }
+  
+  private static final ByteArrayCopier byteArrayCopier;
+  static {
+    boolean isAndroid = true;
+    try {
+      Class.forName("android.content.Context");
+    } catch (ClassNotFoundException e) {
+      isAndroid = false;
+    }
+    
+    byteArrayCopier = isAndroid ? new SystemByteArrayCopier() : new ArraysByteArrayCopier();
+  }
+
+  /**
+   * Cached hash value. Intentionally accessed via a data race, which
+   * is safe because of the Java Memory Model's "no out-of-thin-air values"
+   * guarantees for ints. A value of 0 implies that the hash has not been set.
+   */
+  private int hash = 0;
 
   // This constructor is here to prevent subclassing outside of this package,
   ByteString() {}
@@ -94,7 +154,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @param index index of byte
    * @return the value
-   * @throws ArrayIndexOutOfBoundsException {@code index < 0 or index >= size}
+   * @throws IndexOutOfBoundsException {@code index < 0 or index >= size}
    */
   public abstract byte byteAt(int index);
 
@@ -105,7 +165,38 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @return the iterator
    */
-  public abstract ByteIterator iterator();
+  @Override
+  public final ByteIterator iterator() {
+    return new ByteIterator() {
+      private int position = 0;
+      private final int limit = size();
+
+      @Override
+      public boolean hasNext() {
+        return position < limit;
+      }
+
+      @Override
+      public Byte next() {
+        // Boxing calls Byte.valueOf(byte), which does not instantiate.
+        return nextByte();
+      }
+
+      @Override
+      public byte nextByte() {
+        try {
+          return byteAt(position++);
+        } catch (IndexOutOfBoundsException e) {
+          throw new NoSuchElementException(e.getMessage());
+        }
+      }
+
+      @Override
+      public void remove() {
+        throw new UnsupportedOperationException();
+      }
+    };
+  }
 
   /**
    * This interface extends {@code Iterator<Byte>}, so that we can return an
@@ -134,7 +225,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @return true if this is zero bytes long
    */
-  public boolean isEmpty() {
+  public final boolean isEmpty() {
     return size() == 0;
   }
 
@@ -150,7 +241,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @throws IndexOutOfBoundsException if {@code beginIndex < 0} or
    *     {@code beginIndex > size()}.
    */
-  public ByteString substring(int beginIndex) {
+  public final ByteString substring(int beginIndex) {
     return substring(beginIndex, size());
   }
 
@@ -175,7 +266,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *         argument is a prefix of the byte sequence represented by
    *         this string; <code>false</code> otherwise.
    */
-  public boolean startsWith(ByteString prefix) {
+  public final boolean startsWith(ByteString prefix) {
     return size() >= prefix.size() &&
            substring(0, prefix.size()).equals(prefix);
   }
@@ -189,7 +280,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *         argument is a suffix of the byte sequence represented by
    *         this string; <code>false</code> otherwise.
    */
-  public boolean endsWith(ByteString suffix) {
+  public final boolean endsWith(ByteString suffix) {
     return size() >= suffix.size() &&
         substring(size() - suffix.size()).equals(suffix);
   }
@@ -206,9 +297,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @return new {@code ByteString}
    */
   public static ByteString copyFrom(byte[] bytes, int offset, int size) {
-    byte[] copy = new byte[size];
-    System.arraycopy(bytes, offset, copy, 0, size);
-    return new LiteralByteString(copy);
+    return new LiteralByteString(byteArrayCopier.copyFrom(bytes, offset, size));
   }
 
   /**
@@ -220,6 +309,24 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
   public static ByteString copyFrom(byte[] bytes) {
     return copyFrom(bytes, 0, bytes.length);
   }
+  
+  /**
+   * Wraps the given bytes into a {@code ByteString}. Intended for internal only
+   * usage to force a classload of ByteString before LiteralByteString.
+   */
+  static ByteString wrap(byte[] bytes) {
+    // TODO(dweis): Return EMPTY when bytes are empty to reduce allocations?
+    return new LiteralByteString(bytes);
+  }
+
+  /**
+   * Wraps the given bytes into a {@code ByteString}. Intended for internal only
+   * usage to force a classload of ByteString before BoundedByteString and
+   * LiteralByteString.
+   */
+  static ByteString wrap(byte[] bytes, int offset, int length) {
+    return new BoundedByteString(bytes, offset, length);
+  }
 
   /**
    * Copies the next {@code size} bytes from a {@code java.nio.ByteBuffer} into
@@ -309,8 +416,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    */
   public static ByteString readFrom(InputStream streamToDrain)
       throws IOException {
-    return readFrom(
-        streamToDrain, MIN_READ_FROM_CHUNK_SIZE, MAX_READ_FROM_CHUNK_SIZE);
+    return readFrom(streamToDrain, MIN_READ_FROM_CHUNK_SIZE, MAX_READ_FROM_CHUNK_SIZE);
   }
 
   /**
@@ -383,10 +489,10 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
 
       if (bytesRead == 0) {
         return null;
-      } else {
-        // Always make a copy since InputStream could steal a reference to buf.
-        return ByteString.copyFrom(buf, 0, bytesRead);
       }
+
+      // Always make a copy since InputStream could steal a reference to buf.
+      return ByteString.copyFrom(buf, 0, bytesRead);
   }
 
   // =================================================================
@@ -402,12 +508,10 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @param other string to concatenate
    * @return a new {@code ByteString} instance
    */
-  public ByteString concat(ByteString other) {
-    int thisSize = size();
-    int otherSize = other.size();
-    if ((long) thisSize + otherSize >= Integer.MAX_VALUE) {
+  public final ByteString concat(ByteString other) {
+    if (Integer.MAX_VALUE - size() < other.size()) {
       throw new IllegalArgumentException("ByteString would be too long: " +
-                                         thisSize + "+" + otherSize);
+          size() + "+" + other.size());
     }
 
     return RopeByteString.concatenate(this, other);
@@ -426,29 +530,29 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @return new {@code ByteString}
    */
   public static ByteString copyFrom(Iterable<ByteString> byteStrings) {
-    Collection<ByteString> collection;
+    // Determine the size;
+    final int size;
     if (!(byteStrings instanceof Collection)) {
-      collection = new ArrayList<ByteString>();
-      for (ByteString byteString : byteStrings) {
-        collection.add(byteString);
+      int tempSize = 0;
+      for (Iterator<ByteString> iter = byteStrings.iterator(); iter.hasNext();
+          iter.next(), ++tempSize) {
       }
+      size = tempSize;
     } else {
-      collection = (Collection<ByteString>) byteStrings;
+      size = ((Collection<ByteString>) byteStrings).size();
     }
-    ByteString result;
-    if (collection.isEmpty()) {
-      result = EMPTY;
-    } else {
-      result = balancedConcat(collection.iterator(), collection.size());
+
+    if (size == 0) {
+      return EMPTY;
     }
-    return result;
+
+    return balancedConcat(byteStrings.iterator(), size);
   }
 
   // Internal function used by copyFrom(Iterable<ByteString>).
   // Create a balanced concatenation of the next "length" elements from the
   // iterable.
-  private static ByteString balancedConcat(Iterator<ByteString> iterator,
-      int length) {
+  private static ByteString balancedConcat(Iterator<ByteString> iterator, int length) {
     assert length >= 1;
     ByteString result;
     if (length == 1) {
@@ -486,25 +590,10 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @throws IndexOutOfBoundsException if an offset or size is negative or too
    *     large
    */
-  public void copyTo(byte[] target, int sourceOffset, int targetOffset,
+  public final void copyTo(byte[] target, int sourceOffset, int targetOffset,
       int numberToCopy) {
-    if (sourceOffset < 0) {
-      throw new IndexOutOfBoundsException("Source offset < 0: " + sourceOffset);
-    }
-    if (targetOffset < 0) {
-      throw new IndexOutOfBoundsException("Target offset < 0: " + targetOffset);
-    }
-    if (numberToCopy < 0) {
-      throw new IndexOutOfBoundsException("Length < 0: " + numberToCopy);
-    }
-    if (sourceOffset + numberToCopy > size()) {
-      throw new IndexOutOfBoundsException(
-          "Source end offset < 0: " + (sourceOffset + numberToCopy));
-    }
-    if (targetOffset + numberToCopy > target.length) {
-      throw new IndexOutOfBoundsException(
-          "Target end offset < 0: " + (targetOffset + numberToCopy));
-    }
+    checkRange(sourceOffset, sourceOffset + numberToCopy, size());
+    checkRange(targetOffset, targetOffset + numberToCopy, target.length);
     if (numberToCopy > 0) {
       copyToInternal(target, sourceOffset, targetOffset, numberToCopy);
     }
@@ -534,8 +623,8 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @return copied bytes
    */
-  public byte[] toByteArray() {
-    int size = size();
+  public final byte[] toByteArray() {
+    final int size = size();
     if (size == 0) {
       return Internal.EMPTY_BYTE_ARRAY;
     }
@@ -545,8 +634,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
   }
 
   /**
-   * Writes the complete contents of this byte string to
-   * the specified output stream argument.
+   * Writes a copy of the contents of this byte string to the specified output stream argument.
    *
    * @param  out  the output stream to which to write the data.
    * @throws IOException  if an I/O error occurs.
@@ -560,33 +648,36 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @param  sourceOffset offset within these bytes
    * @param  numberToWrite number of bytes to write
    * @throws IOException  if an I/O error occurs.
-   * @throws IndexOutOfBoundsException if an offset or size is negative or too
-   *     large
+   * @throws IndexOutOfBoundsException if an offset or size is negative or too large
    */
-  void writeTo(OutputStream out, int sourceOffset, int numberToWrite)
+  final void writeTo(OutputStream out, int sourceOffset, int numberToWrite)
       throws IOException {
-    if (sourceOffset < 0) {
-      throw new IndexOutOfBoundsException("Source offset < 0: " + sourceOffset);
-    }
-    if (numberToWrite < 0) {
-      throw new IndexOutOfBoundsException("Length < 0: " + numberToWrite);
-    }
-    if (sourceOffset + numberToWrite > size()) {
-      throw new IndexOutOfBoundsException(
-          "Source end offset exceeded: " + (sourceOffset + numberToWrite));
-    }
+    checkRange(sourceOffset, sourceOffset + numberToWrite, size());
     if (numberToWrite > 0) {
       writeToInternal(out, sourceOffset, numberToWrite);
     }
-
   }
 
   /**
    * Internal version of {@link #writeTo(OutputStream,int,int)} that assumes
    * all error checking has already been done.
    */
-  abstract void writeToInternal(OutputStream out, int sourceOffset,
-      int numberToWrite) throws IOException;
+  abstract void writeToInternal(OutputStream out, int sourceOffset, int numberToWrite)
+      throws IOException;
+
+  /**
+   * Writes this {@link ByteString} to the provided {@link ByteOutput}. Calling
+   * this method may result in multiple operations on the target {@link ByteOutput}.
+   *
+   * <p>This method may expose internal backing buffers of the {@link ByteString} to the {@link
+   * ByteOutput} in order to avoid additional copying overhead. It would be possible for a malicious
+   * {@link ByteOutput} to corrupt the {@link ByteString}. Use with caution!
+   *
+   * @param  byteOutput  the output target to receive the bytes
+   * @throws IOException  if an I/O error occurs
+   * @see UnsafeByteOperations#unsafeWriteTo(ByteString, ByteOutput)
+   */
+  abstract void writeTo(ByteOutput byteOutput) throws IOException;
 
   /**
    * Constructs a read-only {@code java.nio.ByteBuffer} whose content
@@ -618,7 +709,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @return new string
    * @throws UnsupportedEncodingException if charset isn't recognized
    */
-  public String toString(String charsetName)
+  public final String toString(String charsetName)
       throws UnsupportedEncodingException {
     try {
       return toString(Charset.forName(charsetName));
@@ -636,7 +727,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @param charset encode using this charset
    * @return new string
    */
-  public String toString(Charset charset) {
+  public final String toString(Charset charset) {
     return size() == 0 ? "" : toStringInternal(charset);
   }
 
@@ -657,7 +748,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @return new string using UTF-8 encoding
    */
-  public String toStringUtf8() {
+  public final String toStringUtf8() {
     return toString(Internal.UTF_8);
   }
 
@@ -716,13 +807,51 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
   public abstract boolean equals(Object o);
 
   /**
-   * Return a non-zero hashCode depending only on the sequence of bytes
-   * in this ByteString.
+   * Base class for leaf {@link ByteString}s (i.e. non-ropes).
+   */
+  abstract static class LeafByteString extends ByteString {
+    @Override
+    protected final int getTreeDepth() {
+      return 0;
+    }
+
+    @Override
+    protected final boolean isBalanced() {
+      return true;
+    }
+
+    /**
+     * Check equality of the substring of given length of this object starting at
+     * zero with another {@code ByteString} substring starting at offset.
+     *
+     * @param other  what to compare a substring in
+     * @param offset offset into other
+     * @param length number of bytes to compare
+     * @return true for equality of substrings, else false.
+     */
+    abstract boolean equalsRange(ByteString other, int offset, int length);
+  }
+
+  /**
+   * Compute the hashCode using the traditional algorithm from {@link
+   * ByteString}.
    *
-   * @return hashCode value for this object
+   * @return hashCode value
    */
   @Override
-  public abstract int hashCode();
+  public final int hashCode() {
+    int h = hash;
+
+    if (h == 0) {
+      int size = size();
+      h = partialHash(size, 0, size);
+      if (h == 0) {
+        h = 1;
+      }
+      hash = h;
+    }
+    return h;
+  }
 
   // =================================================================
   // Input stream
@@ -1034,7 +1163,9 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @return value of cached hash code or 0 if not computed yet
    */
-  protected abstract int peekCachedHashCode();
+  protected final int peekCachedHashCode() {
+    return hash;
+  }
 
   /**
    * Compute the hash across the value bytes starting with the given hash, and
@@ -1049,9 +1180,365 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    */
   protected abstract int partialHash(int h, int offset, int length);
 
+  /**
+   * Checks that the given index falls within the specified array size.
+   *
+   * @param index the index position to be tested
+   * @param size the length of the array
+   * @throws IndexOutOfBoundsException if the index does not fall within the array.
+   */
+  static void checkIndex(int index, int size) {
+    if ((index | (size - (index + 1))) < 0) {
+      if (index < 0) {
+        throw new ArrayIndexOutOfBoundsException("Index < 0: " + index);
+      }
+      throw new ArrayIndexOutOfBoundsException("Index > length: " + index + ", " + size);
+    }
+  }
+
+  /**
+   * Checks that the given range falls within the bounds of an array
+   *
+   * @param startIndex the start index of the range (inclusive)
+   * @param endIndex the end index of the range (exclusive)
+   * @param size the size of the array.
+   * @return the length of the range.
+   * @throws IndexOutOfBoundsException some or all of the range falls outside of the array.
+   */
+  static int checkRange(int startIndex, int endIndex, int size) {
+    final int length = endIndex - startIndex;
+    if ((startIndex | endIndex | length | (size - endIndex)) < 0) {
+      if (startIndex < 0) {
+        throw new IndexOutOfBoundsException("Beginning index: " + startIndex + " < 0");
+      }
+      if (endIndex < startIndex) {
+        throw new IndexOutOfBoundsException(
+            "Beginning index larger than ending index: " + startIndex + ", " + endIndex);
+      }
+      // endIndex >= size
+      throw new IndexOutOfBoundsException("End index: " + endIndex + " >= " + size);
+    }
+    return length;
+  }
+
   @Override
-  public String toString() {
+  public final String toString() {
     return String.format("<ByteString@%s size=%d>",
         Integer.toHexString(System.identityHashCode(this)), size());
   }
+  
+  /**
+   * This class implements a {@link com.google.protobuf.ByteString} backed by a
+   * single array of bytes, contiguous in memory. It supports substring by
+   * pointing to only a sub-range of the underlying byte array, meaning that a
+   * substring will reference the full byte-array of the string it's made from,
+   * exactly as with {@link String}.
+   *
+   * @author carlanton@google.com (Carl Haverl)
+   */
+  // Keep this class private to avoid deadlocks in classloading across threads as ByteString's
+  // static initializer loads LiteralByteString and another thread loads LiteralByteString.
+  private static class LiteralByteString extends ByteString.LeafByteString {
+    private static final long serialVersionUID = 1L;
+
+    protected final byte[] bytes;
+
+    /**
+     * Creates a {@code LiteralByteString} backed by the given array, without
+     * copying.
+     *
+     * @param bytes array to wrap
+     */
+    LiteralByteString(byte[] bytes) {
+      this.bytes = bytes;
+    }
+
+    @Override
+    public byte byteAt(int index) {
+      // Unlike most methods in this class, this one is a direct implementation
+      // ignoring the potential offset because we need to do range-checking in the
+      // substring case anyway.
+      return bytes[index];
+    }
+
+    @Override
+    public int size() {
+      return bytes.length;
+    }
+
+    // =================================================================
+    // ByteString -> substring
+
+    @Override
+    public final ByteString substring(int beginIndex, int endIndex) {
+      final int length = checkRange(beginIndex, endIndex, size());
+
+      if (length == 0) {
+        return ByteString.EMPTY;
+      }
+
+      return new BoundedByteString(bytes, getOffsetIntoBytes() + beginIndex, length);
+    }
+
+    // =================================================================
+    // ByteString -> byte[]
+
+    @Override
+    protected void copyToInternal(
+        byte[] target, int sourceOffset, int targetOffset, int numberToCopy) {
+      // Optimized form, not for subclasses, since we don't call
+      // getOffsetIntoBytes() or check the 'numberToCopy' parameter.
+      // TODO(nathanmittler): Is not calling getOffsetIntoBytes really saving that much?
+      System.arraycopy(bytes, sourceOffset, target, targetOffset, numberToCopy);
+    }
+
+    @Override
+    public final void copyTo(ByteBuffer target) {
+      target.put(bytes, getOffsetIntoBytes(), size()); // Copies bytes
+    }
+
+    @Override
+    public final ByteBuffer asReadOnlyByteBuffer() {
+      return ByteBuffer.wrap(bytes, getOffsetIntoBytes(), size()).asReadOnlyBuffer();
+    }
+
+    @Override
+    public final List<ByteBuffer> asReadOnlyByteBufferList() {
+      return Collections.singletonList(asReadOnlyByteBuffer());
+    }
+
+    @Override
+    public final void writeTo(OutputStream outputStream) throws IOException {
+      outputStream.write(toByteArray());
+    }
+
+    @Override
+    final void writeToInternal(OutputStream outputStream, int sourceOffset, int numberToWrite)
+        throws IOException {
+      outputStream.write(bytes, getOffsetIntoBytes() + sourceOffset, numberToWrite);
+    }
+
+    @Override
+    final void writeTo(ByteOutput output) throws IOException {
+      output.writeLazy(bytes, getOffsetIntoBytes(), size());
+    }
+
+    @Override
+    protected final String toStringInternal(Charset charset) {
+      return new String(bytes, getOffsetIntoBytes(), size(), charset);
+    }
+
+    // =================================================================
+    // UTF-8 decoding
+
+    @Override
+    public final boolean isValidUtf8() {
+      int offset = getOffsetIntoBytes();
+      return Utf8.isValidUtf8(bytes, offset, offset + size());
+    }
+
+    @Override
+    protected final int partialIsValidUtf8(int state, int offset, int length) {
+      int index = getOffsetIntoBytes() + offset;
+      return Utf8.partialIsValidUtf8(state, bytes, index, index + length);
+    }
+
+    // =================================================================
+    // equals() and hashCode()
+
+    @Override
+    public final boolean equals(Object other) {
+      if (other == this) {
+        return true;
+      }
+      if (!(other instanceof ByteString)) {
+        return false;
+      }
+
+      if (size() != ((ByteString) other).size()) {
+        return false;
+      }
+      if (size() == 0) {
+        return true;
+      }
+
+      if (other instanceof LiteralByteString) {
+        LiteralByteString otherAsLiteral = (LiteralByteString) other;
+        // If we know the hash codes and they are not equal, we know the byte
+        // strings are not equal.
+        int thisHash = peekCachedHashCode();
+        int thatHash = otherAsLiteral.peekCachedHashCode();
+        if (thisHash != 0 && thatHash != 0 && thisHash != thatHash) {
+          return false;
+        }
+
+        return equalsRange((LiteralByteString) other, 0, size());
+      } else {
+        // RopeByteString and NioByteString.
+        return other.equals(this);
+      }
+    }
+
+    /**
+     * Check equality of the substring of given length of this object starting at
+     * zero with another {@code LiteralByteString} substring starting at offset.
+     *
+     * @param other  what to compare a substring in
+     * @param offset offset into other
+     * @param length number of bytes to compare
+     * @return true for equality of substrings, else false.
+     */
+    @Override
+    final boolean equalsRange(ByteString other, int offset, int length) {
+      if (length > other.size()) {
+        throw new IllegalArgumentException("Length too large: " + length + size());
+      }
+      if (offset + length > other.size()) {
+        throw new IllegalArgumentException(
+            "Ran off end of other: " + offset + ", " + length + ", " + other.size());
+      }
+
+      if (other instanceof LiteralByteString) {
+        LiteralByteString lbsOther = (LiteralByteString) other;
+        byte[] thisBytes = bytes;
+        byte[] otherBytes = lbsOther.bytes;
+        int thisLimit = getOffsetIntoBytes() + length;
+        for (
+            int thisIndex = getOffsetIntoBytes(),
+                otherIndex = lbsOther.getOffsetIntoBytes() + offset;
+            (thisIndex < thisLimit); ++thisIndex, ++otherIndex) {
+          if (thisBytes[thisIndex] != otherBytes[otherIndex]) {
+            return false;
+          }
+        }
+        return true;
+      }
+
+      return other.substring(offset, offset + length).equals(substring(0, length));
+    }
+
+    @Override
+    protected final int partialHash(int h, int offset, int length) {
+      return Internal.partialHash(h, bytes, getOffsetIntoBytes() + offset, length);
+    }
+
+    // =================================================================
+    // Input stream
+
+    @Override
+    public final InputStream newInput() {
+      return new ByteArrayInputStream(bytes, getOffsetIntoBytes(), size()); // No copy
+    }
+
+    @Override
+    public final CodedInputStream newCodedInput() {
+      // We trust CodedInputStream not to modify the bytes, or to give anyone
+      // else access to them.
+      return CodedInputStream.newInstance(
+          bytes, getOffsetIntoBytes(), size(), true /* bufferIsImmutable */);
+    }
+
+    // =================================================================
+    // Internal methods
+
+    /**
+     * Offset into {@code bytes[]} to use, non-zero for substrings.
+     *
+     * @return always 0 for this class
+     */
+    protected int getOffsetIntoBytes() {
+      return 0;
+    }
+  }
+  
+  /**
+   * This class is used to represent the substring of a {@link ByteString} over a
+   * single byte array. In terms of the public API of {@link ByteString}, you end
+   * up here by calling {@link ByteString#copyFrom(byte[])} followed by {@link
+   * ByteString#substring(int, int)}.
+   *
+   * <p>This class contains most of the overhead involved in creating a substring
+   * from a {@link LiteralByteString}.  The overhead involves some range-checking
+   * and two extra fields.
+   *
+   * @author carlanton@google.com (Carl Haverl)
+   */
+  // Keep this class private to avoid deadlocks in classloading across threads as ByteString's
+  // static initializer loads LiteralByteString and another thread loads BoundedByteString.
+  private static final class BoundedByteString extends LiteralByteString {
+
+    private final int bytesOffset;
+    private final int bytesLength;
+
+    /**
+     * Creates a {@code BoundedByteString} backed by the sub-range of given array,
+     * without copying.
+     *
+     * @param bytes  array to wrap
+     * @param offset index to first byte to use in bytes
+     * @param length number of bytes to use from bytes
+     * @throws IllegalArgumentException if {@code offset < 0}, {@code length < 0},
+     *                                  or if {@code offset + length >
+     *                                  bytes.length}.
+     */
+    BoundedByteString(byte[] bytes, int offset, int length) {
+      super(bytes);
+      checkRange(offset, offset + length, bytes.length);
+
+      this.bytesOffset = offset;
+      this.bytesLength = length;
+    }
+
+    /**
+     * Gets the byte at the given index.
+     * Throws {@link ArrayIndexOutOfBoundsException}
+     * for backwards-compatibility reasons although it would more properly be
+     * {@link IndexOutOfBoundsException}.
+     *
+     * @param index index of byte
+     * @return the value
+     * @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size
+     */
+    @Override
+    public byte byteAt(int index) {
+      // We must check the index ourselves as we cannot rely on Java array index
+      // checking for substrings.
+      checkIndex(index, size());
+      return bytes[bytesOffset + index];
+    }
+
+    @Override
+    public int size() {
+      return bytesLength;
+    }
+
+    @Override
+    protected int getOffsetIntoBytes() {
+      return bytesOffset;
+    }
+
+    // =================================================================
+    // ByteString -> byte[]
+
+    @Override
+    protected void copyToInternal(byte[] target, int sourceOffset, int targetOffset,
+        int numberToCopy) {
+      System.arraycopy(bytes, getOffsetIntoBytes() + sourceOffset, target,
+          targetOffset, numberToCopy);
+    }
+
+    // =================================================================
+    // Serializable
+
+    private static final long serialVersionUID = 1L;
+
+    Object writeReplace() {
+      return ByteString.wrap(toByteArray());
+    }
+
+    private void readObject(@SuppressWarnings("unused") ObjectInputStream in) throws IOException {
+      throw new InvalidObjectException(
+          "BoundedByteStream instances are not to be serialized directly");
+    }
+  }
 }
diff --git a/java/src/main/java/com/google/protobuf/CodedInputStream.java b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
index d201f7c5..e8860651 100644
--- a/java/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
@@ -55,7 +55,14 @@ public final class CodedInputStream {
    * Create a new CodedInputStream wrapping the given InputStream.
    */
   public static CodedInputStream newInstance(final InputStream input) {
-    return new CodedInputStream(input);
+    return new CodedInputStream(input, BUFFER_SIZE);
+  }
+  
+  /**
+   * Create a new CodedInputStream wrapping the given InputStream.
+   */
+  static CodedInputStream newInstance(final InputStream input, int bufferSize) {
+    return new CodedInputStream(input, bufferSize);
   }
 
   /**
@@ -70,7 +77,15 @@ public final class CodedInputStream {
    */
   public static CodedInputStream newInstance(final byte[] buf, final int off,
                                              final int len) {
-    CodedInputStream result = new CodedInputStream(buf, off, len);
+    return newInstance(buf, off, len, false /* bufferIsImmutable */);
+  }
+  
+  /**
+   * Create a new CodedInputStream wrapping the given byte array slice.
+   */
+  static CodedInputStream newInstance(
+      final byte[] buf, final int off, final int len, final boolean bufferIsImmutable) {
+    CodedInputStream result = new CodedInputStream(buf, off, len, bufferIsImmutable);
     try {
       // Some uses of CodedInputStream can be more efficient if they know
       // exactly how many bytes are available.  By pushing the end point of the
@@ -113,31 +128,6 @@ public final class CodedInputStream {
     }
   }
 
-  /**
-   * Create a new CodedInputStream wrapping a LiteralByteString.
-   */
-  static CodedInputStream newInstance(LiteralByteString byteString) {
-    CodedInputStream result = new CodedInputStream(byteString);
-    try {
-      // Some uses of CodedInputStream can be more efficient if they know
-      // exactly how many bytes are available.  By pushing the end point of the
-      // buffer as a limit, we allow them to get this information via
-      // getBytesUntilLimit().  Pushing a limit that we know is at the end of
-      // the stream can never hurt, since we can never past that point anyway.
-      result.pushLimit(byteString.size());
-    } catch (InvalidProtocolBufferException ex) {
-      // The only reason pushLimit() might throw an exception here is if len
-      // is negative. Normally pushLimit()'s parameter comes directly off the
-      // wire, so it's important to catch exceptions in case of corrupt or
-      // malicious data. However, in this case, we expect that len is not a
-      // user-supplied value, so we can assume that it being negative indicates
-      // a programming error. Therefore, throwing an unchecked exception is
-      // appropriate.
-      throw new IllegalArgumentException(ex);
-    }
-    return result;
-  }
-
   // -----------------------------------------------------------------
 
   /**
@@ -378,6 +368,11 @@ public final class CodedInputStream {
       return result;
     } else if (size == 0) {
       return "";
+    } else if (size <= bufferSize) {
+      refillBuffer(size);
+      String result = new String(buffer, bufferPos, size, Internal.UTF_8);
+      bufferPos += size;
+      return result;
     } else {
       // Slow path:  Build a byte array first then copy it.
       return new String(readRawBytesSlowPath(size), Internal.UTF_8);
@@ -392,14 +387,21 @@ public final class CodedInputStream {
   public String readStringRequireUtf8() throws IOException {
     final int size = readRawVarint32();
     final byte[] bytes;
-    int pos = bufferPos;
-    if (size <= (bufferSize - pos) && size > 0) {
+    final int oldPos = bufferPos;
+    final int pos;
+    if (size <= (bufferSize - oldPos) && size > 0) {
       // Fast path:  We already have the bytes in a contiguous buffer, so
       //   just copy directly from it.
       bytes = buffer;
-      bufferPos = pos + size;
+      bufferPos = oldPos + size;
+      pos = oldPos;
     } else if (size == 0) {
       return "";
+    } else if (size <= bufferSize) {
+      refillBuffer(size);
+      bytes = buffer;
+      pos = 0;
+      bufferPos = pos + size;
     } else {
       // Slow path:  Build a byte array first then copy it.
       bytes = readRawBytesSlowPath(size);
@@ -506,7 +508,7 @@ public final class CodedInputStream {
       // Fast path:  We already have the bytes in a contiguous buffer, so
       //   just copy directly from it.
       final ByteString result = bufferIsImmutable && enableAliasing
-          ? new BoundedByteString(buffer, bufferPos, size)
+          ? ByteString.wrap(buffer, bufferPos, size)
           : ByteString.copyFrom(buffer, bufferPos, size);
       bufferPos += size;
       return result;
@@ -514,7 +516,7 @@ public final class CodedInputStream {
       return ByteString.EMPTY;
     } else {
       // Slow path:  Build a byte array first then copy it.
-      return new LiteralByteString(readRawBytesSlowPath(size));
+      return ByteString.wrap(readRawBytesSlowPath(size));
     }
   }
 
@@ -886,17 +888,18 @@ public final class CodedInputStream {
   private static final int DEFAULT_SIZE_LIMIT = 64 << 20;  // 64MB
   private static final int BUFFER_SIZE = 4096;
 
-  private CodedInputStream(final byte[] buffer, final int off, final int len) {
+  private CodedInputStream(
+      final byte[] buffer, final int off, final int len, boolean bufferIsImmutable) {
     this.buffer = buffer;
     bufferSize = off + len;
     bufferPos = off;
     totalBytesRetired = -off;
     input = null;
-    bufferIsImmutable = false;
+    this.bufferIsImmutable = bufferIsImmutable;
   }
 
-  private CodedInputStream(final InputStream input) {
-    buffer = new byte[BUFFER_SIZE];
+  private CodedInputStream(final InputStream input, int bufferSize) {
+    buffer = new byte[bufferSize];
     bufferSize = 0;
     bufferPos = 0;
     totalBytesRetired = 0;
@@ -904,15 +907,6 @@ public final class CodedInputStream {
     bufferIsImmutable = false;
   }
 
-  private CodedInputStream(final LiteralByteString byteString) {
-    buffer = byteString.bytes;
-    bufferPos = byteString.getOffsetIntoBytes();
-    bufferSize = bufferPos + byteString.size();
-    totalBytesRetired = -bufferPos;
-    input = null;
-    bufferIsImmutable = true;
-  }
-
   public void enableAliasing(boolean enabled) {
     this.enableAliasing = enabled;
   }
@@ -1056,20 +1050,6 @@ public final class CodedInputStream {
   private RefillCallback refillCallback = null;
 
   /**
-   * Ensures that at least {@code n} bytes are available in the buffer, reading
-   * more bytes from the input if necessary to make it so.  Caller must ensure
-   * that the requested space is less than BUFFER_SIZE.
-   *
-   * @throws InvalidProtocolBufferException The end of the stream or the current
-   *                                        limit was reached.
-   */
-  private void ensureAvailable(int n) throws IOException {
-    if (bufferSize - bufferPos < n) {
-      refillBuffer(n);
-    }
-  }
-
-  /**
    * Reads more bytes from the input, making at least {@code n} bytes available
    * in the buffer.  Caller must ensure that the requested space is not yet
    * available, and that the requested space is less than BUFFER_SIZE.
@@ -1180,86 +1160,97 @@ public final class CodedInputStream {
       }
     }
 
-    if (totalBytesRetired + bufferPos + size > currentLimit) {
+    // Verify that the message size so far has not exceeded sizeLimit.
+    int currentMessageSize = totalBytesRetired + bufferPos + size;
+    if (currentMessageSize > sizeLimit) {
+      throw InvalidProtocolBufferException.sizeLimitExceeded();
+    }
+
+    // Verify that the message size so far has not exceeded currentLimit.
+    if (currentMessageSize > currentLimit) {
       // Read to the end of the stream anyway.
       skipRawBytes(currentLimit - totalBytesRetired - bufferPos);
-      // Then fail.
       throw InvalidProtocolBufferException.truncatedMessage();
     }
 
-    if (size < BUFFER_SIZE) {
-      // Reading more bytes than are in the buffer, but not an excessive number
-      // of bytes.  We can safely allocate the resulting array ahead of time.
+    // We need the input stream to proceed.
+    if (input == null) {
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
 
-      // First copy what we have.
+    final int originalBufferPos = bufferPos;
+    final int bufferedBytes = bufferSize - bufferPos;
+
+    // Mark the current buffer consumed.
+    totalBytesRetired += bufferSize;
+    bufferPos = 0;
+    bufferSize = 0;
+
+    // Determine the number of bytes we need to read from the input stream.
+    int sizeLeft = size - bufferedBytes;
+    // TODO(nathanmittler): Consider using a value larger than BUFFER_SIZE.
+    if (sizeLeft < BUFFER_SIZE || sizeLeft <= input.available()) {
+      // Either the bytes we need are known to be available, or the required buffer is
+      // within an allowed threshold - go ahead and allocate the buffer now.
       final byte[] bytes = new byte[size];
-      int pos = bufferSize - bufferPos;
-      System.arraycopy(buffer, bufferPos, bytes, 0, pos);
-      bufferPos = bufferSize;
 
-      // We want to refill the buffer and then copy from the buffer into our
-      // byte array rather than reading directly into our byte array because
-      // the input may be unbuffered.
-      ensureAvailable(size - pos);
-      System.arraycopy(buffer, 0, bytes, pos, size - pos);
-      bufferPos = size - pos;
+      // Copy all of the buffered bytes to the result buffer.
+      System.arraycopy(buffer, originalBufferPos, bytes, 0, bufferedBytes);
 
-      return bytes;
-    } else {
-      // The size is very large.  For security reasons, we can't allocate the
-      // entire byte array yet.  The size comes directly from the input, so a
-      // maliciously-crafted message could provide a bogus very large size in
-      // order to trick the app into allocating a lot of memory.  We avoid this
-      // by allocating and reading only a small chunk at a time, so that the
-      // malicious message must actually *be* extremely large to cause
-      // problems.  Meanwhile, we limit the allowed size of a message elsewhere.
-
-      // Remember the buffer markers since we'll have to copy the bytes out of
-      // it later.
-      final int originalBufferPos = bufferPos;
-      final int originalBufferSize = bufferSize;
-
-      // Mark the current buffer consumed.
-      totalBytesRetired += bufferSize;
-      bufferPos = 0;
-      bufferSize = 0;
-
-      // Read all the rest of the bytes we need.
-      int sizeLeft = size - (originalBufferSize - originalBufferPos);
-      final List<byte[]> chunks = new ArrayList<byte[]>();
-
-      while (sizeLeft > 0) {
-        final byte[] chunk = new byte[Math.min(sizeLeft, BUFFER_SIZE)];
-        int pos = 0;
-        while (pos < chunk.length) {
-          final int n = (input == null) ? -1 :
-            input.read(chunk, pos, chunk.length - pos);
-          if (n == -1) {
-            throw InvalidProtocolBufferException.truncatedMessage();
-          }
-          totalBytesRetired += n;
-          pos += n;
+      // Fill the remaining bytes from the input stream.
+      int pos = bufferedBytes;
+      while (pos < bytes.length) {
+        int n = input.read(bytes, pos, size - pos);
+        if (n == -1) {
+          throw InvalidProtocolBufferException.truncatedMessage();
         }
-        sizeLeft -= chunk.length;
-        chunks.add(chunk);
+        totalBytesRetired += n;
+        pos += n;
       }
 
-      // OK, got everything.  Now concatenate it all into one buffer.
-      final byte[] bytes = new byte[size];
-
-      // Start by copying the leftover bytes from this.buffer.
-      int pos = originalBufferSize - originalBufferPos;
-      System.arraycopy(buffer, originalBufferPos, bytes, 0, pos);
+      return bytes;
+    }
 
-      // And now all the chunks.
-      for (final byte[] chunk : chunks) {
-        System.arraycopy(chunk, 0, bytes, pos, chunk.length);
-        pos += chunk.length;
+    // The size is very large.  For security reasons, we can't allocate the
+    // entire byte array yet.  The size comes directly from the input, so a
+    // maliciously-crafted message could provide a bogus very large size in
+    // order to trick the app into allocating a lot of memory.  We avoid this
+    // by allocating and reading only a small chunk at a time, so that the
+    // malicious message must actually *be* extremely large to cause
+    // problems.  Meanwhile, we limit the allowed size of a message elsewhere.
+    final List<byte[]> chunks = new ArrayList<byte[]>();
+
+    while (sizeLeft > 0) {
+      // TODO(nathanmittler): Consider using a value larger than BUFFER_SIZE.
+      final byte[] chunk = new byte[Math.min(sizeLeft, BUFFER_SIZE)];
+      int pos = 0;
+      while (pos < chunk.length) {
+        final int n = input.read(chunk, pos, chunk.length - pos);
+        if (n == -1) {
+          throw InvalidProtocolBufferException.truncatedMessage();
+        }
+        totalBytesRetired += n;
+        pos += n;
       }
+      sizeLeft -= chunk.length;
+      chunks.add(chunk);
+    }
 
-      // Done.
-      return bytes;
+    // OK, got everything.  Now concatenate it all into one buffer.
+    final byte[] bytes = new byte[size];
+
+    // Start by copying the leftover bytes from this.buffer.
+    System.arraycopy(buffer, originalBufferPos, bytes, 0, bufferedBytes);
+
+    // And now all the chunks.
+    int pos = bufferedBytes;
+    for (final byte[] chunk : chunks) {
+      System.arraycopy(chunk, 0, bytes, pos, chunk.length);
+      pos += chunk.length;
     }
+
+    // Done.
+    return bytes;
   }
 
   /**
diff --git a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
new file mode 100644
index 00000000..ad174d0f
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
@@ -0,0 +1,2664 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.lang.Math.max;
+
+import com.google.protobuf.Utf8.UnpairedSurrogateException;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.reflect.Field;
+import java.nio.BufferOverflowException;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.security.AccessController;
+import java.security.PrivilegedExceptionAction;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Encodes and writes protocol message fields.
+ *
+ * <p>This class contains two kinds of methods:  methods that write specific
+ * protocol message constructs and field types (e.g. {@link #writeTag} and
+ * {@link #writeInt32}) and methods that write low-level values (e.g.
+ * {@link #writeRawVarint32} and {@link #writeRawBytes}).  If you are
+ * writing encoded protocol messages, you should use the former methods, but if
+ * you are writing some other format of your own design, use the latter.
+ *
+ * <p>This class is totally unsynchronized.
+ */
+public abstract class CodedOutputStream extends ByteOutput {
+  private static final Logger logger = Logger.getLogger(CodedOutputStream.class.getName());
+  private static final sun.misc.Unsafe UNSAFE = getUnsafe();
+  private static final boolean HAS_UNSAFE_ARRAY_OPERATIONS = supportsUnsafeArrayOperations();
+  private static final long ARRAY_BASE_OFFSET = byteArrayBaseOffset();
+
+  private static final int FIXED_32_SIZE = 4;
+  private static final int FIXED_64_SIZE = 8;
+  private static final int MAX_VARINT_SIZE = 10;
+
+  /**
+   * @deprecated Use {@link #computeFixed32SizeNoTag(int)} instead.
+   */
+  @Deprecated
+  public static final int LITTLE_ENDIAN_32_SIZE = FIXED_32_SIZE;
+
+  /**
+   * The buffer size used in {@link #newInstance(OutputStream)}.
+   */
+  public static final int DEFAULT_BUFFER_SIZE = 4096;
+
+  /**
+   * Returns the buffer size to efficiently write dataLength bytes to this
+   * CodedOutputStream. Used by AbstractMessageLite.
+   *
+   * @return the buffer size to efficiently write dataLength bytes to this
+   *         CodedOutputStream.
+   */
+  static int computePreferredBufferSize(int dataLength) {
+    if (dataLength > DEFAULT_BUFFER_SIZE) {
+      return DEFAULT_BUFFER_SIZE;
+    }
+    return dataLength;
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} wrapping the given {@code OutputStream}.
+   *
+   * <p> NOTE: The provided {@link OutputStream} <strong>MUST NOT</strong> retain access or
+   * modify the provided byte arrays. Doing so may result in corrupted data, which would be
+   * difficult to debug.
+   */
+  public static CodedOutputStream newInstance(final OutputStream output) {
+    return newInstance(output, DEFAULT_BUFFER_SIZE);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} wrapping the given {@code OutputStream} with a given
+   * buffer size.
+   *
+   * <p> NOTE: The provided {@link OutputStream} <strong>MUST NOT</strong> retain access or
+   * modify the provided byte arrays. Doing so may result in corrupted data, which would be
+   * difficult to debug.
+   */
+  public static CodedOutputStream newInstance(final OutputStream output, final int bufferSize) {
+    return new OutputStreamEncoder(output, bufferSize);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes directly to the given
+   * byte array.  If more bytes are written than fit in the array,
+   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
+   * array is faster than writing to an {@code OutputStream}.  See also
+   * {@link ByteString#newCodedBuilder}.
+   */
+  public static CodedOutputStream newInstance(final byte[] flatArray) {
+    return newInstance(flatArray, 0, flatArray.length);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes directly to the given
+   * byte array slice.  If more bytes are written than fit in the slice,
+   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
+   * array is faster than writing to an {@code OutputStream}.  See also
+   * {@link ByteString#newCodedBuilder}.
+   */
+  public static CodedOutputStream newInstance(
+      final byte[] flatArray, final int offset, final int length) {
+    return new ArrayEncoder(flatArray, offset, length);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes to the given {@link ByteBuffer}.
+   */
+  public static CodedOutputStream newInstance(ByteBuffer byteBuffer) {
+    if (byteBuffer.hasArray()) {
+      return new NioHeapEncoder(byteBuffer);
+    }
+    return new NioEncoder(byteBuffer);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes to the given {@link ByteBuffer}.
+   *
+   * @deprecated the size parameter is no longer used since use of an internal buffer is useless
+   * (and wasteful) when writing to a {@link ByteBuffer}. Use {@link #newInstance(ByteBuffer)}
+   * instead.
+   */
+  @Deprecated
+  public static CodedOutputStream newInstance(ByteBuffer byteBuffer,
+      @SuppressWarnings("unused") int unused) {
+    return newInstance(byteBuffer);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes to the provided {@link ByteOutput}.
+   *
+   * <p> NOTE: The {@link ByteOutput} <strong>MUST NOT</strong> modify the provided buffers. Doing
+   * so may result in corrupted data, which would be difficult to debug.
+   *
+   * @param byteOutput the output target for encoded bytes.
+   * @param bufferSize the size of the internal scratch buffer to be used for string encoding.
+   * Setting this to {@code 0} will disable buffering, requiring an allocation for each encoded
+   * string.
+   */
+  static CodedOutputStream newInstance(ByteOutput byteOutput, int bufferSize) {
+    if (bufferSize < 0) {
+      throw new IllegalArgumentException("bufferSize must be positive");
+    }
+
+    return new ByteOutputEncoder(byteOutput, bufferSize);
+  }
+
+  // Disallow construction outside of this class.
+  private CodedOutputStream() {
+  }
+
+  // -----------------------------------------------------------------
+
+  /** Encode and write a tag. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeTag(int fieldNumber, int wireType) throws IOException;
+
+  /** Write an {@code int32} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeInt32(int fieldNumber, int value) throws IOException;
+
+  /** Write a {@code uint32} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeUInt32(int fieldNumber, int value) throws IOException;
+
+  /** Write a {@code sint32} field, including tag, to the stream. */
+  public final void writeSInt32(final int fieldNumber, final int value) throws IOException {
+    writeUInt32(fieldNumber, encodeZigZag32(value));
+  }
+
+  /** Write a {@code fixed32} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeFixed32(int fieldNumber, int value) throws IOException;
+
+  /** Write an {@code sfixed32} field, including tag, to the stream. */
+  public final void writeSFixed32(final int fieldNumber, final int value) throws IOException {
+    writeFixed32(fieldNumber, value);
+  }
+
+  /** Write an {@code int64} field, including tag, to the stream. */
+  public final void writeInt64(final int fieldNumber, final long value) throws IOException {
+    writeUInt64(fieldNumber, value);
+  }
+
+  /** Write a {@code uint64} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeUInt64(int fieldNumber, long value) throws IOException;
+
+  /** Write an {@code sint64} field, including tag, to the stream. */
+  public final void writeSInt64(final int fieldNumber, final long value) throws IOException {
+    writeUInt64(fieldNumber, encodeZigZag64(value));
+  }
+
+  /** Write a {@code fixed64} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeFixed64(int fieldNumber, long value) throws IOException;
+
+  /** Write an {@code sfixed64} field, including tag, to the stream. */
+  public final void writeSFixed64(final int fieldNumber, final long value) throws IOException {
+    writeFixed64(fieldNumber, value);
+  }
+
+  /** Write a {@code float} field, including tag, to the stream. */
+  public final void writeFloat(final int fieldNumber, final float value) throws IOException {
+    writeFixed32(fieldNumber, Float.floatToRawIntBits(value));
+  }
+
+  /** Write a {@code double} field, including tag, to the stream. */
+  public final void writeDouble(final int fieldNumber, final double value) throws IOException {
+    writeFixed64(fieldNumber, Double.doubleToRawLongBits(value));
+  }
+
+  /** Write a {@code bool} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeBool(int fieldNumber, boolean value) throws IOException;
+
+  /**
+   * Write an enum field, including tag, to the stream. The provided value is the numeric
+   * value used to represent the enum value on the wire (not the enum ordinal value).
+   */
+  public final void writeEnum(final int fieldNumber, final int value) throws IOException {
+    writeInt32(fieldNumber, value);
+  }
+
+  /** Write a {@code string} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeString(int fieldNumber, String value) throws IOException;
+
+  /** Write a {@code bytes} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeBytes(int fieldNumber, ByteString value) throws IOException;
+
+  /** Write a {@code bytes} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeByteArray(int fieldNumber, byte[] value) throws IOException;
+
+  /** Write a {@code bytes} field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeByteArray(int fieldNumber, byte[] value, int offset, int length)
+      throws IOException;
+
+  /**
+   * Write a {@code bytes} field, including tag, to the stream.
+   * This method will write all content of the ByteBuffer regardless of the
+   * current position and limit (i.e., the number of bytes to be written is
+   * value.capacity(), not value.remaining()). Furthermore, this method doesn't
+   * alter the state of the passed-in ByteBuffer. Its position, limit, mark,
+   * etc. will remain unchanged. If you only want to write the remaining bytes
+   * of a ByteBuffer, you can call
+   * {@code writeByteBuffer(fieldNumber, byteBuffer.slice())}.
+   */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeByteBuffer(int fieldNumber, ByteBuffer value) throws IOException;
+
+  /**
+   * Write a single byte.
+   */
+  public final void writeRawByte(final byte value) throws IOException {
+    write(value);
+  }
+
+  /** Write a single byte, represented by an integer value. */
+  public final void writeRawByte(final int value) throws IOException {
+    write((byte) value);
+  }
+
+  /** Write an array of bytes. */
+  public final void writeRawBytes(final byte[] value) throws IOException {
+    write(value, 0, value.length);
+  }
+
+  /**
+   * Write part of an array of bytes.
+   */
+  public final void writeRawBytes(final byte[] value, int offset, int length) throws IOException {
+    write(value, offset, length);
+  }
+
+  /** Write a byte string. */
+  public final void writeRawBytes(final ByteString value) throws IOException {
+    value.writeTo(this);
+  }
+
+  /**
+   * Write a ByteBuffer. This method will write all content of the ByteBuffer
+   * regardless of the current position and limit (i.e., the number of bytes
+   * to be written is value.capacity(), not value.remaining()). Furthermore,
+   * this method doesn't alter the state of the passed-in ByteBuffer. Its
+   * position, limit, mark, etc. will remain unchanged. If you only want to
+   * write the remaining bytes of a ByteBuffer, you can call
+   * {@code writeRawBytes(byteBuffer.slice())}.
+   */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeRawBytes(final ByteBuffer value) throws IOException;
+
+  /** Write an embedded message field, including tag, to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeMessage(final int fieldNumber, final MessageLite value)
+      throws IOException;
+
+  /**
+   * Write a MessageSet extension field to the stream.  For historical reasons,
+   * the wire format differs from normal fields.
+   */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeMessageSetExtension(final int fieldNumber, final MessageLite value)
+      throws IOException;
+
+  /**
+   * Write an unparsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeRawMessageSetExtension(final int fieldNumber, final ByteString value)
+      throws IOException;
+
+  // -----------------------------------------------------------------
+
+  /** Write an {@code int32} field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeInt32NoTag(final int value) throws IOException;
+
+  /** Write a {@code uint32} field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeUInt32NoTag(int value) throws IOException;
+
+  /** Write a {@code sint32} field to the stream. */
+  public final void writeSInt32NoTag(final int value) throws IOException {
+    writeUInt32NoTag(encodeZigZag32(value));
+  }
+
+  /** Write a {@code fixed32} field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeFixed32NoTag(int value) throws IOException;
+
+  /** Write a {@code sfixed32} field to the stream. */
+  public final void writeSFixed32NoTag(final int value) throws IOException {
+    writeFixed32NoTag(value);
+  }
+
+  /** Write an {@code int64} field to the stream. */
+  public final void writeInt64NoTag(final long value) throws IOException {
+    writeUInt64NoTag(value);
+  }
+
+  /** Write a {@code uint64} field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeUInt64NoTag(long value) throws IOException;
+
+  /** Write a {@code sint64} field to the stream. */
+  public final void writeSInt64NoTag(final long value) throws IOException {
+    writeUInt64NoTag(encodeZigZag64(value));
+  }
+
+  /** Write a {@code fixed64} field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeFixed64NoTag(long value) throws IOException;
+
+  /** Write a {@code sfixed64} field to the stream. */
+  public final void writeSFixed64NoTag(final long value) throws IOException {
+    writeFixed64NoTag(value);
+  }
+
+  /** Write a {@code float} field to the stream. */
+  public final void writeFloatNoTag(final float value) throws IOException {
+    writeFixed32NoTag(Float.floatToRawIntBits(value));
+  }
+
+  /** Write a {@code double} field to the stream. */
+  public final void writeDoubleNoTag(final double value) throws IOException {
+    writeFixed64NoTag(Double.doubleToRawLongBits(value));
+  }
+
+  /** Write a {@code bool} field to the stream. */
+  public final void writeBoolNoTag(final boolean value) throws IOException {
+    write((byte) (value ? 1 : 0));
+  }
+
+  /**
+   * Write an enum field to the stream. The provided value is the numeric
+   * value used to represent the enum value on the wire (not the enum ordinal value).
+   */
+  public final void writeEnumNoTag(final int value) throws IOException {
+    writeInt32NoTag(value);
+  }
+
+  /** Write a {@code string} field to the stream. */
+  // TODO(dweis): Document behavior on ill-formed UTF-16 input.
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeStringNoTag(String value) throws IOException;
+
+  /** Write a {@code bytes} field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeBytesNoTag(final ByteString value) throws IOException;
+
+  /** Write a {@code bytes} field to the stream. */
+  public final void writeByteArrayNoTag(final byte[] value) throws IOException {
+    writeByteArrayNoTag(value, 0, value.length);
+  }
+
+  /** Write an embedded message field to the stream. */
+  // Abstract to avoid overhead of additional virtual method calls.
+  public abstract void writeMessageNoTag(final MessageLite value) throws IOException;
+
+  //=================================================================
+
+  @ExperimentalApi
+  @Override
+  public abstract void write(byte value) throws IOException;
+
+  @ExperimentalApi
+  @Override
+  public abstract void write(byte[] value, int offset, int length) throws IOException;
+
+  @ExperimentalApi
+  @Override
+  public abstract void writeLazy(byte[] value, int offset, int length) throws IOException;
+
+  @Override
+  public abstract void write(ByteBuffer value) throws IOException;
+
+  @ExperimentalApi
+  @Override
+  public abstract void writeLazy(ByteBuffer value) throws IOException;
+
+  // =================================================================
+  // =================================================================
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int32} field, including tag.
+   */
+  public static int computeInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint32} field, including tag.
+   */
+  public static int computeUInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeUInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint32} field, including tag.
+   */
+  public static int computeSInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeSInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed32} field, including tag.
+   */
+  public static int computeFixed32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeFixed32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed32} field, including tag.
+   */
+  public static int computeSFixed32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeSFixed32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int64} field, including tag.
+   */
+  public static int computeInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint64} field, including tag.
+   */
+  public static int computeUInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeUInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint64} field, including tag.
+   */
+  public static int computeSInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeSInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed64} field, including tag.
+   */
+  public static int computeFixed64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeFixed64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed64} field, including tag.
+   */
+  public static int computeSFixed64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeSFixed64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code float} field, including tag.
+   */
+  public static int computeFloatSize(final int fieldNumber, final float value) {
+    return computeTagSize(fieldNumber) + computeFloatSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code double} field, including tag.
+   */
+  public static int computeDoubleSize(final int fieldNumber, final double value) {
+    return computeTagSize(fieldNumber) + computeDoubleSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bool} field, including tag.
+   */
+  public static int computeBoolSize(final int fieldNumber, final boolean value) {
+    return computeTagSize(fieldNumber) + computeBoolSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * enum field, including tag. The provided value is the numeric
+   * value used to represent the enum value on the wire (not the enum ordinal value).
+   */
+  public static int computeEnumSize(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeEnumSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code string} field, including tag.
+   */
+  public static int computeStringSize(final int fieldNumber, final String value) {
+    return computeTagSize(fieldNumber) + computeStringSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field, including tag.
+   */
+  public static int computeBytesSize(final int fieldNumber, final ByteString value) {
+    return computeTagSize(fieldNumber) + computeBytesSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field, including tag.
+   */
+  public static int computeByteArraySize(final int fieldNumber, final byte[] value) {
+    return computeTagSize(fieldNumber) + computeByteArraySizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field, including tag.
+   */
+  public static int computeByteBufferSize(final int fieldNumber, final ByteBuffer value) {
+    return computeTagSize(fieldNumber) + computeByteBufferSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * embedded message in lazy field, including tag.
+   */
+  public static int computeLazyFieldSize(final int fieldNumber, final LazyFieldLite value) {
+    return computeTagSize(fieldNumber) + computeLazyFieldSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * embedded message field, including tag.
+   */
+  public static int computeMessageSize(final int fieldNumber, final MessageLite value) {
+    return computeTagSize(fieldNumber) + computeMessageSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * MessageSet extension to the stream.  For historical reasons,
+   * the wire format differs from normal fields.
+   */
+  public static int computeMessageSetExtensionSize(final int fieldNumber, final MessageLite value) {
+    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2
+        + computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber)
+        + computeMessageSize(WireFormat.MESSAGE_SET_MESSAGE, value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * unparsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+  public static int computeRawMessageSetExtensionSize(
+      final int fieldNumber, final ByteString value) {
+    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2
+        + computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber)
+        + computeBytesSize(WireFormat.MESSAGE_SET_MESSAGE, value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * lazily parsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+  public static int computeLazyFieldMessageSetExtensionSize(
+      final int fieldNumber, final LazyFieldLite value) {
+    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2
+        + computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber)
+        + computeLazyFieldSize(WireFormat.MESSAGE_SET_MESSAGE, value);
+  }
+
+  // -----------------------------------------------------------------
+
+  /** Compute the number of bytes that would be needed to encode a tag. */
+  public static int computeTagSize(final int fieldNumber) {
+    return computeUInt32SizeNoTag(WireFormat.makeTag(fieldNumber, 0));
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int32} field, including tag.
+   */
+  public static int computeInt32SizeNoTag(final int value) {
+    if (value >= 0) {
+      return computeUInt32SizeNoTag(value);
+    } else {
+      // Must sign-extend.
+      return MAX_VARINT_SIZE;
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint32} field.
+   */
+  public static int computeUInt32SizeNoTag(final int value) {
+    if ((value & (~0 <<  7)) == 0) {
+      return 1;
+    }
+    if ((value & (~0 << 14)) == 0) {
+      return 2;
+    }
+    if ((value & (~0 << 21)) == 0) {
+      return 3;
+    }
+    if ((value & (~0 << 28)) == 0) {
+      return 4;
+    }
+    return 5;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint32} field.
+   */
+  public static int computeSInt32SizeNoTag(final int value) {
+    return computeUInt32SizeNoTag(encodeZigZag32(value));
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed32} field.
+   */
+  public static int computeFixed32SizeNoTag(@SuppressWarnings("unused") final int unused) {
+    return FIXED_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed32} field.
+   */
+  public static int computeSFixed32SizeNoTag(@SuppressWarnings("unused") final int unused) {
+    return FIXED_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int64} field, including tag.
+   */
+  public static int computeInt64SizeNoTag(final long value) {
+    return computeUInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint64} field, including tag.
+   */
+  public static int computeUInt64SizeNoTag(long value) {
+    // handle two popular special cases up front ...
+    if ((value & (~0L << 7)) == 0L) {
+      return 1;
+    }
+    if (value < 0L) {
+      return 10;
+    }
+    // ... leaving us with 8 remaining, which we can divide and conquer
+    int n = 2;
+    if ((value & (~0L << 35)) != 0L) {
+      n += 4; value >>>= 28;
+    }
+    if ((value & (~0L << 21)) != 0L) {
+      n += 2; value >>>= 14;
+    }
+    if ((value & (~0L << 14)) != 0L) {
+      n += 1;
+    }
+    return n;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint64} field.
+   */
+  public static int computeSInt64SizeNoTag(final long value) {
+    return computeUInt64SizeNoTag(encodeZigZag64(value));
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed64} field.
+   */
+  public static int computeFixed64SizeNoTag(@SuppressWarnings("unused") final long unused) {
+    return FIXED_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed64} field.
+   */
+  public static int computeSFixed64SizeNoTag(@SuppressWarnings("unused") final long unused) {
+    return FIXED_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code float} field, including tag.
+   */
+  public static int computeFloatSizeNoTag(@SuppressWarnings("unused") final float unused) {
+    return FIXED_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code double} field, including tag.
+   */
+  public static int computeDoubleSizeNoTag(@SuppressWarnings("unused") final double unused) {
+    return FIXED_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bool} field.
+   */
+  public static int computeBoolSizeNoTag(@SuppressWarnings("unused") final boolean unused) {
+    return 1;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an enum field.
+   * The provided value is the numeric value used to represent the enum value on the wire
+   * (not the enum ordinal value).
+   */
+  public static int computeEnumSizeNoTag(final int value) {
+    return computeInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code string} field.
+   */
+  public static int computeStringSizeNoTag(final String value) {
+    int length;
+    try {
+      length = Utf8.encodedLength(value);
+    } catch (UnpairedSurrogateException e) {
+      // TODO(dweis): Consider using nio Charset methods instead.
+      final byte[] bytes = value.getBytes(Internal.UTF_8);
+      length = bytes.length;
+    }
+
+    return computeLengthDelimitedFieldSize(length);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an embedded
+   * message stored in lazy field.
+   */
+  public static int computeLazyFieldSizeNoTag(final LazyFieldLite value) {
+    return computeLengthDelimitedFieldSize(value.getSerializedSize());
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field.
+   */
+  public static int computeBytesSizeNoTag(final ByteString value) {
+    return computeLengthDelimitedFieldSize(value.size());
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field.
+   */
+  public static int computeByteArraySizeNoTag(final byte[] value) {
+    return computeLengthDelimitedFieldSize(value.length);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field.
+   */
+  public static int computeByteBufferSizeNoTag(final ByteBuffer value) {
+    return computeLengthDelimitedFieldSize(value.capacity());
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an embedded
+   * message field.
+   */
+  public static int computeMessageSizeNoTag(final MessageLite value) {
+    return computeLengthDelimitedFieldSize(value.getSerializedSize());
+  }
+
+  private static int computeLengthDelimitedFieldSize(int fieldLength) {
+    return computeUInt32SizeNoTag(fieldLength) + fieldLength;
+  }
+
+  /**
+   * Encode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 32-bit integer.
+   * @return An unsigned 32-bit integer, stored in a signed int because
+   *         Java has no explicit unsigned support.
+   */
+  public static int encodeZigZag32(final int n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 31);
+  }
+
+  /**
+   * Encode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 64-bit integer.
+   * @return An unsigned 64-bit integer, stored in a signed int because
+   *         Java has no explicit unsigned support.
+   */
+  public static long encodeZigZag64(final long n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 63);
+  }
+
+  // =================================================================
+
+  /**
+   * Flushes the stream and forces any buffered bytes to be written.  This
+   * does not flush the underlying OutputStream.
+   */
+  public abstract void flush() throws IOException;
+
+  /**
+   * If writing to a flat array, return the space left in the array.
+   * Otherwise, throws {@code UnsupportedOperationException}.
+   */
+  public abstract int spaceLeft();
+
+  /**
+   * Verifies that {@link #spaceLeft()} returns zero.  It's common to create
+   * a byte array that is exactly big enough to hold a message, then write to
+   * it with a {@code CodedOutputStream}.  Calling {@code checkNoSpaceLeft()}
+   * after writing verifies that the message was actually as big as expected,
+   * which can help catch bugs.
+   */
+  public final void checkNoSpaceLeft() {
+    if (spaceLeft() != 0) {
+      throw new IllegalStateException("Did not write as much data as expected.");
+    }
+  }
+
+  /**
+   * If you create a CodedOutputStream around a simple flat array, you must
+   * not attempt to write more bytes than the array has space.  Otherwise,
+   * this exception will be thrown.
+   */
+  public static class OutOfSpaceException extends IOException {
+    private static final long serialVersionUID = -6947486886997889499L;
+
+    private static final String MESSAGE =
+        "CodedOutputStream was writing to a flat byte array and ran out of space.";
+
+    OutOfSpaceException() {
+      super(MESSAGE);
+    }
+
+    OutOfSpaceException(Throwable cause) {
+      super(MESSAGE, cause);
+    }
+  }
+
+  /**
+   * Get the total number of bytes successfully written to this stream.  The
+   * returned value is not guaranteed to be accurate if exceptions have been
+   * found in the middle of writing.
+   */
+  public abstract int getTotalBytesWritten();
+
+  // =================================================================
+
+  /** Write a {@code bytes} field to the stream. Visible for testing. */
+  abstract void writeByteArrayNoTag(final byte[] value, final int offset, final int length)
+      throws IOException;
+
+  final void inefficientWriteStringNoTag(String value, UnpairedSurrogateException cause)
+      throws IOException {
+    logger.log(Level.WARNING,
+        "Converting ill-formed UTF-16. Your Protocol Buffer will not round trip correctly!", cause);
+
+    // Unfortunately there does not appear to be any way to tell Java to encode
+    // UTF-8 directly into our buffer, so we have to let it create its own byte
+    // array and then copy.
+    // TODO(dweis): Consider using nio Charset methods instead.
+    final byte[] bytes = value.getBytes(Internal.UTF_8);
+    try {
+      writeUInt32NoTag(bytes.length);
+      writeLazy(bytes, 0, bytes.length);
+    } catch (IndexOutOfBoundsException e) {
+      throw new OutOfSpaceException(e);
+    } catch (OutOfSpaceException e) {
+      throw e;
+    }
+  }
+
+  // =================================================================
+
+  /**
+   * Write a {@code group} field, including tag, to the stream.
+   *
+   * @deprecated groups are deprecated.
+   */
+  @Deprecated
+  public final void writeGroup(final int fieldNumber, final MessageLite value) throws IOException {
+    writeTag(fieldNumber, WireFormat.WIRETYPE_START_GROUP);
+    writeGroupNoTag(value);
+    writeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP);
+  }
+
+  /**
+   * Write a {@code group} field to the stream.
+   *
+   * @deprecated groups are deprecated.
+   */
+  @Deprecated
+  public final void writeGroupNoTag(final MessageLite value) throws IOException {
+    value.writeTo(this);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code group} field, including tag.
+   *
+   * @deprecated groups are deprecated.
+   */
+  @Deprecated
+  public static int computeGroupSize(final int fieldNumber, final MessageLite value) {
+    return computeTagSize(fieldNumber) * 2 + computeGroupSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code group} field.
+   */
+  @Deprecated
+  public static int computeGroupSizeNoTag(final MessageLite value) {
+    return value.getSerializedSize();
+  }
+
+  /**
+   * Encode and write a varint.  {@code value} is treated as
+   * unsigned, so it won't be sign-extended if negative.
+   *
+   * @deprecated use {@link #writeUInt32NoTag} instead.
+   */
+  @Deprecated
+  public final void writeRawVarint32(int value) throws IOException {
+    writeUInt32NoTag(value);
+  }
+
+  /**
+   * Encode and write a varint.
+   *
+   * @deprecated use {@link #writeUInt64NoTag} instead.
+   */
+  @Deprecated
+  public final void writeRawVarint64(long value) throws IOException {
+    writeUInt64NoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a varint.
+   * {@code value} is treated as unsigned, so it won't be sign-extended if
+   * negative.
+   *
+   * @deprecated use {@link #computeUInt32SizeNoTag(int)} instead.
+   */
+  @Deprecated
+  public static int computeRawVarint32Size(final int value) {
+    return computeUInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a varint.
+   *
+   * @deprecated use {@link #computeUInt64SizeNoTag(long)} instead.
+   */
+  @Deprecated
+  public static int computeRawVarint64Size(long value) {
+    return computeUInt64SizeNoTag(value);
+  }
+
+  /**
+   * Write a little-endian 32-bit integer.
+   *
+   * @deprecated Use {@link #writeFixed32NoTag} instead.
+   */
+  @Deprecated
+  public final void writeRawLittleEndian32(final int value) throws IOException {
+    writeFixed32NoTag(value);
+  }
+
+  /**
+   * Write a little-endian 64-bit integer.
+   *
+   * @deprecated Use {@link #writeFixed64NoTag} instead.
+   */
+  @Deprecated
+  public final void writeRawLittleEndian64(final long value) throws IOException {
+    writeFixed64NoTag(value);
+  }
+
+  // =================================================================
+
+  /**
+   * A {@link CodedOutputStream} that writes directly to a byte array.
+   */
+  private static class ArrayEncoder extends CodedOutputStream {
+    private final byte[] buffer;
+    private final int offset;
+    private final int limit;
+    private int position;
+
+    ArrayEncoder(byte[] buffer, int offset, int length) {
+      if (buffer == null) {
+        throw new NullPointerException("buffer");
+      }
+      if ((offset | length | (buffer.length - (offset + length))) < 0) {
+        throw new IllegalArgumentException(String.format(
+            "Array range is invalid. Buffer.length=%d, offset=%d, length=%d",
+            buffer.length, offset, length));
+      }
+      this.buffer = buffer;
+      this.offset = offset;
+      position = offset;
+      limit = offset + length;
+    }
+
+    @Override
+    public final void writeTag(final int fieldNumber, final int wireType) throws IOException {
+      writeUInt32NoTag(WireFormat.makeTag(fieldNumber, wireType));
+    }
+
+    @Override
+    public final void writeInt32(final int fieldNumber, final int value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      writeInt32NoTag(value);
+    }
+
+    @Override
+    public final void writeUInt32(final int fieldNumber, final int value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      writeUInt32NoTag(value);
+    }
+
+    @Override
+    public final void writeFixed32(final int fieldNumber, final int value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
+      writeFixed32NoTag(value);
+    }
+
+    @Override
+    public final void writeUInt64(final int fieldNumber, final long value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      writeUInt64NoTag(value);
+    }
+
+    @Override
+    public final void writeFixed64(final int fieldNumber, final long value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
+      writeFixed64NoTag(value);
+    }
+
+    @Override
+    public final void writeBool(final int fieldNumber, final boolean value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      write((byte) (value ? 1 : 0));
+    }
+
+    @Override
+    public final void writeString(final int fieldNumber, final String value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeStringNoTag(value);
+    }
+
+    @Override
+    public final void writeBytes(final int fieldNumber, final ByteString value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeBytesNoTag(value);
+    }
+
+    @Override
+    public final void writeByteArray(final int fieldNumber, final byte[] value) throws IOException {
+      writeByteArray(fieldNumber, value, 0, value.length);
+    }
+
+    @Override
+    public final void writeByteArray(
+        final int fieldNumber, final byte[] value, final int offset, final int length)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeByteArrayNoTag(value, offset, length);
+    }
+
+    @Override
+    public final void writeByteBuffer(final int fieldNumber, final ByteBuffer value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeUInt32NoTag(value.capacity());
+      writeRawBytes(value);
+    }
+
+    @Override
+    public final void writeBytesNoTag(final ByteString value) throws IOException {
+      writeUInt32NoTag(value.size());
+      value.writeTo(this);
+    }
+
+    @Override
+    public final void writeByteArrayNoTag(final byte[] value, int offset, int length)
+        throws IOException {
+      writeUInt32NoTag(length);
+      write(value, offset, length);
+    }
+
+    @Override
+    public final void writeRawBytes(final ByteBuffer value) throws IOException {
+      if (value.hasArray()) {
+        write(value.array(), value.arrayOffset(), value.capacity());
+      } else {
+        ByteBuffer duplicated = value.duplicate();
+        duplicated.clear();
+        write(duplicated);
+      }
+    }
+
+    @Override
+    public final void writeMessage(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeMessageNoTag(value);
+    }
+
+    @Override
+    public final void writeMessageSetExtension(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeMessage(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public final void writeRawMessageSetExtension(final int fieldNumber, final ByteString value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeBytes(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public final void writeMessageNoTag(final MessageLite value) throws IOException {
+      writeUInt32NoTag(value.getSerializedSize());
+      value.writeTo(this);
+    }
+
+    @Override
+    public final void write(byte value) throws IOException {
+      try {
+        buffer[position++] = value;
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(new IndexOutOfBoundsException(
+            String.format("Pos: %d, limit: %d, len: %d", position, limit, 1)));
+      }
+    }
+
+    @Override
+    public final void writeInt32NoTag(int value) throws IOException {
+      if (value >= 0) {
+        writeUInt32NoTag(value);
+      } else {
+        // Must sign-extend.
+        writeUInt64NoTag(value);
+      }
+    }
+
+    @Override
+    public final void writeUInt32NoTag(int value) throws IOException {
+      if (HAS_UNSAFE_ARRAY_OPERATIONS && spaceLeft() >= MAX_VARINT_SIZE) {
+        long pos = ARRAY_BASE_OFFSET + position;
+        while (true) {
+          if ((value & ~0x7F) == 0) {
+            UNSAFE.putByte(buffer, pos++, (byte) value);
+            position++;
+            return;
+          } else {
+            UNSAFE.putByte(buffer, pos++, (byte) ((value & 0x7F) | 0x80));
+            position++;
+            value >>>= 7;
+          }
+        }
+      } else {
+        try {
+          while (true) {
+            if ((value & ~0x7F) == 0) {
+              buffer[position++] = (byte) value;
+              return;
+            } else {
+              buffer[position++] = (byte) ((value & 0x7F) | 0x80);
+              value >>>= 7;
+            }
+          }
+        } catch (IndexOutOfBoundsException e) {
+          throw new OutOfSpaceException(
+              new IndexOutOfBoundsException(
+                  String.format("Pos: %d, limit: %d, len: %d", position, limit, 1)));
+        }
+      }
+    }
+
+    @Override
+    public final void writeFixed32NoTag(int value) throws IOException {
+      try {
+        buffer[position++] = (byte) (value & 0xFF);
+        buffer[position++] = (byte) ((value >> 8) & 0xFF);
+        buffer[position++] = (byte) ((value >> 16) & 0xFF);
+        buffer[position++] = (byte) ((value >> 24) & 0xFF);
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(
+            new IndexOutOfBoundsException(
+                String.format("Pos: %d, limit: %d, len: %d", position, limit, 1)));
+      }
+    }
+
+    @Override
+    public final void writeUInt64NoTag(long value) throws IOException {
+      if (HAS_UNSAFE_ARRAY_OPERATIONS && spaceLeft() >= MAX_VARINT_SIZE) {
+        long pos = ARRAY_BASE_OFFSET + position;
+        while (true) {
+          if ((value & ~0x7FL) == 0) {
+            UNSAFE.putByte(buffer, pos++, (byte) value);
+            position++;
+            return;
+          } else {
+            UNSAFE.putByte(buffer, pos++, (byte) (((int) value & 0x7F) | 0x80));
+            position++;
+            value >>>= 7;
+          }
+        }
+      } else {
+        try {
+          while (true) {
+            if ((value & ~0x7FL) == 0) {
+              buffer[position++] = (byte) value;
+              return;
+            } else {
+              buffer[position++] = (byte) (((int) value & 0x7F) | 0x80);
+              value >>>= 7;
+            }
+          }
+        } catch (IndexOutOfBoundsException e) {
+          throw new OutOfSpaceException(
+              new IndexOutOfBoundsException(
+                  String.format("Pos: %d, limit: %d, len: %d", position, limit, 1)));
+        }
+      }
+    }
+
+    @Override
+    public final void writeFixed64NoTag(long value) throws IOException {
+      try {
+        buffer[position++] = (byte) ((int) (value) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 8) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 16) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 24) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 32) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 40) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 48) & 0xFF);
+        buffer[position++] = (byte) ((int) (value >> 56) & 0xFF);
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(
+            new IndexOutOfBoundsException(
+                String.format("Pos: %d, limit: %d, len: %d", position, limit, 1)));
+      }
+    }
+
+    @Override
+    public final void write(byte[] value, int offset, int length) throws IOException {
+      try {
+        System.arraycopy(value, offset, buffer, position, length);
+        position += length;
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(
+            new IndexOutOfBoundsException(
+                String.format("Pos: %d, limit: %d, len: %d", position, limit, length)));
+      }
+    }
+
+    @Override
+    public final void writeLazy(byte[] value, int offset, int length) throws IOException {
+      write(value, offset, length);
+    }
+
+    @Override
+    public final void write(ByteBuffer value) throws IOException {
+      final int length = value.remaining();
+      try {
+        value.get(buffer, position, length);
+        position += length;
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(
+            new IndexOutOfBoundsException(
+                String.format("Pos: %d, limit: %d, len: %d", position, limit, length)));
+      }
+    }
+
+    @Override
+    public final void writeLazy(ByteBuffer value) throws IOException {
+      write(value);
+    }
+
+    @Override
+    public final void writeStringNoTag(String value) throws IOException {
+      final int oldPosition = position;
+      try {
+        // UTF-8 byte length of the string is at least its UTF-16 code unit length (value.length()),
+        // and at most 3 times of it. We take advantage of this in both branches below.
+        final int maxLength = value.length() * Utf8.MAX_BYTES_PER_CHAR;
+        final int maxLengthVarIntSize = computeUInt32SizeNoTag(maxLength);
+        final int minLengthVarIntSize = computeUInt32SizeNoTag(value.length());
+        if (minLengthVarIntSize == maxLengthVarIntSize) {
+          position = oldPosition + minLengthVarIntSize;
+          int newPosition = Utf8.encode(value, buffer, position, spaceLeft());
+          // Since this class is stateful and tracks the position, we rewind and store the state,
+          // prepend the length, then reset it back to the end of the string.
+          position = oldPosition;
+          int length = newPosition - oldPosition - minLengthVarIntSize;
+          writeUInt32NoTag(length);
+          position = newPosition;
+        } else {
+          int length = Utf8.encodedLength(value);
+          writeUInt32NoTag(length);
+          position = Utf8.encode(value, buffer, position, spaceLeft());
+        }
+      } catch (UnpairedSurrogateException e) {
+        // Roll back the change - we fall back to inefficient path.
+        position = oldPosition;
+
+        // TODO(nathanmittler): We should throw an IOException here instead.
+        inefficientWriteStringNoTag(value, e);
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void flush() {
+      // Do nothing.
+    }
+
+    @Override
+    public final int spaceLeft() {
+      return limit - position;
+    }
+
+    @Override
+    public final int getTotalBytesWritten() {
+      return position - offset;
+    }
+  }
+
+  /**
+   * A {@link CodedOutputStream} that writes directly to a heap {@link ByteBuffer}. Writes are
+   * done directly to the underlying array. The buffer position is only updated after a flush.
+   */
+  private static final class NioHeapEncoder extends ArrayEncoder {
+    private final ByteBuffer byteBuffer;
+    private int initialPosition;
+
+    NioHeapEncoder(ByteBuffer byteBuffer) {
+      super(byteBuffer.array(), byteBuffer.arrayOffset() + byteBuffer.position(),
+          byteBuffer.remaining());
+      this.byteBuffer = byteBuffer;
+      this.initialPosition = byteBuffer.position();
+    }
+
+    @Override
+    public void flush() {
+      // Update the position on the buffer.
+      byteBuffer.position(initialPosition + getTotalBytesWritten());
+    }
+  }
+
+  /**
+   * A {@link CodedOutputStream} that writes directly to a {@link ByteBuffer}.
+   */
+  private static final class NioEncoder extends CodedOutputStream {
+    private final ByteBuffer originalBuffer;
+    private final ByteBuffer buffer;
+    private final int initialPosition;
+
+    NioEncoder(ByteBuffer buffer) {
+      this.originalBuffer = buffer;
+      this.buffer = buffer.duplicate().order(ByteOrder.LITTLE_ENDIAN);
+      initialPosition = buffer.position();
+    }
+
+    @Override
+    public void writeTag(final int fieldNumber, final int wireType) throws IOException {
+      writeUInt32NoTag(WireFormat.makeTag(fieldNumber, wireType));
+    }
+
+    @Override
+    public void writeInt32(final int fieldNumber, final int value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      writeInt32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt32(final int fieldNumber, final int value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      writeUInt32NoTag(value);
+    }
+
+    @Override
+    public void writeFixed32(final int fieldNumber, final int value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
+      writeFixed32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt64(final int fieldNumber, final long value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      writeUInt64NoTag(value);
+    }
+
+    @Override
+    public void writeFixed64(final int fieldNumber, final long value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
+      writeFixed64NoTag(value);
+    }
+
+    @Override
+    public void writeBool(final int fieldNumber, final boolean value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      write((byte) (value ? 1 : 0));
+    }
+
+    @Override
+    public void writeString(final int fieldNumber, final String value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeStringNoTag(value);
+    }
+
+    @Override
+    public void writeBytes(final int fieldNumber, final ByteString value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeBytesNoTag(value);
+    }
+
+    @Override
+    public void writeByteArray(final int fieldNumber, final byte[] value) throws IOException {
+      writeByteArray(fieldNumber, value, 0, value.length);
+    }
+
+    @Override
+    public void writeByteArray(
+        final int fieldNumber, final byte[] value, final int offset, final int length)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeByteArrayNoTag(value, offset, length);
+    }
+
+    @Override
+    public void writeByteBuffer(final int fieldNumber, final ByteBuffer value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeUInt32NoTag(value.capacity());
+      writeRawBytes(value);
+    }
+
+    @Override
+    public void writeMessage(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeMessageNoTag(value);
+    }
+
+    @Override
+    public void writeMessageSetExtension(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeMessage(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public void writeRawMessageSetExtension(final int fieldNumber, final ByteString value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeBytes(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public void writeMessageNoTag(final MessageLite value) throws IOException {
+      writeUInt32NoTag(value.getSerializedSize());
+      value.writeTo(this);
+    }
+
+    @Override
+    public void write(byte value) throws IOException {
+      try {
+        buffer.put(value);
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void writeBytesNoTag(final ByteString value) throws IOException {
+      writeUInt32NoTag(value.size());
+      value.writeTo(this);
+    }
+
+    @Override
+    public void writeByteArrayNoTag(final byte[] value, int offset, int length) throws IOException {
+      writeUInt32NoTag(length);
+      write(value, offset, length);
+    }
+
+    @Override
+    public void writeRawBytes(final ByteBuffer value) throws IOException {
+      if (value.hasArray()) {
+        write(value.array(), value.arrayOffset(), value.capacity());
+      } else {
+        ByteBuffer duplicated = value.duplicate();
+        duplicated.clear();
+        write(duplicated);
+      }
+    }
+
+    @Override
+    public void writeInt32NoTag(int value) throws IOException {
+      if (value >= 0) {
+        writeUInt32NoTag(value);
+      } else {
+        // Must sign-extend.
+        writeUInt64NoTag(value);
+      }
+    }
+
+    @Override
+    public void writeUInt32NoTag(int value) throws IOException {
+      try {
+        while (true) {
+          if ((value & ~0x7F) == 0) {
+            buffer.put((byte) value);
+            return;
+          } else {
+            buffer.put((byte) ((value & 0x7F) | 0x80));
+            value >>>= 7;
+          }
+        }
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void writeFixed32NoTag(int value) throws IOException {
+      try {
+        buffer.putInt(value);
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void writeUInt64NoTag(long value) throws IOException {
+      try {
+        while (true) {
+          if ((value & ~0x7FL) == 0) {
+            buffer.put((byte) value);
+            return;
+          } else {
+            buffer.put((byte) (((int) value & 0x7F) | 0x80));
+            value >>>= 7;
+          }
+        }
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void writeFixed64NoTag(long value) throws IOException {
+      try {
+        buffer.putLong(value);
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void write(byte[] value, int offset, int length) throws IOException {
+      try {
+        buffer.put(value, offset, length);
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(e);
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void writeLazy(byte[] value, int offset, int length) throws IOException {
+      write(value, offset, length);
+    }
+
+    @Override
+    public void write(ByteBuffer value) throws IOException {
+      try {
+        buffer.put(value);
+      } catch (BufferOverflowException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void writeLazy(ByteBuffer value) throws IOException {
+      write(value);
+    }
+
+    @Override
+    public void writeStringNoTag(String value) throws IOException {
+      final int startPos = buffer.position();
+      try {
+        // UTF-8 byte length of the string is at least its UTF-16 code unit length (value.length()),
+        // and at most 3 times of it. We take advantage of this in both branches below.
+        final int maxEncodedSize = value.length() * Utf8.MAX_BYTES_PER_CHAR;
+        final int maxLengthVarIntSize = computeUInt32SizeNoTag(maxEncodedSize);
+        final int minLengthVarIntSize = computeUInt32SizeNoTag(value.length());
+        if (minLengthVarIntSize == maxLengthVarIntSize) {
+          // Save the current position and increment past the length field. We'll come back
+          // and write the length field after the encoding is complete.
+          final int startOfBytes = buffer.position() + minLengthVarIntSize;
+          buffer.position(startOfBytes);
+
+          // Encode the string.
+          encode(value);
+
+          // Now go back to the beginning and write the length.
+          int endOfBytes = buffer.position();
+          buffer.position(startPos);
+          writeUInt32NoTag(endOfBytes - startOfBytes);
+
+          // Reposition the buffer past the written data.
+          buffer.position(endOfBytes);
+        } else {
+          final int length = Utf8.encodedLength(value);
+          writeUInt32NoTag(length);
+          encode(value);
+        }
+      } catch (UnpairedSurrogateException e) {
+        // Roll back the change and convert to an IOException.
+        buffer.position(startPos);
+
+        // TODO(nathanmittler): We should throw an IOException here instead.
+        inefficientWriteStringNoTag(value, e);
+      } catch (IllegalArgumentException e) {
+        // Thrown by buffer.position() if out of range.
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void flush() {
+      // Update the position of the original buffer.
+      originalBuffer.position(buffer.position());
+    }
+
+    @Override
+    public int spaceLeft() {
+      return buffer.remaining();
+    }
+
+    @Override
+    public int getTotalBytesWritten() {
+      return buffer.position() - initialPosition;
+    }
+
+    private void encode(String value) throws IOException {
+      try {
+        Utf8.encodeUtf8(value, buffer);
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+  }
+
+  /**
+   * Abstract base class for buffered encoders.
+   */
+  private abstract static class AbstractBufferedEncoder extends CodedOutputStream {
+    final byte[] buffer;
+    final int limit;
+    int position;
+    int totalBytesWritten;
+
+    AbstractBufferedEncoder(int bufferSize) {
+      if (bufferSize < 0) {
+        throw new IllegalArgumentException("bufferSize must be >= 0");
+      }
+      // As an optimization, we require that the buffer be able to store at least 2
+      // varints so that we can buffer any integer write (tag + value). This reduces the
+      // number of range checks for a single write to 1 (i.e. if there is not enough space
+      // to buffer the tag+value, flush and then buffer it).
+      this.buffer = new byte[max(bufferSize, MAX_VARINT_SIZE * 2)];
+      this.limit = buffer.length;
+    }
+
+    @Override
+    public final int spaceLeft() {
+      throw new UnsupportedOperationException(
+          "spaceLeft() can only be called on CodedOutputStreams that are "
+              + "writing to a flat array or ByteBuffer.");
+    }
+
+    @Override
+    public final int getTotalBytesWritten() {
+      return totalBytesWritten;
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void buffer(byte value) {
+      buffer[position++] = value;
+      totalBytesWritten++;
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void bufferTag(final int fieldNumber, final int wireType) {
+      bufferUInt32NoTag(WireFormat.makeTag(fieldNumber, wireType));
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void bufferInt32NoTag(final int value) {
+      if (value >= 0) {
+        bufferUInt32NoTag(value);
+      } else {
+        // Must sign-extend.
+        bufferUInt64NoTag(value);
+      }
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void bufferUInt32NoTag(int value) {
+      if (HAS_UNSAFE_ARRAY_OPERATIONS) {
+        final long originalPos = ARRAY_BASE_OFFSET + position;
+        long pos = originalPos;
+        while (true) {
+          if ((value & ~0x7F) == 0) {
+            UNSAFE.putByte(buffer, pos++, (byte) value);
+            break;
+          } else {
+            UNSAFE.putByte(buffer, pos++, (byte) ((value & 0x7F) | 0x80));
+            value >>>= 7;
+          }
+        }
+        int delta = (int) (pos - originalPos);
+        position += delta;
+        totalBytesWritten += delta;
+      } else {
+        while (true) {
+          if ((value & ~0x7F) == 0) {
+            buffer[position++] = (byte) value;
+            totalBytesWritten++;
+            return;
+          } else {
+            buffer[position++] = (byte) ((value & 0x7F) | 0x80);
+            totalBytesWritten++;
+            value >>>= 7;
+          }
+        }
+      }
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void bufferUInt64NoTag(long value) {
+      if (HAS_UNSAFE_ARRAY_OPERATIONS) {
+        final long originalPos = ARRAY_BASE_OFFSET + position;
+        long pos = originalPos;
+        while (true) {
+          if ((value & ~0x7FL) == 0) {
+            UNSAFE.putByte(buffer, pos++, (byte) value);
+            break;
+          } else {
+            UNSAFE.putByte(buffer, pos++, (byte) (((int) value & 0x7F) | 0x80));
+            value >>>= 7;
+          }
+        }
+        int delta = (int) (pos - originalPos);
+        position += delta;
+        totalBytesWritten += delta;
+      } else {
+        while (true) {
+          if ((value & ~0x7FL) == 0) {
+            buffer[position++] = (byte) value;
+            totalBytesWritten++;
+            return;
+          } else {
+            buffer[position++] = (byte) (((int) value & 0x7F) | 0x80);
+            totalBytesWritten++;
+            value >>>= 7;
+          }
+        }
+      }
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void bufferFixed32NoTag(int value) {
+      buffer[position++] = (byte) (value & 0xFF);
+      buffer[position++] = (byte) ((value >> 8) & 0xFF);
+      buffer[position++] = (byte) ((value >> 16) & 0xFF);
+      buffer[position++] = (byte) ((value >> 24) & 0xFF);
+      totalBytesWritten += FIXED_32_SIZE;
+    }
+
+    /**
+     * This method does not perform bounds checking on the array. Checking array bounds is the
+     * responsibility of the caller.
+     */
+    final void bufferFixed64NoTag(long value) {
+      buffer[position++] = (byte) (value & 0xFF);
+      buffer[position++] = (byte) ((value >> 8) & 0xFF);
+      buffer[position++] = (byte) ((value >> 16) & 0xFF);
+      buffer[position++] = (byte) ((value >> 24) & 0xFF);
+      buffer[position++] = (byte) ((int) (value >> 32) & 0xFF);
+      buffer[position++] = (byte) ((int) (value >> 40) & 0xFF);
+      buffer[position++] = (byte) ((int) (value >> 48) & 0xFF);
+      buffer[position++] = (byte) ((int) (value >> 56) & 0xFF);
+      totalBytesWritten += FIXED_64_SIZE;
+    }
+  }
+
+  /**
+   * A {@link CodedOutputStream} that decorates a {@link ByteOutput}. It internal buffer only to
+   * support string encoding operations. All other writes are just passed through to the
+   * {@link ByteOutput}.
+   */
+  private static final class ByteOutputEncoder extends AbstractBufferedEncoder {
+    private final ByteOutput out;
+
+    ByteOutputEncoder(ByteOutput out, int bufferSize) {
+      super(bufferSize);
+      if (out == null) {
+        throw new NullPointerException("out");
+      }
+      this.out = out;
+    }
+
+    @Override
+    public void writeTag(final int fieldNumber, final int wireType) throws IOException {
+      writeUInt32NoTag(WireFormat.makeTag(fieldNumber, wireType));
+    }
+
+    @Override
+    public void writeInt32(final int fieldNumber, final int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE * 2);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      bufferInt32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt32(final int fieldNumber, final int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE * 2);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      bufferUInt32NoTag(value);
+    }
+
+    @Override
+    public void writeFixed32(final int fieldNumber, final int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE + FIXED_32_SIZE);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
+      bufferFixed32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt64(final int fieldNumber, final long value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE * 2);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      bufferUInt64NoTag(value);
+    }
+
+    @Override
+    public void writeFixed64(final int fieldNumber, final long value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE + FIXED_64_SIZE);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
+      bufferFixed64NoTag(value);
+    }
+
+    @Override
+    public void writeBool(final int fieldNumber, final boolean value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE + 1);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      buffer((byte) (value ? 1 : 0));
+    }
+
+    @Override
+    public void writeString(final int fieldNumber, final String value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeStringNoTag(value);
+    }
+
+    @Override
+    public void writeBytes(final int fieldNumber, final ByteString value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeBytesNoTag(value);
+    }
+
+    @Override
+    public void writeByteArray(final int fieldNumber, final byte[] value) throws IOException {
+      writeByteArray(fieldNumber, value, 0, value.length);
+    }
+
+    @Override
+    public void writeByteArray(
+        final int fieldNumber, final byte[] value, final int offset, final int length)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeByteArrayNoTag(value, offset, length);
+    }
+
+    @Override
+    public void writeByteBuffer(final int fieldNumber, final ByteBuffer value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeUInt32NoTag(value.capacity());
+      writeRawBytes(value);
+    }
+
+    @Override
+    public void writeBytesNoTag(final ByteString value) throws IOException {
+      writeUInt32NoTag(value.size());
+      value.writeTo(this);
+    }
+
+    @Override
+    public void writeByteArrayNoTag(final byte[] value, int offset, int length) throws IOException {
+      writeUInt32NoTag(length);
+      write(value, offset, length);
+    }
+
+    @Override
+    public void writeRawBytes(final ByteBuffer value) throws IOException {
+      if (value.hasArray()) {
+        write(value.array(), value.arrayOffset(), value.capacity());
+      } else {
+        ByteBuffer duplicated = value.duplicate();
+        duplicated.clear();
+        write(duplicated);
+      }
+    }
+
+    @Override
+    public void writeMessage(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeMessageNoTag(value);
+    }
+
+    @Override
+    public void writeMessageSetExtension(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeMessage(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public void writeRawMessageSetExtension(final int fieldNumber, final ByteString value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeBytes(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public void writeMessageNoTag(final MessageLite value) throws IOException {
+      writeUInt32NoTag(value.getSerializedSize());
+      value.writeTo(this);
+    }
+
+    @Override
+    public void write(byte value) throws IOException {
+      if (position == limit) {
+        doFlush();
+      }
+
+      buffer(value);
+    }
+
+    @Override
+    public void writeInt32NoTag(int value) throws IOException {
+      if (value >= 0) {
+        writeUInt32NoTag(value);
+      } else {
+        // Must sign-extend.
+        writeUInt64NoTag(value);
+      }
+    }
+
+    @Override
+    public void writeUInt32NoTag(int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE);
+      bufferUInt32NoTag(value);
+    }
+
+    @Override
+    public void writeFixed32NoTag(final int value) throws IOException {
+      flushIfNotAvailable(FIXED_32_SIZE);
+      bufferFixed32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt64NoTag(long value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE);
+      bufferUInt64NoTag(value);
+    }
+
+    @Override
+    public void writeFixed64NoTag(final long value) throws IOException {
+      flushIfNotAvailable(FIXED_64_SIZE);
+      bufferFixed64NoTag(value);
+    }
+
+    @Override
+    public void writeStringNoTag(String value) throws IOException {
+      // UTF-8 byte length of the string is at least its UTF-16 code unit length (value.length()),
+      // and at most 3 times of it. We take advantage of this in both branches below.
+      final int maxLength = value.length() * Utf8.MAX_BYTES_PER_CHAR;
+      final int maxLengthVarIntSize = computeUInt32SizeNoTag(maxLength);
+
+      // If we are streaming and the potential length is too big to fit in our buffer, we take the
+      // slower path.
+      if (maxLengthVarIntSize + maxLength > limit) {
+        // Allocate a byte[] that we know can fit the string and encode into it. String.getBytes()
+        // does the same internally and then does *another copy* to return a byte[] of exactly the
+        // right size. We can skip that copy and just writeRawBytes up to the actualLength of the
+        // UTF-8 encoded bytes.
+        final byte[] encodedBytes = new byte[maxLength];
+        int actualLength = Utf8.encode(value, encodedBytes, 0, maxLength);
+        writeUInt32NoTag(actualLength);
+        writeLazy(encodedBytes, 0, actualLength);
+        return;
+      }
+
+      // Fast path: we have enough space available in our buffer for the string...
+      if (maxLengthVarIntSize + maxLength > limit - position) {
+        // Flush to free up space.
+        doFlush();
+      }
+
+      final int oldPosition = position;
+      try {
+        // Optimize for the case where we know this length results in a constant varint length as
+        // this saves a pass for measuring the length of the string.
+        final int minLengthVarIntSize = computeUInt32SizeNoTag(value.length());
+
+        if (minLengthVarIntSize == maxLengthVarIntSize) {
+          position = oldPosition + minLengthVarIntSize;
+          int newPosition = Utf8.encode(value, buffer, position, limit - position);
+          // Since this class is stateful and tracks the position, we rewind and store the state,
+          // prepend the length, then reset it back to the end of the string.
+          position = oldPosition;
+          int length = newPosition - oldPosition - minLengthVarIntSize;
+          bufferUInt32NoTag(length);
+          position = newPosition;
+          totalBytesWritten += length;
+        } else {
+          int length = Utf8.encodedLength(value);
+          bufferUInt32NoTag(length);
+          position = Utf8.encode(value, buffer, position, length);
+          totalBytesWritten += length;
+        }
+      } catch (UnpairedSurrogateException e) {
+        // Roll back the change and convert to an IOException.
+        totalBytesWritten -= position - oldPosition;
+        position = oldPosition;
+
+        // TODO(nathanmittler): We should throw an IOException here instead.
+        inefficientWriteStringNoTag(value, e);
+      } catch (IndexOutOfBoundsException e) {
+        throw new OutOfSpaceException(e);
+      }
+    }
+
+    @Override
+    public void flush() throws IOException {
+      if (position > 0) {
+        // Flush the buffer.
+        doFlush();
+      }
+    }
+
+    @Override
+    public void write(byte[] value, int offset, int length) throws IOException {
+      flush();
+      out.write(value, offset, length);
+      totalBytesWritten += length;
+    }
+
+    @Override
+    public void writeLazy(byte[] value, int offset, int length) throws IOException {
+      flush();
+      out.writeLazy(value, offset, length);
+      totalBytesWritten += length;
+    }
+
+    @Override
+    public void write(ByteBuffer value) throws IOException {
+      flush();
+      int length = value.remaining();
+      out.write(value);
+      totalBytesWritten += length;
+    }
+
+    @Override
+    public void writeLazy(ByteBuffer value) throws IOException {
+      flush();
+      int length = value.remaining();
+      out.writeLazy(value);
+      totalBytesWritten += length;
+    }
+
+    private void flushIfNotAvailable(int requiredSize) throws IOException {
+      if (limit - position < requiredSize) {
+        doFlush();
+      }
+    }
+
+    private void doFlush() throws IOException {
+      out.write(buffer, 0, position);
+      position = 0;
+    }
+  }
+
+  /**
+   * An {@link CodedOutputStream} that decorates an {@link OutputStream}. It performs internal
+   * buffering to optimize writes to the {@link OutputStream}.
+   */
+  private static final class OutputStreamEncoder extends AbstractBufferedEncoder {
+    private final OutputStream out;
+
+    OutputStreamEncoder(OutputStream out, int bufferSize) {
+      super(bufferSize);
+      if (out == null) {
+        throw new NullPointerException("out");
+      }
+      this.out = out;
+    }
+
+    @Override
+    public void writeTag(final int fieldNumber, final int wireType) throws IOException {
+      writeUInt32NoTag(WireFormat.makeTag(fieldNumber, wireType));
+    }
+
+    @Override
+    public void writeInt32(final int fieldNumber, final int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE * 2);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      bufferInt32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt32(final int fieldNumber, final int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE * 2);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      bufferUInt32NoTag(value);
+    }
+
+    @Override
+    public void writeFixed32(final int fieldNumber, final int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE + FIXED_32_SIZE);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
+      bufferFixed32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt64(final int fieldNumber, final long value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE * 2);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      bufferUInt64NoTag(value);
+    }
+
+    @Override
+    public void writeFixed64(final int fieldNumber, final long value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE + FIXED_64_SIZE);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
+      bufferFixed64NoTag(value);
+    }
+
+    @Override
+    public void writeBool(final int fieldNumber, final boolean value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE + 1);
+      bufferTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
+      buffer((byte) (value ? 1 : 0));
+    }
+
+    @Override
+    public void writeString(final int fieldNumber, final String value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeStringNoTag(value);
+    }
+
+    @Override
+    public void writeBytes(final int fieldNumber, final ByteString value) throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeBytesNoTag(value);
+    }
+
+    @Override
+    public void writeByteArray(final int fieldNumber, final byte[] value) throws IOException {
+      writeByteArray(fieldNumber, value, 0, value.length);
+    }
+
+    @Override
+    public void writeByteArray(
+        final int fieldNumber, final byte[] value, final int offset, final int length)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeByteArrayNoTag(value, offset, length);
+    }
+
+    @Override
+    public void writeByteBuffer(final int fieldNumber, final ByteBuffer value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeUInt32NoTag(value.capacity());
+      writeRawBytes(value);
+    }
+
+    @Override
+    public void writeBytesNoTag(final ByteString value) throws IOException {
+      writeUInt32NoTag(value.size());
+      value.writeTo(this);
+    }
+
+    @Override
+    public void writeByteArrayNoTag(final byte[] value, int offset, int length) throws IOException {
+      writeUInt32NoTag(length);
+      write(value, offset, length);
+    }
+
+    @Override
+    public void writeRawBytes(final ByteBuffer value) throws IOException {
+      if (value.hasArray()) {
+        write(value.array(), value.arrayOffset(), value.capacity());
+      } else {
+        ByteBuffer duplicated = value.duplicate();
+        duplicated.clear();
+        write(duplicated);
+      }
+    }
+
+    @Override
+    public void writeMessage(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+      writeMessageNoTag(value);
+    }
+
+    @Override
+    public void writeMessageSetExtension(final int fieldNumber, final MessageLite value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeMessage(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public void writeRawMessageSetExtension(final int fieldNumber, final ByteString value)
+        throws IOException {
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
+      writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
+      writeBytes(WireFormat.MESSAGE_SET_MESSAGE, value);
+      writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
+    }
+
+    @Override
+    public void writeMessageNoTag(final MessageLite value) throws IOException {
+      writeUInt32NoTag(value.getSerializedSize());
+      value.writeTo(this);
+    }
+
+    @Override
+    public void write(byte value) throws IOException {
+      if (position == limit) {
+        doFlush();
+      }
+
+      buffer(value);
+    }
+
+    @Override
+    public void writeInt32NoTag(int value) throws IOException {
+      if (value >= 0) {
+        writeUInt32NoTag(value);
+      } else {
+        // Must sign-extend.
+        writeUInt64NoTag(value);
+      }
+    }
+
+    @Override
+    public void writeUInt32NoTag(int value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE);
+      bufferUInt32NoTag(value);
+    }
+
+    @Override
+    public void writeFixed32NoTag(final int value) throws IOException {
+      flushIfNotAvailable(FIXED_32_SIZE);
+      bufferFixed32NoTag(value);
+    }
+
+    @Override
+    public void writeUInt64NoTag(long value) throws IOException {
+      flushIfNotAvailable(MAX_VARINT_SIZE);
+      bufferUInt64NoTag(value);
+    }
+
+    @Override
+    public void writeFixed64NoTag(final long value) throws IOException {
+      flushIfNotAvailable(FIXED_64_SIZE);
+      bufferFixed64NoTag(value);
+    }
+
+    @Override
+    public void writeStringNoTag(String value) throws IOException {
+      try {
+        // UTF-8 byte length of the string is at least its UTF-16 code unit length (value.length()),
+        // and at most 3 times of it. We take advantage of this in both branches below.
+        final int maxLength = value.length() * Utf8.MAX_BYTES_PER_CHAR;
+        final int maxLengthVarIntSize = computeUInt32SizeNoTag(maxLength);
+
+        // If we are streaming and the potential length is too big to fit in our buffer, we take the
+        // slower path.
+        if (maxLengthVarIntSize + maxLength > limit) {
+          // Allocate a byte[] that we know can fit the string and encode into it. String.getBytes()
+          // does the same internally and then does *another copy* to return a byte[] of exactly the
+          // right size. We can skip that copy and just writeRawBytes up to the actualLength of the
+          // UTF-8 encoded bytes.
+          final byte[] encodedBytes = new byte[maxLength];
+          int actualLength = Utf8.encode(value, encodedBytes, 0, maxLength);
+          writeUInt32NoTag(actualLength);
+          writeLazy(encodedBytes, 0, actualLength);
+          return;
+        }
+
+        // Fast path: we have enough space available in our buffer for the string...
+        if (maxLengthVarIntSize + maxLength > limit - position) {
+          // Flush to free up space.
+          doFlush();
+        }
+
+        // Optimize for the case where we know this length results in a constant varint length as
+        // this saves a pass for measuring the length of the string.
+        final int minLengthVarIntSize = computeUInt32SizeNoTag(value.length());
+        int oldPosition = position;
+        final int length;
+        try {
+          if (minLengthVarIntSize == maxLengthVarIntSize) {
+            position = oldPosition + minLengthVarIntSize;
+            int newPosition = Utf8.encode(value, buffer, position, limit - position);
+            // Since this class is stateful and tracks the position, we rewind and store the
+            // state, prepend the length, then reset it back to the end of the string.
+            position = oldPosition;
+            length = newPosition - oldPosition - minLengthVarIntSize;
+            bufferUInt32NoTag(length);
+            position = newPosition;
+          } else {
+            length = Utf8.encodedLength(value);
+            bufferUInt32NoTag(length);
+            position = Utf8.encode(value, buffer, position, length);
+          }
+          totalBytesWritten += length;
+        } catch (UnpairedSurrogateException e) {
+          // Be extra careful and restore the original position for retrying the write with the
+          // less efficient path.
+          totalBytesWritten -= position - oldPosition;
+          position = oldPosition;
+          throw e;
+        } catch (ArrayIndexOutOfBoundsException e) {
+          throw new OutOfSpaceException(e);
+        }
+      } catch (UnpairedSurrogateException e) {
+        inefficientWriteStringNoTag(value, e);
+      }
+    }
+
+    @Override
+    public void flush() throws IOException {
+      if (position > 0) {
+        // Flush the buffer.
+        doFlush();
+      }
+    }
+
+    @Override
+    public void write(byte[] value, int offset, int length)
+        throws IOException {
+      if (limit - position >= length) {
+        // We have room in the current buffer.
+        System.arraycopy(value, offset, buffer, position, length);
+        position += length;
+        totalBytesWritten += length;
+      } else {
+        // Write extends past current buffer.  Fill the rest of this buffer and
+        // flush.
+        final int bytesWritten = limit - position;
+        System.arraycopy(value, offset, buffer, position, bytesWritten);
+        offset += bytesWritten;
+        length -= bytesWritten;
+        position = limit;
+        totalBytesWritten += bytesWritten;
+        doFlush();
+
+        // Now deal with the rest.
+        // Since we have an output stream, this is our buffer
+        // and buffer offset == 0
+        if (length <= limit) {
+          // Fits in new buffer.
+          System.arraycopy(value, offset, buffer, 0, length);
+          position = length;
+        } else {
+          // Write is very big.  Let's do it all at once.
+          out.write(value, offset, length);
+        }
+        totalBytesWritten += length;
+      }
+    }
+
+    @Override
+    public void writeLazy(byte[] value, int offset, int length) throws IOException {
+      write(value, offset, length);
+    }
+
+    @Override
+    public void write(ByteBuffer value) throws IOException {
+      int length = value.remaining();
+      if (limit - position >= length) {
+        // We have room in the current buffer.
+        value.get(buffer, position, length);
+        position += length;
+        totalBytesWritten += length;
+      } else {
+        // Write extends past current buffer.  Fill the rest of this buffer and
+        // flush.
+        final int bytesWritten = limit - position;
+        value.get(buffer, position, bytesWritten);
+        length -= bytesWritten;
+        position = limit;
+        totalBytesWritten += bytesWritten;
+        doFlush();
+
+        // Now deal with the rest.
+        // Since we have an output stream, this is our buffer
+        // and buffer offset == 0
+        while (length > limit) {
+          // Copy data into the buffer before writing it to OutputStream.
+          value.get(buffer, 0, limit);
+          out.write(buffer, 0, limit);
+          length -= limit;
+          totalBytesWritten += limit;
+        }
+        value.get(buffer, 0, length);
+        position = length;
+        totalBytesWritten += length;
+      }
+    }
+
+    @Override
+    public void writeLazy(ByteBuffer value) throws IOException {
+      write(value);
+    }
+
+    private void flushIfNotAvailable(int requiredSize) throws IOException {
+      if (limit - position < requiredSize) {
+        doFlush();
+      }
+    }
+
+    private void doFlush() throws IOException {
+      out.write(buffer, 0, position);
+      position = 0;
+    }
+  }
+
+  /**
+   * Gets the {@code sun.misc.Unsafe} instance, or {@code null} if not available on this
+   * platform.
+   */
+  private static sun.misc.Unsafe getUnsafe() {
+    sun.misc.Unsafe unsafe = null;
+    try {
+      unsafe = AccessController.doPrivileged(new PrivilegedExceptionAction<sun.misc.Unsafe>() {
+        @Override
+        public sun.misc.Unsafe run() throws Exception {
+          Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
+
+          for (Field f : k.getDeclaredFields()) {
+            f.setAccessible(true);
+            Object x = f.get(null);
+            if (k.isInstance(x)) {
+              return k.cast(x);
+            }
+          }
+          // The sun.misc.Unsafe field does not exist.
+          return null;
+        }
+      });
+    } catch (Throwable e) {
+      // Catching Throwable here due to the fact that Google AppEngine raises NoClassDefFoundError
+      // for Unsafe.
+    }
+
+    logger.log(Level.FINEST, "sun.misc.Unsafe: {}",
+        unsafe != null ? "available" : "unavailable");
+    return unsafe;
+  }
+
+  /**
+   * Indicates whether or not unsafe array operations are supported on this platform.
+   */
+  // TODO(nathanmittler): Add support for Android's MemoryBlock.
+  private static boolean supportsUnsafeArrayOperations() {
+    boolean supported = false;
+    if (UNSAFE != null) {
+      try {
+        UNSAFE.getClass().getMethod("arrayBaseOffset", Class.class);
+        UNSAFE.getClass().getMethod("putByte", Object.class, long.class, byte.class);
+        supported = true;
+      } catch (Throwable e) {
+        // Do nothing.
+      }
+    }
+    logger.log(Level.FINEST, "Unsafe array operations: {}",
+        supported ? "available" : "unavailable");
+    return supported;
+  }
+
+  /**
+   * Get the base offset for byte arrays, or {@code -1} if {@code sun.misc.Unsafe} is not
+   * available.
+   */
+  private static <T> int byteArrayBaseOffset() {
+    return HAS_UNSAFE_ARRAY_OPERATIONS ? UNSAFE.arrayBaseOffset(byte[].class) : -1;
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/Descriptors.java b/java/core/src/main/java/com/google/protobuf/Descriptors.java
index 7cfc47f7..e00ea342 100644
--- a/java/src/main/java/com/google/protobuf/Descriptors.java
+++ b/java/core/src/main/java/com/google/protobuf/Descriptors.java
@@ -74,16 +74,28 @@ public final class Descriptors {
    */
   public static final class FileDescriptor extends GenericDescriptor {
     /** Convert the descriptor to its protocol message representation. */
-    public FileDescriptorProto toProto() { return proto; }
+    @Override
+    public FileDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the file name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /** Returns this object. */
-    public FileDescriptor getFile() { return this; }
+    @Override
+    public FileDescriptor getFile() {
+      return this;
+    }
 
     /** Returns the same as getName(). */
-    public String getFullName() { return proto.getName(); }
+    @Override
+    public String getFullName() {
+      return proto.getName();
+    }
 
     /**
      * Get the proto package name.  This is the package name given by the
@@ -272,7 +284,7 @@ public final class Descriptors {
      *           because a field has an undefined type or because two messages
      *           were defined with the same name.
      */
-    private static FileDescriptor buildFrom(
+    public static FileDescriptor buildFrom(
         final FileDescriptorProto proto, final FileDescriptor[] dependencies,
         final boolean allowUnknownDependencies)
         throws DescriptorValidationException {
@@ -582,10 +594,16 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public DescriptorProto toProto() { return proto; }
+    @Override
+    public DescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the type's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the type's fully-qualified name, within the proto language's
@@ -598,10 +616,16 @@ public final class Descriptors {
      * </pre>
      * {@code Baz}'s full name is "foo.bar.Baz".
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** If this is a nested type, get the outer descriptor, otherwise null. */
     public Descriptor getContainingType() { return containingType; }
@@ -875,19 +899,36 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public FieldDescriptorProto toProto() { return proto; }
+    @Override
+    public FieldDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the field's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /** Get the field's number. */
-    public int getNumber() { return proto.getNumber(); }
+    @Override
+    public int getNumber() {
+      return proto.getNumber();
+    }
 
     /**
      * Get the field's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
+
+    /** Get the JSON name of this field. */
+    public String getJsonName() {
+      return jsonName;
+    }
 
     /**
      * Get the field's java type.  This is just for convenience.  Every
@@ -896,17 +937,22 @@ public final class Descriptors {
     public JavaType getJavaType() { return type.getJavaType(); }
 
     /** For internal use only. */
+    @Override
     public WireFormat.JavaType getLiteJavaType() {
       return getLiteType().getJavaType();
     }
 
     /** Get the {@code FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the field's declared type. */
     public Type getType() { return type; }
 
     /** For internal use only. */
+    @Override
     public WireFormat.FieldType getLiteType() {
       return table[type.ordinal()];
     }
@@ -948,6 +994,7 @@ public final class Descriptors {
     }
 
     /** Is this field declared repeated? */
+    @Override
     public boolean isRepeated() {
       return proto.getLabel() == FieldDescriptorProto.Label.LABEL_REPEATED;
     }
@@ -955,6 +1002,7 @@ public final class Descriptors {
     /** Does this field have the {@code [packed = true]} option or is this field
      *  packable in proto3 and not explicitly setted to unpacked?
      */
+    @Override
     public boolean isPacked() {
       if (!isPackable()) {
         return false;
@@ -1043,6 +1091,7 @@ public final class Descriptors {
     }
 
     /** For enum fields, gets the field's type. */
+    @Override
     public EnumDescriptor getEnumType() {
       if (getJavaType() != JavaType.ENUM) {
         throw new UnsupportedOperationException(
@@ -1061,6 +1110,7 @@ public final class Descriptors {
      * @return negative, zero, or positive if {@code this} is less than,
      *         equal to, or greater than {@code other}, respectively.
      */
+    @Override
     public int compareTo(final FieldDescriptor other) {
       if (other.containingType != containingType) {
         throw new IllegalArgumentException(
@@ -1079,6 +1129,7 @@ public final class Descriptors {
 
     private FieldDescriptorProto proto;
     private final String fullName;
+    private final String jsonName;
     private final FileDescriptor file;
     private final Descriptor extensionScope;
 
@@ -1117,7 +1168,7 @@ public final class Descriptors {
       private JavaType javaType;
 
       public FieldDescriptorProto.Type toProto() {
-        return FieldDescriptorProto.Type.valueOf(ordinal() + 1);
+        return FieldDescriptorProto.Type.forNumber(ordinal() + 1);
       }
       public JavaType getJavaType() { return javaType; }
 
@@ -1157,6 +1208,38 @@ public final class Descriptors {
       private final Object defaultDefault;
     }
 
+    // TODO(xiaofeng): Implement it consistently across different languages. See b/24751348.
+    private static String fieldNameToLowerCamelCase(String name) {
+      StringBuilder result = new StringBuilder(name.length());
+      boolean isNextUpperCase = false;
+      for (int i = 0; i < name.length(); i++) {
+        Character ch = name.charAt(i);
+        if (Character.isLowerCase(ch)) {
+          if (isNextUpperCase) {
+            result.append(Character.toUpperCase(ch));
+          } else {
+            result.append(ch);
+          }
+          isNextUpperCase = false;
+        } else if (Character.isUpperCase(ch)) {
+          if (i == 0) {
+            // Force first letter to lower-case.
+            result.append(Character.toLowerCase(ch));
+          } else {
+            // Capital letters after the first are left as-is.
+            result.append(ch);
+          }
+          isNextUpperCase = false;
+        } else if (Character.isDigit(ch)) {
+          result.append(ch);
+          isNextUpperCase = false;
+        } else {
+          isNextUpperCase = true;
+        }
+      }
+      return result.toString();
+    }
+
     private FieldDescriptor(final FieldDescriptorProto proto,
                             final FileDescriptor file,
                             final Descriptor parent,
@@ -1167,6 +1250,11 @@ public final class Descriptors {
       this.proto = proto;
       fullName = computeFullName(file, parent, proto.getName());
       this.file = file;
+      if (proto.hasJsonName()) {
+        jsonName = proto.getJsonName();
+      } else {
+        jsonName = fieldNameToLowerCamelCase(proto.getName());
+      }
 
       if (proto.hasType()) {
         type = Type.valueOf(proto.getType());
@@ -1423,8 +1511,8 @@ public final class Descriptors {
      * For internal use only.  This is to satisfy the FieldDescriptorLite
      * interface.
      */
-    public MessageLite.Builder internalMergeFrom(
-        MessageLite.Builder to, MessageLite from) {
+    @Override
+    public MessageLite.Builder internalMergeFrom(MessageLite.Builder to, MessageLite from) {
       // FieldDescriptors are only used with non-lite messages so we can just
       // down-cast and call mergeFrom directly.
       return ((Message.Builder) to).mergeFrom((Message) from);
@@ -1444,19 +1532,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public EnumDescriptorProto toProto() { return proto; }
+    @Override
+    public EnumDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the type's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the type's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** If this is a nested type, get the outer descriptor, otherwise null. */
     public Descriptor getContainingType() { return containingType; }
@@ -1490,6 +1590,7 @@ public final class Descriptors {
      * @param number The value's number.
      * @return the value's descriptor, or {@code null} if not found.
      */
+    @Override
     public EnumValueDescriptor findValueByNumber(final int number) {
       return file.pool.enumValuesByNumber.get(
         new DescriptorPool.DescriptorIntPair(this, number));
@@ -1616,13 +1717,22 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public EnumValueDescriptorProto toProto() { return proto; }
+    @Override
+    public EnumValueDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the value's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /** Get the value's number. */
-    public int getNumber() { return proto.getNumber(); }
+    @Override
+    public int getNumber() {
+      return proto.getNumber();
+    }
 
     @Override
     public String toString() { return proto.getName(); }
@@ -1631,10 +1741,16 @@ public final class Descriptors {
      * Get the value's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the value's enum type. */
     public EnumDescriptor getType() { return type; }
@@ -1702,19 +1818,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public ServiceDescriptorProto toProto() { return proto; }
+    @Override
+    public ServiceDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the type's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the type's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the {@code ServiceOptions}, defined in {@code descriptor.proto}. */
     public ServiceOptions getOptions() { return proto.getOptions(); }
@@ -1792,19 +1920,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public MethodDescriptorProto toProto() { return proto; }
+    @Override
+    public MethodDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the method's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the method's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the method's service type. */
     public ServiceDescriptor getService() { return service; }
@@ -2205,10 +2345,22 @@ public final class Descriptors {
      * that has the same name as an existing package.
      */
     private static final class PackageDescriptor extends GenericDescriptor {
-      public Message toProto()        { return file.toProto(); }
-      public String getName()         { return name;           }
-      public String getFullName()     { return fullName;       }
-      public FileDescriptor getFile() { return file;           }
+      @Override
+      public Message toProto() {
+        return file.toProto();
+      }
+      @Override
+      public String getName() {
+        return name;
+      }
+      @Override
+      public String getFullName() {
+        return fullName;
+      }
+      @Override
+      public FileDescriptor getFile() {
+        return file;
+      }
 
       PackageDescriptor(final String name, final String fullName,
                         final FileDescriptor file) {
diff --git a/java/src/main/java/com/google/protobuf/DoubleArrayList.java b/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
index 90ebe109..a9543b83 100644
--- a/java/src/main/java/com/google/protobuf/DoubleArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.DoubleList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -45,8 +44,6 @@ import java.util.RandomAccess;
 final class DoubleArrayList
     extends AbstractProtobufList<Double> implements DoubleList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final DoubleArrayList EMPTY_LIST = new DoubleArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -68,28 +65,59 @@ final class DoubleArrayList
   private int size;
 
   /**
-   * Constructs a new mutable {@code DoubleArrayList}.
+   * Constructs a new mutable {@code DoubleArrayList} with default capacity.
    */
   DoubleArrayList() {
-    array = new double[DEFAULT_CAPACITY];
-    size = 0;
+    this(new double[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code DoubleArrayList} containing the same elements as {@code other}.
    */
-  DoubleArrayList(List<Double> other) {
-    if (other instanceof DoubleArrayList) {
-      DoubleArrayList list = (DoubleArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new double[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private DoubleArrayList(double[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof DoubleArrayList)) {
+      return super.equals(o);
+    }
+    DoubleArrayList other = (DoubleArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final double[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      long bits = Double.doubleToLongBits(array[i]);
+      result = (31 * result) + Internal.hashLong(bits);
+    }
+    return result;
+  }
+
+  @Override
+  public DoubleList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new DoubleArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override
diff --git a/java/src/main/java/com/google/protobuf/DynamicMessage.java b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
index 3ea1b688..859a9e8f 100644
--- a/java/src/main/java/com/google/protobuf/DynamicMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
@@ -156,18 +156,22 @@ public final class DynamicMessage extends AbstractMessage {
   // -----------------------------------------------------------------
   // Implementation of Message interface.
 
+  @Override
   public Descriptor getDescriptorForType() {
     return type;
   }
 
+  @Override
   public DynamicMessage getDefaultInstanceForType() {
     return getDefaultInstance(type);
   }
 
+  @Override
   public Map<FieldDescriptor, Object> getAllFields() {
     return fields.getAllFields();
   }
 
+  @Override
   public boolean hasOneof(OneofDescriptor oneof) {
     verifyOneofContainingType(oneof);
     FieldDescriptor field = oneofCases[oneof.getIndex()];
@@ -177,16 +181,19 @@ public final class DynamicMessage extends AbstractMessage {
     return true;
   }
 
+  @Override
   public FieldDescriptor getOneofFieldDescriptor(OneofDescriptor oneof) {
     verifyOneofContainingType(oneof);
     return oneofCases[oneof.getIndex()];
   }
 
+  @Override
   public boolean hasField(FieldDescriptor field) {
     verifyContainingType(field);
     return fields.hasField(field);
   }
 
+  @Override
   public Object getField(FieldDescriptor field) {
     verifyContainingType(field);
     Object result = fields.getField(field);
@@ -202,16 +209,19 @@ public final class DynamicMessage extends AbstractMessage {
     return result;
   }
 
+  @Override
   public int getRepeatedFieldCount(FieldDescriptor field) {
     verifyContainingType(field);
     return fields.getRepeatedFieldCount(field);
   }
 
+  @Override
   public Object getRepeatedField(FieldDescriptor field, int index) {
     verifyContainingType(field);
     return fields.getRepeatedField(field, index);
   }
 
+  @Override
   public UnknownFieldSet getUnknownFields() {
     return unknownFields;
   }
@@ -264,19 +274,22 @@ public final class DynamicMessage extends AbstractMessage {
     return size;
   }
 
+  @Override
   public Builder newBuilderForType() {
     return new Builder(type);
   }
 
+  @Override
   public Builder toBuilder() {
     return newBuilderForType().mergeFrom(this);
   }
 
+  @Override
   public Parser<DynamicMessage> getParserForType() {
     return new AbstractParser<DynamicMessage>() {
+      @Override
       public DynamicMessage parsePartialFrom(
-          CodedInputStream input,
-          ExtensionRegistryLite extensionRegistry)
+          CodedInputStream input, ExtensionRegistryLite extensionRegistry)
           throws InvalidProtocolBufferException {
         Builder builder = newBuilder(type);
         try {
@@ -370,6 +383,7 @@ public final class DynamicMessage extends AbstractMessage {
       }
     }
 
+    @Override
     public DynamicMessage build() {
       if (!isInitialized()) {
         throw newUninitializedMessageException(
@@ -394,6 +408,7 @@ public final class DynamicMessage extends AbstractMessage {
       return buildPartial();
     }
 
+    @Override
     public DynamicMessage buildPartial() {
       fields.makeImmutable();
       DynamicMessage result =
@@ -411,22 +426,27 @@ public final class DynamicMessage extends AbstractMessage {
       return result;
     }
 
+    @Override
     public boolean isInitialized() {
       return DynamicMessage.isInitialized(type, fields);
     }
 
+    @Override
     public Descriptor getDescriptorForType() {
       return type;
     }
 
+    @Override
     public DynamicMessage getDefaultInstanceForType() {
       return getDefaultInstance(type);
     }
 
+    @Override
     public Map<FieldDescriptor, Object> getAllFields() {
       return fields.getAllFields();
     }
 
+    @Override
     public Builder newBuilderForField(FieldDescriptor field) {
       verifyContainingType(field);
 
@@ -438,6 +458,7 @@ public final class DynamicMessage extends AbstractMessage {
       return new Builder(field.getMessageType());
     }
 
+    @Override
     public boolean hasOneof(OneofDescriptor oneof) {
       verifyOneofContainingType(oneof);
       FieldDescriptor field = oneofCases[oneof.getIndex()];
@@ -447,11 +468,13 @@ public final class DynamicMessage extends AbstractMessage {
       return true;
     }
 
+    @Override
     public FieldDescriptor getOneofFieldDescriptor(OneofDescriptor oneof) {
       verifyOneofContainingType(oneof);
       return oneofCases[oneof.getIndex()];
     }
 
+    @Override
     public Builder clearOneof(OneofDescriptor oneof) {
       verifyOneofContainingType(oneof);
       FieldDescriptor field = oneofCases[oneof.getIndex()];
@@ -461,11 +484,13 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public boolean hasField(FieldDescriptor field) {
       verifyContainingType(field);
       return fields.hasField(field);
     }
 
+    @Override
     public Object getField(FieldDescriptor field) {
       verifyContainingType(field);
       Object result = fields.getField(field);
@@ -481,6 +506,7 @@ public final class DynamicMessage extends AbstractMessage {
       return result;
     }
 
+    @Override
     public Builder setField(FieldDescriptor field, Object value) {
       verifyContainingType(field);
       ensureIsMutable();
@@ -505,6 +531,7 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public Builder clearField(FieldDescriptor field) {
       verifyContainingType(field);
       ensureIsMutable();
@@ -519,24 +546,27 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public int getRepeatedFieldCount(FieldDescriptor field) {
       verifyContainingType(field);
       return fields.getRepeatedFieldCount(field);
     }
 
+    @Override
     public Object getRepeatedField(FieldDescriptor field, int index) {
       verifyContainingType(field);
       return fields.getRepeatedField(field, index);
     }
 
-    public Builder setRepeatedField(FieldDescriptor field,
-                                    int index, Object value) {
+    @Override
+    public Builder setRepeatedField(FieldDescriptor field, int index, Object value) {
       verifyContainingType(field);
       ensureIsMutable();
       fields.setRepeatedField(field, index, value);
       return this;
     }
 
+    @Override
     public Builder addRepeatedField(FieldDescriptor field, Object value) {
       verifyContainingType(field);
       ensureIsMutable();
@@ -544,10 +574,12 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public UnknownFieldSet getUnknownFields() {
       return unknownFields;
     }
 
+    @Override
     public Builder setUnknownFields(UnknownFieldSet unknownFields) {
       if (getDescriptorForType().getFile().getSyntax()
           == Descriptors.FileDescriptor.Syntax.PROTO3) {
diff --git a/java/core/src/main/java/com/google/protobuf/ExperimentalApi.java b/java/core/src/main/java/com/google/protobuf/ExperimentalApi.java
new file mode 100644
index 00000000..3cd4c884
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/ExperimentalApi.java
@@ -0,0 +1,66 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates a public API that can change at any time, and has no guarantee of API stability and
+ * backward-compatibility.
+ *
+ * <p>Usage guidelines:
+ * <ol>
+ * <li>This annotation is used only on public API. Internal interfaces should not use it.</li>
+ * <li>This annotation should only be added to new APIs. Adding it to an existing API is
+ * considered API-breaking.</li>
+ * <li>Removing this annotation from an API gives it stable status.</li>
+ * </ol>
+ */
+@Retention(RetentionPolicy.SOURCE)
+@Target({
+    ElementType.ANNOTATION_TYPE,
+    ElementType.CONSTRUCTOR,
+    ElementType.FIELD,
+    ElementType.METHOD,
+    ElementType.PACKAGE,
+    ElementType.TYPE})
+@Documented
+public @interface ExperimentalApi {
+  /**
+   * Context information such as links to discussion thread, tracking issue etc.
+   */
+  String value() default "";
+}
+
diff --git a/java/src/main/java/com/google/protobuf/Extension.java b/java/core/src/main/java/com/google/protobuf/Extension.java
index 68d29f33..08ec5b45 100644
--- a/java/src/main/java/com/google/protobuf/Extension.java
+++ b/java/core/src/main/java/com/google/protobuf/Extension.java
@@ -42,6 +42,7 @@ public abstract class Extension<ContainingType extends MessageLite, Type>
   public abstract Descriptors.FieldDescriptor getDescriptor();
 
   /** Returns whether or not this extension is a Lite Extension. */
+  @Override
   final boolean isLite() {
     return false;
   }
diff --git a/java/src/main/java/com/google/protobuf/ExtensionLite.java b/java/core/src/main/java/com/google/protobuf/ExtensionLite.java
index f8f5bd2c..f8f5bd2c 100644
--- a/java/src/main/java/com/google/protobuf/ExtensionLite.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionLite.java
diff --git a/java/src/main/java/com/google/protobuf/ExtensionRegistry.java b/java/core/src/main/java/com/google/protobuf/ExtensionRegistry.java
index 0067392f..0067392f 100644
--- a/java/src/main/java/com/google/protobuf/ExtensionRegistry.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionRegistry.java
diff --git a/java/src/main/java/com/google/protobuf/ExtensionRegistryLite.java b/java/core/src/main/java/com/google/protobuf/ExtensionRegistryLite.java
index 65cf7385..65cf7385 100644
--- a/java/src/main/java/com/google/protobuf/ExtensionRegistryLite.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionRegistryLite.java
diff --git a/java/src/main/java/com/google/protobuf/FieldSet.java b/java/core/src/main/java/com/google/protobuf/FieldSet.java
index 47924b65..4e89709f 100644
--- a/java/src/main/java/com/google/protobuf/FieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/FieldSet.java
@@ -120,6 +120,25 @@ final class FieldSet<FieldDescriptorType extends
   public boolean isImmutable() {
     return isImmutable;
   }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    
+    if (!(o instanceof FieldSet)) {
+      return false;
+    }
+    
+    FieldSet<?> other = (FieldSet<?>) o;
+    return other.fields.equals(other.fields);
+  }
+  
+  @Override
+  public int hashCode() {
+    return fields.hashCode();
+  }
 
   /**
    * Clones the FieldSet. The returned FieldSet will be mutable even if the
diff --git a/java/src/main/java/com/google/protobuf/FloatArrayList.java b/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
index 293eaff6..63cb6d77 100644
--- a/java/src/main/java/com/google/protobuf/FloatArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.FloatList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -44,8 +43,6 @@ import java.util.RandomAccess;
  */
 final class FloatArrayList extends AbstractProtobufList<Float> implements FloatList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final FloatArrayList EMPTY_LIST = new FloatArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -67,28 +64,58 @@ final class FloatArrayList extends AbstractProtobufList<Float> implements FloatL
   private int size;
 
   /**
-   * Constructs a new mutable {@code FloatArrayList}.
+   * Constructs a new mutable {@code FloatArrayList} with default capacity.
    */
   FloatArrayList() {
-    array = new float[DEFAULT_CAPACITY];
-    size = 0;
+    this(new float[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code FloatArrayList} containing the same elements as {@code other}.
    */
-  FloatArrayList(List<Float> other) {
-    if (other instanceof FloatArrayList) {
-      FloatArrayList list = (FloatArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new float[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private FloatArrayList(float[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof FloatArrayList)) {
+      return super.equals(o);
+    }
+    FloatArrayList other = (FloatArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final float[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + Float.floatToIntBits(array[i]);
+    }
+    return result;
+  }
+
+  @Override
+  public FloatList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new FloatArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override
diff --git a/java/src/main/java/com/google/protobuf/GeneratedMessage.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessage.java
index d84fa75c..790cb622 100644
--- a/java/src/main/java/com/google/protobuf/GeneratedMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessage.java
@@ -36,15 +36,13 @@ import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
-import com.google.protobuf.GeneratedMessageLite.ExtendableMessage;
-import com.google.protobuf.GeneratedMessageLite.GeneratedExtension;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
@@ -82,6 +80,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     unknownFields = builder.getUnknownFields();
   }
 
+  @Override
   public Parser<? extends GeneratedMessage> getParserForType() {
     throw new UnsupportedOperationException(
         "This is supposed to be overridden by subclasses.");
@@ -104,7 +103,7 @@ public abstract class GeneratedMessage extends AbstractMessage
    */
   protected abstract FieldAccessorTable internalGetFieldAccessorTable();
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Descriptor getDescriptorForType() {
     return internalGetFieldAccessorTable().descriptor;
   }
@@ -193,7 +192,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     return true;
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Map<FieldDescriptor, Object> getAllFields() {
     return Collections.unmodifiableMap(
         getAllFieldsMutable(/* getBytesForString = */ false));
@@ -214,22 +213,22 @@ public abstract class GeneratedMessage extends AbstractMessage
         getAllFieldsMutable(/* getBytesForString = */ true));
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public boolean hasOneof(final OneofDescriptor oneof) {
     return internalGetFieldAccessorTable().getOneof(oneof).has(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public FieldDescriptor getOneofFieldDescriptor(final OneofDescriptor oneof) {
     return internalGetFieldAccessorTable().getOneof(oneof).get(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public boolean hasField(final FieldDescriptor field) {
     return internalGetFieldAccessorTable().getField(field).has(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Object getField(final FieldDescriptor field) {
     return internalGetFieldAccessorTable().getField(field).get(this);
   }
@@ -246,19 +245,19 @@ public abstract class GeneratedMessage extends AbstractMessage
     return internalGetFieldAccessorTable().getField(field).getRaw(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public int getRepeatedFieldCount(final FieldDescriptor field) {
     return internalGetFieldAccessorTable().getField(field)
       .getRepeatedCount(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Object getRepeatedField(final FieldDescriptor field, final int index) {
     return internalGetFieldAccessorTable().getField(field)
       .getRepeated(this, index);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public UnknownFieldSet getUnknownFields() {
     throw new UnsupportedOperationException(
         "This is supposed to be overridden by subclasses.");
@@ -276,6 +275,60 @@ public abstract class GeneratedMessage extends AbstractMessage
     return unknownFields.mergeFieldFrom(tag, input);
   }
 
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser, InputStream input)
+      throws IOException {
+    try {
+      return parser.parseFrom(input);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser, InputStream input,
+      ExtensionRegistryLite extensions) throws IOException {
+    try {
+      return parser.parseFrom(input, extensions);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser,
+      CodedInputStream input) throws IOException {
+    try {
+      return parser.parseFrom(input);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser,
+      CodedInputStream input, ExtensionRegistryLite extensions) throws IOException {
+    try {
+      return parser.parseFrom(input, extensions);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseDelimitedWithIOException(Parser<M> parser,
+      InputStream input) throws IOException {
+    try {
+      return parser.parseDelimitedFrom(input);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseDelimitedWithIOException(Parser<M> parser,
+      InputStream input, ExtensionRegistryLite extensions) throws IOException {
+    try {
+      return parser.parseDelimitedFrom(input, extensions);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
   @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
     MessageReflection.writeMessageTo(this, getAllFieldsRaw(), output, false);
@@ -328,7 +381,7 @@ public abstract class GeneratedMessage extends AbstractMessage
   }
 
   @SuppressWarnings("unchecked")
-  public abstract static class Builder <BuilderType extends Builder>
+  public abstract static class Builder <BuilderType extends Builder<BuilderType>>
       extends AbstractMessage.Builder<BuilderType> {
 
     private BuilderParent builderParent;
@@ -392,6 +445,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * Called by the initialization and clear code paths to allow subclasses to
      * reset any of their builtin fields back to the initial values.
      */
+    @Override
     public BuilderType clear() {
       unknownFields = UnknownFieldSet.getDefaultInstance();
       onChanged();
@@ -405,12 +459,12 @@ public abstract class GeneratedMessage extends AbstractMessage
      */
     protected abstract FieldAccessorTable internalGetFieldAccessorTable();
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Descriptor getDescriptorForType() {
       return internalGetFieldAccessorTable().descriptor;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Map<FieldDescriptor, Object> getAllFields() {
       return Collections.unmodifiableMap(getAllFieldsMutable());
     }
@@ -458,39 +512,38 @@ public abstract class GeneratedMessage extends AbstractMessage
       return result;
     }
 
-    public Message.Builder newBuilderForField(
-        final FieldDescriptor field) {
+    @Override
+    public Message.Builder newBuilderForField(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field).newBuilder();
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Message.Builder getFieldBuilder(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field).getBuilder(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field,
-        int index) {
+    @Override
+    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field, int index) {
       return internalGetFieldAccessorTable().getField(field).getRepeatedBuilder(
           this, index);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean hasOneof(final OneofDescriptor oneof) {
       return internalGetFieldAccessorTable().getOneof(oneof).has(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public FieldDescriptor getOneofFieldDescriptor(final OneofDescriptor oneof) {
       return internalGetFieldAccessorTable().getOneof(oneof).get(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean hasField(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field).has(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Object getField(final FieldDescriptor field) {
       Object object = internalGetFieldAccessorTable().getField(field).get(this);
       if (field.isRepeated()) {
@@ -502,52 +555,52 @@ public abstract class GeneratedMessage extends AbstractMessage
       }
     }
 
-    public BuilderType setField(final FieldDescriptor field,
-                                final Object value) {
+    @Override
+    public BuilderType setField(final FieldDescriptor field, final Object value) {
       internalGetFieldAccessorTable().getField(field).set(this, value);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public BuilderType clearField(final FieldDescriptor field) {
       internalGetFieldAccessorTable().getField(field).clear(this);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public BuilderType clearOneof(final OneofDescriptor oneof) {
       internalGetFieldAccessorTable().getOneof(oneof).clear(this);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public int getRepeatedFieldCount(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field)
           .getRepeatedCount(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public Object getRepeatedField(final FieldDescriptor field,
-                                   final int index) {
+    @Override
+    public Object getRepeatedField(final FieldDescriptor field, final int index) {
       return internalGetFieldAccessorTable().getField(field)
           .getRepeated(this, index);
     }
 
-    public BuilderType setRepeatedField(final FieldDescriptor field,
-                                        final int index, final Object value) {
+    @Override
+    public BuilderType setRepeatedField(
+        final FieldDescriptor field, final int index, final Object value) {
       internalGetFieldAccessorTable().getField(field)
         .setRepeated(this, index, value);
       return (BuilderType) this;
     }
 
-    public BuilderType addRepeatedField(final FieldDescriptor field,
-                                        final Object value) {
+    @Override
+    public BuilderType addRepeatedField(final FieldDescriptor field, final Object value) {
       internalGetFieldAccessorTable().getField(field).addRepeated(this, value);
       return (BuilderType) this;
     }
 
-    public BuilderType setUnknownFields(
-        final UnknownFieldSet unknownFields) {
+    @Override
+    public BuilderType setUnknownFields(final UnknownFieldSet unknownFields) {
       this.unknownFields = unknownFields;
       onChanged();
       return (BuilderType) this;
@@ -564,7 +617,7 @@ public abstract class GeneratedMessage extends AbstractMessage
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean isInitialized() {
       for (final FieldDescriptor field : getDescriptorForType().getFields()) {
         // Check that all required fields are present.
@@ -594,7 +647,7 @@ public abstract class GeneratedMessage extends AbstractMessage
       return true;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final UnknownFieldSet getUnknownFields() {
       return unknownFields;
     }
@@ -618,7 +671,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      */
     private class BuilderParentImpl implements BuilderParent {
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public void markDirty() {
         onChanged();
       }
@@ -667,7 +720,7 @@ public abstract class GeneratedMessage extends AbstractMessage
           "No map fields found in " + getClass().getName());
     }
 
-    /** Like {@link internalGetMapField} but return a mutable version. */
+    /** Like {@link #internalGetMapField} but return a mutable version. */
     @SuppressWarnings({"unused", "rawtypes"})
     protected MapField internalGetMutableMapField(int fieldNumber) {
       // Note that we can't use descriptor names here because this method will
@@ -683,6 +736,7 @@ public abstract class GeneratedMessage extends AbstractMessage
   public interface ExtendableMessageOrBuilder<
       MessageType extends ExtendableMessage> extends MessageOrBuilder {
     // Re-define for return type covariance.
+    @Override
     Message getDefaultInstanceForType();
 
     /** Check if a singular extension is present. */
@@ -743,6 +797,8 @@ public abstract class GeneratedMessage extends AbstractMessage
       extends GeneratedMessage
       implements ExtendableMessageOrBuilder<MessageType> {
 
+    private static final long serialVersionUID = 1L;
+
     private final FieldSet<FieldDescriptor> extensions;
 
     protected ExtendableMessage() {
@@ -769,9 +825,8 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -779,7 +834,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extensionLite) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
@@ -790,10 +845,9 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -815,11 +869,10 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get one element of a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extensionLite,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extensionLite, final int index) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -967,7 +1020,9 @@ public abstract class GeneratedMessage extends AbstractMessage
         verifyContainingType(field);
         final Object value = extensions.getField(field);
         if (value == null) {
-          if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
+          if (field.isRepeated()) {
+            return Collections.emptyList();
+          } else if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
             // Lacking an ExtensionRegistry, we have no way to determine the
             // extension's real type, so we return a DynamicMessage.
             return DynamicMessage.getDefaultInstance(field.getMessageType());
@@ -1051,7 +1106,7 @@ public abstract class GeneratedMessage extends AbstractMessage
   @SuppressWarnings("unchecked")
   public abstract static class ExtendableBuilder<
         MessageType extends ExtendableMessage,
-        BuilderType extends ExtendableBuilder>
+        BuilderType extends ExtendableBuilder<MessageType, BuilderType>>
       extends Builder<BuilderType>
       implements ExtendableMessageOrBuilder<MessageType> {
 
@@ -1103,9 +1158,8 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1113,7 +1167,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extensionLite) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
@@ -1124,9 +1178,8 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    @Override
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1148,10 +1201,9 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get one element of a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extensionLite,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extensionLite, final int index) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1404,10 +1456,9 @@ public abstract class GeneratedMessage extends AbstractMessage
     // obtained.
     return new GeneratedExtension<ContainingType, Type>(
         new CachedDescriptorRetriever() {
-          //@Override (Java 1.6 override semantics, but we must support 1.5)
+          @Override
           public FieldDescriptor loadDescriptor() {
-            return scope.getDescriptorForType().getExtensions()
-                .get(descriptorIndex);
+            return scope.getDescriptorForType().getExtensions().get(descriptorIndex);
           }
         },
         singularType,
@@ -1435,6 +1486,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     private volatile FieldDescriptor descriptor;
     protected abstract FieldDescriptor loadDescriptor();
 
+    @Override
     public FieldDescriptor getDescriptor() {
       if (descriptor == null) {
         synchronized (this) {
@@ -1464,6 +1516,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     // obtained.
     return new GeneratedExtension<ContainingType, Type>(
         new CachedDescriptorRetriever() {
+          @Override
           protected FieldDescriptor loadDescriptor() {
             return scope.getDescriptorForType().findFieldByName(name);
           }
@@ -1490,17 +1543,18 @@ public abstract class GeneratedMessage extends AbstractMessage
     // used to obtain the extension's FieldDescriptor.
     return new GeneratedExtension<ContainingType, Type>(
         new CachedDescriptorRetriever() {
+          @Override
           protected FieldDescriptor loadDescriptor() {
             try {
-              Class clazz =
-                  singularType.getClassLoader().loadClass(descriptorOuterClass);
-              FileDescriptor file =
-                  (FileDescriptor) clazz.getField("descriptor").get(null);
+              Class clazz = singularType.getClassLoader().loadClass(descriptorOuterClass);
+              FileDescriptor file = (FileDescriptor) clazz.getField("descriptor").get(null);
               return file.findExtensionByName(extensionName);
             } catch (Exception e) {
               throw new RuntimeException(
-                  "Cannot load descriptors: " + descriptorOuterClass +
-                  " is not a valid descriptor class name", e);
+                  "Cannot load descriptors: "
+                      + descriptorOuterClass
+                      + " is not a valid descriptor class name",
+                  e);
             }
           }
         },
@@ -1582,12 +1636,13 @@ public abstract class GeneratedMessage extends AbstractMessage
       if (descriptorRetriever != null) {
         throw new IllegalStateException("Already initialized.");
       }
-      descriptorRetriever = new ExtensionDescriptorRetriever() {
-          //@Override (Java 1.6 override semantics, but we must support 1.5)
-          public FieldDescriptor getDescriptor() {
-            return descriptor;
-          }
-        };
+      descriptorRetriever =
+          new ExtensionDescriptorRetriever() {
+            @Override
+            public FieldDescriptor getDescriptor() {
+              return descriptor;
+            }
+          };
     }
 
     private ExtensionDescriptorRetriever descriptorRetriever;
@@ -1597,6 +1652,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     private final Method enumGetValueDescriptor;
     private final ExtensionType extensionType;
 
+    @Override
     public FieldDescriptor getDescriptor() {
       if (descriptorRetriever == null) {
         throw new IllegalStateException(
@@ -1609,10 +1665,12 @@ public abstract class GeneratedMessage extends AbstractMessage
      * If the extension is an embedded message or group, returns the default
      * instance of the message.
      */
+    @Override
     public Message getMessageDefaultInstance() {
       return messageDefaultInstance;
     }
 
+    @Override
     protected ExtensionType getExtensionType() {
       return extensionType;
     }
@@ -1623,7 +1681,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * EnumValueDescriptors but the native accessors use the generated enum
      * type.
      */
-    // @Override
+    @Override
     @SuppressWarnings("unchecked")
     protected Object fromReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
@@ -1648,7 +1706,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * Like {@link #fromReflectionType(Object)}, but if the type is a repeated
      * type, this converts a single element.
      */
-    // @Override
+    @Override
     protected Object singularFromReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
       switch (descriptor.getJavaType()) {
@@ -1672,7 +1730,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * EnumValueDescriptors but the native accessors use the generated enum
      * type.
      */
-    // @Override
+    @Override
     @SuppressWarnings("unchecked")
     protected Object toReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
@@ -1696,7 +1754,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * Like {@link #toReflectionType(Object)}, but if the type is a repeated
      * type, this converts a single element.
      */
-    // @Override
+    @Override
     protected Object singularToReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
       switch (descriptor.getJavaType()) {
@@ -1707,22 +1765,22 @@ public abstract class GeneratedMessage extends AbstractMessage
       }
     }
 
-    // @Override
+    @Override
     public int getNumber() {
       return getDescriptor().getNumber();
     }
 
-    // @Override
+    @Override
     public WireFormat.FieldType getLiteType() {
       return getDescriptor().getLiteType();
     }
 
-    // @Override
+    @Override
     public boolean isRepeated() {
       return getDescriptor().isRepeated();
     }
 
-    // @Override
+    @Override
     @SuppressWarnings("unchecked")
     public Type getDefaultValue() {
       if (isRepeated()) {
@@ -2072,49 +2130,57 @@ public abstract class GeneratedMessage extends AbstractMessage
         return ((Internal.EnumLite) invokeOrDie(caseMethodBuilder, builder)).getNumber();
       }
 
+      @Override
       public Object get(final GeneratedMessage message) {
         return invokeOrDie(getMethod, message);
       }
+      @Override
       public Object get(GeneratedMessage.Builder builder) {
         return invokeOrDie(getMethodBuilder, builder);
       }
+      @Override
       public Object getRaw(final GeneratedMessage message) {
         return get(message);
       }
+      @Override
       public Object getRaw(GeneratedMessage.Builder builder) {
         return get(builder);
       }
+      @Override
       public void set(final Builder builder, final Object value) {
         invokeOrDie(setMethod, builder, value);
       }
-      public Object getRepeated(final GeneratedMessage message,
-                                final int index) {
+      @Override
+      public Object getRepeated(final GeneratedMessage message, final int index) {
         throw new UnsupportedOperationException(
           "getRepeatedField() called on a singular field.");
       }
-      public Object getRepeatedRaw(final GeneratedMessage message,
-                                final int index) {
+      @Override
+      public Object getRepeatedRaw(final GeneratedMessage message, final int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldRaw() called on a singular field.");
       }
+      @Override
       public Object getRepeated(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedField() called on a singular field.");
       }
-      public Object getRepeatedRaw(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Object getRepeatedRaw(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldRaw() called on a singular field.");
       }
-      public void setRepeated(final Builder builder, final int index,
-          final Object value) {
+      @Override
+      public void setRepeated(final Builder builder, final int index, final Object value) {
         throw new UnsupportedOperationException(
           "setRepeatedField() called on a singular field.");
       }
+      @Override
       public void addRepeated(final Builder builder, final Object value) {
         throw new UnsupportedOperationException(
           "addRepeatedField() called on a singular field.");
       }
+      @Override
       public boolean has(final GeneratedMessage message) {
         if (!hasHasMethod) {
           if (isOneofField) {
@@ -2124,6 +2190,7 @@ public abstract class GeneratedMessage extends AbstractMessage
         }
         return (Boolean) invokeOrDie(hasMethod, message);
       }
+      @Override
       public boolean has(GeneratedMessage.Builder builder) {
         if (!hasHasMethod) {
           if (isOneofField) {
@@ -2133,27 +2200,32 @@ public abstract class GeneratedMessage extends AbstractMessage
         }
         return (Boolean) invokeOrDie(hasMethodBuilder, builder);
       }
+      @Override
       public int getRepeatedCount(final GeneratedMessage message) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldSize() called on a singular field.");
       }
+      @Override
       public int getRepeatedCount(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldSize() called on a singular field.");
       }
+      @Override
       public void clear(final Builder builder) {
         invokeOrDie(clearMethod, builder);
       }
+      @Override
       public Message.Builder newBuilder() {
         throw new UnsupportedOperationException(
           "newBuilderForField() called on a non-Message type.");
       }
+      @Override
       public Message.Builder getBuilder(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "getFieldBuilder() called on a non-Message type.");
       }
-      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldBuilder() called on a non-Message type.");
       }
@@ -2197,18 +2269,23 @@ public abstract class GeneratedMessage extends AbstractMessage
         clearMethod = getMethodOrDie(builderClass, "clear" + camelCaseName);
       }
 
+      @Override
       public Object get(final GeneratedMessage message) {
         return invokeOrDie(getMethod, message);
       }
+      @Override
       public Object get(GeneratedMessage.Builder builder) {
         return invokeOrDie(getMethodBuilder, builder);
       }
+      @Override
       public Object getRaw(final GeneratedMessage message) {
         return get(message);
       }
+      @Override
       public Object getRaw(GeneratedMessage.Builder builder) {
         return get(builder);
       }
+      @Override
       public void set(final Builder builder, final Object value) {
         // Add all the elements individually.  This serves two purposes:
         // 1) Verifies that each element has the correct type.
@@ -2219,54 +2296,64 @@ public abstract class GeneratedMessage extends AbstractMessage
           addRepeated(builder, element);
         }
       }
-      public Object getRepeated(final GeneratedMessage message,
-                                final int index) {
+      @Override
+      public Object getRepeated(final GeneratedMessage message, final int index) {
         return invokeOrDie(getRepeatedMethod, message, index);
       }
+      @Override
       public Object getRepeated(GeneratedMessage.Builder builder, int index) {
         return invokeOrDie(getRepeatedMethodBuilder, builder, index);
       }
+      @Override
       public Object getRepeatedRaw(GeneratedMessage message, int index) {
         return getRepeated(message, index);
       }
-      public Object getRepeatedRaw(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Object getRepeatedRaw(GeneratedMessage.Builder builder, int index) {
         return getRepeated(builder, index);
       }
-      public void setRepeated(final Builder builder,
-                              final int index, final Object value) {
+      @Override
+      public void setRepeated(final Builder builder, final int index, final Object value) {
         invokeOrDie(setRepeatedMethod, builder, index, value);
       }
+      @Override
       public void addRepeated(final Builder builder, final Object value) {
         invokeOrDie(addRepeatedMethod, builder, value);
       }
+      @Override
       public boolean has(final GeneratedMessage message) {
         throw new UnsupportedOperationException(
           "hasField() called on a repeated field.");
       }
+      @Override
       public boolean has(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "hasField() called on a repeated field.");
       }
+      @Override
       public int getRepeatedCount(final GeneratedMessage message) {
         return (Integer) invokeOrDie(getCountMethod, message);
       }
+      @Override
       public int getRepeatedCount(GeneratedMessage.Builder builder) {
         return (Integer) invokeOrDie(getCountMethodBuilder, builder);
       }
+      @Override
       public void clear(final Builder builder) {
         invokeOrDie(clearMethod, builder);
       }
+      @Override
       public Message.Builder newBuilder() {
         throw new UnsupportedOperationException(
           "newBuilderForField() called on a non-Message type.");
       }
+      @Override
       public Message.Builder getBuilder(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "getFieldBuilder() called on a non-Message type.");
       }
-      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldBuilder() called on a non-Message type.");
       }
@@ -2303,6 +2390,7 @@ public abstract class GeneratedMessage extends AbstractMessage
             field.getNumber());
       }
 
+      @Override
       public Object get(GeneratedMessage message) {
         List result = new ArrayList();
         for (int i = 0; i < getRepeatedCount(message); i++) {
@@ -2311,6 +2399,7 @@ public abstract class GeneratedMessage extends AbstractMessage
         return Collections.unmodifiableList(result);
       }
 
+      @Override
       public Object get(Builder builder) {
         List result = new ArrayList();
         for (int i = 0; i < getRepeatedCount(builder); i++) {
@@ -2319,14 +2408,17 @@ public abstract class GeneratedMessage extends AbstractMessage
         return Collections.unmodifiableList(result);
       }
 
+      @Override
       public Object getRaw(GeneratedMessage message) {
         return get(message);
       }
 
+      @Override
       public Object getRaw(GeneratedMessage.Builder builder) {
         return get(builder);
       }
 
+      @Override
       public void set(Builder builder, Object value) {
         clear(builder);
         for (Object entry : (List) value) {
@@ -2334,63 +2426,76 @@ public abstract class GeneratedMessage extends AbstractMessage
         }
       }
 
+      @Override
       public Object getRepeated(GeneratedMessage message, int index) {
         return getMapField(message).getList().get(index);
       }
 
+      @Override
       public Object getRepeated(Builder builder, int index) {
         return getMapField(builder).getList().get(index);
       }
 
+      @Override
       public Object getRepeatedRaw(GeneratedMessage message, int index) {
         return getRepeated(message, index);
       }
 
+      @Override
       public Object getRepeatedRaw(Builder builder, int index) {
         return getRepeated(builder, index);
       }
 
+      @Override
       public void setRepeated(Builder builder, int index, Object value) {
         getMutableMapField(builder).getMutableList().set(index, (Message) value);
       }
 
+      @Override
       public void addRepeated(Builder builder, Object value) {
         getMutableMapField(builder).getMutableList().add((Message) value);
       }
 
+      @Override
       public boolean has(GeneratedMessage message) {
         throw new UnsupportedOperationException(
             "hasField() is not supported for repeated fields.");
       }
 
+      @Override
       public boolean has(Builder builder) {
         throw new UnsupportedOperationException(
             "hasField() is not supported for repeated fields.");
       }
 
+      @Override
       public int getRepeatedCount(GeneratedMessage message) {
         return getMapField(message).getList().size();
       }
 
+      @Override
       public int getRepeatedCount(Builder builder) {
         return getMapField(builder).getList().size();
       }
 
+      @Override
       public void clear(Builder builder) {
         getMutableMapField(builder).getMutableList().clear();
       }
 
+      @Override
       public com.google.protobuf.Message.Builder newBuilder() {
         return mapEntryMessageDefaultInstance.newBuilderForType();
       }
 
+      @Override
       public com.google.protobuf.Message.Builder getBuilder(Builder builder) {
         throw new UnsupportedOperationException(
             "Nested builder not supported for map fields.");
       }
 
-      public com.google.protobuf.Message.Builder getRepeatedBuilder(
-          Builder builder, int index) {
+      @Override
+      public com.google.protobuf.Message.Builder getRepeatedBuilder(Builder builder, int index) {
         throw new UnsupportedOperationException(
             "Nested builder not supported for map fields.");
       }
diff --git a/java/src/main/java/com/google/protobuf/GeneratedMessageLite.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
index 4316efee..c5adc5ad 100644
--- a/java/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import com.google.protobuf.AbstractMessageLite.Builder.LimitedInputStream;
+import com.google.protobuf.GeneratedMessageLite.EqualsVisitor.NotEqualsException;
 import com.google.protobuf.Internal.BooleanList;
 import com.google.protobuf.Internal.DoubleList;
 import com.google.protobuf.Internal.FloatList;
@@ -39,6 +41,7 @@ import com.google.protobuf.Internal.ProtobufList;
 import com.google.protobuf.WireFormat.FieldType;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
@@ -57,32 +60,108 @@ import java.util.Map;
 public abstract class GeneratedMessageLite<
     MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
     BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>> 
-        extends AbstractMessageLite
-        implements Serializable {
-
-  private static final long serialVersionUID = 1L;
+        extends AbstractMessageLite<MessageType, BuilderType> {
 
   /** For use by generated code only. Lazily initialized to reduce allocations. */
-  protected UnknownFieldSetLite unknownFields = null;
+  protected UnknownFieldSetLite unknownFields = UnknownFieldSetLite.getDefaultInstance();
   
   /** For use by generated code only.  */
   protected int memoizedSerializedSize = -1;
   
+  @Override
   @SuppressWarnings("unchecked") // Guaranteed by runtime.
   public final Parser<MessageType> getParserForType() {
     return (Parser<MessageType>) dynamicMethod(MethodToInvoke.GET_PARSER);
   }
 
+  @Override
   @SuppressWarnings("unchecked") // Guaranteed by runtime.
   public final MessageType getDefaultInstanceForType() {
     return (MessageType) dynamicMethod(MethodToInvoke.GET_DEFAULT_INSTANCE);
   }
 
+  @Override
   @SuppressWarnings("unchecked") // Guaranteed by runtime.
   public final BuilderType newBuilderForType() {
     return (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
   }
 
+  /**
+   * A reflective toString function. This is primarily intended as a developer aid, while keeping
+   * binary size down. The first line of the {@code toString()} representation includes a commented
+   * version of {@code super.toString()} to act as an indicator that this should not be relied on
+   * for comparisons.
+   * <p>
+   * NOTE: This method relies on the field getter methods not being stripped or renamed by proguard.
+   * If they are, the fields will not be included in the returned string representation.
+   * <p>
+   * NOTE: This implementation is liable to change in the future, and should not be relied on in
+   * code.
+   */
+  @Override
+  public String toString() {
+    return MessageLiteToString.toString(this, super.toString());
+  }
+
+  @SuppressWarnings("unchecked") // Guaranteed by runtime
+  @Override
+  public int hashCode() {
+    if (memoizedHashCode == 0) {
+      HashCodeVisitor visitor = new HashCodeVisitor();
+      visit(visitor, (MessageType) this);
+      memoizedHashCode = visitor.hashCode;
+    }
+    return memoizedHashCode;
+  }
+  
+  @SuppressWarnings("unchecked") // Guaranteed by runtime
+  int hashCode(HashCodeVisitor visitor) {
+    if (memoizedHashCode == 0) {
+      int inProgressHashCode = visitor.hashCode;
+      visitor.hashCode = 0;
+      visit(visitor, (MessageType) this);
+      memoizedHashCode = visitor.hashCode;
+      visitor.hashCode = inProgressHashCode;
+    }
+    return memoizedHashCode;
+  }
+  
+  @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
+  @Override
+  public boolean equals(Object other) {
+    if (this == other) {
+      return true;
+    }
+    
+    if (!getDefaultInstanceForType().getClass().isInstance(other)) {
+      return false;
+    }
+    
+    try {
+      visit(EqualsVisitor.INSTANCE, (MessageType) other);
+    } catch (NotEqualsException e) {
+      return false;
+    }
+    return true;
+  }
+  
+  /**
+   * Same as {@link #equals(Object)} but throws {@code NotEqualsException}.
+   */
+  @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
+  boolean equals(EqualsVisitor visitor, MessageLite other) {
+    if (this == other) {
+      return true;
+    }
+    
+    if (!getDefaultInstanceForType().getClass().isInstance(other)) {
+      return false;
+    }
+
+    visit(visitor, (MessageType) other);
+    return true;
+  }
+  
   // The general strategy for unknown fields is to use an UnknownFieldSetLite that is treated as
   // mutable during the parsing constructor and immutable after. This allows us to avoid
   // any unnecessary intermediary allocations while reducing the generated code size.
@@ -91,7 +170,7 @@ public abstract class GeneratedMessageLite<
    * Lazily initializes unknown fields.
    */
   private final void ensureUnknownFieldsInitialized() {
-    if (unknownFields == null) {
+    if (unknownFields == UnknownFieldSetLite.getDefaultInstance()) {
       unknownFields = UnknownFieldSetLite.newInstance();
     }
   }
@@ -102,6 +181,11 @@ public abstract class GeneratedMessageLite<
    * @return {@code true} unless the tag is an end-group tag.
    */
   protected boolean parseUnknownField(int tag, CodedInputStream input) throws IOException {
+    // This will avoid the allocation of unknown fields when a group tag is encountered.
+    if (WireFormat.getTagWireType(tag) == WireFormat.WIRETYPE_END_GROUP) {
+      return false;
+    }
+    
     ensureUnknownFieldsInitialized();
     return unknownFields.mergeFieldFrom(tag, input);
   }
@@ -125,18 +209,18 @@ public abstract class GeneratedMessageLite<
   /**
    * Called by subclasses to complete parsing. For use by generated code only.
    */
-  protected void doneParsing() {
-    if (unknownFields == null) {
-      unknownFields = UnknownFieldSetLite.getDefaultInstance();
-    } else {
-      unknownFields.makeImmutable();
-    }
+  protected void makeImmutable() {
+    dynamicMethod(MethodToInvoke.MAKE_IMMUTABLE);
+
+    unknownFields.makeImmutable();
   }
 
+  @Override
   public final boolean isInitialized() {
     return dynamicMethod(MethodToInvoke.IS_INITIALIZED, Boolean.TRUE) != null;
   }
 
+  @Override
   public final BuilderType toBuilder() {
     BuilderType builder = (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
     builder.mergeFrom((MessageType) this);
@@ -150,11 +234,14 @@ public abstract class GeneratedMessageLite<
    * For use by generated code only.
    */
   public static enum MethodToInvoke {
+    // Rely on/modify instance state
     IS_INITIALIZED,
-    PARSE_PARTIAL_FROM,
-    MERGE_FROM,
+    VISIT,
+    MERGE_FROM_STREAM,
     MAKE_IMMUTABLE,
-    NEW_INSTANCE,
+
+    // Rely on static state
+    NEW_MUTABLE_INSTANCE,
     NEW_BUILDER,
     GET_DEFAULT_INSTANCE,
     GET_PARSER;
@@ -166,17 +253,18 @@ public abstract class GeneratedMessageLite<
    * builders in the runtime. This method bundles those operations to reduce the generated methods
    * count.
    * <ul>
-   * <li>{@code PARSE_PARTIAL_FROM} is parameterized with an {@link CodedInputStream} and
+   * <li>{@code MERGE_FROM_STREAM} is parameterized with an {@link CodedInputStream} and
    * {@link ExtensionRegistryLite}. It consumes the input stream, parsing the contents into the
    * returned protocol buffer. If parsing throws an {@link InvalidProtocolBufferException}, the
-   * implementation wraps it in a RuntimeException
-   * <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer
+   * implementation wraps it in a RuntimeException.
+   * <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer that has not yet been
+   * made immutable. See {@code MAKE_IMMUTABLE}.
    * <li>{@code IS_INITIALIZED} is parameterized with a {@code Boolean} detailing whether to
    * memoize. It returns {@code null} for false and the default instance for true. We optionally
    * memoize to support the Builder case, where memoization is not desired.
    * <li>{@code NEW_BUILDER} returns a {@code BuilderType} instance.
-   * <li>{@code MERGE_FROM} is parameterized with a {@code MessageType} and merges the fields from
-   * that instance into this instance.
+   * <li>{@code VISIT} is parameterized with a {@code Visitor} and a {@code MessageType} and
+   * recursively iterates through the fields side by side between this and the instance.
    * <li>{@code MAKE_IMMUTABLE} sets all internal fields to an immutable state.
    * </ul>
    * This method, plus the implementation of the Builder, enables the Builder class to be proguarded
@@ -200,6 +288,11 @@ public abstract class GeneratedMessageLite<
     return dynamicMethod(method, null, null);
   }
 
+  void visit(Visitor visitor, MessageType other) {
+    dynamicMethod(MethodToInvoke.VISIT, visitor, other);
+    unknownFields = visitor.visitUnknownFields(unknownFields, other.unknownFields);
+  }
+  
   /**
    * Merge some unknown fields into the {@link UnknownFieldSetLite} for this
    * message.
@@ -214,7 +307,7 @@ public abstract class GeneratedMessageLite<
   public abstract static class Builder<
       MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
       BuilderType extends Builder<MessageType, BuilderType>>
-          extends AbstractMessageLite.Builder<BuilderType> {
+          extends AbstractMessageLite.Builder<MessageType, BuilderType> {
 
     private final MessageType defaultInstance;
     protected MessageType instance;
@@ -222,7 +315,8 @@ public abstract class GeneratedMessageLite<
 
     protected Builder(MessageType defaultInstance) {
       this.defaultInstance = defaultInstance;
-      this.instance = (MessageType) defaultInstance.dynamicMethod(MethodToInvoke.NEW_INSTANCE);
+      this.instance =
+          (MessageType) defaultInstance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
       isBuilt = false;
     }
 
@@ -232,26 +326,27 @@ public abstract class GeneratedMessageLite<
      */
     protected void copyOnWrite() {
       if (isBuilt) {
-        MessageType newInstance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_INSTANCE);
-        newInstance.dynamicMethod(MethodToInvoke.MERGE_FROM, instance);
+        MessageType newInstance =
+            (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
+        newInstance.visit(MergeFromVisitor.INSTANCE, instance);
         instance = newInstance;
         isBuilt = false;
       }
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final boolean isInitialized() {
       return GeneratedMessageLite.isInitialized(instance, false /* shouldMemoize */);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final BuilderType clear() {
       // No need to copy on write since we're dropping the instance anyways.
-      instance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_INSTANCE);
+      instance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public BuilderType clone() {
       BuilderType builder =
           (BuilderType) getDefaultInstanceForType().newBuilderForType();
@@ -259,20 +354,19 @@ public abstract class GeneratedMessageLite<
       return builder;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public MessageType buildPartial() {
       if (isBuilt) {
         return instance;
       }
       
-      instance.dynamicMethod(MethodToInvoke.MAKE_IMMUTABLE);
-      instance.unknownFields.makeImmutable();
+      instance.makeImmutable();
       
       isBuilt = true;
       return instance;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final MessageType build() {
       MessageType result = buildPartial();
       if (!result.isInitialized()) {
@@ -281,33 +375,36 @@ public abstract class GeneratedMessageLite<
       return result;
     }
     
+    @Override
+    protected BuilderType internalMergeFrom(MessageType message) {
+      return mergeFrom(message);
+    }
+    
     /** All subclasses implement this. */
     public BuilderType mergeFrom(MessageType message) {
       copyOnWrite();
-      instance.dynamicMethod(MethodToInvoke.MERGE_FROM, message);
+      instance.visit(MergeFromVisitor.INSTANCE, message);
       return (BuilderType) this;
     }
     
+    @Override
     public MessageType getDefaultInstanceForType() {
       return defaultInstance;
     }
     
+    @Override
     public BuilderType mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-        throws java.io.IOException {
-      MessageType parsedMessage = null;
+        throws IOException {
+      copyOnWrite();
       try {
-        parsedMessage =
-            (MessageType) getDefaultInstanceForType().getParserForType().parsePartialFrom(
-                input, extensionRegistry);
-      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage = (MessageType) e.getUnfinishedMessage();
-        throw e;
-      } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
+        instance.dynamicMethod(MethodToInvoke.MERGE_FROM_STREAM, input, extensionRegistry);
+      } catch (RuntimeException e) {
+        if (e.getCause() instanceof IOException) {
+          throw (IOException) e.getCause();
         }
+        throw e;
       }
       return (BuilderType) this;
     }
@@ -363,6 +460,12 @@ public abstract class GeneratedMessageLite<
       }
       extensions.mergeFrom(((ExtendableMessage) other).extensions);
     }
+
+    @Override
+    final void visit(Visitor visitor, MessageType other) {
+      super.visit(visitor, other);
+      extensions = visitor.visitExtensions(extensions, other.extensions);
+    }
     
     /**
      * Parse an unknown field or an extension. For use by generated code only.
@@ -500,9 +603,8 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extension) {
       GeneratedExtension<MessageType, Type> extensionLite =
           checkIsLite(extension);
       
@@ -511,7 +613,7 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extension) {
       GeneratedExtension<MessageType, List<Type>> extensionLite =
@@ -522,10 +624,9 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extension) {
       GeneratedExtension<MessageType, Type> extensionLite =
           checkIsLite(extension);
       
@@ -539,11 +640,10 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get one element of a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extension,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extension, final int index) {
       GeneratedExtension<MessageType, List<Type>> extensionLite =
           checkIsLite(extension);
 
@@ -557,10 +657,9 @@ public abstract class GeneratedMessageLite<
       return extensions.isInitialized();
     }
 
-
     @Override
-    protected final void doneParsing() {
-      super.doneParsing();
+    protected final void makeImmutable() {
+      super.makeImmutable();
       
       extensions.makeImmutable();
     }
@@ -649,7 +748,7 @@ public abstract class GeneratedMessageLite<
       instance.extensions = extensions;
     }
 
-    // @Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     protected void copyOnWrite() {
       if (!isBuilt) {
         return;
@@ -659,7 +758,7 @@ public abstract class GeneratedMessageLite<
       instance.extensions = instance.extensions.clone();
     }
 
-    // @Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final MessageType buildPartial() {
       if (isBuilt) {
         return instance;
@@ -681,33 +780,30 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extension) {
       return instance.hasExtension(extension);
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extension) {
       return instance.getExtensionCount(extension);
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extension) {
       return instance.getExtension(extension);
     }
 
     /** Get one element of a repeated extension. */
+    @Override
     @SuppressWarnings("unchecked")
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extension,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extension, final int index) {
       return instance.getExtension(extension, index);
     }
 
@@ -839,37 +935,44 @@ public abstract class GeneratedMessageLite<
     final boolean isRepeated;
     final boolean isPacked;
 
+    @Override
     public int getNumber() {
       return number;
     }
 
+    @Override
     public WireFormat.FieldType getLiteType() {
       return type;
     }
 
+    @Override
     public WireFormat.JavaType getLiteJavaType() {
       return type.getJavaType();
     }
 
+    @Override
     public boolean isRepeated() {
       return isRepeated;
     }
 
+    @Override
     public boolean isPacked() {
       return isPacked;
     }
 
+    @Override
     public Internal.EnumLiteMap<?> getEnumType() {
       return enumTypeMap;
     }
 
+    @Override
     @SuppressWarnings("unchecked")
-    public MessageLite.Builder internalMergeFrom(
-        MessageLite.Builder to, MessageLite from) {
+    public MessageLite.Builder internalMergeFrom(MessageLite.Builder to, MessageLite from) {
       return ((Builder) to).mergeFrom((GeneratedMessageLite) from);
     }
 
 
+    @Override
     public int compareTo(ExtensionDescriptor other) {
       return number - other.number;
     }
@@ -964,6 +1067,7 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get the field number. */
+    @Override
     public int getNumber() {
       return descriptor.getNumber();
     }
@@ -973,6 +1077,7 @@ public abstract class GeneratedMessageLite<
      * If the extension is an embedded message or group, returns the default
      * instance of the message.
      */
+    @Override
     public MessageLite getMessageDefaultInstance() {
       return messageDefaultInstance;
     }
@@ -1027,14 +1132,17 @@ public abstract class GeneratedMessageLite<
       }
     }
 
+    @Override
     public FieldType getLiteType() {
       return descriptor.getLiteType();
     }
 
+    @Override
     public boolean isRepeated() {
       return descriptor.isRepeated;
     }
 
+    @Override
     public Type getDefaultValue() {
       return defaultValue;
     }
@@ -1044,7 +1152,12 @@ public abstract class GeneratedMessageLite<
    * A serialized (serializable) form of the generated message.  Stores the
    * message as a class name and a byte array.
    */
-  static final class SerializedForm implements Serializable {
+  protected static final class SerializedForm implements Serializable {
+
+    public static SerializedForm of(MessageLite message) {
+      return new SerializedForm(message);
+    }
+    
     private static final long serialVersionUID = 0L;
 
     private final String messageClassName;
@@ -1088,16 +1201,6 @@ public abstract class GeneratedMessageLite<
       }
     }
   }
-
-  /**
-   * Replaces this object in the output stream with a serialized form.
-   * Part of Java's serialization magic.  Generated sub-classes must override
-   * this method by calling {@code return super.writeReplace();}
-   * @return a SerializedForm of this message
-   */
-  protected Object writeReplace() throws ObjectStreamException {
-    return new SerializedForm(this);
-  }
   
   /**
    * Checks that the {@link Extension} is Lite and returns it as a
@@ -1124,30 +1227,72 @@ public abstract class GeneratedMessageLite<
   protected static final <T extends GeneratedMessageLite<T, ?>> boolean isInitialized(
       T message, boolean shouldMemoize) {
     return message.dynamicMethod(MethodToInvoke.IS_INITIALIZED, shouldMemoize) != null;
-  }
+  } 
   
   protected static final <T extends GeneratedMessageLite<T, ?>> void makeImmutable(T message) {
     message.dynamicMethod(MethodToInvoke.MAKE_IMMUTABLE);
   }
+
+  protected static IntList emptyIntList() {
+    return IntArrayList.emptyList();
+  }
+
+  protected static IntList mutableCopy(IntList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static LongList emptyLongList() {
+    return LongArrayList.emptyList();
+  }
   
-  /**
-   * A static helper method for parsing a partial from input using the extension registry and the
-   * instance.
-   */
-  static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
-      T instance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
-          throws InvalidProtocolBufferException {
-    try {
-      return (T) instance.dynamicMethod(
-          MethodToInvoke.PARSE_PARTIAL_FROM, input, extensionRegistry);
-    } catch (RuntimeException e) {
-      if (e.getCause() instanceof InvalidProtocolBufferException) {
-        throw (InvalidProtocolBufferException) e.getCause();
-      }
-      throw e;
-    }
+  protected static LongList mutableCopy(LongList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static FloatList emptyFloatList() {
+    return FloatArrayList.emptyList();
+  }
+  
+  protected static FloatList mutableCopy(FloatList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static DoubleList emptyDoubleList() {
+    return DoubleArrayList.emptyList();
   }
   
+  protected static DoubleList mutableCopy(DoubleList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static BooleanList emptyBooleanList() {
+    return BooleanArrayList.emptyList();
+  }
+  
+  protected static BooleanList mutableCopy(BooleanList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static <E> ProtobufList<E> emptyProtobufList() {
+    return ProtobufArrayList.emptyList();
+  }
+  
+  protected static <E> ProtobufList<E> mutableCopy(ProtobufList<E> list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
   /**
    * A {@link Parser} implementation that delegates to the default instance.
    * <p>
@@ -1169,79 +1314,929 @@ public abstract class GeneratedMessageLite<
     }
   }
   
-  protected static IntList newIntList() {
-    return new IntArrayList();
+  /**
+   * A static helper method for parsing a partial from input using the extension registry and the
+   * instance.
+   */
+  // TODO(dweis): Should this verify that the last tag was 0?
+  static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T instance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+          throws InvalidProtocolBufferException {
+    @SuppressWarnings("unchecked") // Guaranteed by protoc
+    T result = (T) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
+    try {
+      result.dynamicMethod(MethodToInvoke.MERGE_FROM_STREAM, input, extensionRegistry);
+      result.makeImmutable();
+    } catch (RuntimeException e) {
+      if (e.getCause() instanceof InvalidProtocolBufferException) {
+        throw (InvalidProtocolBufferException) e.getCause();
+      }
+      throw e;
+    }
+    return result;
   }
   
-  protected static IntList newIntList(List<Integer> toCopy) {
-    return new IntArrayList(toCopy);
+  protected static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T defaultInstance,
+      CodedInputStream input)
+      throws InvalidProtocolBufferException {
+    return parsePartialFrom(defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry());
   }
   
-  protected static IntList emptyIntList() {
-    return IntArrayList.emptyList();
+  /**
+   * Helper method to check if message is initialized.
+   *
+   * @throws InvalidProtocolBufferException if it is not initialized.
+   * @return The message to check.
+   */
+  private static <T extends GeneratedMessageLite<T, ?>> T checkMessageInitialized(T message)
+      throws InvalidProtocolBufferException {
+    if (message != null && !message.isInitialized()) {
+      throw message.newUninitializedMessageException()
+          .asInvalidProtocolBufferException()
+          .setUnfinishedMessage(message);
+    }
+    return message;
   }
-  
-  protected static LongList newLongList() {
-    return new LongArrayList();
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, ByteString data)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parseFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static LongList newLongList(List<Long> toCopy) {
-    return new LongArrayList(toCopy);
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, ByteString data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(parsePartialFrom(defaultInstance, data, extensionRegistry));
   }
   
-  protected static LongList emptyLongList() {
-    return LongArrayList.emptyList();
+  // This is a special case since we want to verify that the last tag is 0. We assume we exhaust the
+  // ByteString.
+  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T defaultInstance, ByteString data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    T message;
+    try {
+      CodedInputStream input = data.newCodedInput();
+      message = parsePartialFrom(defaultInstance, input, extensionRegistry);
+      try {
+        input.checkLastTagWas(0);
+      } catch (InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(message);
+      }
+      return message;
+    } catch (InvalidProtocolBufferException e) {
+      throw e;
+    }
   }
   
-  protected static FloatList newFloatList() {
-    return new FloatArrayList();
+  // This is a special case since we want to verify that the last tag is 0. We assume we exhaust the
+  // ByteString.
+  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T defaultInstance, byte[] data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    T message;
+    try {
+      CodedInputStream input = CodedInputStream.newInstance(data);
+      message = parsePartialFrom(defaultInstance, input, extensionRegistry);
+      try {
+        input.checkLastTagWas(0);
+      } catch (InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(message);
+      }
+      return message;
+    } catch (InvalidProtocolBufferException e) {
+      throw e;
+    }
   }
-  
-  protected static FloatList newFloatList(List<Float> toCopy) {
-    return new FloatArrayList(toCopy);
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, byte[] data)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static FloatList emptyFloatList() {
-    return FloatArrayList.emptyList();
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, byte[] data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(parsePartialFrom(defaultInstance, data, extensionRegistry));
   }
-  
-  protected static DoubleList newDoubleList() {
-    return new DoubleArrayList();
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, InputStream input)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, CodedInputStream.newInstance(input),
+            ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static DoubleList newDoubleList(List<Double> toCopy) {
-    return new DoubleArrayList(toCopy);
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, CodedInputStream.newInstance(input), extensionRegistry));
   }
-  
-  protected static DoubleList emptyDoubleList() {
-    return DoubleArrayList.emptyList();
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, CodedInputStream input)
+      throws InvalidProtocolBufferException {
+    return parseFrom(defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry());
   }
-  
-  protected static BooleanList newBooleanList() {
-    return new BooleanArrayList();
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, input, extensionRegistry));
   }
-  
-  protected static BooleanList newBooleanList(List<Boolean> toCopy) {
-    return new BooleanArrayList(toCopy);
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseDelimitedFrom(
+      T defaultInstance, InputStream input)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialDelimitedFrom(defaultInstance, input,
+            ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static BooleanList emptyBooleanList() {
-    return BooleanArrayList.emptyList();
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseDelimitedFrom(
+      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialDelimitedFrom(defaultInstance, input, extensionRegistry));
   }
   
-  protected static <E> ProtobufList<E> newProtobufList() {
-    return new ProtobufArrayList<E>();
+  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialDelimitedFrom(
+      T defaultInstance,
+      InputStream input,
+      ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    int size;
+    try {
+      int firstByte = input.read();
+      if (firstByte == -1) {
+        return null;
+      }
+      size = CodedInputStream.readRawVarint32(firstByte, input);
+    } catch (IOException e) {
+      throw new InvalidProtocolBufferException(e.getMessage());
+    }
+    InputStream limitedInput = new LimitedInputStream(input, size);
+    CodedInputStream codedInput = CodedInputStream.newInstance(limitedInput);
+    T message = parsePartialFrom(defaultInstance, codedInput, extensionRegistry);
+    try {
+      codedInput.checkLastTagWas(0);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(message);
+    }
+    return message;
   }
-  
-  protected static <E> ProtobufList<E> newProtobufList(List<E> toCopy) {
-    return new ProtobufArrayList<E>(toCopy);
+
+  /**
+   * An abstract visitor that the generated code calls into that we use to implement various
+   * features. Fields that are not members of oneofs are always visited. Members of a oneof are only
+   * visited when they are the set oneof case value on the "other" proto. The visitOneofNotSet
+   * method is invoked if other's oneof case is not set.
+   */
+  protected interface Visitor {
+    boolean visitBoolean(boolean minePresent, boolean mine, boolean otherPresent, boolean other);
+    int visitInt(boolean minePresent, int mine, boolean otherPresent, int other);
+    double visitDouble(boolean minePresent, double mine, boolean otherPresent, double other);
+    float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other);
+    long visitLong(boolean minePresent, long mine, boolean otherPresent, long other);
+    String visitString(boolean minePresent, String mine, boolean otherPresent, String other);
+    ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other);
+
+    Object visitOneofBoolean(boolean minePresent, Object mine, Object other);
+    Object visitOneofInt(boolean minePresent, Object mine, Object other);
+    Object visitOneofDouble(boolean minePresent, Object mine, Object other);
+    Object visitOneofFloat(boolean minePresent, Object mine, Object other);
+    Object visitOneofLong(boolean minePresent, Object mine, Object other);
+    Object visitOneofString(boolean minePresent, Object mine, Object other);
+    Object visitOneofByteString(boolean minePresent, Object mine, Object other);
+    Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other);
+    Object visitOneofMessage(boolean minePresent, Object mine, Object other);
+    void visitOneofNotSet(boolean minePresent);
+    
+    /**
+     * Message fields use null sentinals.
+     */
+    <T extends MessageLite> T visitMessage(T mine, T other);
+    LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other);
+
+    <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other);
+    BooleanList visitBooleanList(BooleanList mine, BooleanList other);
+    IntList visitIntList(IntList mine, IntList other);
+    DoubleList visitDoubleList(DoubleList mine, DoubleList other);
+    FloatList visitFloatList(FloatList mine, FloatList other);
+    LongList visitLongList(LongList mine, LongList other);
+    FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine, FieldSet<ExtensionDescriptor> other);
+    UnknownFieldSetLite visitUnknownFields(UnknownFieldSetLite mine, UnknownFieldSetLite other);
+    <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other);
   }
-  
-  protected static <E> ProtobufList<E> emptyProtobufList() {
-    return ProtobufArrayList.emptyList();
+
+  /**
+   * Implements equals. Throws a {@link NotEqualsException} when not equal.
+   */
+  static class EqualsVisitor implements Visitor {
+
+    static final class NotEqualsException extends RuntimeException {}
+
+    static final EqualsVisitor INSTANCE = new EqualsVisitor();
+
+    static final NotEqualsException NOT_EQUALS = new NotEqualsException();
+
+    private EqualsVisitor() {}
+
+    @Override
+    public boolean visitBoolean(
+        boolean minePresent, boolean mine, boolean otherPresent, boolean other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public int visitInt(boolean minePresent, int mine, boolean otherPresent, int other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public double visitDouble(
+        boolean minePresent, double mine, boolean otherPresent, double other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public long visitLong(boolean minePresent, long mine, boolean otherPresent, long other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public String visitString(
+        boolean minePresent, String mine, boolean otherPresent, String other) {
+      if (minePresent != otherPresent || !mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other) {
+      if (minePresent != otherPresent || !mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofBoolean(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofInt(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofDouble(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofFloat(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofLong(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofString(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofByteString(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+    
+    @Override
+    public Object visitOneofMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent && ((GeneratedMessageLite<?, ?>) mine).equals(this, (MessageLite) other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+    
+    @Override
+    public void visitOneofNotSet(boolean minePresent) {
+      if (minePresent) {
+        throw NOT_EQUALS;
+      }
+    }
+
+    @Override
+    public <T extends MessageLite> T visitMessage(T mine, T other) {
+      if (mine == null && other == null) {
+        return null;
+      }
+
+      if (mine == null || other == null) {
+        throw NOT_EQUALS;
+      }
+
+      ((GeneratedMessageLite<?, ?>) mine).equals(this, other);
+
+      return mine;
+    }
+    
+    @Override
+    public LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other) {
+      if (!minePresent && !otherPresent) {
+        return mine;
+      } else if (minePresent && otherPresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public BooleanList visitBooleanList(BooleanList mine, BooleanList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public IntList visitIntList(IntList mine, IntList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public DoubleList visitDoubleList(DoubleList mine, DoubleList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public FloatList visitFloatList(FloatList mine, FloatList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public LongList visitLongList(LongList mine, LongList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine,
+        FieldSet<ExtensionDescriptor> other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public UnknownFieldSetLite visitUnknownFields(
+        UnknownFieldSetLite mine,
+        UnknownFieldSetLite other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
   }
-  
-  protected static LazyStringArrayList emptyLazyStringArrayList() {
-    return LazyStringArrayList.emptyList();
+
+  /**
+   * Implements hashCode by accumulating state.
+   */
+  private static class HashCodeVisitor implements Visitor {
+
+    // The caller must ensure that the visitor is invoked parameterized with this and this such that
+    // other is this. This is required due to how oneof cases are handled. See the class comment
+    // on Visitor for more information.
+    
+    private int hashCode = 0;
+
+    @Override
+    public boolean visitBoolean(
+        boolean minePresent, boolean mine, boolean otherPresent, boolean other) {
+      hashCode = (53 * hashCode) + Internal.hashBoolean(mine);
+      return mine;
+    }
+
+    @Override
+    public int visitInt(boolean minePresent, int mine, boolean otherPresent, int other) {
+      hashCode = (53 * hashCode) + mine;
+      return mine;
+    }
+
+    @Override
+    public double visitDouble(
+        boolean minePresent, double mine, boolean otherPresent, double other) {
+      hashCode = (53 * hashCode) + Internal.hashLong(Double.doubleToLongBits(mine));
+      return mine;
+    }
+
+    @Override
+    public float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other) {
+      hashCode = (53 * hashCode) + Float.floatToIntBits(mine);
+      return mine;
+    }
+
+    @Override
+    public long visitLong(boolean minePresent, long mine, boolean otherPresent, long other) {
+      hashCode = (53 * hashCode) + Internal.hashLong(mine);
+      return mine;
+    }
+
+    @Override
+    public String visitString(
+        boolean minePresent, String mine, boolean otherPresent, String other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofBoolean(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Internal.hashBoolean(((Boolean) mine));
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofInt(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + (Integer) mine;
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofDouble(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Internal.hashLong(Double.doubleToLongBits((Double) mine));
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofFloat(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Float.floatToIntBits((Float) mine);
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofLong(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Internal.hashLong((Long) mine);
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofString(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofByteString(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+    
+    @Override
+    public Object visitOneofMessage(boolean minePresent, Object mine, Object other) {
+      return visitMessage((MessageLite) mine, (MessageLite) other);
+    }
+
+    @Override
+    public void visitOneofNotSet(boolean minePresent) {
+      if (minePresent) {
+        throw new IllegalStateException(); // Can't happen if other == this. 
+      }
+    }
+
+    @Override
+    public <T extends MessageLite> T visitMessage(T mine, T other) {
+      final int protoHash;
+      if (mine != null) {
+        if (mine instanceof GeneratedMessageLite) {
+          protoHash = ((GeneratedMessageLite) mine).hashCode(this);
+        } else {
+          protoHash = mine.hashCode();
+        }
+      } else {
+        protoHash = 37;
+      }
+      hashCode = (53 * hashCode) + protoHash;
+      return mine;
+    }
+
+    @Override
+    public LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public BooleanList visitBooleanList(BooleanList mine, BooleanList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public IntList visitIntList(IntList mine, IntList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public DoubleList visitDoubleList(DoubleList mine, DoubleList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public FloatList visitFloatList(FloatList mine, FloatList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public LongList visitLongList(LongList mine, LongList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine,
+        FieldSet<ExtensionDescriptor> other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public UnknownFieldSetLite visitUnknownFields(
+        UnknownFieldSetLite mine,
+        UnknownFieldSetLite other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+    
+    @Override
+    public <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+  }
+
+  /**
+   * Implements field merging semantics over the visitor interface.
+   */
+  protected static class MergeFromVisitor implements Visitor {
+
+    public static final MergeFromVisitor INSTANCE = new MergeFromVisitor();
+
+    private MergeFromVisitor() {}
+
+    @Override
+    public boolean visitBoolean(
+        boolean minePresent, boolean mine, boolean otherPresent, boolean other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public int visitInt(boolean minePresent, int mine, boolean otherPresent, int other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public double visitDouble(
+        boolean minePresent, double mine, boolean otherPresent, double other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public long visitLong(boolean minePresent, long mine, boolean otherPresent, long other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public String visitString(
+        boolean minePresent, String mine, boolean otherPresent, String other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public Object visitOneofBoolean(boolean minePresent, Object mine, Object other) {
+      return other;
+    }
+
+    @Override
+    public Object visitOneofInt(boolean minePresent, Object mine, Object other) {
+      return other;
+    }
+
+    @Override
+    public Object visitOneofDouble(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofFloat(boolean minePresent, Object mine, Object other) {
+      return other;
+    }
+
+    @Override
+    public Object visitOneofLong(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofString(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofByteString(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent) {
+        LazyFieldLite lazy = (LazyFieldLite) mine;
+        lazy.merge((LazyFieldLite) other);
+        return lazy;
+      }
+      return other;
+    }
+    
+    @Override
+    public Object visitOneofMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent) {
+        return visitMessage((MessageLite) mine, (MessageLite) other);
+      }
+      return other;
+    }
+    
+    @Override
+    public void visitOneofNotSet(boolean minePresent) {
+      return;
+    }
+
+    @SuppressWarnings("unchecked") // Guaranteed by runtime.
+    @Override
+    public <T extends MessageLite> T visitMessage(T mine, T other) {
+      if (mine != null && other != null) {
+        return (T) mine.toBuilder().mergeFrom(other).build();
+      }
+
+      return mine != null ? mine : other;
+    }
+
+    @Override
+    public LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other) {
+      // LazyFieldLite's are never null so we can just copy across. Necessary to avoid leakage
+      // from builder into immutable message.
+      // TODO(dweis): Change to null sentinels?
+      mine.merge(other);
+      return mine;
+    }
+
+    @Override
+    public <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public BooleanList visitBooleanList(BooleanList mine, BooleanList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public IntList visitIntList(IntList mine, IntList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public DoubleList visitDoubleList(DoubleList mine, DoubleList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public FloatList visitFloatList(FloatList mine, FloatList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public LongList visitLongList(LongList mine, LongList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine,
+        FieldSet<ExtensionDescriptor> other) {
+      if (mine.isImmutable()) {
+        mine = mine.clone();
+      }
+      mine.mergeFrom(other);
+      return mine;
+    }
+
+    @Override
+    public UnknownFieldSetLite visitUnknownFields(
+        UnknownFieldSetLite mine,
+        UnknownFieldSetLite other) {
+      return other == UnknownFieldSetLite.getDefaultInstance()
+          ? mine : UnknownFieldSetLite.mutableCopyOf(mine, other);
+    }
+    
+    @Override
+    public <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other) {
+      mine.mergeFrom(other);
+      return mine;
+    }
   }
 }
diff --git a/java/src/main/java/com/google/protobuf/IntArrayList.java b/java/core/src/main/java/com/google/protobuf/IntArrayList.java
index f7609cc9..6d6ece5a 100644
--- a/java/src/main/java/com/google/protobuf/IntArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/IntArrayList.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.IntList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -44,8 +43,6 @@ import java.util.RandomAccess;
  */
 final class IntArrayList extends AbstractProtobufList<Integer> implements IntList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final IntArrayList EMPTY_LIST = new IntArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -67,28 +64,58 @@ final class IntArrayList extends AbstractProtobufList<Integer> implements IntLis
   private int size;
 
   /**
-   * Constructs a new mutable {@code IntArrayList}.
+   * Constructs a new mutable {@code IntArrayList} with default capacity.
    */
   IntArrayList() {
-    array = new int[DEFAULT_CAPACITY];
-    size = 0;
+    this(new int[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code IntArrayList} containing the same elements as {@code other}.
    */
-  IntArrayList(List<Integer> other) {
-    if (other instanceof IntArrayList) {
-      IntArrayList list = (IntArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new int[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private IntArrayList(int[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof IntArrayList)) {
+      return super.equals(o);
+    }
+    IntArrayList other = (IntArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final int[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + array[i];
+    }
+    return result;
+  }
+
+  @Override
+  public IntList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new IntArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override
diff --git a/java/src/main/java/com/google/protobuf/Internal.java b/java/core/src/main/java/com/google/protobuf/Internal.java
index 11901998..d1de375e 100644
--- a/java/src/main/java/com/google/protobuf/Internal.java
+++ b/java/core/src/main/java/com/google/protobuf/Internal.java
@@ -41,6 +41,7 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.RandomAccess;
 import java.util.Set;
 
 /**
@@ -51,10 +52,12 @@ import java.util.Set;
  *
  * @author kenton@google.com (Kenton Varda)
  */
-public class Internal {
+public final class Internal {
 
-  protected static final Charset UTF_8 = Charset.forName("UTF-8");
-  protected static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
+  private Internal() {}
+
+  static final Charset UTF_8 = Charset.forName("UTF-8");
+  static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
 
   /**
    * Helper called by generated code to construct default values for string
@@ -283,10 +286,32 @@ public class Internal {
     // ByteString with the same content. This is to ensure that the generated
     // hashCode() method will return the same value as the pure reflection
     // based hashCode() method.
-    return LiteralByteString.hashCode(bytes);
+    return Internal.hashCode(bytes, 0, bytes.length);
+  }
+  
+  /**
+   * Helper method for implementing {@link LiteralByteString#hashCode()}.
+   */
+  static int hashCode(byte[] bytes, int offset, int length) {
+    // The hash code for a byte array should be the same as the hash code for a
+    // ByteString with the same content. This is to ensure that the generated
+    // hashCode() method will return the same value as the pure reflection
+    // based hashCode() method.
+    int h = Internal.partialHash(length, bytes, offset, length);
+    return h == 0 ? 1 : h;
   }
 
   /**
+   * Helper method for continuously hashing bytes.
+   */
+  static int partialHash(int h, byte[] bytes, int offset, int length) {
+    for (int i = offset; i < offset + length; i++) {
+      h = h * 31 + bytes[i];
+    }
+    return h;
+  }
+  
+  /**
    * Helper method for implementing {@link Message#equals(Object)} for bytes
    * field.
    */
@@ -337,8 +362,7 @@ public class Internal {
   public static int hashCodeByteBuffer(ByteBuffer bytes) {
     if (bytes.hasArray()) {
       // Fast path.
-      int h = LiteralByteString.hashCode(bytes.capacity(), bytes.array(),
-          bytes.arrayOffset(), bytes.capacity());
+      int h = partialHash(bytes.capacity(), bytes.array(), bytes.arrayOffset(), bytes.capacity());
       return h == 0 ? 1 : h;
     } else {
       // Read the data into a temporary byte array before calculating the
@@ -353,7 +377,7 @@ public class Internal {
         final int length = duplicated.remaining() <= bufferSize ?
             duplicated.remaining() : bufferSize;
         duplicated.get(buffer, 0, length);
-        h = LiteralByteString.hashCode(h, buffer, 0, length);
+        h = partialHash(h, buffer, 0, length);
       }
       return h == 0 ? 1 : h;
     }
@@ -434,10 +458,13 @@ public class Internal {
     public static <T extends EnumLite> Converter<Integer, T> newEnumConverter(
         final EnumLiteMap<T> enumMap, final T unrecognizedValue) {
       return new Converter<Integer, T>() {
+        @Override
         public T doForward(Integer value) {
           T result = enumMap.findValueByNumber(value);
           return result == null ? unrecognizedValue : result;
         }
+
+        @Override
         public Integer doBackward(T value) {
           return value.getNumber();
         }
@@ -550,8 +577,10 @@ public class Internal {
   /**
    * Extends {@link List} to add the capability to make the list immutable and inspect if it is
    * modifiable.
+   * <p>
+   * All implementations must support efficient random access.
    */
-  public static interface ProtobufList<E> extends List<E> {
+  public static interface ProtobufList<E> extends List<E>, RandomAccess {
 
     /**
      * Makes this list immutable. All subsequent modifications will throw an
@@ -563,6 +592,11 @@ public class Internal {
      * Returns whether this list can be modified via the publicly accessible {@link List} methods.
      */
     boolean isModifiable();
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    ProtobufList<E> mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -577,14 +611,20 @@ public class Internal {
     int getInt(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Integer)} but more efficient in that it doesn't box the element.
      */
     void addInt(int element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Integer)} but more efficient in that it doesn't box the element.
      */
     int setInt(int index, int element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    IntList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -599,14 +639,20 @@ public class Internal {
     boolean getBoolean(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Boolean)} but more efficient in that it doesn't box the element.
      */
     void addBoolean(boolean element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Boolean)} but more efficient in that it doesn't box the element.
      */
     boolean setBoolean(int index, boolean element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    BooleanList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -621,14 +667,20 @@ public class Internal {
     long getLong(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Long)} but more efficient in that it doesn't box the element.
      */
     void addLong(long element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Long)} but more efficient in that it doesn't box the element.
      */
     long setLong(int index, long element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    LongList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -643,14 +695,20 @@ public class Internal {
     double getDouble(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Double)} but more efficient in that it doesn't box the element.
      */
     void addDouble(double element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Double)} but more efficient in that it doesn't box the element.
      */
     double setDouble(int index, double element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    DoubleList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -665,13 +723,19 @@ public class Internal {
     float getFloat(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Float)} but more efficient in that it doesn't box the element.
      */
     void addFloat(float element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Float)} but more efficient in that it doesn't box the element.
      */
     float setFloat(int index, float element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    FloatList mutableCopyWithCapacity(int capacity);
   }
 }
diff --git a/java/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java b/java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
index 0a761052..85ce7b24 100644
--- a/java/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
+++ b/java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
@@ -46,6 +46,10 @@ public class InvalidProtocolBufferException extends IOException {
     super(description);
   }
 
+  public InvalidProtocolBufferException(IOException e) {
+    super(e.getMessage(), e);
+  }
+
   /**
    * Attaches an unfinished message to the exception to support best-effort
    * parsing in {@code Parser} interface.
@@ -66,6 +70,14 @@ public class InvalidProtocolBufferException extends IOException {
     return unfinishedMessage;
   }
 
+  /**
+   * Unwraps the underlying {@link IOException} if this exception was caused by an I/O
+   * problem. Otherwise, returns {@code this}.
+   */
+  public IOException unwrapIOException() {
+    return getCause() instanceof IOException ? (IOException) getCause() : this;
+  }
+
   static InvalidProtocolBufferException truncatedMessage() {
     return new InvalidProtocolBufferException(
       "While parsing a protocol message, the input ended unexpectedly " +
diff --git a/java/src/main/java/com/google/protobuf/LazyField.java b/java/core/src/main/java/com/google/protobuf/LazyField.java
index 3da8b900..98e13ca1 100644
--- a/java/src/main/java/com/google/protobuf/LazyField.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyField.java
@@ -95,12 +95,12 @@ public class LazyField extends LazyFieldLite {
       this.entry = entry;
     }
 
-    // @Override
+    @Override
     public K getKey() {
       return entry.getKey();
     }
 
-    // @Override
+    @Override
     public Object getValue() {
       LazyField field = entry.getValue();
       if (field == null) {
@@ -113,7 +113,7 @@ public class LazyField extends LazyFieldLite {
       return entry.getValue();
     }
 
-    // @Override
+    @Override
     public Object setValue(Object value) {
       if (!(value instanceof MessageLite)) {
         throw new IllegalArgumentException(
@@ -131,13 +131,13 @@ public class LazyField extends LazyFieldLite {
       this.iterator = iterator;
     }
 
-    // @Override
+    @Override
     public boolean hasNext() {
       return iterator.hasNext();
     }
 
+    @Override
     @SuppressWarnings("unchecked")
-    // @Override
     public Entry<K, Object> next() {
       Entry<K, ?> entry = iterator.next();
       if (entry.getValue() instanceof LazyField) {
@@ -146,7 +146,7 @@ public class LazyField extends LazyFieldLite {
       return (Entry<K, Object>) entry;
     }
 
-    // @Override
+    @Override
     public void remove() {
       iterator.remove();
     }
diff --git a/java/src/main/java/com/google/protobuf/LazyFieldLite.java b/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
index eea1fe3c..2febaace 100644
--- a/java/src/main/java/com/google/protobuf/LazyFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
@@ -30,14 +30,26 @@
 
 package com.google.protobuf;
 
+import java.io.IOException;
+
 /**
  * LazyFieldLite encapsulates the logic of lazily parsing message fields. It stores
- * the message in a ByteString initially and then parse it on-demand.
+ * the message in a ByteString initially and then parses it on-demand.
+ *
+ * LazyFieldLite is thread-compatible: concurrent reads are safe once the proto that this
+ * LazyFieldLite is a part of is no longer being mutated by its Builder. However, explicit
+ * synchronization is needed under read/write situations.
  *
- * LazyField is thread-compatible e.g. concurrent read are safe, however,
- * synchronizations are needed under read/write situations.
+ * When a LazyFieldLite is used in the context of a MessageLite object, its behavior is considered
+ * to be immutable and none of the setter methods in its API are expected to be invoked. All of the
+ * getters are expected to be thread-safe. When used in the context of a MessageLite.Builder,
+ * setters can be invoked, but there is no guarantee of thread safety.
+ * 
+ * TODO(yatin,dweis): Consider splitting this class's functionality and put the mutable methods
+ * into a separate builder class to allow us to give stronger compile-time guarantees.
  *
- * This class is internal implementation detail, so you don't need to use it directly.
+ * This class is internal implementation detail of the protobuf library, so you don't need to use it
+ * directly.
  *
  * @author xiangl@google.com (Xiang Li)
  */
@@ -46,8 +58,34 @@ public class LazyFieldLite {
       ExtensionRegistryLite.getEmptyRegistry();
 
   /**
-   * A delayed-parsed version of the bytes. When this is non-null then {@code extensionRegistry } is
-   * also non-null and {@code value} and {@code memoizedBytes} are null.
+   * The value associated with the LazyFieldLite object is stored in one or more of the following
+   * three fields (delayedBytes, value, memoizedBytes). They should together be interpreted as
+   * follows.
+   * 1) delayedBytes can be non-null, while value and memoizedBytes is null. The object will be in
+   *    this state while the value for the object has not yet been parsed.
+   * 2) Both delayedBytes and value are non-null. The object transitions to this state as soon as
+   *    some caller needs to access the value (by invoking getValue()).
+   * 3) memoizedBytes is merely an optimization for calls to LazyFieldLite.toByteString() to avoid
+   *    recomputing the ByteString representation on each call. Instead, when the value is parsed
+   *    from delayedBytes, we will also assign the contents of delayedBytes to memoizedBytes (since
+   *    that is the ByteString representation of value).
+   * 4) Finally, if the LazyFieldLite was created directly with a parsed MessageLite value, then
+   *    delayedBytes will be null, and memoizedBytes will be initialized only upon the first call to
+   *    LazyFieldLite.toByteString().
+   *
+   * Given the above conditions, any caller that needs a serialized representation of this object
+   * must first check if the memoizedBytes or delayedBytes ByteString is non-null and use it
+   * directly; if both of those are null, it can look at the parsed value field. Similarly, any
+   * caller that needs a parsed value must first check if the value field is already non-null, if
+   * not it must parse the value from delayedBytes.
+   */
+
+  /**
+   * A delayed-parsed version of the contents of this field. When this field is non-null, then the
+   * "value" field is allowed to be null until the time that the value needs to be read.
+   *
+   * When delayedBytes is non-null then {@code extensionRegistry} is required to also be non-null.
+   * {@code value} and {@code memoizedBytes} will be initialized lazily.
    */
   private ByteString delayedBytes;
 
@@ -60,12 +98,15 @@ public class LazyFieldLite {
   private ExtensionRegistryLite extensionRegistry;
 
   /**
-   * The parsed value. When this is non-null then {@code delayedBytes} will be null.
+   * The parsed value. When this is null and a caller needs access to the MessageLite value, then
+   * {@code delayedBytes} will be parsed lazily at that time.
    */
   protected volatile MessageLite value;
 
   /**
-   * The memoized bytes for {@code value}. Will be null when {@code value} is null.
+   * The memoized bytes for {@code value}. This is an optimization for the toByteString() method to
+   * not have to recompute its return-value on each invocation.
+   * TODO(yatin): Figure out whether this optimization is actually necessary.
    */
   private volatile ByteString memoizedBytes;
 
@@ -94,6 +135,43 @@ public class LazyFieldLite {
     return lf;
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    
+    if (!(o instanceof LazyFieldLite)) {
+      return false;
+    }
+
+    LazyFieldLite other = (LazyFieldLite) o;
+    
+    // Lazy fields do not work well with equals... If both are delayedBytes, we do not have a
+    // mechanism to deserialize them so we rely on bytes equality. Otherwise we coerce into an
+    // actual message (if necessary) and call equals on the message itself. This implies that two
+    // messages can by unequal but then be turned equal simply be invoking a getter on a lazy field.
+    MessageLite value1 = value;
+    MessageLite value2 = other.value;
+    if (value1 == null && value2 == null) {
+      return toByteString().equals(other.toByteString());
+    } else if (value1 != null && value2 != null) {
+      return value1.equals(value2);
+    } else if (value1 != null) {
+      return value1.equals(other.getValue(value1.getDefaultInstanceForType()));
+    } else {
+      return getValue(value2.getDefaultInstanceForType()).equals(value2);
+    }
+  }
+  
+  @Override
+  public int hashCode() {
+    // We can't provide a memoizable hash code for lazy fields. The byte strings may have different
+    // hash codes but evaluate to equivalent messages. And we have no facility for constructing
+    // a message here if we were not already holding a value.
+    return 1;
+  }
+  
   /**
    * Determines whether this LazyFieldLite instance represents the default instance of this type.
    */
@@ -230,6 +308,46 @@ public class LazyFieldLite {
       return;
     }
   }
+  
+  /**
+   * Merges another instance's contents from a stream.
+   *
+   * <p>LazyField is not thread-safe for write access. Synchronizations are needed
+   * under read/write situations.
+   */
+  public void mergeFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+      throws IOException {
+    if (this.containsDefaultInstance()) {
+      setByteString(input.readBytes(), extensionRegistry);
+      return;
+    }
+
+    // If the other field has an extension registry but this does not, copy over the other extension
+    // registry.
+    if (this.extensionRegistry == null) {
+      this.extensionRegistry = extensionRegistry;
+    }
+
+    // In the case that both of them are not parsed we simply concatenate the bytes to save time. In
+    // the (probably rare) case that they have different extension registries there is a chance that
+    // some of the extensions may be dropped, but the tradeoff of making this operation fast seems
+    // to outway the benefits of combining the extension registries, which is not normally done for
+    // lite protos anyways.
+    if (this.delayedBytes != null) {
+      setByteString(this.delayedBytes.concat(input.readBytes()), this.extensionRegistry);
+      return;
+    }
+
+    // We are parsed and both contain data. We won't drop any extensions here directly, but in the
+    // case that the extension registries are not the same then we might in the future if we
+    // need to serialize and parse a message again.
+    try {
+      setValue(value.toBuilder().mergeFrom(input, extensionRegistry).build());
+    } catch (InvalidProtocolBufferException e) {
+      // Nothing is logged and no exceptions are thrown. Clients will be unaware that a proto
+      // was invalid.
+    }
+  }
 
   private static MessageLite mergeValueAndBytes(
       MessageLite value, ByteString otherBytes, ExtensionRegistryLite extensionRegistry) {
@@ -259,10 +377,12 @@ public class LazyFieldLite {
    * parsed. Be careful when using this method.
    */
   public int getSerializedSize() {
-    if (delayedBytes != null) {
-      return delayedBytes.size();
-    } else if (memoizedBytes != null) {
+    // We *must* return delayed bytes size if it was ever set because the dependent messages may
+    // have memoized serialized size based off of it.
+    if (memoizedBytes != null) {
       return memoizedBytes.size();
+    } else if (delayedBytes != null) {
+      return delayedBytes.size();
     } else if (value != null) {
       return value.getSerializedSize();
     } else {
@@ -274,12 +394,14 @@ public class LazyFieldLite {
    * Returns a BytesString for this field in a thread-safe way.
    */
   public ByteString toByteString() {
-    if (delayedBytes != null) {
-      return delayedBytes;
-    }
     if (memoizedBytes != null) {
       return memoizedBytes;
     }
+    // We *must* return delayed bytes if it was set because the dependent messages may have
+    // memoized serialized size based off of it.
+    if (delayedBytes != null) {
+      return delayedBytes;
+    }
     synchronized (this) {
       if (memoizedBytes != null) {
         return memoizedBytes;
@@ -311,18 +433,15 @@ public class LazyFieldLite {
               .parseFrom(delayedBytes, extensionRegistry);
           this.value = parsedValue;
           this.memoizedBytes = delayedBytes;
-          this.delayedBytes = null;
         } else {
           this.value = defaultInstance;
           this.memoizedBytes = ByteString.EMPTY;
-          this.delayedBytes = null;
         }
       } catch (InvalidProtocolBufferException e) {
         // Nothing is logged and no exceptions are thrown. Clients will be unaware that this proto
         // was invalid.
         this.value = defaultInstance;
         this.memoizedBytes = ByteString.EMPTY;
-        this.delayedBytes = null;
       }
     }
   }
diff --git a/java/src/main/java/com/google/protobuf/LazyStringArrayList.java b/java/core/src/main/java/com/google/protobuf/LazyStringArrayList.java
index c3be3cca..d474c51e 100644
--- a/java/src/main/java/com/google/protobuf/LazyStringArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyStringArrayList.java
@@ -30,12 +30,12 @@
 
 package com.google.protobuf;
 
-import java.util.Arrays;
-import java.util.List;
 import java.util.AbstractList;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -64,7 +64,7 @@ import java.util.RandomAccess;
  */
 public class LazyStringArrayList extends AbstractProtobufList<String>
     implements LazyStringList, RandomAccess {
-  
+
   private static final LazyStringArrayList EMPTY_LIST = new LazyStringArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -80,11 +80,11 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
   private final List<Object> list;
 
   public LazyStringArrayList() {
-    list = new ArrayList<Object>();
+    this(DEFAULT_CAPACITY);
   }
 
   public LazyStringArrayList(int intialCapacity) {
-    list = new ArrayList<Object>(intialCapacity);
+    this(new ArrayList<Object>(intialCapacity));
   }
 
   public LazyStringArrayList(LazyStringList from) {
@@ -93,7 +93,21 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
   }
 
   public LazyStringArrayList(List<String> from) {
-    list = new ArrayList<Object>(from);
+    this(new ArrayList<Object>(from));
+  }
+  
+  private LazyStringArrayList(ArrayList<Object> list) {
+    this.list = list;
+  }
+
+  @Override
+  public LazyStringArrayList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size()) {
+      throw new IllegalArgumentException();
+    }
+    ArrayList<Object> newList = new ArrayList<Object>(capacity);
+    newList.addAll(list);
+    return new LazyStringArrayList(newList);
   }
 
   @Override
@@ -170,7 +184,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return ret;
   }
 
-  // @Override
+  @Override
   public boolean addAllByteString(Collection<? extends ByteString> values) {
     ensureIsMutable();
     boolean ret = list.addAll(values);
@@ -178,7 +192,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return ret;
   }
 
-  // @Override
+  @Override
   public boolean addAllByteArray(Collection<byte[]> c) {
     ensureIsMutable();
     boolean ret = list.addAll(c);
@@ -201,14 +215,14 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     modCount++;
   }
 
-  // @Override
+  @Override
   public void add(ByteString element) {
     ensureIsMutable();
     list.add(element);
     modCount++;
   }
   
-  // @Override
+  @Override
   public void add(byte[] element) {
     ensureIsMutable();
     list.add(element);
@@ -220,7 +234,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return list.get(index);
   }
   
-  // @Override
+  @Override
   public ByteString getByteString(int index) {
     Object o = list.get(index);
     ByteString b = asByteString(o);
@@ -230,7 +244,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return b;
   }
   
-  // @Override
+  @Override
   public byte[] getByteArray(int index) {
     Object o = list.get(index);
     byte[] b = asByteArray(o);
@@ -240,7 +254,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return b;
   }
 
-  // @Override
+  @Override
   public void set(int index, ByteString s) {
     setAndReturn(index, s);
   }
@@ -250,7 +264,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return list.set(index, s);
   }
 
-  // @Override
+  @Override
   public void set(int index, byte[] s) {
     setAndReturn(index, s);
   }
@@ -290,12 +304,12 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     }
   }
 
-  // @Override
+  @Override
   public List<?> getUnderlyingElements() {
     return Collections.unmodifiableList(list);
   }
 
-  // @Override
+  @Override
   public void mergeFrom(LazyStringList other) {
     ensureIsMutable();
     for (Object o : other.getUnderlyingElements()) {
@@ -349,7 +363,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     }
   }
   
-  // @Override
+  @Override
   public List<byte[]> asByteArrayList() {
     return new ByteArrayListView(this);
   }
@@ -393,12 +407,12 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     }
   }
 
-  // @Override
+  @Override
   public List<ByteString> asByteStringList() {
     return new ByteStringListView(this);
   }
 
-  // @Override
+  @Override
   public LazyStringList getUnmodifiableView() {
     if (isModifiable()) {
       return new UnmodifiableLazyStringList(this);
diff --git a/java/src/main/java/com/google/protobuf/LazyStringList.java b/java/core/src/main/java/com/google/protobuf/LazyStringList.java
index 3eeedca1..3eeedca1 100644
--- a/java/src/main/java/com/google/protobuf/LazyStringList.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyStringList.java
diff --git a/java/src/main/java/com/google/protobuf/LongArrayList.java b/java/core/src/main/java/com/google/protobuf/LongArrayList.java
index 298617ff..bc4475d1 100644
--- a/java/src/main/java/com/google/protobuf/LongArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/LongArrayList.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.LongList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -44,8 +43,6 @@ import java.util.RandomAccess;
  */
 final class LongArrayList extends AbstractProtobufList<Long> implements LongList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final LongArrayList EMPTY_LIST = new LongArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -67,28 +64,58 @@ final class LongArrayList extends AbstractProtobufList<Long> implements LongList
   private int size;
 
   /**
-   * Constructs a new mutable {@code LongArrayList}.
+   * Constructs a new mutable {@code LongArrayList} with default capacity.
    */
   LongArrayList() {
-    array = new long[DEFAULT_CAPACITY];
-    size = 0;
+    this(new long[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code LongArrayList} containing the same elements as {@code other}.
    */
-  LongArrayList(List<Long> other) {
-    if (other instanceof LongArrayList) {
-      LongArrayList list = (LongArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new long[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private LongArrayList(long[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof IntArrayList)) {
+      return super.equals(o);
+    }
+    LongArrayList other = (LongArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final long[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + Internal.hashLong(array[i]);
+    }
+    return result;
+  }
+
+  @Override
+  public LongList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new LongArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override
diff --git a/java/src/main/java/com/google/protobuf/MapEntry.java b/java/core/src/main/java/com/google/protobuf/MapEntry.java
index 31414bb4..31414bb4 100644
--- a/java/src/main/java/com/google/protobuf/MapEntry.java
+++ b/java/core/src/main/java/com/google/protobuf/MapEntry.java
diff --git a/java/src/main/java/com/google/protobuf/MapEntryLite.java b/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
index bcffa946..12c64abb 100644
--- a/java/src/main/java/com/google/protobuf/MapEntryLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
@@ -41,7 +41,8 @@ import java.io.IOException;
  * 
  * Protobuf internal. Users shouldn't use.
  */
-public class MapEntryLite<K, V> extends AbstractMessageLite {
+public class MapEntryLite<K, V>
+    extends AbstractMessageLite<MapEntryLite<K, V>, MapEntryLite.Builder<K, V>> {
   private static class Metadata<K, V> {
     public final MapEntryLite<K, V> defaultInstance;
     public final WireFormat.FieldType keyType;
@@ -233,7 +234,7 @@ public class MapEntryLite<K, V> extends AbstractMessageLite {
    * Builder used to create {@link MapEntryLite} messages.
    */
   public static class Builder<K, V>
-      extends AbstractMessageLite.Builder<Builder<K, V>> {
+      extends AbstractMessageLite.Builder<MapEntryLite<K, V>, Builder<K, V>> {
     private final Metadata<K, V> metadata;
     private K key;
     private V value;
@@ -327,5 +328,10 @@ public class MapEntryLite<K, V> extends AbstractMessageLite {
       this.value = entry.value;
       return this;
     }
+
+    @Override
+    protected Builder<K, V> internalMergeFrom(MapEntryLite<K, V> message) {
+      throw new UnsupportedOperationException();
+    }
   }
 }
diff --git a/java/src/main/java/com/google/protobuf/MapField.java b/java/core/src/main/java/com/google/protobuf/MapField.java
index b290993c..907f0f71 100644
--- a/java/src/main/java/com/google/protobuf/MapField.java
+++ b/java/core/src/main/java/com/google/protobuf/MapField.java
@@ -93,15 +93,18 @@ public class MapField<K, V> implements MutabilityOracle {
       this.defaultEntry = defaultEntry;
     }
     
+    @Override
     public Message convertKeyAndValueToMessage(K key, V value) {
       return defaultEntry.newBuilderForType().setKey(key).setValue(value).buildPartial();
     }
     
+    @Override
     public void convertMessageToKeyAndValue(Message message, Map<K, V> map) {
       MapEntry<K, V> entry = (MapEntry<K, V>) message;
       map.put(entry.getKey(), entry.getValue());
     }
 
+    @Override
     public Message getMessageDefaultInstance() {
       return defaultEntry;
     }
diff --git a/java/src/main/java/com/google/protobuf/MapFieldLite.java b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
index c17fa7b1..960b6339 100644
--- a/java/src/main/java/com/google/protobuf/MapFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import com.google.protobuf.Internal.EnumLite;
+
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -44,7 +46,7 @@ import java.util.Set;
  * This class is a protobuf implementation detail. Users shouldn't use this
  * class directly.
  */
-public class MapFieldLite<K, V> implements MutabilityOracle {
+public final class MapFieldLite<K, V> implements MutabilityOracle {
   private MutatabilityAwareMap<K, V> mapData;
   private boolean isMutable;
   
@@ -134,10 +136,11 @@ public class MapFieldLite<K, V> implements MutabilityOracle {
   
   private static int calculateHashCodeForObject(Object a) {
     if (a instanceof byte[]) {
-      return LiteralByteString.hashCode((byte[]) a);
+      return Internal.hashCode((byte[]) a);
     }
-    if (a instanceof Internal.EnumLite) {
-      return Internal.hashEnum((Internal.EnumLite) a);
+    // Enums should be stored as integers internally.
+    if (a instanceof EnumLite) {
+      throw new UnsupportedOperationException();
     }
     return a.hashCode();
   }
diff --git a/java/src/main/java/com/google/protobuf/Message.java b/java/core/src/main/java/com/google/protobuf/Message.java
index 9516d71f..94590fb9 100644
--- a/java/src/main/java/com/google/protobuf/Message.java
+++ b/java/core/src/main/java/com/google/protobuf/Message.java
@@ -51,6 +51,7 @@ import java.util.Map;
 public interface Message extends MessageLite, MessageOrBuilder {
 
   // (From MessageLite, re-declared here only for return type covariance.)
+  @Override
   Parser<? extends Message> getParserForType();
 
 
@@ -97,7 +98,10 @@ public interface Message extends MessageLite, MessageOrBuilder {
   // Builders
 
   // (From MessageLite, re-declared here only for return type covariance.)
+  @Override
   Builder newBuilderForType();
+
+  @Override
   Builder toBuilder();
 
   /**
@@ -106,6 +110,7 @@ public interface Message extends MessageLite, MessageOrBuilder {
   interface Builder extends MessageLite.Builder, MessageOrBuilder {
     // (From MessageLite.Builder, re-declared here only for return type
     // covariance.)
+    @Override
     Builder clear();
 
     /**
@@ -131,18 +136,27 @@ public interface Message extends MessageLite, MessageOrBuilder {
 
     // (From MessageLite.Builder, re-declared here only for return type
     // covariance.)
+    @Override
     Message build();
+
+    @Override
     Message buildPartial();
+
+    @Override
     Builder clone();
+
+    @Override
     Builder mergeFrom(CodedInputStream input) throws IOException;
-    Builder mergeFrom(CodedInputStream input,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws IOException;
+
+    @Override
+    Builder mergeFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException;
 
     /**
      * Get the message's type's descriptor.
      * See {@link Message#getDescriptorForType()}.
      */
+    @Override
     Descriptors.Descriptor getDescriptorForType();
 
     /**
@@ -240,27 +254,39 @@ public interface Message extends MessageLite, MessageOrBuilder {
 
     // (From MessageLite.Builder, re-declared here only for return type
     // covariance.)
+    @Override
     Builder mergeFrom(ByteString data) throws InvalidProtocolBufferException;
-    Builder mergeFrom(ByteString data,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
+        throws InvalidProtocolBufferException;
+
+    @Override
     Builder mergeFrom(byte[] data) throws InvalidProtocolBufferException;
-    Builder mergeFrom(byte[] data, int off, int len)
-                      throws InvalidProtocolBufferException;
-    Builder mergeFrom(byte[] data,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws InvalidProtocolBufferException;
-    Builder mergeFrom(byte[] data, int off, int len,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(byte[] data, int off, int len) throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
+        throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
+        throws InvalidProtocolBufferException;
+
+    @Override
     Builder mergeFrom(InputStream input) throws IOException;
-    Builder mergeFrom(InputStream input,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws IOException;
-    boolean mergeDelimitedFrom(InputStream input)
-                               throws IOException;
-    boolean mergeDelimitedFrom(InputStream input,
-                               ExtensionRegistryLite extensionRegistry)
-                               throws IOException;
+
+    @Override
+    Builder mergeFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException;
+
+    @Override
+    boolean mergeDelimitedFrom(InputStream input) throws IOException;
+
+    @Override
+    boolean mergeDelimitedFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException;
   }
 }
diff --git a/java/src/main/java/com/google/protobuf/MessageLite.java b/java/core/src/main/java/com/google/protobuf/MessageLite.java
index 798b7943..88f531df 100644
--- a/java/src/main/java/com/google/protobuf/MessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageLite.java
@@ -295,6 +295,27 @@ public interface MessageLite extends MessageLiteOrBuilder {
     Builder mergeFrom(InputStream input,
                       ExtensionRegistryLite extensionRegistry)
                       throws IOException;
+    
+    /**
+     * Merge {@code other} into the message being built.  {@code other} must
+     * have the exact same type as {@code this} (i.e.
+     * {@code getClass().equals(getDefaultInstanceForType().getClass())}).
+     *
+     * Merging occurs as follows.  For each field:<br>
+     * * For singular primitive fields, if the field is set in {@code other},
+     *   then {@code other}'s value overwrites the value in this message.<br>
+     * * For singular message fields, if the field is set in {@code other},
+     *   it is merged into the corresponding sub-message of this message
+     *   using the same merging rules.<br>
+     * * For repeated fields, the elements in {@code other} are concatenated
+     *   with the elements in this message.
+     * * For oneof groups, if the other message has one of the fields set,
+     *   the group of this message is cleared and replaced by the field
+     *   of the other message, so that the oneof constraint is preserved.
+     *
+     * This is equivalent to the {@code Message::MergeFrom} method in C++.
+     */
+    Builder mergeFrom(MessageLite other);
 
     /**
      * Like {@link #mergeFrom(InputStream)}, but does not read until EOF.
diff --git a/java/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java b/java/core/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java
index 818386ce..818386ce 100644
--- a/java/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java
diff --git a/java/core/src/main/java/com/google/protobuf/MessageLiteToString.java b/java/core/src/main/java/com/google/protobuf/MessageLiteToString.java
new file mode 100644
index 00000000..43847651
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/MessageLiteToString.java
@@ -0,0 +1,239 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * Helps generate {@link String} representations of {@link MessageLite} protos.
+ */
+// TODO(dweis): Fix map fields.
+final class MessageLiteToString {
+
+  private static final String LIST_SUFFIX = "List";
+  private static final String BUILDER_LIST_SUFFIX = "OrBuilderList";
+  private static final String BYTES_SUFFIX = "Bytes";
+  
+  /**
+   * Returns a {@link String} representation of the {@link MessageLite} object.  The first line of
+   * the {@code String} representation representation includes a comment string to uniquely identify
+   * the objcet instance. This acts as an indicator that this should not be relied on for
+   * comparisons.
+   *
+   * <p>For use by generated code only.
+   */
+  static String toString(MessageLite messageLite, String commentString) {
+    StringBuilder buffer = new StringBuilder();
+    buffer.append("# ").append(commentString);
+    reflectivePrintWithIndent(messageLite, buffer, 0);
+    return buffer.toString();
+  }
+
+  /**
+   * Reflectively prints the {@link MessageLite} to the buffer at given {@code indent} level.
+   *
+   * @param buffer the buffer to write to
+   * @param indent the number of spaces to indent the proto by
+   */
+  private static void reflectivePrintWithIndent(
+      MessageLite messageLite, StringBuilder buffer, int indent) {
+    // Build a map of method name to method. We're looking for methods like getFoo(), hasFoo(), and
+    // getFooList() which might be useful for building an object's string representation.
+    Map<String, Method> nameToNoArgMethod = new HashMap<String, Method>();
+    Map<String, Method> nameToMethod = new HashMap<String, Method>();
+    Set<String> getters = new TreeSet<String>();
+    for (Method method : messageLite.getClass().getDeclaredMethods()) {
+      nameToMethod.put(method.getName(), method);
+      if (method.getParameterTypes().length == 0) {
+        nameToNoArgMethod.put(method.getName(), method);
+
+        if (method.getName().startsWith("get")) {
+          getters.add(method.getName());
+        }
+      }
+    }
+
+    for (String getter : getters) {
+      String suffix = getter.replaceFirst("get", "");
+      if (suffix.endsWith(LIST_SUFFIX) && !suffix.endsWith(BUILDER_LIST_SUFFIX)) {
+        String camelCase = suffix.substring(0, 1).toLowerCase()
+            + suffix.substring(1, suffix.length() - LIST_SUFFIX.length());
+        // Try to reflectively get the value and toString() the field as if it were repeated. This
+        // only works if the method names have not be proguarded out or renamed.
+        Method listMethod = nameToNoArgMethod.get("get" + suffix);
+        if (listMethod != null) {
+          printField(
+              buffer,
+              indent,
+              camelCaseToSnakeCase(camelCase),
+              GeneratedMessageLite.invokeOrDie(listMethod, messageLite));
+          continue;
+        }
+      }
+
+      Method setter = nameToMethod.get("set" + suffix);
+      if (setter == null) {
+        continue;
+      }
+      if (suffix.endsWith(BYTES_SUFFIX)
+          && nameToNoArgMethod.containsKey(
+              "get" + suffix.substring(0, suffix.length() - "Bytes".length()))) {
+        // Heuristic to skip bytes based accessors for string fields.
+        continue;
+      }
+      
+      String camelCase = suffix.substring(0, 1).toLowerCase() + suffix.substring(1);
+
+      // Try to reflectively get the value and toString() the field as if it were optional. This
+      // only works if the method names have not be proguarded out or renamed.
+      Method getMethod = nameToNoArgMethod.get("get" + suffix);
+      Method hasMethod = nameToNoArgMethod.get("has" + suffix);
+      // TODO(dweis): Fix proto3 semantics.
+      if (getMethod != null) {
+        Object value = GeneratedMessageLite.invokeOrDie(getMethod, messageLite);
+        final boolean hasValue = hasMethod == null
+            ? !isDefaultValue(value)
+            : (Boolean) GeneratedMessageLite.invokeOrDie(hasMethod, messageLite);
+         // TODO(dweis): This doesn't stop printing oneof case twice: value and enum style.
+        if (hasValue) {
+          printField(
+              buffer,
+              indent,
+              camelCaseToSnakeCase(camelCase),
+              value);
+        }
+        continue;
+      }
+    }
+
+    if (messageLite instanceof GeneratedMessageLite.ExtendableMessage) {
+      Iterator<Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object>> iter =
+          ((GeneratedMessageLite.ExtendableMessage<?, ?>) messageLite).extensions.iterator();
+      while (iter.hasNext()) {
+        Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object> entry = iter.next();
+        printField(buffer, indent, "[" + entry.getKey().getNumber() + "]", entry.getValue());
+      }
+    }
+
+    if (((GeneratedMessageLite<?, ?>) messageLite).unknownFields != null) {
+      ((GeneratedMessageLite<?, ?>) messageLite).unknownFields.printWithIndent(buffer, indent);
+    }
+  }
+  
+  private static boolean isDefaultValue(Object o) {
+    if (o instanceof Boolean) {
+      return !((Boolean) o);
+    }
+    if (o instanceof Integer) {
+      return ((Integer) o) == 0;
+    }
+    if (o instanceof Float) {
+      return ((Float) o) == 0f;
+    }
+    if (o instanceof Double) {
+      return ((Double) o) == 0d;
+    }
+    if (o instanceof String) {
+      return o.equals("");
+    }
+    if (o instanceof ByteString) {
+      return o.equals(ByteString.EMPTY);
+    }
+    if (o instanceof MessageLite) { // Can happen in oneofs.
+      return o == ((MessageLite) o).getDefaultInstanceForType();
+    }
+    if (o instanceof java.lang.Enum<?>) { // Catches oneof enums.
+      return ((java.lang.Enum<?>) o).ordinal() == 0;
+    }
+    
+    return false;
+  }
+
+  /**
+   * Formats a text proto field.
+   *
+   * <p>For use by generated code only.
+   *
+   * @param buffer the buffer to write to
+   * @param indent the number of spaces the proto should be indented by
+   * @param name the field name (in lower underscore case)
+   * @param object the object value of the field
+   */
+  static final void printField(StringBuilder buffer, int indent, String name, Object object) {
+    if (object instanceof List<?>) {
+      List<?> list = (List<?>) object;
+      for (Object entry : list) {
+        printField(buffer, indent, name, entry);
+      }
+      return;
+    }
+
+    buffer.append('\n');
+    for (int i = 0; i < indent; i++) {
+      buffer.append(' ');
+    }
+    buffer.append(name);
+
+    if (object instanceof String) {
+      buffer.append(": \"").append(TextFormatEscaper.escapeText((String) object)).append('"');
+    } else if (object instanceof ByteString) {
+      buffer.append(": \"").append(TextFormatEscaper.escapeBytes((ByteString) object)).append('"');
+    } else if (object instanceof GeneratedMessageLite) {
+      buffer.append(" {");
+      reflectivePrintWithIndent((GeneratedMessageLite<?, ?>) object, buffer, indent + 2);
+      buffer.append("\n");
+      for (int i = 0; i < indent; i++) {
+        buffer.append(' ');
+      }
+      buffer.append("}");
+    } else {
+      buffer.append(": ").append(object.toString());
+    }
+  }
+  
+  private static final String camelCaseToSnakeCase(String camelCase) {
+    StringBuilder builder = new StringBuilder();
+    for (int i = 0; i < camelCase.length(); i++) {
+      char ch = camelCase.charAt(i);
+      if (Character.isUpperCase(ch)) {
+        builder.append("_");
+      }
+      builder.append(Character.toLowerCase(ch));
+    }
+    return builder.toString();
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/MessageOrBuilder.java b/java/core/src/main/java/com/google/protobuf/MessageOrBuilder.java
index f0fc4859..5e7d7821 100644
--- a/java/src/main/java/com/google/protobuf/MessageOrBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageOrBuilder.java
@@ -42,7 +42,7 @@ import java.util.Map;
 public interface MessageOrBuilder extends MessageLiteOrBuilder {
 
   // (From MessageLite, re-declared here only for return type covariance.)
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   Message getDefaultInstanceForType();
 
   /**
diff --git a/java/src/main/java/com/google/protobuf/MessageReflection.java b/java/core/src/main/java/com/google/protobuf/MessageReflection.java
index de4bfd3e..7b791d9e 100644
--- a/java/src/main/java/com/google/protobuf/MessageReflection.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageReflection.java
@@ -364,12 +364,14 @@ class MessageReflection {
      * Finishes the merge and returns the underlying object.
      */
     Object finish();
+    
   }
 
   static class BuilderAdapter implements MergeTarget {
 
     private final Message.Builder builder;
 
+    @Override
     public Descriptors.Descriptor getDescriptorForType() {
       return builder.getDescriptorForType();
     }
@@ -378,6 +380,7 @@ class MessageReflection {
       this.builder = builder;
     }
 
+    @Override
     public Object getField(Descriptors.FieldDescriptor field) {
       return builder.getField(field);
     }
@@ -387,25 +390,27 @@ class MessageReflection {
       return builder.hasField(field);
     }
 
-    public MergeTarget setField(Descriptors.FieldDescriptor field,
-        Object value) {
+    @Override
+    public MergeTarget setField(Descriptors.FieldDescriptor field, Object value) {
       builder.setField(field, value);
       return this;
     }
 
+    @Override
     public MergeTarget clearField(Descriptors.FieldDescriptor field) {
       builder.clearField(field);
       return this;
     }
 
+    @Override
     public MergeTarget setRepeatedField(
         Descriptors.FieldDescriptor field, int index, Object value) {
       builder.setRepeatedField(field, index, value);
       return this;
     }
 
-    public MergeTarget addRepeatedField(
-        Descriptors.FieldDescriptor field, Object value) {
+    @Override
+    public MergeTarget addRepeatedField(Descriptors.FieldDescriptor field, Object value) {
       builder.addRepeatedField(field, value);
       return this;
     }
@@ -426,25 +431,30 @@ class MessageReflection {
       return builder.getOneofFieldDescriptor(oneof);
     }
 
+    @Override
     public ContainerType getContainerType() {
       return ContainerType.MESSAGE;
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByName(
         ExtensionRegistry registry, String name) {
       return registry.findImmutableExtensionByName(name);
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByNumber(
-        ExtensionRegistry registry, Descriptors.Descriptor containingType,
-        int fieldNumber) {
+        ExtensionRegistry registry, Descriptors.Descriptor containingType, int fieldNumber) {
       return registry.findImmutableExtensionByNumber(containingType,
           fieldNumber);
     }
 
-    public Object parseGroup(CodedInputStream input,
+    @Override
+    public Object parseGroup(
+        CodedInputStream input,
         ExtensionRegistryLite extensionRegistry,
-        Descriptors.FieldDescriptor field, Message defaultInstance)
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
         throws IOException {
       Message.Builder subBuilder;
       // When default instance is not null. The field is an extension field.
@@ -463,9 +473,12 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessage(CodedInputStream input,
+    @Override
+    public Object parseMessage(
+        CodedInputStream input,
         ExtensionRegistryLite extensionRegistry,
-        Descriptors.FieldDescriptor field, Message defaultInstance)
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
         throws IOException {
       Message.Builder subBuilder;
       // When default instance is not null. The field is an extension field.
@@ -484,9 +497,12 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessageFromBytes(ByteString bytes,
+    @Override
+    public Object parseMessageFromBytes(
+        ByteString bytes,
         ExtensionRegistryLite extensionRegistry,
-        Descriptors.FieldDescriptor field, Message defaultInstance)
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
         throws IOException {
       Message.Builder subBuilder;
       // When default instance is not null. The field is an extension field.
@@ -505,8 +521,9 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public MergeTarget newMergeTargetForField(Descriptors.FieldDescriptor field,
-        Message defaultInstance) {
+    @Override
+    public MergeTarget newMergeTargetForField(
+        Descriptors.FieldDescriptor field, Message defaultInstance) {
       if (defaultInstance != null) {
         return new BuilderAdapter(
             defaultInstance.newBuilderForType());
@@ -515,8 +532,8 @@ class MessageReflection {
       }
     }
 
-    public WireFormat.Utf8Validation
-        getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
+    @Override
+    public WireFormat.Utf8Validation getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
       if (descriptor.needsUtf8Check()) {
         return WireFormat.Utf8Validation.STRICT;
       }
@@ -528,9 +545,11 @@ class MessageReflection {
       return WireFormat.Utf8Validation.LOOSE;
     }
 
+    @Override
     public Object finish() {
       return builder.buildPartial();
     }
+    
   }
 
 
@@ -542,38 +561,43 @@ class MessageReflection {
       this.extensions = extensions;
     }
 
+    @Override
     public Descriptors.Descriptor getDescriptorForType() {
       throw new UnsupportedOperationException(
           "getDescriptorForType() called on FieldSet object");
     }
 
+    @Override
     public Object getField(Descriptors.FieldDescriptor field) {
       return extensions.getField(field);
     }
 
+    @Override
     public boolean hasField(Descriptors.FieldDescriptor field) {
       return extensions.hasField(field);
     }
 
-    public MergeTarget setField(Descriptors.FieldDescriptor field,
-        Object value) {
+    @Override
+    public MergeTarget setField(Descriptors.FieldDescriptor field, Object value) {
       extensions.setField(field, value);
       return this;
     }
 
+    @Override
     public MergeTarget clearField(Descriptors.FieldDescriptor field) {
       extensions.clearField(field);
       return this;
     }
 
+    @Override
     public MergeTarget setRepeatedField(
         Descriptors.FieldDescriptor field, int index, Object value) {
       extensions.setRepeatedField(field, index, value);
       return this;
     }
 
-    public MergeTarget addRepeatedField(
-        Descriptors.FieldDescriptor field, Object value) {
+    @Override
+    public MergeTarget addRepeatedField(Descriptors.FieldDescriptor field, Object value) {
       extensions.addRepeatedField(field, value);
       return this;
     }
@@ -594,25 +618,31 @@ class MessageReflection {
       return null;
     }
 
+    @Override
     public ContainerType getContainerType() {
       return ContainerType.EXTENSION_SET;
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByName(
         ExtensionRegistry registry, String name) {
       return registry.findImmutableExtensionByName(name);
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByNumber(
-        ExtensionRegistry registry, Descriptors.Descriptor containingType,
-        int fieldNumber) {
+        ExtensionRegistry registry, Descriptors.Descriptor containingType, int fieldNumber) {
       return registry.findImmutableExtensionByNumber(containingType,
           fieldNumber);
     }
 
-    public Object parseGroup(CodedInputStream input,
-        ExtensionRegistryLite registry, Descriptors.FieldDescriptor field,
-        Message defaultInstance) throws IOException {
+    @Override
+    public Object parseGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
       Message.Builder subBuilder =
           defaultInstance.newBuilderForType();
       if (!field.isRepeated()) {
@@ -625,9 +655,13 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessage(CodedInputStream input,
-        ExtensionRegistryLite registry, Descriptors.FieldDescriptor field,
-        Message defaultInstance) throws IOException {
+    @Override
+    public Object parseMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
       Message.Builder subBuilder =
           defaultInstance.newBuilderForType();
       if (!field.isRepeated()) {
@@ -640,9 +674,13 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessageFromBytes(ByteString bytes,
-        ExtensionRegistryLite registry, Descriptors.FieldDescriptor field,
-        Message defaultInstance) throws IOException {
+    @Override
+    public Object parseMessageFromBytes(
+        ByteString bytes,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
       Message.Builder subBuilder =  defaultInstance.newBuilderForType();
       if (!field.isRepeated()) {
         Message originalMessage = (Message) getField(field);
@@ -654,14 +692,15 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
+    @Override
     public MergeTarget newMergeTargetForField(
         Descriptors.FieldDescriptor descriptor, Message defaultInstance) {
       throw new UnsupportedOperationException(
           "newMergeTargetForField() called on FieldSet object");
     }
 
-    public WireFormat.Utf8Validation
-        getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
+    @Override
+    public WireFormat.Utf8Validation getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
       if (descriptor.needsUtf8Check()) {
         return WireFormat.Utf8Validation.STRICT;
       }
@@ -669,10 +708,12 @@ class MessageReflection {
       return WireFormat.Utf8Validation.LOOSE;
     }
 
+    @Override
     public Object finish() {
       throw new UnsupportedOperationException(
           "finish() called on FieldSet object");
     }
+    
   }
 
   /**
diff --git a/java/src/main/java/com/google/protobuf/MutabilityOracle.java b/java/core/src/main/java/com/google/protobuf/MutabilityOracle.java
index 82b723c9..82b723c9 100644
--- a/java/src/main/java/com/google/protobuf/MutabilityOracle.java
+++ b/java/core/src/main/java/com/google/protobuf/MutabilityOracle.java
diff --git a/java/core/src/main/java/com/google/protobuf/NioByteString.java b/java/core/src/main/java/com/google/protobuf/NioByteString.java
new file mode 100644
index 00000000..6163c7b1
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/NioByteString.java
@@ -0,0 +1,290 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.InvalidMarkException;
+import java.nio.charset.Charset;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A {@link ByteString} that wraps around a {@link ByteBuffer}.
+ */
+final class NioByteString extends ByteString.LeafByteString {
+  private final ByteBuffer buffer;
+
+  NioByteString(ByteBuffer buffer) {
+    if (buffer == null) {
+      throw new NullPointerException("buffer");
+    }
+
+    this.buffer = buffer.slice().order(ByteOrder.nativeOrder());
+  }
+
+  // =================================================================
+  // Serializable
+
+  /**
+   * Magic method that lets us override serialization behavior.
+   */
+  private Object writeReplace() {
+    return ByteString.copyFrom(buffer.slice());
+  }
+
+  /**
+   * Magic method that lets us override deserialization behavior.
+   */
+  private void readObject(@SuppressWarnings("unused") ObjectInputStream in) throws IOException {
+    throw new InvalidObjectException("NioByteString instances are not to be serialized directly");
+  }
+
+  // =================================================================
+
+  @Override
+  public byte byteAt(int index) {
+    try {
+      return buffer.get(index);
+    } catch (ArrayIndexOutOfBoundsException e) {
+      throw e;
+    } catch (IndexOutOfBoundsException e) {
+      throw new ArrayIndexOutOfBoundsException(e.getMessage());
+    }
+  }
+
+  @Override
+  public int size() {
+    return buffer.remaining();
+  }
+
+  @Override
+  public ByteString substring(int beginIndex, int endIndex) {
+    try {
+      ByteBuffer slice = slice(beginIndex, endIndex);
+      return new NioByteString(slice);
+    } catch (ArrayIndexOutOfBoundsException e) {
+      throw e;
+    } catch (IndexOutOfBoundsException e) {
+      throw new ArrayIndexOutOfBoundsException(e.getMessage());
+    }
+  }
+
+  @Override
+  protected void copyToInternal(
+      byte[] target, int sourceOffset, int targetOffset, int numberToCopy) {
+    ByteBuffer slice = buffer.slice();
+    slice.position(sourceOffset);
+    slice.get(target, targetOffset, numberToCopy);
+  }
+
+  @Override
+  public void copyTo(ByteBuffer target) {
+    target.put(buffer.slice());
+  }
+
+  @Override
+  public void writeTo(OutputStream out) throws IOException {
+    out.write(toByteArray());
+  }
+
+  @Override
+  boolean equalsRange(ByteString other, int offset, int length) {
+    return substring(0, length).equals(other.substring(offset, offset + length));
+  }
+
+  @Override
+  void writeToInternal(OutputStream out, int sourceOffset, int numberToWrite) throws IOException {
+    if (buffer.hasArray()) {
+      // Optimized write for array-backed buffers.
+      // Note that we're taking the risk that a malicious OutputStream could modify the array.
+      int bufferOffset = buffer.arrayOffset() + buffer.position() + sourceOffset;
+      out.write(buffer.array(), bufferOffset, numberToWrite);
+      return;
+    }
+
+    ByteBufferWriter.write(slice(sourceOffset, sourceOffset + numberToWrite), out);
+  }
+
+  @Override
+  void writeTo(ByteOutput output) throws IOException {
+    output.writeLazy(buffer.slice());
+  }
+
+  @Override
+  public ByteBuffer asReadOnlyByteBuffer() {
+    return buffer.asReadOnlyBuffer();
+  }
+
+  @Override
+  public List<ByteBuffer> asReadOnlyByteBufferList() {
+    return Collections.singletonList(asReadOnlyByteBuffer());
+  }
+
+  @Override
+  protected String toStringInternal(Charset charset) {
+    final byte[] bytes;
+    final int offset;
+    final int length;
+    if (buffer.hasArray()) {
+      bytes = buffer.array();
+      offset = buffer.arrayOffset() + buffer.position();
+      length = buffer.remaining();
+    } else {
+      // TODO(nathanmittler): Can we optimize this?
+      bytes = toByteArray();
+      offset = 0;
+      length = bytes.length;
+    }
+    return new String(bytes, offset, length, charset);
+  }
+
+  @Override
+  public boolean isValidUtf8() {
+    return Utf8.isValidUtf8(buffer);
+  }
+
+  @Override
+  protected int partialIsValidUtf8(int state, int offset, int length) {
+    return Utf8.partialIsValidUtf8(state, buffer, offset, offset + length);
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == this) {
+      return true;
+    }
+    if (!(other instanceof ByteString)) {
+      return false;
+    }
+    ByteString otherString = ((ByteString) other);
+    if (size() != otherString.size()) {
+      return false;
+    }
+    if (size() == 0) {
+      return true;
+    }
+    if (other instanceof NioByteString) {
+      return buffer.equals(((NioByteString) other).buffer);
+    }
+    if (other instanceof RopeByteString) {
+      return other.equals(this);
+    }
+    return buffer.equals(otherString.asReadOnlyByteBuffer());
+  }
+
+  @Override
+  protected int partialHash(int h, int offset, int length) {
+    for (int i = offset; i < offset + length; i++) {
+      h = h * 31 + buffer.get(i);
+    }
+    return h;
+  }
+
+  @Override
+  public InputStream newInput() {
+    return new InputStream() {
+      private final ByteBuffer buf = buffer.slice();
+
+      @Override
+      public void mark(int readlimit) {
+        buf.mark();
+      }
+
+      @Override
+      public boolean markSupported() {
+        return true;
+      }
+
+      @Override
+      public void reset() throws IOException {
+        try {
+          buf.reset();
+        } catch (InvalidMarkException e) {
+          throw new IOException(e);
+        }
+      }
+
+      @Override
+      public int available() throws IOException {
+        return buf.remaining();
+      }
+
+      @Override
+      public int read() throws IOException {
+        if (!buf.hasRemaining()) {
+          return -1;
+        }
+        return buf.get() & 0xFF;
+      }
+
+      @Override
+      public int read(byte[] bytes, int off, int len) throws IOException {
+        if (!buf.hasRemaining()) {
+          return -1;
+        }
+
+        len = Math.min(len, buf.remaining());
+        buf.get(bytes, off, len);
+        return len;
+      }
+    };
+  }
+
+  @Override
+  public CodedInputStream newCodedInput() {
+    return CodedInputStream.newInstance(buffer);
+  }
+
+  /**
+   * Creates a slice of a range of this buffer.
+   *
+   * @param beginIndex the beginning index of the slice (inclusive).
+   * @param endIndex the end index of the slice (exclusive).
+   * @return the requested slice.
+   */
+  private ByteBuffer slice(int beginIndex, int endIndex) {
+    if (beginIndex < buffer.position() || endIndex > buffer.limit() || beginIndex > endIndex) {
+      throw new IllegalArgumentException(
+          String.format("Invalid indices [%d, %d]", beginIndex, endIndex));
+    }
+
+    ByteBuffer slice = buffer.slice();
+    slice.position(beginIndex - buffer.position());
+    slice.limit(endIndex - buffer.position());
+    return slice;
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/Parser.java b/java/core/src/main/java/com/google/protobuf/Parser.java
index 227c02b7..6db69247 100644
--- a/java/src/main/java/com/google/protobuf/Parser.java
+++ b/java/core/src/main/java/com/google/protobuf/Parser.java
@@ -37,9 +37,20 @@ import java.io.InputStream;
  *
  * The implementation should be stateless and thread-safe.
  *
+ * <p>All methods may throw {@link InvalidProtocolBufferException}. In the event of invalid data,
+ * like an encoding error, the cause of the thrown exception will be {@code null}. However, if an
+ * I/O problem occurs, an exception is thrown with an {@link IOException} cause.
+ *
  * @author liujisi@google.com (Pherl Liu)
  */
 public interface Parser<MessageType> {
+
+  // NB(jh): Other parts of the protobuf API that parse messages distinguish between an I/O problem
+  // (like failure reading bytes from a socket) and invalid data (encoding error) via the type of
+  // thrown exception. But it would be source-incompatible to make the methods in this interface do
+  // so since they were originally spec'ed to only throw InvalidProtocolBufferException. So callers
+  // must inspect the cause of the exception to distinguish these two cases.
+
   /**
    * Parses a message of {@code MessageType} from the input.
    *
diff --git a/java/src/main/java/com/google/protobuf/ProtobufArrayList.java b/java/core/src/main/java/com/google/protobuf/ProtobufArrayList.java
index 759368c9..81255ec2 100644
--- a/java/src/main/java/com/google/protobuf/ProtobufArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/ProtobufArrayList.java
@@ -38,7 +38,7 @@ import java.util.List;
 /**
  * Implements {@link ProtobufList} for non-primitive and {@link String} types.
  */
-class ProtobufArrayList<E> extends AbstractProtobufList<E> {
+final class ProtobufArrayList<E> extends AbstractProtobufList<E> {
 
   private static final ProtobufArrayList<Object> EMPTY_LIST = new ProtobufArrayList<Object>();
   static {
@@ -51,13 +51,23 @@ class ProtobufArrayList<E> extends AbstractProtobufList<E> {
   }
   
   private final List<E> list;
-  
+
   ProtobufArrayList() {
-    list = new ArrayList<E>();
+    this(new ArrayList<E>(DEFAULT_CAPACITY));
   }
   
-  ProtobufArrayList(List<E> toCopy) {
-    list = new ArrayList<E>(toCopy);
+  private ProtobufArrayList(List<E> list) {
+    this.list = list;
+  }
+
+  @Override
+  public ProtobufArrayList<E> mutableCopyWithCapacity(int capacity) {
+    if (capacity < size()) {
+      throw new IllegalArgumentException();
+    }
+    List<E> newList = new ArrayList<E>(capacity);
+    newList.addAll(list);
+    return new ProtobufArrayList<E>(newList);
   }
   
   @Override
diff --git a/java/src/main/java/com/google/protobuf/ProtocolMessageEnum.java b/java/core/src/main/java/com/google/protobuf/ProtocolMessageEnum.java
index 0c8df989..a596d301 100644
--- a/java/src/main/java/com/google/protobuf/ProtocolMessageEnum.java
+++ b/java/core/src/main/java/com/google/protobuf/ProtocolMessageEnum.java
@@ -42,6 +42,7 @@ public interface ProtocolMessageEnum extends Internal.EnumLite {
   /**
    * Return the value's numeric value as defined in the .proto file.
    */
+  @Override
   int getNumber();
 
   /**
diff --git a/java/src/main/java/com/google/protobuf/ProtocolStringList.java b/java/core/src/main/java/com/google/protobuf/ProtocolStringList.java
index d553b41e..d553b41e 100644
--- a/java/src/main/java/com/google/protobuf/ProtocolStringList.java
+++ b/java/core/src/main/java/com/google/protobuf/ProtocolStringList.java
diff --git a/java/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java b/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java
index f91cdbce..29f567dc 100644
--- a/java/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java
@@ -579,7 +579,7 @@ public class RepeatedFieldBuilder
     }
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void markDirty() {
     onChanged();
   }
@@ -621,10 +621,12 @@ public class RepeatedFieldBuilder
       this.builder = builder;
     }
 
+    @Override
     public int size() {
       return this.builder.getCount();
     }
 
+    @Override
     public MType get(int index) {
       return builder.getMessage(index);
     }
@@ -654,10 +656,12 @@ public class RepeatedFieldBuilder
       this.builder = builder;
     }
 
+    @Override
     public int size() {
       return this.builder.getCount();
     }
 
+    @Override
     public BType get(int index) {
       return builder.getBuilder(index);
     }
@@ -687,10 +691,12 @@ public class RepeatedFieldBuilder
       this.builder = builder;
     }
 
+    @Override
     public int size() {
       return this.builder.getCount();
     }
 
+    @Override
     public IType get(int index) {
       return builder.getMessageOrBuilder(index);
     }
diff --git a/java/src/main/java/com/google/protobuf/RopeByteString.java b/java/core/src/main/java/com/google/protobuf/RopeByteString.java
index 2c332624..3f3e9bd1 100644
--- a/java/src/main/java/com/google/protobuf/RopeByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/RopeByteString.java
@@ -48,10 +48,11 @@ import java.util.Stack;
 /**
  * Class to represent {@code ByteStrings} formed by concatenation of other
  * ByteStrings, without copying the data in the pieces. The concatenation is
- * represented as a tree whose leaf nodes are each a {@link LiteralByteString}.
+ * represented as a tree whose leaf nodes are each a
+ * {@link com.google.protobuf.ByteString.LeafByteString}.
  *
  * <p>Most of the operation here is inspired by the now-famous paper <a
- * href="http://www.cs.ubc.ca/local/reading/proceedings/spe91-95/spe/vol25/issue12/spe986.pdf">
+ * href="https://web.archive.org/web/20060202015456/http://www.cs.ubc.ca/local/reading/proceedings/spe91-95/spe/vol25/issue12/spe986.pdf">
  * BAP95 </a> Ropes: an Alternative to Strings hans-j. boehm, russ atkinson and
  * michael plass
  *
@@ -69,7 +70,7 @@ import java.util.Stack;
  *
  * @author carlanton@google.com (Carl Haverl)
  */
-class RopeByteString extends ByteString {
+final class RopeByteString extends ByteString {
 
   /**
    * BAP95. Let Fn be the nth Fibonacci number. A {@link RopeByteString} of
@@ -139,8 +140,9 @@ class RopeByteString extends ByteString {
   /**
    * Concatenate the given strings while performing various optimizations to
    * slow the growth rate of tree depth and tree node count. The result is
-   * either a {@link LiteralByteString} or a {@link RopeByteString}
-   * depending on which optimizations, if any, were applied.
+   * either a {@link com.google.protobuf.ByteString.LeafByteString} or a
+   * {@link RopeByteString} depending on which optimizations, if any, were
+   * applied.
    *
    * <p>Small pieces of length less than {@link
    * ByteString#CONCATENATE_BY_COPY_SIZE} may be copied by value here, as in
@@ -151,21 +153,24 @@ class RopeByteString extends ByteString {
    * @return concatenation representing the same sequence as the given strings
    */
   static ByteString concatenate(ByteString left, ByteString right) {
-    ByteString result;
-    RopeByteString leftRope =
-        (left instanceof RopeByteString) ? (RopeByteString) left : null;
     if (right.size() == 0) {
-      result = left;
-    } else if (left.size() == 0) {
-      result = right;
-    } else {
-      int newLength = left.size() + right.size();
-      if (newLength < ByteString.CONCATENATE_BY_COPY_SIZE) {
-        // Optimization from BAP95: For short (leaves in paper, but just short
-        // here) total length, do a copy of data to a new leaf.
-        result = concatenateBytes(left, right);
-      } else if (leftRope != null
-          && leftRope.right.size() + right.size() < CONCATENATE_BY_COPY_SIZE) {
+      return left;
+    }
+
+    if (left.size() == 0) {
+      return right;
+    }
+
+    final int newLength = left.size() + right.size();
+    if (newLength < ByteString.CONCATENATE_BY_COPY_SIZE) {
+      // Optimization from BAP95: For short (leaves in paper, but just short
+      // here) total length, do a copy of data to a new leaf.
+      return concatenateBytes(left, right);
+    }
+
+    if (left instanceof RopeByteString) {
+      final RopeByteString leftRope = (RopeByteString) left;
+      if (leftRope.right.size() + right.size() < CONCATENATE_BY_COPY_SIZE) {
         // Optimization from BAP95: As an optimization of the case where the
         // ByteString is constructed by repeated concatenate, recognize the case
         // where a short string is concatenated to a left-hand node whose
@@ -177,30 +182,29 @@ class RopeByteString extends ByteString {
         // new parent node so that the depth of the result is the same as the
         // given left tree.
         ByteString newRight = concatenateBytes(leftRope.right, right);
-        result = new RopeByteString(leftRope.left, newRight);
-      } else if (leftRope != null
-          && leftRope.left.getTreeDepth() > leftRope.right.getTreeDepth()
+        return new RopeByteString(leftRope.left, newRight);
+      }
+
+      if (leftRope.left.getTreeDepth() > leftRope.right.getTreeDepth()
           && leftRope.getTreeDepth() > right.getTreeDepth()) {
         // Typically for concatenate-built strings the left-side is deeper than
         // the right.  This is our final attempt to concatenate without
-        // increasing the tree depth.  We'll redo the the node on the RHS.  This
+        // increasing the tree depth.  We'll redo the node on the RHS.  This
         // is yet another optimization for building the string by repeatedly
         // concatenating on the right.
         ByteString newRight = new RopeByteString(leftRope.right, right);
-        result = new RopeByteString(leftRope.left, newRight);
-      } else {
-        // Fine, we'll add a node and increase the tree depth--unless we
-        // rebalance ;^)
-        int newDepth = Math.max(left.getTreeDepth(), right.getTreeDepth()) + 1;
-        if (newLength >= minLengthByDepth[newDepth]) {
-          // The tree is shallow enough, so don't rebalance
-          result = new RopeByteString(left, right);
-        } else {
-          result = new Balancer().balance(left, right);
-        }
+        return new RopeByteString(leftRope.left, newRight);
       }
     }
-    return result;
+
+    // Fine, we'll add a node and increase the tree depth--unless we rebalance ;^)
+    int newDepth = Math.max(left.getTreeDepth(), right.getTreeDepth()) + 1;
+    if (newLength >= minLengthByDepth[newDepth]) {
+      // The tree is shallow enough, so don't rebalance
+      return new RopeByteString(left, right);
+    }
+
+    return new Balancer().balance(left, right);
   }
 
   /**
@@ -211,14 +215,14 @@ class RopeByteString extends ByteString {
    * @param right string on the right
    * @return string formed by copying data bytes
    */
-  private static LiteralByteString concatenateBytes(ByteString left,
+  private static ByteString concatenateBytes(ByteString left,
       ByteString right) {
     int leftSize = left.size();
     int rightSize = right.size();
     byte[] bytes = new byte[leftSize + rightSize];
     left.copyTo(bytes, 0, 0, leftSize);
     right.copyTo(bytes, 0, leftSize, rightSize);
-    return new LiteralByteString(bytes);  // Constructor wraps bytes
+    return ByteString.wrap(bytes);  // Constructor wraps bytes
   }
 
   /**
@@ -248,22 +252,14 @@ class RopeByteString extends ByteString {
    */
   @Override
   public byte byteAt(int index) {
-    if (index < 0) {
-      throw new ArrayIndexOutOfBoundsException("Index < 0: " + index);
-    }
-    if (index > totalLength) {
-      throw new ArrayIndexOutOfBoundsException(
-          "Index > length: " + index + ", " + totalLength);
-    }
+    checkIndex(index, totalLength);
 
-    byte result;
     // Find the relevant piece by recursive descent
     if (index < leftLength) {
-      result = left.byteAt(index);
-    } else {
-      result = right.byteAt(index - leftLength);
+      return left.byteAt(index);
     }
-    return result;
+
+    return right.byteAt(index - leftLength);
   }
 
   @Override
@@ -300,8 +296,7 @@ class RopeByteString extends ByteString {
    *
    * <p>Substrings of {@code length < 2} should result in at most a single
    * recursive call chain, terminating at a leaf node. Thus the result will be a
-   * {@link LiteralByteString}. {@link #RopeByteString(ByteString,
-   * ByteString)}.
+   * {@link com.google.protobuf.ByteString.LeafByteString}.
    *
    * @param beginIndex start at this index
    * @param endIndex   the last character is the one before this index
@@ -309,48 +304,36 @@ class RopeByteString extends ByteString {
    */
   @Override
   public ByteString substring(int beginIndex, int endIndex) {
-    if (beginIndex < 0) {
-      throw new IndexOutOfBoundsException(
-          "Beginning index: " + beginIndex + " < 0");
+    final int length = checkRange(beginIndex, endIndex, totalLength);
+
+    if (length == 0) {
+      // Empty substring
+      return ByteString.EMPTY;
     }
-    if (endIndex > totalLength) {
-      throw new IndexOutOfBoundsException(
-          "End index: " + endIndex + " > " + totalLength);
+
+    if (length == totalLength) {
+      // The whole string
+      return this;
     }
-    int substringLength = endIndex - beginIndex;
-    if (substringLength < 0) {
-      throw new IndexOutOfBoundsException(
-          "Beginning index larger than ending index: " + beginIndex + ", "
-              + endIndex);
+
+    // Proper substring
+    if (endIndex <= leftLength) {
+      // Substring on the left
+      return left.substring(beginIndex, endIndex);
     }
 
-    ByteString result;
-    if (substringLength == 0) {
-      // Empty substring
-      result = ByteString.EMPTY;
-    } else if (substringLength == totalLength) {
-      // The whole string
-      result = this;
-    } else {
-      // Proper substring
-      if (endIndex <= leftLength) {
-        // Substring on the left
-        result = left.substring(beginIndex, endIndex);
-      } else if (beginIndex >= leftLength) {
-        // Substring on the right
-        result = right
-            .substring(beginIndex - leftLength, endIndex - leftLength);
-      } else {
-        // Split substring
-        ByteString leftSub = left.substring(beginIndex);
-        ByteString rightSub = right.substring(0, endIndex - leftLength);
-        // Intentionally not rebalancing, since in many cases these two
-        // substrings will already be less deep than the top-level
-        // RopeByteString we're taking a substring of.
-        result = new RopeByteString(leftSub, rightSub);
-      }
+    if (beginIndex >= leftLength) {
+      // Substring on the right
+      return right.substring(beginIndex - leftLength, endIndex - leftLength);
     }
-    return result;
+
+    // Split substring
+    ByteString leftSub = left.substring(beginIndex);
+    ByteString rightSub = right.substring(0, endIndex - leftLength);
+    // Intentionally not rebalancing, since in many cases these two
+    // substrings will already be less deep than the top-level
+    // RopeByteString we're taking a substring of.
+    return new RopeByteString(leftSub, rightSub);
   }
 
   // =================================================================
@@ -386,12 +369,12 @@ class RopeByteString extends ByteString {
 
   @Override
   public List<ByteBuffer> asReadOnlyByteBufferList() {
-    // Walk through the list of LiteralByteString's that make up this
+    // Walk through the list of LeafByteString's that make up this
     // rope, and add each one as a read-only ByteBuffer.
     List<ByteBuffer> result = new ArrayList<ByteBuffer>();
     PieceIterator pieces = new PieceIterator(this);
     while (pieces.hasNext()) {
-      LiteralByteString byteString = pieces.next();
+      LeafByteString byteString = pieces.next();
       result.add(byteString.asReadOnlyByteBuffer());
     }
     return result;
@@ -418,6 +401,12 @@ class RopeByteString extends ByteString {
   }
 
   @Override
+  void writeTo(ByteOutput output) throws IOException {
+    left.writeTo(output);
+    right.writeTo(output);
+  }
+
+  @Override
   protected String toStringInternal(Charset charset) {
     return new String(toByteArray(), charset);
   }
@@ -471,11 +460,10 @@ class RopeByteString extends ByteString {
     // hashCode if it's already computed.  It's arguable we should compute the
     // hashCode here, and if we're going to be testing a bunch of byteStrings,
     // it might even make sense.
-    if (hash != 0) {
-      int cachedOtherHash = otherByteString.peekCachedHashCode();
-      if (cachedOtherHash != 0 && hash != cachedOtherHash) {
-        return false;
-      }
+    int thisHash = peekCachedHashCode();
+    int thatHash = otherByteString.peekCachedHashCode();
+    if (thisHash != 0 && thatHash != 0 && thisHash != thatHash) {
+      return false;
     }
 
     return equalsFragments(otherByteString);
@@ -492,12 +480,12 @@ class RopeByteString extends ByteString {
    */
   private boolean equalsFragments(ByteString other) {
     int thisOffset = 0;
-    Iterator<LiteralByteString> thisIter = new PieceIterator(this);
-    LiteralByteString thisString = thisIter.next();
+    Iterator<LeafByteString> thisIter = new PieceIterator(this);
+    LeafByteString thisString = thisIter.next();
 
     int thatOffset = 0;
-    Iterator<LiteralByteString> thatIter = new PieceIterator(other);
-    LiteralByteString thatString = thatIter.next();
+    Iterator<LeafByteString> thatIter = new PieceIterator(other);
+    LeafByteString thatString = thatIter.next();
 
     int pos = 0;
     while (true) {
@@ -536,33 +524,6 @@ class RopeByteString extends ByteString {
     }
   }
 
-  /**
-   * Cached hash value.  Intentionally accessed via a data race, which is safe
-   * because of the Java Memory Model's "no out-of-thin-air values" guarantees
-   * for ints.
-   */
-  private int hash = 0;
-
-  @Override
-  public int hashCode() {
-    int h = hash;
-
-    if (h == 0) {
-      h = totalLength;
-      h = partialHash(h, 0, totalLength);
-      if (h == 0) {
-        h = 1;
-      }
-      hash = h;
-    }
-    return h;
-  }
-
-  @Override
-  protected int peekCachedHashCode() {
-    return hash;
-  }
-
   @Override
   protected int partialHash(int h, int offset, int length) {
     int toIndex = offset + length;
@@ -714,34 +675,34 @@ class RopeByteString extends ByteString {
    * <p>This iterator is used to implement
    * {@link RopeByteString#equalsFragments(ByteString)}.
    */
-  private static class PieceIterator implements Iterator<LiteralByteString> {
+  private static class PieceIterator implements Iterator<LeafByteString> {
 
     private final Stack<RopeByteString> breadCrumbs =
         new Stack<RopeByteString>();
-    private LiteralByteString next;
+    private LeafByteString next;
 
     private PieceIterator(ByteString root) {
       next = getLeafByLeft(root);
     }
 
-    private LiteralByteString getLeafByLeft(ByteString root) {
+    private LeafByteString getLeafByLeft(ByteString root) {
       ByteString pos = root;
       while (pos instanceof RopeByteString) {
         RopeByteString rbs = (RopeByteString) pos;
         breadCrumbs.push(rbs);
         pos = rbs.left;
       }
-      return (LiteralByteString) pos;
+      return (LeafByteString) pos;
     }
 
-    private LiteralByteString getNextNonEmptyLeaf() {
+    private LeafByteString getNextNonEmptyLeaf() {
       while (true) {
         // Almost always, we go through this loop exactly once.  However, if
         // we discover an empty string in the rope, we toss it and try again.
         if (breadCrumbs.isEmpty()) {
           return null;
         } else {
-          LiteralByteString result = getLeafByLeft(breadCrumbs.pop().right);
+          LeafByteString result = getLeafByLeft(breadCrumbs.pop().right);
           if (!result.isEmpty()) {
             return result;
           }
@@ -749,24 +710,28 @@ class RopeByteString extends ByteString {
       }
     }
 
+    @Override
     public boolean hasNext() {
       return next != null;
     }
 
     /**
-     * Returns the next item and advances one {@code LiteralByteString}.
+     * Returns the next item and advances one
+     * {@link com.google.protobuf.ByteString.LeafByteString}.
      *
-     * @return next non-empty LiteralByteString or {@code null}
+     * @return next non-empty LeafByteString or {@code null}
      */
-    public LiteralByteString next() {
+    @Override
+    public LeafByteString next() {
       if (next == null) {
         throw new NoSuchElementException();
       }
-      LiteralByteString result = next;
+      LeafByteString result = next;
       next = getNextNonEmptyLeaf();
       return result;
     }
 
+    @Override
     public void remove() {
       throw new UnsupportedOperationException();
     }
@@ -778,55 +743,14 @@ class RopeByteString extends ByteString {
   private static final long serialVersionUID = 1L;
 
   Object writeReplace() {
-    return new LiteralByteString(toByteArray());
+    return ByteString.wrap(toByteArray());
   }
 
-  private void readObject(ObjectInputStream in) throws IOException {
+  private void readObject(@SuppressWarnings("unused") ObjectInputStream in) throws IOException {
     throw new InvalidObjectException(
         "RopeByteStream instances are not to be serialized directly");
   }
 
-  // =================================================================
-  // ByteIterator
-
-  @Override
-  public ByteIterator iterator() {
-    return new RopeByteIterator();
-  }
-
-  private class RopeByteIterator implements ByteString.ByteIterator {
-
-    private final PieceIterator pieces;
-    private ByteIterator bytes;
-    int bytesRemaining;
-
-    private RopeByteIterator() {
-      pieces = new PieceIterator(RopeByteString.this);
-      bytes = pieces.next().iterator();
-      bytesRemaining = size();
-    }
-
-    public boolean hasNext() {
-      return (bytesRemaining > 0);
-    }
-
-    public Byte next() {
-      return nextByte(); // Does not instantiate a Byte
-    }
-
-    public byte nextByte() {
-      if (!bytes.hasNext()) {
-        bytes = pieces.next().iterator();
-      }
-      --bytesRemaining;
-      return bytes.nextByte();
-    }
-
-    public void remove() {
-      throw new UnsupportedOperationException();
-    }
-  }
-
   /**
    * This class is the {@link RopeByteString} equivalent for
    * {@link ByteArrayInputStream}.
@@ -835,7 +759,7 @@ class RopeByteString extends ByteString {
     // Iterates through the pieces of the rope
     private PieceIterator pieceIterator;
     // The current piece
-    private LiteralByteString currentPiece;
+    private LeafByteString currentPiece;
     // The size of the current piece
     private int currentPieceSize;
     // The index of the next byte to read in the current piece
@@ -872,7 +796,7 @@ class RopeByteString extends ByteString {
     /**
      * Internal implementation of read and skip.  If b != null, then read the
      * next {@code length} bytes into the buffer {@code b} at
-     * offset {@code offset}.  If b == null, then skip the next {@code length)
+     * offset {@code offset}.  If b == null, then skip the next {@code length}
      * bytes.
      * <p>
      * This method assumes that all error checking has already happened.
diff --git a/java/src/main/java/com/google/protobuf/RpcCallback.java b/java/core/src/main/java/com/google/protobuf/RpcCallback.java
index 10752968..10752968 100644
--- a/java/src/main/java/com/google/protobuf/RpcCallback.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcCallback.java
diff --git a/java/src/main/java/com/google/protobuf/RpcChannel.java b/java/core/src/main/java/com/google/protobuf/RpcChannel.java
index f272f4ad..f272f4ad 100644
--- a/java/src/main/java/com/google/protobuf/RpcChannel.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcChannel.java
diff --git a/java/src/main/java/com/google/protobuf/RpcController.java b/java/core/src/main/java/com/google/protobuf/RpcController.java
index a92dd7be..a92dd7be 100644
--- a/java/src/main/java/com/google/protobuf/RpcController.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcController.java
diff --git a/java/src/main/java/com/google/protobuf/RpcUtil.java b/java/core/src/main/java/com/google/protobuf/RpcUtil.java
index 694b8d13..f7d555ae 100644
--- a/java/src/main/java/com/google/protobuf/RpcUtil.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcUtil.java
@@ -71,6 +71,7 @@ public final class RpcUtil {
       final Class<Type> originalClass,
       final Type defaultInstance) {
     return new RpcCallback<Message>() {
+      @Override
       public void run(final Message parameter) {
         Type typedParameter;
         try {
@@ -107,8 +108,9 @@ public final class RpcUtil {
     return new RpcCallback<ParameterType>() {
       private boolean alreadyCalled = false;
 
+      @Override
       public void run(final ParameterType parameter) {
-        synchronized(this) {
+        synchronized (this) {
           if (alreadyCalled) {
             throw new AlreadyCalledException();
           }
diff --git a/java/src/main/java/com/google/protobuf/Service.java b/java/core/src/main/java/com/google/protobuf/Service.java
index ba7b033e..ba7b033e 100644
--- a/java/src/main/java/com/google/protobuf/Service.java
+++ b/java/core/src/main/java/com/google/protobuf/Service.java
diff --git a/java/src/main/java/com/google/protobuf/ServiceException.java b/java/core/src/main/java/com/google/protobuf/ServiceException.java
index 00d57075..00d57075 100644
--- a/java/src/main/java/com/google/protobuf/ServiceException.java
+++ b/java/core/src/main/java/com/google/protobuf/ServiceException.java
diff --git a/java/src/main/java/com/google/protobuf/SingleFieldBuilder.java b/java/core/src/main/java/com/google/protobuf/SingleFieldBuilder.java
index aba65e32..941b5def 100644
--- a/java/src/main/java/com/google/protobuf/SingleFieldBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/SingleFieldBuilder.java
@@ -234,7 +234,7 @@ public class SingleFieldBuilder
     }
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void markDirty() {
     onChanged();
   }
diff --git a/java/src/main/java/com/google/protobuf/SmallSortedMap.java b/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
index 0674d2e2..409fec10 100644
--- a/java/src/main/java/com/google/protobuf/SmallSortedMap.java
+++ b/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
@@ -35,12 +35,12 @@ import java.util.AbstractSet;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
-import java.util.TreeMap;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.SortedMap;
+import java.util.TreeMap;
 
 /**
  * A custom map implementation from FieldDescriptor to Object optimized to
@@ -411,22 +411,22 @@ class SmallSortedMap<K extends Comparable<K>, V> extends AbstractMap<K, V> {
       this.value = value;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public K getKey() {
       return key;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public V getValue() {
       return value;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public int compareTo(Entry other) {
       return getKey().compareTo(other.getKey());
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public V setValue(V newValue) {
       checkMutable();
       final V oldValue = this.value;
@@ -535,13 +535,13 @@ class SmallSortedMap<K extends Comparable<K>, V> extends AbstractMap<K, V> {
     private boolean nextCalledBeforeRemove;
     private Iterator<Map.Entry<K, V>> lazyOverflowIterator;
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean hasNext() {
       return (pos + 1) < entryList.size() ||
           getOverflowIterator().hasNext();
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Map.Entry<K, V> next() {
       nextCalledBeforeRemove = true;
       // Always increment pos so that we know whether the last returned value
@@ -552,7 +552,7 @@ class SmallSortedMap<K extends Comparable<K>, V> extends AbstractMap<K, V> {
       return getOverflowIterator().next();
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public void remove() {
       if (!nextCalledBeforeRemove) {
         throw new IllegalStateException("remove() was called before next()");
@@ -588,31 +588,83 @@ class SmallSortedMap<K extends Comparable<K>, V> extends AbstractMap<K, V> {
    */
   private static class EmptySet {
 
-    private static final Iterator<Object> ITERATOR = new Iterator<Object>() {
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
-      public boolean hasNext() {
-        return false;
-      }
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
-      public Object next() {
-        throw new NoSuchElementException();
-      }
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
-      public void remove() {
-        throw new UnsupportedOperationException();
-      }
-    };
+    private static final Iterator<Object> ITERATOR =
+        new Iterator<Object>() {
+          @Override
+          public boolean hasNext() {
+            return false;
+          }
+          @Override
+          public Object next() {
+            throw new NoSuchElementException();
+          }
+          @Override
+          public void remove() {
+            throw new UnsupportedOperationException();
+          }
+        };
 
-    private static final Iterable<Object> ITERABLE = new Iterable<Object>() {
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
-      public Iterator<Object> iterator() {
-        return ITERATOR;
-      }
-    };
+    private static final Iterable<Object> ITERABLE =
+        new Iterable<Object>() {
+          @Override
+          public Iterator<Object> iterator() {
+            return ITERATOR;
+          }
+        };
 
     @SuppressWarnings("unchecked")
     static <T> Iterable<T> iterable() {
       return (Iterable<T>) ITERABLE;
     }
   }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    
+    if (!(o instanceof SmallSortedMap)) {
+      return super.equals(o);
+    }
+    
+    SmallSortedMap<?, ?> other = (SmallSortedMap<?, ?>) o;
+    final int size = size();
+    if (size != other.size()) {
+      return false;
+    }
+    
+    // Best effort try to avoid allocating an entry set.
+    final int numArrayEntries = getNumArrayEntries();
+    if (numArrayEntries != other.getNumArrayEntries()) {
+      return entrySet().equals(other.entrySet());
+    }
+    
+    for (int i = 0; i < numArrayEntries; i++) {
+      if (!getArrayEntryAt(i).equals(other.getArrayEntryAt(i))) {
+        return false;
+      }
+    }
+    
+    if (numArrayEntries != size) {
+      return overflowEntries.equals(other.overflowEntries);
+    }
+    
+    
+    return true;
+  }
+  
+  @Override
+  public int hashCode() {
+    int h = 0;
+    final int listSize = getNumArrayEntries();
+    for (int i = 0; i < listSize; i++) {
+      h += entryList.get(i).hashCode();
+    }
+    // Avoid the iterator allocation if possible.
+    if (getNumOverflowEntries() > 0) {
+      h += overflowEntries.hashCode();
+    }
+    return h;
+  }
 }
diff --git a/java/src/main/java/com/google/protobuf/TextFormat.java b/java/core/src/main/java/com/google/protobuf/TextFormat.java
index 44d036c1..c1c328fc 100644
--- a/java/src/main/java/com/google/protobuf/TextFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/TextFormat.java
@@ -425,7 +425,7 @@ public final class TextFormat {
         case STRING:
           generator.print("\"");
           generator.print(escapeNonAscii
-              ? escapeText((String) value)
+              ? TextFormatEscaper.escapeText((String) value)
               : escapeDoubleQuotesAndBackslashes((String) value)
                   .replace("\n", "\\n"));
           generator.print("\"");
@@ -661,6 +661,14 @@ public final class TextFormat {
       nextToken();
     }
 
+    int getLine() {
+      return line;
+    }
+
+    int getColumn() {
+      return column;
+    }
+
     /** Are we at the end of the input? */
     public boolean atEnd() {
       return currentToken.length() == 0;
@@ -957,11 +965,13 @@ public final class TextFormat {
      */
     public boolean consumeBoolean() throws ParseException {
       if (currentToken.equals("true")
+          || currentToken.equals("True")
           || currentToken.equals("t")
           || currentToken.equals("1")) {
         nextToken();
         return true;
       } else if (currentToken.equals("false")
+          || currentToken.equals("False")
           || currentToken.equals("f")
           || currentToken.equals("0")) {
         nextToken();
@@ -1074,6 +1084,18 @@ public final class TextFormat {
     private ParseException floatParseException(final NumberFormatException e) {
       return parseException("Couldn't parse number: " + e.getMessage());
     }
+
+    /**
+     * Returns a {@link UnknownFieldParseException} with the line and column
+     * numbers of the previous token in the description, and the unknown field
+     * name, suitable for throwing.
+     */
+    public UnknownFieldParseException unknownFieldParseExceptionPreviousToken(
+        final String unknownField, final String description) {
+      // Note:  People generally prefer one-based line and column numbers.
+      return new UnknownFieldParseException(
+        previousLine + 1, previousColumn + 1, unknownField, description);
+    }
   }
 
   /** Thrown when parsing an invalid text format message. */
@@ -1122,6 +1144,45 @@ public final class TextFormat {
     }
   }
 
+  /**
+   * Thrown when encountering an unknown field while parsing
+   * a text format message.
+   */
+  public static class UnknownFieldParseException extends ParseException {
+    private final String unknownField;
+
+    /**
+     * Create a new instance, with -1 as the line and column numbers, and an
+     * empty unknown field name.
+     */
+    public UnknownFieldParseException(final String message) {
+      this(-1, -1, "", message);
+    }
+
+    /**
+     * Create a new instance
+     *
+     * @param line the line number where the parse error occurred,
+     * using 1-offset.
+     * @param column the column number where the parser error occurred,
+     * using 1-offset.
+     * @param unknownField the name of the unknown field found while parsing.
+     */
+    public UnknownFieldParseException(final int line, final int column,
+        final String unknownField, final String message) {
+      super(line, column, message);
+      this.unknownField = unknownField;
+    }
+
+    /**
+     * Return the name of the unknown field encountered while parsing the
+     * protocol buffer string.
+     */
+    public String getUnknownField() {
+      return unknownField;
+    }
+  }
+
   private static final Parser PARSER = Parser.newBuilder().build();
 
   /**
@@ -1206,11 +1267,14 @@ public final class TextFormat {
 
     private final boolean allowUnknownFields;
     private final SingularOverwritePolicy singularOverwritePolicy;
+    private TextFormatParseInfoTree.Builder parseInfoTreeBuilder;
 
-    private Parser(boolean allowUnknownFields,
-        SingularOverwritePolicy singularOverwritePolicy) {
+    private Parser(
+        boolean allowUnknownFields, SingularOverwritePolicy singularOverwritePolicy,
+        TextFormatParseInfoTree.Builder parseInfoTreeBuilder) {
       this.allowUnknownFields = allowUnknownFields;
       this.singularOverwritePolicy = singularOverwritePolicy;
+      this.parseInfoTreeBuilder = parseInfoTreeBuilder;
     }
 
     /**
@@ -1227,6 +1291,7 @@ public final class TextFormat {
       private boolean allowUnknownFields = false;
       private SingularOverwritePolicy singularOverwritePolicy =
           SingularOverwritePolicy.ALLOW_SINGULAR_OVERWRITES;
+      private TextFormatParseInfoTree.Builder parseInfoTreeBuilder = null;
 
 
       /**
@@ -1237,8 +1302,15 @@ public final class TextFormat {
         return this;
       }
 
+      public Builder setParseInfoTreeBuilder(
+          TextFormatParseInfoTree.Builder parseInfoTreeBuilder) {
+        this.parseInfoTreeBuilder = parseInfoTreeBuilder;
+        return this;
+      }
+
       public Parser build() {
-        return new Parser(allowUnknownFields, singularOverwritePolicy);
+        return new Parser(
+            allowUnknownFields, singularOverwritePolicy, parseInfoTreeBuilder);
       }
     }
 
@@ -1329,7 +1401,21 @@ public final class TextFormat {
                             final ExtensionRegistry extensionRegistry,
                             final MessageReflection.MergeTarget target)
                             throws ParseException {
+      mergeField(tokenizer, extensionRegistry, target, parseInfoTreeBuilder);
+    }
+
+    /**
+     * Parse a single field from {@code tokenizer} and merge it into
+     * {@code builder}.
+     */
+    private void mergeField(final Tokenizer tokenizer,
+                            final ExtensionRegistry extensionRegistry,
+                            final MessageReflection.MergeTarget target,
+                            TextFormatParseInfoTree.Builder parseTreeBuilder)
+                            throws ParseException {
       FieldDescriptor field = null;
+      int startLine = tokenizer.getLine();
+      int startColumn = tokenizer.getColumn();
       final Descriptor type = target.getDescriptorForType();
       ExtensionRegistry.ExtensionInfo extension = null;
 
@@ -1388,7 +1474,8 @@ public final class TextFormat {
 
         if (field == null) {
           if (!allowUnknownFields) {
-            throw tokenizer.parseExceptionPreviousToken(
+            throw tokenizer.unknownFieldParseExceptionPreviousToken(
+              name,
               "Message type \"" + type.getFullName()
               + "\" has no field named \"" + name + "\".");
           } else {
@@ -1420,14 +1507,51 @@ public final class TextFormat {
       // Handle potential ':'.
       if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
         tokenizer.tryConsume(":");  // optional
+        if (parseTreeBuilder != null) {
+          TextFormatParseInfoTree.Builder childParseTreeBuilder =
+              parseTreeBuilder.getBuilderForSubMessageField(field);
+          consumeFieldValues(tokenizer, extensionRegistry, target, field, extension,
+              childParseTreeBuilder);
+        } else {
+          consumeFieldValues(tokenizer, extensionRegistry, target, field, extension,
+              parseTreeBuilder);
+        }
       } else {
         tokenizer.consume(":");  // required
+        consumeFieldValues(
+            tokenizer, extensionRegistry, target, field, extension, parseTreeBuilder);
+      }
+
+      if (parseTreeBuilder != null) {
+        parseTreeBuilder.setLocation(
+            field, TextFormatParseLocation.create(startLine, startColumn));
+      }
+
+      // For historical reasons, fields may optionally be separated by commas or
+      // semicolons.
+      if (!tokenizer.tryConsume(";")) {
+        tokenizer.tryConsume(",");
       }
+    }
+
+    /**
+     * Parse a one or more field values from {@code tokenizer} and merge it into
+     * {@code builder}.
+     */
+    private void consumeFieldValues(
+        final Tokenizer tokenizer,
+        final ExtensionRegistry extensionRegistry,
+        final MessageReflection.MergeTarget target,
+        final FieldDescriptor field,
+        final ExtensionRegistry.ExtensionInfo extension,
+        final TextFormatParseInfoTree.Builder parseTreeBuilder)
+        throws ParseException {
       // Support specifying repeated field values as a comma-separated list.
       // Ex."foo: [1, 2, 3]"
       if (field.isRepeated() && tokenizer.tryConsume("[")) {
         while (true) {
-          consumeFieldValue(tokenizer, extensionRegistry, target, field, extension);
+          consumeFieldValue(tokenizer, extensionRegistry, target, field, extension,
+              parseTreeBuilder);
           if (tokenizer.tryConsume("]")) {
             // End of list.
             break;
@@ -1435,13 +1559,8 @@ public final class TextFormat {
           tokenizer.consume(",");
         }
       } else {
-        consumeFieldValue(tokenizer, extensionRegistry, target, field, extension);
-      }
-
-      // For historical reasons, fields may optionally be separated by commas or
-      // semicolons.
-      if (!tokenizer.tryConsume(";")) {
-        tokenizer.tryConsume(",");
+        consumeFieldValue(
+            tokenizer, extensionRegistry, target, field, extension, parseTreeBuilder);
       }
     }
 
@@ -1454,7 +1573,8 @@ public final class TextFormat {
         final ExtensionRegistry extensionRegistry,
         final MessageReflection.MergeTarget target,
         final FieldDescriptor field,
-        final ExtensionRegistry.ExtensionInfo extension)
+        final ExtensionRegistry.ExtensionInfo extension,
+        final TextFormatParseInfoTree.Builder parseTreeBuilder)
         throws ParseException {
       Object value = null;
 
@@ -1476,7 +1596,7 @@ public final class TextFormat {
             throw tokenizer.parseException(
               "Expected \"" + endToken + "\".");
           }
-          mergeField(tokenizer, extensionRegistry, subField);
+          mergeField(tokenizer, extensionRegistry, subField, parseTreeBuilder);
         }
 
         value = subField.finish();
@@ -1652,11 +1772,6 @@ public final class TextFormat {
   // Some of these methods are package-private because Descriptors.java uses
   // them.
 
-  private interface ByteSequence {
-    int size();
-    byte byteAt(int offset);
-  }
-
   /**
    * Escapes bytes in the format used in protocol buffer text format, which
    * is the same as the format used for C string literals.  All bytes
@@ -1665,74 +1780,15 @@ public final class TextFormat {
    * which no defined short-hand escape sequence is defined will be escaped
    * using 3-digit octal sequences.
    */
-  public static String escapeBytes(final ByteSequence input) {
-    final StringBuilder builder = new StringBuilder(input.size());
-    for (int i = 0; i < input.size(); i++) {
-      final byte b = input.byteAt(i);
-      switch (b) {
-        // Java does not recognize \a or \v, apparently.
-        case 0x07: builder.append("\\a"); break;
-        case '\b': builder.append("\\b"); break;
-        case '\f': builder.append("\\f"); break;
-        case '\n': builder.append("\\n"); break;
-        case '\r': builder.append("\\r"); break;
-        case '\t': builder.append("\\t"); break;
-        case 0x0b: builder.append("\\v"); break;
-        case '\\': builder.append("\\\\"); break;
-        case '\'': builder.append("\\\'"); break;
-        case '"' : builder.append("\\\""); break;
-        default:
-          // Only ASCII characters between 0x20 (space) and 0x7e (tilde) are
-          // printable.  Other byte values must be escaped.
-          if (b >= 0x20 && b <= 0x7e) {
-            builder.append((char) b);
-          } else {
-            builder.append('\\');
-            builder.append((char) ('0' + ((b >>> 6) & 3)));
-            builder.append((char) ('0' + ((b >>> 3) & 7)));
-            builder.append((char) ('0' + (b & 7)));
-          }
-          break;
-      }
-    }
-    return builder.toString();
-  }
-
-  /**
-   * Escapes bytes in the format used in protocol buffer text format, which
-   * is the same as the format used for C string literals.  All bytes
-   * that are not printable 7-bit ASCII characters are escaped, as well as
-   * backslash, single-quote, and double-quote characters.  Characters for
-   * which no defined short-hand escape sequence is defined will be escaped
-   * using 3-digit octal sequences.
-   */
-  public static String escapeBytes(final ByteString input) {
-    return escapeBytes(new ByteSequence() {
-      @Override
-      public int size() {
-        return input.size();
-      }
-      @Override
-      public byte byteAt(int offset) {
-        return input.byteAt(offset);
-      }
-    });
+  public static String escapeBytes(ByteString input) {
+    return TextFormatEscaper.escapeBytes(input);
   }
 
   /**
    * Like {@link #escapeBytes(ByteString)}, but used for byte array.
    */
-  public static String escapeBytes(final byte[] input) {
-    return escapeBytes(new ByteSequence() {
-      @Override
-      public int size() {
-        return input.length;
-      }
-      @Override
-      public byte byteAt(int offset) {
-        return input[offset];
-      }
-    });
+  public static String escapeBytes(byte[] input) {
+    return TextFormatEscaper.escapeBytes(input);
   }
 
   /**
@@ -1816,7 +1872,9 @@ public final class TextFormat {
       }
     }
 
-    return ByteString.copyFrom(result, 0, pos);
+    return result.length == pos
+        ? ByteString.wrap(result)  // This reference has not been out of our control.
+        : ByteString.copyFrom(result, 0, pos);
   }
 
   /**
@@ -1844,7 +1902,7 @@ public final class TextFormat {
    * Escape double quotes and backslashes in a String for unicode output of a message.
    */
   public static String escapeDoubleQuotesAndBackslashes(final String input) {
-    return input.replace("\\", "\\\\").replace("\"", "\\\"");
+    return TextFormatEscaper.escapeDoubleQuotesAndBackslashes(input);
   }
 
   /**
diff --git a/java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java b/java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java
new file mode 100644
index 00000000..da9ceadd
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java
@@ -0,0 +1,137 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+/**
+ * Provide text format escaping support for proto2 instances.
+ */
+final class TextFormatEscaper {
+  private TextFormatEscaper() {}
+
+  private interface ByteSequence {
+    int size();
+    byte byteAt(int offset);
+  }
+
+  /**
+   * Escapes bytes in the format used in protocol buffer text format, which
+   * is the same as the format used for C string literals.  All bytes
+   * that are not printable 7-bit ASCII characters are escaped, as well as
+   * backslash, single-quote, and double-quote characters.  Characters for
+   * which no defined short-hand escape sequence is defined will be escaped
+   * using 3-digit octal sequences.
+   */
+  static String escapeBytes(final ByteSequence input) {
+    final StringBuilder builder = new StringBuilder(input.size());
+    for (int i = 0; i < input.size(); i++) {
+      final byte b = input.byteAt(i);
+      switch (b) {
+        // Java does not recognize \a or \v, apparently.
+        case 0x07: builder.append("\\a"); break;
+        case '\b': builder.append("\\b"); break;
+        case '\f': builder.append("\\f"); break;
+        case '\n': builder.append("\\n"); break;
+        case '\r': builder.append("\\r"); break;
+        case '\t': builder.append("\\t"); break;
+        case 0x0b: builder.append("\\v"); break;
+        case '\\': builder.append("\\\\"); break;
+        case '\'': builder.append("\\\'"); break;
+        case '"' : builder.append("\\\""); break;
+        default:
+          // Only ASCII characters between 0x20 (space) and 0x7e (tilde) are
+          // printable.  Other byte values must be escaped.
+          if (b >= 0x20 && b <= 0x7e) {
+            builder.append((char) b);
+          } else {
+            builder.append('\\');
+            builder.append((char) ('0' + ((b >>> 6) & 3)));
+            builder.append((char) ('0' + ((b >>> 3) & 7)));
+            builder.append((char) ('0' + (b & 7)));
+          }
+          break;
+      }
+    }
+    return builder.toString();
+  }
+
+  /**
+   * Escapes bytes in the format used in protocol buffer text format, which
+   * is the same as the format used for C string literals.  All bytes
+   * that are not printable 7-bit ASCII characters are escaped, as well as
+   * backslash, single-quote, and double-quote characters.  Characters for
+   * which no defined short-hand escape sequence is defined will be escaped
+   * using 3-digit octal sequences.
+   */
+  static String escapeBytes(final ByteString input) {
+    return escapeBytes(new ByteSequence() {
+      @Override
+      public int size() {
+        return input.size();
+      }
+      @Override
+      public byte byteAt(int offset) {
+        return input.byteAt(offset);
+      }
+    });
+  }
+
+  /**
+   * Like {@link #escapeBytes(ByteString)}, but used for byte array.
+   */
+  static String escapeBytes(final byte[] input) {
+    return escapeBytes(new ByteSequence() {
+      @Override
+      public int size() {
+        return input.length;
+      }
+      @Override
+      public byte byteAt(int offset) {
+        return input[offset];
+      }
+    });
+  }
+
+  /**
+   * Like {@link #escapeBytes(ByteString)}, but escapes a text string.
+   * Non-ASCII characters are first encoded as UTF-8, then each byte is escaped
+   * individually as a 3-digit octal escape.  Yes, it's weird.
+   */
+  static String escapeText(final String input) {
+    return escapeBytes(ByteString.copyFromUtf8(input));
+  }
+
+  /**
+   * Escape double quotes and backslashes in a String for unicode output of a message.
+   */
+  static String escapeDoubleQuotesAndBackslashes(final String input) {
+    return input.replace("\\", "\\\\").replace("\"", "\\\"");
+  }
+}
diff --git a/java/core/src/main/java/com/google/protobuf/TextFormatParseInfoTree.java b/java/core/src/main/java/com/google/protobuf/TextFormatParseInfoTree.java
new file mode 100644
index 00000000..2ecf912e
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/TextFormatParseInfoTree.java
@@ -0,0 +1,225 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.FieldDescriptor;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+
+/**
+ * Data structure which is populated with the locations of each field value parsed from the text.
+ *
+ * <p>The locations of primary fields values are retrieved by {@code getLocation} or
+ * {@code getLocations}.  The locations of sub message values are within nested
+ * {@code TextFormatParseInfoTree}s and are retrieve by {@getNestedTree} or {code @getNestedTrees}.
+ *
+ * <p>The {@code TextFormatParseInfoTree} is created by a Builder.
+ */
+public class TextFormatParseInfoTree {
+
+  // Defines a mapping between each field's descriptor to the list of locations where
+  // its value(s) were was encountered.
+  private Map<FieldDescriptor, List<TextFormatParseLocation>> locationsFromField;
+
+  // Defines a mapping between a field's descriptor to a list of TextFormatParseInfoTrees for
+  // sub message location information.
+  Map<FieldDescriptor, List<TextFormatParseInfoTree>> subtreesFromField;
+
+  /**
+   * Construct a {@code TextFormatParseInfoTree}.
+   *
+   * @param locationsFromField a map of fields to location in the source code
+   * @param subtreeBuildersFromField a map of fields to parse tree location information builders
+   */
+  private TextFormatParseInfoTree(
+      Map<FieldDescriptor, List<TextFormatParseLocation>> locationsFromField,
+      Map<FieldDescriptor, List<TextFormatParseInfoTree.Builder>> subtreeBuildersFromField) {
+
+    // The maps are unmodifiable.  The values in the maps are unmodifiable.
+    Map<FieldDescriptor, List<TextFormatParseLocation>> locs =
+        new HashMap<FieldDescriptor, List<TextFormatParseLocation>>();
+    for (Entry<FieldDescriptor, List<TextFormatParseLocation>> kv : locationsFromField.entrySet()) {
+      locs.put(kv.getKey(), Collections.unmodifiableList(kv.getValue()));
+    }
+    this.locationsFromField = Collections.unmodifiableMap(locs);
+
+    Map<FieldDescriptor, List<TextFormatParseInfoTree>> subs =
+        new HashMap<FieldDescriptor, List<TextFormatParseInfoTree>>();
+    for (Entry<FieldDescriptor, List<Builder>> kv : subtreeBuildersFromField.entrySet()) {
+      List<TextFormatParseInfoTree> submessagesOfField = new ArrayList<TextFormatParseInfoTree>();
+      for (Builder subBuilder : kv.getValue()) {
+        submessagesOfField.add(subBuilder.build());
+      }
+      subs.put(kv.getKey(), Collections.unmodifiableList(submessagesOfField));
+    }
+    this.subtreesFromField = Collections.unmodifiableMap(subs);
+  }
+
+ /**
+  * Retrieve all the locations of a field.
+  *
+  * @param fieldDescriptor the the @{link FieldDescriptor} of the desired field
+  * @return a list of the locations of values of the field.  If there are not values
+  *         or the field doesn't exist, an empty list is returned.
+  */
+  public List<TextFormatParseLocation> getLocations(final FieldDescriptor fieldDescriptor) {
+    List<TextFormatParseLocation> result = locationsFromField.get(fieldDescriptor);
+    return (result == null) ? Collections.<TextFormatParseLocation>emptyList() : result;
+  }
+
+  /**
+   * Get the location in the source of a field's value.
+   *
+   * <p>Returns the {@link TextFormatParseLocation} for index-th value of the field in the parsed
+   * text.
+   *
+   * @param fieldDescriptor the @{link FieldDescriptor} of the desired field
+   * @param index the index of the value.
+   * @return the {@link TextFormatParseLocation} of the value
+   * @throws IllegalArgumentException index is out of range
+   */
+  public TextFormatParseLocation getLocation(final FieldDescriptor fieldDescriptor, int index) {
+    return getFromList(getLocations(fieldDescriptor), index, fieldDescriptor);
+  }
+
+  /**
+   * Retrieve a list of all the location information trees for a sub message field.
+   *
+   * @param fieldDescriptor the @{link FieldDescriptor} of the desired field
+   * @return A list of {@link TextFormatParseInfoTree}
+   */
+  public List<TextFormatParseInfoTree> getNestedTrees(final FieldDescriptor fieldDescriptor) {
+    List<TextFormatParseInfoTree> result = subtreesFromField.get(fieldDescriptor);
+    return result == null ? Collections.<TextFormatParseInfoTree>emptyList() : result;
+  }
+
+  /**
+   * Returns the parse info tree for the given field, which must be a message type.
+   *
+   * @param fieldDescriptor the @{link FieldDescriptor} of the desired sub message
+   * @param index the index of message value.
+   * @return the {@code ParseInfoTree} of the message value. {@code null} is returned if the field
+   *         doesn't exist or the index is out of range.
+   * @throws IllegalArgumentException if index is out of range
+   */
+  public TextFormatParseInfoTree getNestedTree(final FieldDescriptor fieldDescriptor, int index) {
+    return getFromList(getNestedTrees(fieldDescriptor), index, fieldDescriptor);
+  }
+
+  /**
+   * Create a builder for a {@code ParseInfoTree}.
+   *
+   * @return the builder
+   */
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  private static <T> T getFromList(List<T> list, int index, FieldDescriptor fieldDescriptor) {
+    if (index >= list.size() || index < 0)  {
+      throw new IllegalArgumentException(String.format("Illegal index field: %s, index %d",
+          fieldDescriptor == null ? "<null>" : fieldDescriptor.getName(), index));
+    }
+    return list.get(index);
+  }
+
+  /**
+   * Builder for a {@link TextFormatParseInfoTree}.
+   */
+  public static class Builder {
+
+    private Map<FieldDescriptor, List<TextFormatParseLocation>> locationsFromField;
+
+    // Defines a mapping between a field's descriptor to a list of ParseInfoTrees builders for
+    // sub message location information.
+    private Map<FieldDescriptor, List<Builder>> subtreeBuildersFromField;
+
+     /**
+     * Create a root level {@ParseInfoTree} builder.
+     */
+    private Builder() {
+      locationsFromField = new HashMap<FieldDescriptor, List<TextFormatParseLocation>>();
+      subtreeBuildersFromField = new HashMap<FieldDescriptor, List<Builder>>();
+    }
+
+    /**
+     * Record the starting location of a single value for a field.
+     *
+     * @param fieldDescriptor the field
+     * @param location source code location information
+     */
+    public Builder setLocation(
+        final FieldDescriptor fieldDescriptor, TextFormatParseLocation location) {
+      List<TextFormatParseLocation> fieldLocations = locationsFromField.get(fieldDescriptor);
+      if (fieldLocations == null) {
+        fieldLocations = new ArrayList<TextFormatParseLocation>();
+        locationsFromField.put(fieldDescriptor, fieldLocations);
+      }
+      fieldLocations.add(location);
+      return this;
+    }
+
+    /**
+     * Set for a sub message.
+     *
+     * <p>A new builder is created for a sub message. The builder that is returned is a new builder.
+     * The return is <emph>not</emph> the invoked {@code builder.getBuilderForSubMessageField}.
+     *
+     * @param fieldDescriptor the field whose value is the submessage
+     * @return a new Builder for the sub message
+     */
+    public Builder getBuilderForSubMessageField(final FieldDescriptor fieldDescriptor) {
+      List<Builder> submessageBuilders = subtreeBuildersFromField.get(fieldDescriptor);
+      if (submessageBuilders == null) {
+        submessageBuilders = new ArrayList<Builder>();
+        subtreeBuildersFromField.put(fieldDescriptor, submessageBuilders);
+      }
+      Builder subtreeBuilder = new Builder();
+      submessageBuilders.add(subtreeBuilder);
+      return subtreeBuilder;
+    }
+
+    /**
+     * Build the {@code TextFormatParseInfoTree}.
+     *
+     * @return the {@code TextFormatParseInfoTree}
+     */
+    public TextFormatParseInfoTree build() {
+      return new TextFormatParseInfoTree(locationsFromField, subtreeBuildersFromField);
+    }
+  }
+}
diff --git a/java/core/src/main/java/com/google/protobuf/TextFormatParseLocation.java b/java/core/src/main/java/com/google/protobuf/TextFormatParseLocation.java
new file mode 100644
index 00000000..cce286e1
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/TextFormatParseLocation.java
@@ -0,0 +1,104 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.util.Arrays;
+
+/**
+ * A location in the source code.
+ *
+ * <p>A location is the starting line number and starting column number.
+ */
+public final class TextFormatParseLocation {
+
+  /**
+   * The empty location.
+   */
+  public static final TextFormatParseLocation EMPTY = new TextFormatParseLocation(-1, -1);
+
+  /**
+   * Create a location.
+   *
+   * @param line the starting line number
+   * @param column the starting column number
+   * @return a {@code ParseLocation}
+   */
+  static TextFormatParseLocation create(int line, int column) {
+    if (line == -1 && column == -1) {
+      return EMPTY;
+    }
+    if (line < 0 || column < 0) {
+      throw new IllegalArgumentException(
+          String.format("line and column values must be >= 0: line %d, column: %d", line, column));
+    }
+    return new TextFormatParseLocation(line, column);
+  }
+
+  private final int line;
+  private final int column;
+
+  private TextFormatParseLocation(int line, int column) {
+    this.line = line;
+    this.column = column;
+  }
+
+  public int getLine() {
+    return line;
+  }
+
+  public int getColumn() {
+    return column;
+  }
+
+  @Override
+  public String toString() {
+    return String.format("ParseLocation{line=%d, column=%d}", line, column);
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof TextFormatParseLocation)) {
+      return false;
+    }
+    TextFormatParseLocation that = (TextFormatParseLocation) o;
+    return (this.line == that.getLine())
+         && (this.column == that.getColumn());
+  }
+
+  @Override
+  public int hashCode() {
+    int[] values = {line, column};
+    return Arrays.hashCode(values);
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/UninitializedMessageException.java b/java/core/src/main/java/com/google/protobuf/UninitializedMessageException.java
index 5714c063..5714c063 100644
--- a/java/src/main/java/com/google/protobuf/UninitializedMessageException.java
+++ b/java/core/src/main/java/com/google/protobuf/UninitializedMessageException.java
diff --git a/java/src/main/java/com/google/protobuf/UnknownFieldSet.java b/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
index 7cd2250e..c906420d 100644
--- a/java/src/main/java/com/google/protobuf/UnknownFieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
@@ -76,6 +76,7 @@ public final class UnknownFieldSet implements MessageLite {
   public static UnknownFieldSet getDefaultInstance() {
     return defaultInstance;
   }
+  @Override
   public UnknownFieldSet getDefaultInstanceForType() {
     return defaultInstance;
   }
@@ -126,6 +127,7 @@ public final class UnknownFieldSet implements MessageLite {
   }
 
   /** Serializes the set and writes it to {@code output}. */
+  @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
     for (final Map.Entry<Integer, Field> entry : fields.entrySet()) {
       entry.getValue().writeTo(entry.getKey(), output);
@@ -146,6 +148,7 @@ public final class UnknownFieldSet implements MessageLite {
    * Serializes the message to a {@code ByteString} and returns it. This is
    * just a trivial wrapper around {@link #writeTo(CodedOutputStream)}.
    */
+  @Override
   public ByteString toByteString() {
     try {
       final ByteString.CodedBuilder out =
@@ -163,6 +166,7 @@ public final class UnknownFieldSet implements MessageLite {
    * Serializes the message to a {@code byte} array and returns it.  This is
    * just a trivial wrapper around {@link #writeTo(CodedOutputStream)}.
    */
+  @Override
   public byte[] toByteArray() {
     try {
       final byte[] result = new byte[getSerializedSize()];
@@ -181,12 +185,14 @@ public final class UnknownFieldSet implements MessageLite {
    * Serializes the message and writes it to {@code output}.  This is just a
    * trivial wrapper around {@link #writeTo(CodedOutputStream)}.
    */
+  @Override
   public void writeTo(final OutputStream output) throws IOException {
     final CodedOutputStream codedOutput = CodedOutputStream.newInstance(output);
     writeTo(codedOutput);
     codedOutput.flush();
   }
 
+  @Override
   public void writeDelimitedTo(OutputStream output) throws IOException {
     final CodedOutputStream codedOutput = CodedOutputStream.newInstance(output);
     codedOutput.writeRawVarint32(getSerializedSize());
@@ -195,6 +201,7 @@ public final class UnknownFieldSet implements MessageLite {
   }
 
   /** Get the number of bytes required to encode this set. */
+  @Override
   public int getSerializedSize() {
     int result = 0;
     for (final Map.Entry<Integer, Field> entry : fields.entrySet()) {
@@ -228,6 +235,7 @@ public final class UnknownFieldSet implements MessageLite {
     return result;
   }
 
+  @Override
   public boolean isInitialized() {
     // UnknownFieldSets do not have required fields, so they are always
     // initialized.
@@ -258,10 +266,12 @@ public final class UnknownFieldSet implements MessageLite {
     return newBuilder().mergeFrom(input).build();
   }
 
+  @Override
   public Builder newBuilderForType() {
     return newBuilder();
   }
 
+  @Override
   public Builder toBuilder() {
     return newBuilder().mergeFrom(this);
   }
@@ -329,6 +339,7 @@ public final class UnknownFieldSet implements MessageLite {
      * in undefined behavior and can cause a {@code NullPointerException} to be
      * thrown.
      */
+    @Override
     public UnknownFieldSet build() {
       getFieldBuilder(0);  // Force lastField to be built.
       final UnknownFieldSet result;
@@ -341,6 +352,7 @@ public final class UnknownFieldSet implements MessageLite {
       return result;
     }
 
+    @Override
     public UnknownFieldSet buildPartial() {
       // No required fields, so this is the same as build().
       return build();
@@ -353,6 +365,7 @@ public final class UnknownFieldSet implements MessageLite {
           new UnknownFieldSet(fields));
     }
 
+    @Override
     public UnknownFieldSet getDefaultInstanceForType() {
       return UnknownFieldSet.getDefaultInstance();
     }
@@ -364,6 +377,7 @@ public final class UnknownFieldSet implements MessageLite {
     }
 
     /** Reset the builder to an empty set. */
+    @Override
     public Builder clear() {
       reinitialize();
       return this;
@@ -487,6 +501,7 @@ public final class UnknownFieldSet implements MessageLite {
      * Parse an entire message from {@code input} and merge its fields into
      * this set.
      */
+    @Override
     public Builder mergeFrom(final CodedInputStream input) throws IOException {
       while (true) {
         final int tag = input.readTag();
@@ -536,8 +551,8 @@ public final class UnknownFieldSet implements MessageLite {
      * set being built.  This is just a small wrapper around
      * {@link #mergeFrom(CodedInputStream)}.
      */
-    public Builder mergeFrom(final ByteString data)
-        throws InvalidProtocolBufferException {
+    @Override
+    public Builder mergeFrom(final ByteString data) throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input = data.newCodedInput();
         mergeFrom(input);
@@ -557,8 +572,8 @@ public final class UnknownFieldSet implements MessageLite {
      * set being built.  This is just a small wrapper around
      * {@link #mergeFrom(CodedInputStream)}.
      */
-    public Builder mergeFrom(final byte[] data)
-        throws InvalidProtocolBufferException {
+    @Override
+    public Builder mergeFrom(final byte[] data) throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input = CodedInputStream.newInstance(data);
         mergeFrom(input);
@@ -578,6 +593,7 @@ public final class UnknownFieldSet implements MessageLite {
      * set being built.  This is just a small wrapper around
      * {@link #mergeFrom(CodedInputStream)}.
      */
+    @Override
     public Builder mergeFrom(final InputStream input) throws IOException {
       final CodedInputStream codedInput = CodedInputStream.newInstance(input);
       mergeFrom(codedInput);
@@ -585,8 +601,8 @@ public final class UnknownFieldSet implements MessageLite {
       return this;
     }
 
-    public boolean mergeDelimitedFrom(InputStream input)
-        throws IOException {
+    @Override
+    public boolean mergeDelimitedFrom(InputStream input) throws IOException {
       final int firstByte = input.read();
       if (firstByte == -1) {
         return false;
@@ -597,30 +613,29 @@ public final class UnknownFieldSet implements MessageLite {
       return true;
     }
 
-    public boolean mergeDelimitedFrom(
-        InputStream input,
-        ExtensionRegistryLite extensionRegistry) throws IOException {
+    @Override
+    public boolean mergeDelimitedFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException {
       // UnknownFieldSet has no extensions.
       return mergeDelimitedFrom(input);
     }
 
-    public Builder mergeFrom(
-        CodedInputStream input,
-        ExtensionRegistryLite extensionRegistry) throws IOException {
+    @Override
+    public Builder mergeFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException {
       // UnknownFieldSet has no extensions.
       return mergeFrom(input);
     }
 
-    public Builder mergeFrom(
-        ByteString data,
-        ExtensionRegistryLite extensionRegistry)
+    @Override
+    public Builder mergeFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       // UnknownFieldSet has no extensions.
       return mergeFrom(data);
     }
 
-    public Builder mergeFrom(byte[] data, int off, int len)
-        throws InvalidProtocolBufferException {
+    @Override
+    public Builder mergeFrom(byte[] data, int off, int len) throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input =
             CodedInputStream.newInstance(data, off, len);
@@ -636,29 +651,37 @@ public final class UnknownFieldSet implements MessageLite {
       }
     }
 
-    public Builder mergeFrom(
-        byte[] data,
-        ExtensionRegistryLite extensionRegistry)
+    @Override
+    public Builder mergeFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       // UnknownFieldSet has no extensions.
       return mergeFrom(data);
     }
 
-    public Builder mergeFrom(
-        byte[] data, int off, int len,
-        ExtensionRegistryLite extensionRegistry)
+    @Override
+    public Builder mergeFrom(byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       // UnknownFieldSet has no extensions.
       return mergeFrom(data, off, len);
     }
 
-    public Builder mergeFrom(
-        InputStream input,
-        ExtensionRegistryLite extensionRegistry) throws IOException {
+    @Override
+    public Builder mergeFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException {
       // UnknownFieldSet has no extensions.
       return mergeFrom(input);
     }
 
+    @Override
+    public Builder mergeFrom(MessageLite m) {
+      if (m instanceof UnknownFieldSet) {
+        return mergeFrom((UnknownFieldSet) m);
+      }
+      throw new IllegalArgumentException(
+          "mergeFrom(MessageLite) can only merge messages of the same type.");
+    }
+
+    @Override
     public boolean isInitialized() {
       // UnknownFieldSets do not have required fields, so they are always
       // initialized.
@@ -987,6 +1010,7 @@ public final class UnknownFieldSet implements MessageLite {
    * Parser to implement MessageLite interface.
    */
   public static final class Parser extends AbstractParser<UnknownFieldSet> {
+    @Override
     public UnknownFieldSet parsePartialFrom(
         CodedInputStream input, ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
@@ -1004,6 +1028,7 @@ public final class UnknownFieldSet implements MessageLite {
   }
 
   private static final Parser PARSER = new Parser();
+  @Override
   public final Parser getParserForType() {
     return PARSER;
   }
diff --git a/java/src/main/java/com/google/protobuf/UnknownFieldSetLite.java b/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
index 435ad4d4..9500f905 100644
--- a/java/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
+++ b/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
@@ -61,15 +61,6 @@ public final class UnknownFieldSetLite {
   public static UnknownFieldSetLite getDefaultInstance() {
     return DEFAULT_INSTANCE;
   }
-
-  /**
-   * Returns an empty {@code UnknownFieldSetLite.Builder}.
-   *
-   * <p>For use by generated code only.
-   */
-  public static Builder newBuilder() {
-    return new Builder();
-  }
   
   /**
    * Returns a new mutable instance.
@@ -262,6 +253,21 @@ public final class UnknownFieldSetLite {
     return hashCode;
   }
 
+  /**
+   * Prints a String representation of the unknown field set.
+   *
+   * <p>For use by generated code only.
+   *
+   * @param buffer the buffer to write to
+   * @param indent the number of spaces the fields should be indented by
+   */
+  final void printWithIndent(StringBuilder buffer, int indent) {
+    for (int i = 0; i < count; i++) {
+      int fieldNumber = WireFormat.getTagFieldNumber(tags[i]);
+      MessageLiteToString.printField(buffer, indent, String.valueOf(fieldNumber), objects[i]);
+    }
+  }
+
   private void storeField(int tag, Object value) {
     ensureCapacity();
     
@@ -369,90 +375,4 @@ public final class UnknownFieldSetLite {
     }
     return this;
   }
-  
-  /**
-   * Builder for {@link UnknownFieldSetLite}s.
-   *
-   * <p>Use {@link UnknownFieldSet#newBuilder()} to construct a {@code Builder}.
-   *
-   * <p>For use by generated code only.
-   */
-  // TODO(dweis): Update the mutable API to no longer need this builder and delete.
-  public static final class Builder {
-
-    private UnknownFieldSetLite set;
-    
-    private Builder() {
-      this.set = null;
-    }
-
-    /**
-     * Ensures internal state is initialized for use.
-     */
-    private void ensureNotBuilt() {
-      if (set == null) {
-        set = new UnknownFieldSetLite();
-      }
-      
-      set.checkMutable();
-    }
-    
-    /**
-     * Parse a single field from {@code input} and merge it into this set.
-     *
-     * <p>For use by generated code only.
-     *
-     * @param tag The field's tag number, which was already parsed.
-     * @return {@code false} if the tag is an end group tag.
-     */
-    boolean mergeFieldFrom(final int tag, final CodedInputStream input) throws IOException {
-      ensureNotBuilt();
-      return set.mergeFieldFrom(tag, input);
-    }
-
-    /**
-     * Convenience method for merging a new field containing a single varint
-     * value. This is used in particular when an unknown enum value is
-     * encountered.
-     *
-     * <p>For use by generated code only.
-     */
-    Builder mergeVarintField(int fieldNumber, int value) {
-      ensureNotBuilt();
-      set.mergeVarintField(fieldNumber, value);
-      return this;
-    }
-    
-    /**
-     * Convenience method for merging a length-delimited field.
-     *
-     * <p>For use by generated code only.
-     */
-    public Builder mergeLengthDelimitedField(final int fieldNumber, final ByteString value) {
-      ensureNotBuilt();  
-      set.mergeLengthDelimitedField(fieldNumber, value);
-      return this;
-    }
-    
-    /**
-     * Build the {@link UnknownFieldSetLite} and return it.
-     *
-     * <p>Once {@code build()} has been called, the {@code Builder} will no
-     * longer be usable.  Calling any method after {@code build()} will result
-     * in undefined behavior and can cause an
-     * {@code UnsupportedOperationException} to be thrown.
-     *
-     * <p>For use by generated code only.
-     */
-    public UnknownFieldSetLite build() {
-      if (set == null) {
-        return DEFAULT_INSTANCE;
-      }
-      
-      set.checkMutable();
-      set.makeImmutable();
-
-      return set;
-    }
-  }
 }
diff --git a/java/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java b/java/core/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java
index 5257c5a2..30e87911 100644
--- a/java/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java
+++ b/java/core/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java
@@ -68,42 +68,42 @@ public class UnmodifiableLazyStringList extends AbstractList<String>
     return list.size();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public ByteString getByteString(int index) {
     return list.getByteString(index);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void add(ByteString element) {
     throw new UnsupportedOperationException();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void set(int index, ByteString element) {
     throw new UnsupportedOperationException();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public boolean addAllByteString(Collection<? extends ByteString> element) {
     throw new UnsupportedOperationException();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public byte[] getByteArray(int index) {
     return list.getByteArray(index);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void add(byte[] element) {
     throw new UnsupportedOperationException();
   }
   
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void set(int index, byte[] element) {
     throw new UnsupportedOperationException();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public boolean addAllByteArray(Collection<byte[]> element) {
     throw new UnsupportedOperationException();
   }
@@ -113,47 +113,47 @@ public class UnmodifiableLazyStringList extends AbstractList<String>
     return new ListIterator<String>() {
       ListIterator<String> iter = list.listIterator(index);
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public boolean hasNext() {
         return iter.hasNext();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public String next() {
         return iter.next();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public boolean hasPrevious() {
         return iter.hasPrevious();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public String previous() {
         return iter.previous();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public int nextIndex() {
         return iter.nextIndex();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public int previousIndex() {
         return iter.previousIndex();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public void remove() {
         throw new UnsupportedOperationException();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public void set(String o) {
         throw new UnsupportedOperationException();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public void add(String o) {
         throw new UnsupportedOperationException();
       }
@@ -165,45 +165,45 @@ public class UnmodifiableLazyStringList extends AbstractList<String>
     return new Iterator<String>() {
       Iterator<String> iter = list.iterator();
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public boolean hasNext() {
         return iter.hasNext();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public String next() {
         return iter.next();
       }
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public void remove() {
         throw new UnsupportedOperationException();
       }
     };
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public List<?> getUnderlyingElements() {
     // The returned value is already unmodifiable.
     return list.getUnderlyingElements();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void mergeFrom(LazyStringList other) {
     throw new UnsupportedOperationException();
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public List<byte[]> asByteArrayList() {
     return Collections.unmodifiableList(list.asByteArrayList());
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public List<ByteString> asByteStringList() {
     return Collections.unmodifiableList(list.asByteStringList());
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public LazyStringList getUnmodifiableView() {
     return this;
   }
diff --git a/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java b/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java
new file mode 100644
index 00000000..0fbf4d40
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java
@@ -0,0 +1,84 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * Provides a number of unsafe byte operations to be used by advanced applications with high
+ * performance requirements. These methods are referred to as "unsafe" due to the fact that they
+ * potentially expose the backing buffer of a {@link ByteString} to the application.
+ *
+ * <p><strong>DISCLAIMER:</strong> The methods in this class should only be called if it is
+ * guaranteed that the buffer backing the {@link ByteString} will never change! Mutation of a
+ * {@link ByteString} can lead to unexpected and undesirable consequences in your application,
+ * and will likely be difficult to debug. Proceed with caution!
+ */
+@ExperimentalApi
+public final class UnsafeByteOperations {
+  private UnsafeByteOperations() {}
+
+  /**
+   * An unsafe operation that returns a {@link ByteString} that is backed by the provided buffer.
+   *
+   * @param buffer the Java NIO buffer to be wrapped
+   * @return a {@link ByteString} backed by the provided buffer
+   */
+  public static ByteString unsafeWrap(ByteBuffer buffer) {
+    if (buffer.hasArray()) {
+      final int offset = buffer.arrayOffset();
+      return ByteString.wrap(buffer.array(), offset + buffer.position(), buffer.remaining());
+    } else {
+      return new NioByteString(buffer);
+    }
+  }
+
+  /**
+   * Writes the given {@link ByteString} to the provided {@link ByteOutput}. Calling this method may
+   * result in multiple operations on the target {@link ByteOutput}
+   * (i.e. for roped {@link ByteString}s).
+   *
+   * <p>This method exposes the internal backing buffer(s) of the {@link ByteString} to the {@link
+   * ByteOutput} in order to avoid additional copying overhead. It would be possible for a malicious
+   * {@link ByteOutput} to corrupt the {@link ByteString}. Use with caution!
+   *
+   * <p> NOTE: The {@link ByteOutput} <strong>MUST NOT</strong> modify the provided buffers. Doing
+   * so may result in corrupted data, which would be difficult to debug.
+   *
+   * @param bytes the {@link ByteString} to be written
+   * @param  output  the output to receive the bytes
+   * @throws IOException  if an I/O error occurs
+   */
+  public static void unsafeWriteTo(ByteString bytes, ByteOutput output) throws IOException {
+    bytes.writeTo(output);
+  }
+}
diff --git a/java/core/src/main/java/com/google/protobuf/Utf8.java b/java/core/src/main/java/com/google/protobuf/Utf8.java
new file mode 100644
index 00000000..308c69e9
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/Utf8.java
@@ -0,0 +1,1683 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.lang.Character.MAX_SURROGATE;
+import static java.lang.Character.MIN_SURROGATE;
+import static java.lang.Character.isSurrogatePair;
+import static java.lang.Character.toCodePoint;
+
+import java.lang.reflect.Field;
+import java.nio.Buffer;
+import java.nio.ByteBuffer;
+import java.security.AccessController;
+import java.security.PrivilegedExceptionAction;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A set of low-level, high-performance static utility methods related
+ * to the UTF-8 character encoding.  This class has no dependencies
+ * outside of the core JDK libraries.
+ *
+ * <p>There are several variants of UTF-8.  The one implemented by
+ * this class is the restricted definition of UTF-8 introduced in
+ * Unicode 3.1, which mandates the rejection of "overlong" byte
+ * sequences as well as rejection of 3-byte surrogate codepoint byte
+ * sequences.  Note that the UTF-8 decoder included in Oracle's JDK
+ * has been modified to also reject "overlong" byte sequences, but (as
+ * of 2011) still accepts 3-byte surrogate codepoint byte sequences.
+ *
+ * <p>The byte sequences considered valid by this class are exactly
+ * those that can be roundtrip converted to Strings and back to bytes
+ * using the UTF-8 charset, without loss: <pre> {@code
+ * Arrays.equals(bytes, new String(bytes, Internal.UTF_8).getBytes(Internal.UTF_8))
+ * }</pre>
+ *
+ * <p>See the Unicode Standard,</br>
+ * Table 3-6. <em>UTF-8 Bit Distribution</em>,</br>
+ * Table 3-7. <em>Well Formed UTF-8 Byte Sequences</em>.
+ *
+ * <p>This class supports decoding of partial byte sequences, so that the
+ * bytes in a complete UTF-8 byte sequences can be stored in multiple
+ * segments.  Methods typically return {@link #MALFORMED} if the partial
+ * byte sequence is definitely not well-formed, {@link #COMPLETE} if it is
+ * well-formed in the absence of additional input, or if the byte sequence
+ * apparently terminated in the middle of a character, an opaque integer
+ * "state" value containing enough information to decode the character when
+ * passed to a subsequent invocation of a partial decoding method.
+ *
+ * @author martinrb@google.com (Martin Buchholz)
+ */
+// TODO(nathanmittler): Copy changes in this class back to Guava
+final class Utf8 {
+  private static final Logger logger = Logger.getLogger(Utf8.class.getName());
+
+  /**
+   * UTF-8 is a runtime hot spot so we attempt to provide heavily optimized implementations
+   * depending on what is available on the platform. The processor is the platform-optimized
+   * delegate for which all methods are delegated directly to.
+   */
+  private static final Processor processor =
+      UnsafeProcessor.isAvailable() ? new UnsafeProcessor() : new SafeProcessor();
+
+  /**
+   * A mask used when performing unsafe reads to determine if a long value contains any non-ASCII
+   * characters (i.e. any byte >= 0x80).
+   */
+  private static final long ASCII_MASK_LONG = 0x8080808080808080L;
+
+  /**
+   * Maximum number of bytes per Java UTF-16 char in UTF-8.
+   * @see java.nio.charset.CharsetEncoder#maxBytesPerChar()
+   */
+  static final int MAX_BYTES_PER_CHAR = 3;
+
+  /**
+   * State value indicating that the byte sequence is well-formed and
+   * complete (no further bytes are needed to complete a character).
+   */
+  public static final int COMPLETE = 0;
+
+  /**
+   * State value indicating that the byte sequence is definitely not
+   * well-formed.
+   */
+  public static final int MALFORMED = -1;
+
+  /**
+   * Used by {@code Unsafe} UTF-8 string validation logic to determine the minimum string length
+   * above which to employ an optimized algorithm for counting ASCII characters. The reason for this
+   * threshold is that for small strings, the optimization may not be beneficial or may even
+   * negatively impact performance since it requires additional logic to avoid unaligned reads
+   * (when calling {@code Unsafe.getLong}). This threshold guarantees that even if the initial
+   * offset is unaligned, we're guaranteed to make at least one call to {@code Unsafe.getLong()}
+   * which provides a performance improvement that entirely subsumes the cost of the additional
+   * logic.
+   */
+  private static final int UNSAFE_COUNT_ASCII_THRESHOLD = 16;
+
+  // Other state values include the partial bytes of the incomplete
+  // character to be decoded in the simplest way: we pack the bytes
+  // into the state int in little-endian order.  For example:
+  //
+  // int state = byte1 ^ (byte2 << 8) ^ (byte3 << 16);
+  //
+  // Such a state is unpacked thus (note the ~ operation for byte2 to
+  // undo byte1's sign-extension bits):
+  //
+  // int byte1 = (byte) state;
+  // int byte2 = (byte) ~(state >> 8);
+  // int byte3 = (byte) (state >> 16);
+  //
+  // We cannot store a zero byte in the state because it would be
+  // indistinguishable from the absence of a byte.  But we don't need
+  // to, because partial bytes must always be negative.  When building
+  // a state, we ensure that byte1 is negative and subsequent bytes
+  // are valid trailing bytes.
+
+  /**
+   * Returns {@code true} if the given byte array is a well-formed
+   * UTF-8 byte sequence.
+   *
+   * <p>This is a convenience method, equivalent to a call to {@code
+   * isValidUtf8(bytes, 0, bytes.length)}.
+   */
+  public static boolean isValidUtf8(byte[] bytes) {
+    return processor.isValidUtf8(bytes, 0, bytes.length);
+  }
+
+  /**
+   * Returns {@code true} if the given byte array slice is a
+   * well-formed UTF-8 byte sequence.  The range of bytes to be
+   * checked extends from index {@code index}, inclusive, to {@code
+   * limit}, exclusive.
+   *
+   * <p>This is a convenience method, equivalent to {@code
+   * partialIsValidUtf8(bytes, index, limit) == Utf8.COMPLETE}.
+   */
+  public static boolean isValidUtf8(byte[] bytes, int index, int limit) {
+    return processor.isValidUtf8(bytes, index, limit);
+  }
+
+  /**
+   * Tells whether the given byte array slice is a well-formed,
+   * malformed, or incomplete UTF-8 byte sequence.  The range of bytes
+   * to be checked extends from index {@code index}, inclusive, to
+   * {@code limit}, exclusive.
+   *
+   * @param state either {@link Utf8#COMPLETE} (if this is the initial decoding
+   * operation) or the value returned from a call to a partial decoding method
+   * for the previous bytes
+   *
+   * @return {@link #MALFORMED} if the partial byte sequence is
+   * definitely not well-formed, {@link #COMPLETE} if it is well-formed
+   * (no additional input needed), or if the byte sequence is
+   * "incomplete", i.e. apparently terminated in the middle of a character,
+   * an opaque integer "state" value containing enough information to
+   * decode the character when passed to a subsequent invocation of a
+   * partial decoding method.
+   */
+  public static int partialIsValidUtf8(int state, byte[] bytes, int index, int limit) {
+    return processor.partialIsValidUtf8(state, bytes, index, limit);
+  }
+
+  private static int incompleteStateFor(int byte1) {
+    return (byte1 > (byte) 0xF4) ?
+        MALFORMED : byte1;
+  }
+
+  private static int incompleteStateFor(int byte1, int byte2) {
+    return (byte1 > (byte) 0xF4 ||
+            byte2 > (byte) 0xBF) ?
+        MALFORMED : byte1 ^ (byte2 << 8);
+  }
+
+  private static int incompleteStateFor(int byte1, int byte2, int byte3) {
+    return (byte1 > (byte) 0xF4 ||
+            byte2 > (byte) 0xBF ||
+            byte3 > (byte) 0xBF) ?
+        MALFORMED : byte1 ^ (byte2 << 8) ^ (byte3 << 16);
+  }
+
+  private static int incompleteStateFor(byte[] bytes, int index, int limit) {
+    int byte1 = bytes[index - 1];
+    switch (limit - index) {
+      case 0: return incompleteStateFor(byte1);
+      case 1: return incompleteStateFor(byte1, bytes[index]);
+      case 2: return incompleteStateFor(byte1, bytes[index], bytes[index + 1]);
+      default: throw new AssertionError();
+    }
+  }
+
+  private static int incompleteStateFor(
+      final ByteBuffer buffer, final int byte1, final int index, final int remaining) {
+    switch (remaining) {
+      case 0:
+        return incompleteStateFor(byte1);
+      case 1:
+        return incompleteStateFor(byte1, buffer.get(index));
+      case 2:
+        return incompleteStateFor(byte1, buffer.get(index), buffer.get(index + 1));
+      default:
+        throw new AssertionError();
+    }
+  }
+
+  // These UTF-8 handling methods are copied from Guava's Utf8 class with a modification to throw
+  // a protocol buffer local exception. This exception is then caught in CodedOutputStream so it can
+  // fallback to more lenient behavior.
+  
+  static class UnpairedSurrogateException extends IllegalArgumentException {
+    private UnpairedSurrogateException(int index, int length) {
+      super("Unpaired surrogate at index " + index + " of " + length);
+    }
+  }
+
+  /**
+   * Returns the number of bytes in the UTF-8-encoded form of {@code sequence}. For a string,
+   * this method is equivalent to {@code string.getBytes(UTF_8).length}, but is more efficient in
+   * both time and space.
+   *
+   * @throws IllegalArgumentException if {@code sequence} contains ill-formed UTF-16 (unpaired
+   *     surrogates)
+   */
+  static int encodedLength(CharSequence sequence) {
+    // Warning to maintainers: this implementation is highly optimized.
+    int utf16Length = sequence.length();
+    int utf8Length = utf16Length;
+    int i = 0;
+
+    // This loop optimizes for pure ASCII.
+    while (i < utf16Length && sequence.charAt(i) < 0x80) {
+      i++;
+    }
+
+    // This loop optimizes for chars less than 0x800.
+    for (; i < utf16Length; i++) {
+      char c = sequence.charAt(i);
+      if (c < 0x800) {
+        utf8Length += ((0x7f - c) >>> 31);  // branch free!
+      } else {
+        utf8Length += encodedLengthGeneral(sequence, i);
+        break;
+      }
+    }
+
+    if (utf8Length < utf16Length) {
+      // Necessary and sufficient condition for overflow because of maximum 3x expansion
+      throw new IllegalArgumentException("UTF-8 length does not fit in int: "
+              + (utf8Length + (1L << 32)));
+    }
+    return utf8Length;
+  }
+
+  private static int encodedLengthGeneral(CharSequence sequence, int start) {
+    int utf16Length = sequence.length();
+    int utf8Length = 0;
+    for (int i = start; i < utf16Length; i++) {
+      char c = sequence.charAt(i);
+      if (c < 0x800) {
+        utf8Length += (0x7f - c) >>> 31; // branch free!
+      } else {
+        utf8Length += 2;
+        // jdk7+: if (Character.isSurrogate(c)) {
+        if (Character.MIN_SURROGATE <= c && c <= Character.MAX_SURROGATE) {
+          // Check that we have a well-formed surrogate pair.
+          int cp = Character.codePointAt(sequence, i);
+          if (cp < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
+            throw new UnpairedSurrogateException(i, utf16Length);
+          }
+          i++;
+        }
+      }
+    }
+    return utf8Length;
+  }
+
+  static int encode(CharSequence in, byte[] out, int offset, int length) {
+    return processor.encodeUtf8(in, out, offset, length);
+  }
+  // End Guava UTF-8 methods.
+
+  /**
+   * Determines if the given {@link ByteBuffer} is a valid UTF-8 string.
+   *
+   * <p>Selects an optimal algorithm based on the type of {@link ByteBuffer} (i.e. heap or direct)
+   * and the capabilities of the platform.
+   *
+   * @param buffer the buffer to check.
+   * @see Utf8#isValidUtf8(byte[], int, int)
+   */
+  static boolean isValidUtf8(ByteBuffer buffer) {
+    return processor.isValidUtf8(buffer, buffer.position(), buffer.remaining());
+  }
+
+  /**
+   * Determines if the given {@link ByteBuffer} is a partially valid UTF-8 string.
+   *
+   * <p>Selects an optimal algorithm based on the type of {@link ByteBuffer} (i.e. heap or direct)
+   * and the capabilities of the platform.
+   *
+   * @param buffer the buffer to check.
+   * @see Utf8#partialIsValidUtf8(int, byte[], int, int)
+   */
+  static int partialIsValidUtf8(int state, ByteBuffer buffer, int index, int limit) {
+    return processor.partialIsValidUtf8(state, buffer, index, limit);
+  }
+
+  /**
+   * Encodes the given characters to the target {@link ByteBuffer} using UTF-8 encoding.
+   *
+   * <p>Selects an optimal algorithm based on the type of {@link ByteBuffer} (i.e. heap or direct)
+   * and the capabilities of the platform.
+   *
+   * @param in the source string to be encoded
+   * @param out the target buffer to receive the encoded string.
+   * @see Utf8#encode(CharSequence, byte[], int, int)
+   */
+  static void encodeUtf8(CharSequence in, ByteBuffer out) {
+    processor.encodeUtf8(in, out);
+  }
+
+  /**
+   * Counts (approximately) the number of consecutive ASCII characters in the given buffer.
+   * The byte order of the {@link ByteBuffer} does not matter, so performance can be improved if
+   * native byte order is used (i.e. no byte-swapping in {@link ByteBuffer#getLong(int)}).
+   *
+   * @param buffer the buffer to be scanned for ASCII chars
+   * @param index the starting index of the scan
+   * @param limit the limit within buffer for the scan
+   * @return the number of ASCII characters found. The stopping position will be at or
+   * before the first non-ASCII byte.
+   */
+  private static int estimateConsecutiveAscii(ByteBuffer buffer, int index, int limit) {
+    int i = index;
+    final int lim = limit - 7;
+    // This simple loop stops when we encounter a byte >= 0x80 (i.e. non-ASCII).
+    // To speed things up further, we're reading longs instead of bytes so we use a mask to
+    // determine if any byte in the current long is non-ASCII.
+    for (; i < lim && (buffer.getLong(i) & ASCII_MASK_LONG) == 0; i += 8) {}
+    return i - index;
+  }
+
+  /**
+   * A processor of UTF-8 strings, providing methods for checking validity and encoding.
+   */
+  // TODO(nathanmittler): Add support for Memory/MemoryBlock on Android.
+  abstract static class Processor {
+    /**
+     * Returns {@code true} if the given byte array slice is a
+     * well-formed UTF-8 byte sequence.  The range of bytes to be
+     * checked extends from index {@code index}, inclusive, to {@code
+     * limit}, exclusive.
+     *
+     * <p>This is a convenience method, equivalent to {@code
+     * partialIsValidUtf8(bytes, index, limit) == Utf8.COMPLETE}.
+     */
+    final boolean isValidUtf8(byte[] bytes, int index, int limit) {
+      return partialIsValidUtf8(COMPLETE, bytes, index, limit) == COMPLETE;
+    }
+
+    /**
+     * Tells whether the given byte array slice is a well-formed,
+     * malformed, or incomplete UTF-8 byte sequence.  The range of bytes
+     * to be checked extends from index {@code index}, inclusive, to
+     * {@code limit}, exclusive.
+     *
+     * @param state either {@link Utf8#COMPLETE} (if this is the initial decoding
+     * operation) or the value returned from a call to a partial decoding method
+     * for the previous bytes
+     *
+     * @return {@link #MALFORMED} if the partial byte sequence is
+     * definitely not well-formed, {@link #COMPLETE} if it is well-formed
+     * (no additional input needed), or if the byte sequence is
+     * "incomplete", i.e. apparently terminated in the middle of a character,
+     * an opaque integer "state" value containing enough information to
+     * decode the character when passed to a subsequent invocation of a
+     * partial decoding method.
+     */
+    abstract int partialIsValidUtf8(int state, byte[] bytes, int index, int limit);
+
+    /**
+     * Returns {@code true} if the given portion of the {@link ByteBuffer} is a
+     * well-formed UTF-8 byte sequence.  The range of bytes to be
+     * checked extends from index {@code index}, inclusive, to {@code
+     * limit}, exclusive.
+     *
+     * <p>This is a convenience method, equivalent to {@code
+     * partialIsValidUtf8(bytes, index, limit) == Utf8.COMPLETE}.
+     */
+    final boolean isValidUtf8(ByteBuffer buffer, int index, int limit) {
+      return partialIsValidUtf8(COMPLETE, buffer, index, limit) == COMPLETE;
+    }
+
+    /**
+     * Indicates whether or not the given buffer contains a valid UTF-8 string.
+     *
+     * @param buffer the buffer to check.
+     * @return {@code true} if the given buffer contains a valid UTF-8 string.
+     */
+    final int partialIsValidUtf8(
+        final int state, final ByteBuffer buffer, int index, final int limit) {
+      if (buffer.hasArray()) {
+        final int offset = buffer.arrayOffset();
+        return partialIsValidUtf8(state, buffer.array(), offset + index, offset + limit);
+      } else if (buffer.isDirect()){
+        return partialIsValidUtf8Direct(state, buffer, index, limit);
+      }
+      return partialIsValidUtf8Default(state, buffer, index, limit);
+    }
+
+    /**
+     * Performs validation for direct {@link ByteBuffer} instances.
+     */
+    abstract int partialIsValidUtf8Direct(
+        final int state, final ByteBuffer buffer, int index, final int limit);
+
+    /**
+     * Performs validation for {@link ByteBuffer} instances using the {@link ByteBuffer} API rather
+     * than potentially faster approaches. This first completes validation for the current
+     * character (provided by {@code state}) and then finishes validation for the sequence.
+     */
+    final int partialIsValidUtf8Default(
+        final int state, final ByteBuffer buffer, int index, final int limit) {
+      if (state != COMPLETE) {
+        // The previous decoding operation was incomplete (or malformed).
+        // We look for a well-formed sequence consisting of bytes from
+        // the previous decoding operation (stored in state) together
+        // with bytes from the array slice.
+        //
+        // We expect such "straddler characters" to be rare.
+
+        if (index >= limit) { // No bytes? No progress.
+          return state;
+        }
+
+        byte byte1 = (byte) state;
+        // byte1 is never ASCII.
+        if (byte1 < (byte) 0xE0) {
+          // two-byte form
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2
+              // byte2 trailing-byte test
+              || buffer.get(index++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // three-byte form
+
+          // Get byte2 from saved state or array
+          byte byte2 = (byte) ~(state >> 8);
+          if (byte2 == 0) {
+            byte2 = buffer.get(index++);
+            if (index >= limit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          }
+          if (byte2 > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // illegal surrogate codepoint?
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || buffer.get(index++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // four-byte form
+
+          // Get byte2 and byte3 from saved state or array
+          byte byte2 = (byte) ~(state >> 8);
+          byte byte3 = 0;
+          if (byte2 == 0) {
+            byte2 = buffer.get(index++);
+            if (index >= limit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          } else {
+            byte3 = (byte) (state >> 16);
+          }
+          if (byte3 == 0) {
+            byte3 = buffer.get(index++);
+            if (index >= limit) {
+              return incompleteStateFor(byte1, byte2, byte3);
+            }
+          }
+
+          // If we were called with state == MALFORMED, then byte1 is 0xFF,
+          // which never occurs in well-formed UTF-8, and so we will return
+          // MALFORMED again below.
+
+          if (byte2 > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || byte3 > (byte) 0xBF
+              // byte4 trailing-byte test
+              || buffer.get(index++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+
+      // Finish validation for the sequence.
+      return partialIsValidUtf8(buffer, index, limit);
+    }
+
+    /**
+     * Performs validation for {@link ByteBuffer} instances using the {@link ByteBuffer} API rather
+     * than potentially faster approaches.
+     */
+    private static int partialIsValidUtf8(final ByteBuffer buffer, int index, final int limit) {
+      index += estimateConsecutiveAscii(buffer, index, limit);
+
+      for (;;) {
+        // Optimize for interior runs of ASCII bytes.
+        // TODO(nathanmittler): Consider checking 8 bytes at a time after some threshold?
+        // Maybe after seeing a few in a row that are ASCII, go back to fast mode?
+        int byte1;
+        do {
+          if (index >= limit) {
+            return COMPLETE;
+          }
+        } while ((byte1 = buffer.get(index++)) >= 0);
+
+        // If we're here byte1 is not ASCII. Only need to handle 2-4 byte forms.
+        if (byte1 < (byte) 0xE0) {
+          // Two-byte form (110xxxxx 10xxxxxx)
+          if (index >= limit) {
+            // Incomplete sequence
+            return byte1;
+          }
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2 || buffer.get(index) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+          index++;
+        } else if (byte1 < (byte) 0xF0) {
+          // Three-byte form (1110xxxx 10xxxxxx 10xxxxxx)
+          if (index >= limit - 1) {
+            // Incomplete sequence
+            return incompleteStateFor(buffer, byte1, index, limit - index);
+          }
+
+          final byte byte2 = buffer.get(index++);
+          if (byte2 > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // check for illegal surrogate codepoints
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || buffer.get(index) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+          index++;
+        } else {
+          // Four-byte form (1110xxxx 10xxxxxx 10xxxxxx 10xxxxxx)
+          if (index >= limit - 2) {
+            // Incomplete sequence
+            return incompleteStateFor(buffer, byte1, index, limit - index);
+          }
+
+          // TODO(nathanmittler): Consider using getInt() to improve performance.
+          final int byte2 = buffer.get(index++);
+          if (byte2 > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || buffer.get(index++) > (byte) 0xBF
+              // byte4 trailing-byte test
+              || buffer.get(index++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+    }
+
+    /**
+     * Encodes an input character sequence ({@code in}) to UTF-8 in the target array ({@code out}).
+     * For a string, this method is similar to
+     * <pre>{@code
+     * byte[] a = string.getBytes(UTF_8);
+     * System.arraycopy(a, 0, bytes, offset, a.length);
+     * return offset + a.length;
+     * }</pre>
+     *
+     * but is more efficient in both time and space. One key difference is that this method
+     * requires paired surrogates, and therefore does not support chunking.
+     * While {@code String.getBytes(UTF_8)} replaces unpaired surrogates with the default
+     * replacement character, this method throws {@link UnpairedSurrogateException}.
+     *
+     * <p>To ensure sufficient space in the output buffer, either call {@link #encodedLength} to
+     * compute the exact amount needed, or leave room for 
+     * {@code Utf8.MAX_BYTES_PER_CHAR * sequence.length()}, which is the largest possible number
+     * of bytes that any input can be encoded to.
+     *
+     * @param in the input character sequence to be encoded
+     * @param out the target array
+     * @param offset the starting offset in {@code bytes} to start writing at
+     * @param length the length of the {@code bytes}, starting from {@code offset}
+     * @throws UnpairedSurrogateException if {@code sequence} contains ill-formed UTF-16 (unpaired
+     *     surrogates)
+     * @throws ArrayIndexOutOfBoundsException if {@code sequence} encoded in UTF-8 is longer than
+     *     {@code bytes.length - offset}
+     * @return the new offset, equivalent to {@code offset + Utf8.encodedLength(sequence)}
+     */
+    abstract int encodeUtf8(CharSequence in, byte[] out, int offset, int length);
+
+    /**
+     * Encodes an input character sequence ({@code in}) to UTF-8 in the target buffer ({@code out}).
+     * Upon returning from this method, the {@code out} position will point to the position after
+     * the last encoded byte. This method requires paired surrogates, and therefore does not
+     * support chunking.
+     *
+     * <p>To ensure sufficient space in the output buffer, either call {@link #encodedLength} to
+     * compute the exact amount needed, or leave room for
+     * {@code Utf8.MAX_BYTES_PER_CHAR * in.length()}, which is the largest possible number
+     * of bytes that any input can be encoded to.
+     *
+     * @param in the source character sequence to be encoded
+     * @param out the target buffer
+     * @throws UnpairedSurrogateException if {@code in} contains ill-formed UTF-16 (unpaired
+     *     surrogates)
+     * @throws ArrayIndexOutOfBoundsException if {@code in} encoded in UTF-8 is longer than
+     *     {@code out.remaining()}
+     */
+    final void encodeUtf8(CharSequence in, ByteBuffer out) {
+      if (out.hasArray()) {
+        final int offset = out.arrayOffset();
+        int endIndex =
+            Utf8.encode(in, out.array(), offset + out.position(), out.remaining());
+        out.position(endIndex - offset);
+      } else if (out.isDirect()) {
+        encodeUtf8Direct(in, out);
+      } else {
+        encodeUtf8Default(in, out);
+      }
+    }
+
+    /**
+     * Encodes the input character sequence to a direct {@link ByteBuffer} instance.
+     */
+    abstract void encodeUtf8Direct(CharSequence in, ByteBuffer out);
+
+    /**
+     * Encodes the input character sequence to a {@link ByteBuffer} instance using the {@link
+     * ByteBuffer} API, rather than potentially faster approaches.
+     */
+    final void encodeUtf8Default(CharSequence in, ByteBuffer out) {
+      final int inLength = in.length();
+      int outIx = out.position();
+      int inIx = 0;
+
+      // Since ByteBuffer.putXXX() already checks boundaries for us, no need to explicitly check
+      // access. Assume the buffer is big enough and let it handle the out of bounds exception
+      // if it occurs.
+      try {
+        // Designed to take advantage of
+        // https://wikis.oracle.com/display/HotSpotInternals/RangeCheckElimination
+        for (char c; inIx < inLength && (c = in.charAt(inIx)) < 0x80; ++inIx) {
+          out.put(outIx + inIx, (byte) c);
+        }
+        if (inIx == inLength) {
+          // Successfully encoded the entire string.
+          out.position(outIx + inIx);
+          return;
+        }
+
+        outIx += inIx;
+        for (char c; inIx < inLength; ++inIx, ++outIx) {
+          c = in.charAt(inIx);
+          if (c < 0x80) {
+            // One byte (0xxx xxxx)
+            out.put(outIx, (byte) c);
+          } else if (c < 0x800) {
+            // Two bytes (110x xxxx 10xx xxxx)
+
+            // Benchmarks show put performs better than putShort here (for HotSpot).
+            out.put(outIx++, (byte) (0xC0 | (c >>> 6)));
+            out.put(outIx, (byte) (0x80 | (0x3F & c)));
+          } else if (c < MIN_SURROGATE || MAX_SURROGATE < c) {
+            // Three bytes (1110 xxxx 10xx xxxx 10xx xxxx)
+            // Maximum single-char code point is 0xFFFF, 16 bits.
+
+            // Benchmarks show put performs better than putShort here (for HotSpot).
+            out.put(outIx++, (byte) (0xE0 | (c >>> 12)));
+            out.put(outIx++, (byte) (0x80 | (0x3F & (c >>> 6))));
+            out.put(outIx, (byte) (0x80 | (0x3F & c)));
+          } else {
+            // Four bytes (1111 xxxx 10xx xxxx 10xx xxxx 10xx xxxx)
+
+            // Minimum code point represented by a surrogate pair is 0x10000, 17 bits, four UTF-8
+            // bytes
+            final char low;
+            if (inIx + 1 == inLength || !isSurrogatePair(c, (low = in.charAt(++inIx)))) {
+              throw new UnpairedSurrogateException(inIx, inLength);
+            }
+            // TODO(nathanmittler): Consider using putInt() to improve performance.
+            int codePoint = toCodePoint(c, low);
+            out.put(outIx++, (byte) ((0xF << 4) | (codePoint >>> 18)));
+            out.put(outIx++, (byte) (0x80 | (0x3F & (codePoint >>> 12))));
+            out.put(outIx++, (byte) (0x80 | (0x3F & (codePoint >>> 6))));
+            out.put(outIx, (byte) (0x80 | (0x3F & codePoint)));
+          }
+        }
+
+        // Successfully encoded the entire string.
+        out.position(outIx);
+      } catch (IndexOutOfBoundsException e) {
+        // TODO(nathanmittler): Consider making the API throw IndexOutOfBoundsException instead.
+
+        // If we failed in the outer ASCII loop, outIx will not have been updated. In this case,
+        // use inIx to determine the bad write index.
+        int badWriteIndex = out.position() + Math.max(inIx, outIx - out.position() + 1);
+        throw new ArrayIndexOutOfBoundsException(
+            "Failed writing " + in.charAt(inIx) + " at index " + badWriteIndex);
+      }
+    }
+  }
+
+  /**
+   * {@link Processor} implementation that does not use any {@code sun.misc.Unsafe} methods.
+   */
+  static final class SafeProcessor extends Processor {
+    @Override
+    int partialIsValidUtf8(int state, byte[] bytes, int index, int limit) {
+      if (state != COMPLETE) {
+        // The previous decoding operation was incomplete (or malformed).
+        // We look for a well-formed sequence consisting of bytes from
+        // the previous decoding operation (stored in state) together
+        // with bytes from the array slice.
+        //
+        // We expect such "straddler characters" to be rare.
+
+        if (index >= limit) {  // No bytes? No progress.
+          return state;
+        }
+        int byte1 = (byte) state;
+        // byte1 is never ASCII.
+        if (byte1 < (byte) 0xE0) {
+          // two-byte form
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2
+              // byte2 trailing-byte test
+              || bytes[index++] > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // three-byte form
+
+          // Get byte2 from saved state or array
+          int byte2 = (byte) ~(state >> 8);
+          if (byte2 == 0) {
+            byte2 = bytes[index++];
+            if (index >= limit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          }
+          if (byte2 > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // illegal surrogate codepoint?
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || bytes[index++] > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // four-byte form
+
+          // Get byte2 and byte3 from saved state or array
+          int byte2 = (byte) ~(state >> 8);
+          int byte3 = 0;
+          if (byte2 == 0) {
+            byte2 = bytes[index++];
+            if (index >= limit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          } else {
+            byte3 = (byte) (state >> 16);
+          }
+          if (byte3 == 0) {
+            byte3 = bytes[index++];
+            if (index >= limit) {
+              return incompleteStateFor(byte1, byte2, byte3);
+            }
+          }
+
+          // If we were called with state == MALFORMED, then byte1 is 0xFF,
+          // which never occurs in well-formed UTF-8, and so we will return
+          // MALFORMED again below.
+
+          if (byte2 > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || byte3 > (byte) 0xBF
+              // byte4 trailing-byte test
+              || bytes[index++] > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+
+      return partialIsValidUtf8(bytes, index, limit);
+    }
+
+    @Override
+    int partialIsValidUtf8Direct(int state, ByteBuffer buffer, int index, int limit) {
+      // For safe processing, we have to use the ByteBuffer API.
+      return partialIsValidUtf8Default(state, buffer, index, limit);
+    }
+
+    @Override
+    int encodeUtf8(CharSequence in, byte[] out, int offset, int length) {
+      int utf16Length = in.length();
+      int j = offset;
+      int i = 0;
+      int limit = offset + length;
+      // Designed to take advantage of
+      // https://wikis.oracle.com/display/HotSpotInternals/RangeCheckElimination
+      for (char c; i < utf16Length && i + j < limit && (c = in.charAt(i)) < 0x80; i++) {
+        out[j + i] = (byte) c;
+      }
+      if (i == utf16Length) {
+        return j + utf16Length;
+      }
+      j += i;
+      for (char c; i < utf16Length; i++) {
+        c = in.charAt(i);
+        if (c < 0x80 && j < limit) {
+          out[j++] = (byte) c;
+        } else if (c < 0x800 && j <= limit - 2) { // 11 bits, two UTF-8 bytes
+          out[j++] = (byte) ((0xF << 6) | (c >>> 6));
+          out[j++] = (byte) (0x80 | (0x3F & c));
+        } else if ((c < Character.MIN_SURROGATE || Character.MAX_SURROGATE < c) && j <= limit - 3) {
+          // Maximum single-char code point is 0xFFFF, 16 bits, three UTF-8 bytes
+          out[j++] = (byte) ((0xF << 5) | (c >>> 12));
+          out[j++] = (byte) (0x80 | (0x3F & (c >>> 6)));
+          out[j++] = (byte) (0x80 | (0x3F & c));
+        } else if (j <= limit - 4) {
+          // Minimum code point represented by a surrogate pair is 0x10000, 17 bits,
+          // four UTF-8 bytes
+          final char low;
+          if (i + 1 == in.length()
+                  || !Character.isSurrogatePair(c, (low = in.charAt(++i)))) {
+            throw new UnpairedSurrogateException((i - 1), utf16Length);
+          }
+          int codePoint = Character.toCodePoint(c, low);
+          out[j++] = (byte) ((0xF << 4) | (codePoint >>> 18));
+          out[j++] = (byte) (0x80 | (0x3F & (codePoint >>> 12)));
+          out[j++] = (byte) (0x80 | (0x3F & (codePoint >>> 6)));
+          out[j++] = (byte) (0x80 | (0x3F & codePoint));
+        } else {
+          // If we are surrogates and we're not a surrogate pair, always throw an
+          // UnpairedSurrogateException instead of an ArrayOutOfBoundsException.
+          if ((Character.MIN_SURROGATE <= c && c <= Character.MAX_SURROGATE)
+              && (i + 1 == in.length()
+                  || !Character.isSurrogatePair(c, in.charAt(i + 1)))) {
+            throw new UnpairedSurrogateException(i, utf16Length);
+          }
+          throw new ArrayIndexOutOfBoundsException("Failed writing " + c + " at index " + j);
+        }
+      }
+      return j;
+    }
+
+    @Override
+    void encodeUtf8Direct(CharSequence in, ByteBuffer out) {
+      // For safe processing, we have to use the ByteBuffer API.
+      encodeUtf8Default(in, out);
+    }
+
+    private static int partialIsValidUtf8(byte[] bytes, int index, int limit) {
+      // Optimize for 100% ASCII (Hotspot loves small simple top-level loops like this).
+      // This simple loop stops when we encounter a byte >= 0x80 (i.e. non-ASCII).
+      while (index < limit && bytes[index] >= 0) {
+        index++;
+      }
+
+      return (index >= limit) ? COMPLETE : partialIsValidUtf8NonAscii(bytes, index, limit);
+    }
+
+    private static int partialIsValidUtf8NonAscii(byte[] bytes, int index, int limit) {
+      for (;;) {
+        int byte1, byte2;
+
+        // Optimize for interior runs of ASCII bytes.
+        do {
+          if (index >= limit) {
+            return COMPLETE;
+          }
+        } while ((byte1 = bytes[index++]) >= 0);
+
+        if (byte1 < (byte) 0xE0) {
+          // two-byte form
+
+          if (index >= limit) {
+            // Incomplete sequence
+            return byte1;
+          }
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2
+              || bytes[index++] > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // three-byte form
+
+          if (index >= limit - 1) { // incomplete sequence
+            return incompleteStateFor(bytes, index, limit);
+          }
+          if ((byte2 = bytes[index++]) > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // check for illegal surrogate codepoints
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || bytes[index++] > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // four-byte form
+
+          if (index >= limit - 2) {  // incomplete sequence
+            return incompleteStateFor(bytes, index, limit);
+          }
+          if ((byte2 = bytes[index++]) > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || bytes[index++] > (byte) 0xBF
+              // byte4 trailing-byte test
+              || bytes[index++] > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * {@link Processor} that uses {@code sun.misc.Unsafe} where possible to improve performance.
+   */
+  static final class UnsafeProcessor extends Processor {
+    private static final sun.misc.Unsafe UNSAFE = getUnsafe();
+    private static final long BUFFER_ADDRESS_OFFSET =
+        fieldOffset(field(Buffer.class, "address"));
+    private static final int ARRAY_BASE_OFFSET = byteArrayBaseOffset();
+
+    /**
+     * We only use Unsafe operations if we have access to direct {@link ByteBuffer}'s address
+     * and the array base offset is a multiple of 8 (needed by Unsafe.getLong()).
+     */
+    private static final boolean AVAILABLE =
+        BUFFER_ADDRESS_OFFSET != -1 && ARRAY_BASE_OFFSET % 8 == 0;
+
+    /**
+     * Indicates whether or not all required unsafe operations are supported on this platform.
+     */
+    static boolean isAvailable() {
+      return AVAILABLE;
+    }
+
+    @Override
+    int partialIsValidUtf8(int state, byte[] bytes, final int index, final int limit) {
+      if ((index | limit | bytes.length - limit) < 0) {
+        throw new ArrayIndexOutOfBoundsException(
+            String.format("Array length=%d, index=%d, limit=%d", bytes.length, index, limit));
+      }
+      long offset = ARRAY_BASE_OFFSET + index;
+      final long offsetLimit = ARRAY_BASE_OFFSET + limit;
+      if (state != COMPLETE) {
+        // The previous decoding operation was incomplete (or malformed).
+        // We look for a well-formed sequence consisting of bytes from
+        // the previous decoding operation (stored in state) together
+        // with bytes from the array slice.
+        //
+        // We expect such "straddler characters" to be rare.
+
+        if (offset >= offsetLimit) {  // No bytes? No progress.
+          return state;
+        }
+        int byte1 = (byte) state;
+        // byte1 is never ASCII.
+        if (byte1 < (byte) 0xE0) {
+          // two-byte form
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2
+              // byte2 trailing-byte test
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // three-byte form
+
+          // Get byte2 from saved state or array
+          int byte2 = (byte) ~(state >> 8);
+          if (byte2 == 0) {
+            byte2 = UNSAFE.getByte(bytes, offset++);
+            if (offset >= offsetLimit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          }
+          if (byte2 > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // illegal surrogate codepoint?
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // four-byte form
+
+          // Get byte2 and byte3 from saved state or array
+          int byte2 = (byte) ~(state >> 8);
+          int byte3 = 0;
+          if (byte2 == 0) {
+            byte2 = UNSAFE.getByte(bytes, offset++);
+            if (offset >= offsetLimit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          } else {
+            byte3 = (byte) (state >> 16);
+          }
+          if (byte3 == 0) {
+            byte3 = UNSAFE.getByte(bytes, offset++);
+            if (offset >= offsetLimit) {
+              return incompleteStateFor(byte1, byte2, byte3);
+            }
+          }
+
+          // If we were called with state == MALFORMED, then byte1 is 0xFF,
+          // which never occurs in well-formed UTF-8, and so we will return
+          // MALFORMED again below.
+
+          if (byte2 > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || byte3 > (byte) 0xBF
+              // byte4 trailing-byte test
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+
+      return partialIsValidUtf8(bytes, offset, (int) (offsetLimit - offset));
+    }
+
+    @Override
+    int partialIsValidUtf8Direct(
+        final int state, ByteBuffer buffer, final int index, final int limit) {
+      if ((index | limit | buffer.limit() - limit) < 0) {
+        throw new ArrayIndexOutOfBoundsException(
+            String.format("buffer limit=%d, index=%d, limit=%d", buffer.limit(), index, limit));
+      }
+      long address = addressOffset(buffer) + index;
+      final long addressLimit = address + (limit - index);
+      if (state != COMPLETE) {
+        // The previous decoding operation was incomplete (or malformed).
+        // We look for a well-formed sequence consisting of bytes from
+        // the previous decoding operation (stored in state) together
+        // with bytes from the array slice.
+        //
+        // We expect such "straddler characters" to be rare.
+
+        if (address >= addressLimit) { // No bytes? No progress.
+          return state;
+        }
+
+        final int byte1 = (byte) state;
+        // byte1 is never ASCII.
+        if (byte1 < (byte) 0xE0) {
+          // two-byte form
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2
+              // byte2 trailing-byte test
+              || UNSAFE.getByte(address++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // three-byte form
+
+          // Get byte2 from saved state or array
+          int byte2 = (byte) ~(state >> 8);
+          if (byte2 == 0) {
+            byte2 = UNSAFE.getByte(address++);
+            if (address >= addressLimit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          }
+          if (byte2 > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // illegal surrogate codepoint?
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || UNSAFE.getByte(address++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // four-byte form
+
+          // Get byte2 and byte3 from saved state or array
+          int byte2 = (byte) ~(state >> 8);
+          int byte3 = 0;
+          if (byte2 == 0) {
+            byte2 = UNSAFE.getByte(address++);
+            if (address >= addressLimit) {
+              return incompleteStateFor(byte1, byte2);
+            }
+          } else {
+            byte3 = (byte) (state >> 16);
+          }
+          if (byte3 == 0) {
+            byte3 = UNSAFE.getByte(address++);
+            if (address >= addressLimit) {
+              return incompleteStateFor(byte1, byte2, byte3);
+            }
+          }
+
+          // If we were called with state == MALFORMED, then byte1 is 0xFF,
+          // which never occurs in well-formed UTF-8, and so we will return
+          // MALFORMED again below.
+
+          if (byte2 > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || byte3 > (byte) 0xBF
+              // byte4 trailing-byte test
+              || UNSAFE.getByte(address++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+
+      return partialIsValidUtf8(address, (int) (addressLimit - address));
+    }
+
+    @Override
+    int encodeUtf8(final CharSequence in, final byte[] out, final int offset, final int length) {
+      long outIx = ARRAY_BASE_OFFSET + offset;
+      final long outLimit = outIx + length;
+      final int inLimit = in.length();
+      if (inLimit > length || out.length - length < offset) {
+        // Not even enough room for an ASCII-encoded string.
+        throw new ArrayIndexOutOfBoundsException(
+            "Failed writing " + in.charAt(inLimit - 1) + " at index " + (offset + length));
+      }
+
+      // Designed to take advantage of
+      // https://wikis.oracle.com/display/HotSpotInternals/RangeCheckElimination
+      int inIx = 0;
+      for (char c; inIx < inLimit && (c = in.charAt(inIx)) < 0x80; ++inIx) {
+        UNSAFE.putByte(out, outIx++, (byte) c);
+      }
+      if (inIx == inLimit) {
+        // We're done, it was ASCII encoded.
+        return (int) (outIx - ARRAY_BASE_OFFSET);
+      }
+
+      for (char c; inIx < inLimit; ++inIx) {
+        c = in.charAt(inIx);
+        if (c < 0x80 && outIx < outLimit) {
+          UNSAFE.putByte(out, outIx++, (byte) c);
+        } else if (c < 0x800 && outIx <= outLimit - 2L) { // 11 bits, two UTF-8 bytes
+          UNSAFE.putByte(out, outIx++, (byte) ((0xF << 6) | (c >>> 6)));
+          UNSAFE.putByte(out, outIx++, (byte) (0x80 | (0x3F & c)));
+        } else if ((c < MIN_SURROGATE || MAX_SURROGATE < c) && outIx <= outLimit - 3L) {
+          // Maximum single-char code point is 0xFFFF, 16 bits, three UTF-8 bytes
+          UNSAFE.putByte(out, outIx++, (byte) ((0xF << 5) | (c >>> 12)));
+          UNSAFE.putByte(out, outIx++, (byte) (0x80 | (0x3F & (c >>> 6))));
+          UNSAFE.putByte(out, outIx++, (byte) (0x80 | (0x3F & c)));
+        } else if (outIx <= outLimit - 4L) {
+          // Minimum code point represented by a surrogate pair is 0x10000, 17 bits, four UTF-8
+          // bytes
+          final char low;
+          if (inIx + 1 == inLimit || !isSurrogatePair(c, (low = in.charAt(++inIx)))) {
+            throw new UnpairedSurrogateException((inIx - 1), inLimit);
+          }
+          int codePoint = toCodePoint(c, low);
+          UNSAFE.putByte(out, outIx++, (byte) ((0xF << 4) | (codePoint >>> 18)));
+          UNSAFE.putByte(out, outIx++, (byte) (0x80 | (0x3F & (codePoint >>> 12))));
+          UNSAFE.putByte(out, outIx++, (byte) (0x80 | (0x3F & (codePoint >>> 6))));
+          UNSAFE.putByte(out, outIx++, (byte) (0x80 | (0x3F & codePoint)));
+        } else {
+          if ((MIN_SURROGATE <= c && c <= MAX_SURROGATE)
+              && (inIx + 1 == inLimit || !isSurrogatePair(c, in.charAt(inIx + 1)))) {
+            // We are surrogates and we're not a surrogate pair.
+            throw new UnpairedSurrogateException(inIx, inLimit);
+          }
+          // Not enough space in the output buffer.
+          throw new ArrayIndexOutOfBoundsException("Failed writing " + c + " at index " + outIx);
+        }
+      }
+
+      // All bytes have been encoded.
+      return (int) (outIx - ARRAY_BASE_OFFSET);
+    }
+
+    @Override
+    void encodeUtf8Direct(CharSequence in, ByteBuffer out) {
+      final long address = addressOffset(out);
+      long outIx = address + out.position();
+      final long outLimit = address + out.limit();
+      final int inLimit = in.length();
+      if (inLimit > outLimit - outIx) {
+        // Not even enough room for an ASCII-encoded string.
+        throw new ArrayIndexOutOfBoundsException(
+            "Failed writing " + in.charAt(inLimit - 1) + " at index " + out.limit());
+      }
+
+      // Designed to take advantage of
+      // https://wikis.oracle.com/display/HotSpotInternals/RangeCheckElimination
+      int inIx = 0;
+      for (char c; inIx < inLimit && (c = in.charAt(inIx)) < 0x80; ++inIx) {
+        UNSAFE.putByte(outIx++, (byte) c);
+      }
+      if (inIx == inLimit) {
+        // We're done, it was ASCII encoded.
+        out.position((int) (outIx - address));
+        return;
+      }
+
+      for (char c; inIx < inLimit; ++inIx) {
+        c = in.charAt(inIx);
+        if (c < 0x80 && outIx < outLimit) {
+          UNSAFE.putByte(outIx++, (byte) c);
+        } else if (c < 0x800 && outIx <= outLimit - 2L) { // 11 bits, two UTF-8 bytes
+          UNSAFE.putByte(outIx++, (byte) ((0xF << 6) | (c >>> 6)));
+          UNSAFE.putByte(outIx++, (byte) (0x80 | (0x3F & c)));
+        } else if ((c < MIN_SURROGATE || MAX_SURROGATE < c) && outIx <= outLimit - 3L) {
+          // Maximum single-char code point is 0xFFFF, 16 bits, three UTF-8 bytes
+          UNSAFE.putByte(outIx++, (byte) ((0xF << 5) | (c >>> 12)));
+          UNSAFE.putByte(outIx++, (byte) (0x80 | (0x3F & (c >>> 6))));
+          UNSAFE.putByte(outIx++, (byte) (0x80 | (0x3F & c)));
+        } else if (outIx <= outLimit - 4L) {
+          // Minimum code point represented by a surrogate pair is 0x10000, 17 bits, four UTF-8
+          // bytes
+          final char low;
+          if (inIx + 1 == inLimit || !isSurrogatePair(c, (low = in.charAt(++inIx)))) {
+            throw new UnpairedSurrogateException((inIx - 1), inLimit);
+          }
+          int codePoint = toCodePoint(c, low);
+          UNSAFE.putByte(outIx++, (byte) ((0xF << 4) | (codePoint >>> 18)));
+          UNSAFE.putByte(outIx++, (byte) (0x80 | (0x3F & (codePoint >>> 12))));
+          UNSAFE.putByte(outIx++, (byte) (0x80 | (0x3F & (codePoint >>> 6))));
+          UNSAFE.putByte(outIx++, (byte) (0x80 | (0x3F & codePoint)));
+        } else {
+          if ((MIN_SURROGATE <= c && c <= MAX_SURROGATE)
+              && (inIx + 1 == inLimit || !isSurrogatePair(c, in.charAt(inIx + 1)))) {
+            // We are surrogates and we're not a surrogate pair.
+            throw new UnpairedSurrogateException(inIx, inLimit);
+          }
+          // Not enough space in the output buffer.
+          throw new ArrayIndexOutOfBoundsException("Failed writing " + c + " at index " + outIx);
+        }
+      }
+
+      // All bytes have been encoded.
+      out.position((int) (outIx - address));
+    }
+
+    /**
+     * Counts (approximately) the number of consecutive ASCII characters starting from the given
+     * position, using the most efficient method available to the platform.
+     *
+     * @param bytes the array containing the character sequence
+     * @param offset the offset position of the index (same as index + arrayBaseOffset)
+     * @param maxChars the maximum number of characters to count
+     * @return the number of ASCII characters found. The stopping position will be at or
+     * before the first non-ASCII byte.
+     */
+    private static int unsafeEstimateConsecutiveAscii(
+        byte[] bytes, long offset, final int maxChars) {
+      int remaining = maxChars;
+      if (remaining < UNSAFE_COUNT_ASCII_THRESHOLD) {
+        // Don't bother with small strings.
+        return 0;
+      }
+
+      // Read bytes until 8-byte aligned so that we can read longs in the loop below.
+      // Byte arrays are already either 8 or 16-byte aligned, so we just need to make sure that
+      // the index (relative to the start of the array) is also 8-byte aligned. We do this by
+      // ANDing the index with 7 to determine the number of bytes that need to be read before
+      // we're 8-byte aligned.
+      final int unaligned = (int) offset & 7;
+      for (int j = unaligned; j > 0; j--) {
+        if (UNSAFE.getByte(bytes, offset++) < 0) {
+          return unaligned - j;
+        }
+      }
+
+      // This simple loop stops when we encounter a byte >= 0x80 (i.e. non-ASCII).
+      // To speed things up further, we're reading longs instead of bytes so we use a mask to
+      // determine if any byte in the current long is non-ASCII.
+      remaining -= unaligned;
+      for (; remaining >= 8 && (UNSAFE.getLong(bytes, offset) & ASCII_MASK_LONG) == 0;
+          offset += 8, remaining -= 8) {}
+      return maxChars - remaining;
+    }
+
+    /**
+     * Same as {@link Utf8#estimateConsecutiveAscii(ByteBuffer, int, int)} except that it uses the
+     * most efficient method available to the platform.
+     */
+    private static int unsafeEstimateConsecutiveAscii(long address, final int maxChars) {
+      int remaining = maxChars;
+      if (remaining < UNSAFE_COUNT_ASCII_THRESHOLD) {
+        // Don't bother with small strings.
+        return 0;
+      }
+
+      // Read bytes until 8-byte aligned so that we can read longs in the loop below.
+      // We do this by ANDing the address with 7 to determine the number of bytes that need to
+      // be read before we're 8-byte aligned.
+      final int unaligned = (int) address & 7;
+      for (int j = unaligned; j > 0; j--) {
+        if (UNSAFE.getByte(address++) < 0) {
+          return unaligned - j;
+        }
+      }
+
+      // This simple loop stops when we encounter a byte >= 0x80 (i.e. non-ASCII).
+      // To speed things up further, we're reading longs instead of bytes so we use a mask to
+      // determine if any byte in the current long is non-ASCII.
+      remaining -= unaligned;
+      for (; remaining >= 8 && (UNSAFE.getLong(address) & ASCII_MASK_LONG) == 0;
+          address += 8, remaining -= 8) {}
+      return maxChars - remaining;
+    }
+
+    private static int partialIsValidUtf8(final byte[] bytes, long offset, int remaining) {
+      // Skip past ASCII characters as quickly as possible. 
+      final int skipped = unsafeEstimateConsecutiveAscii(bytes, offset, remaining);
+      remaining -= skipped;
+      offset += skipped;
+
+      for (;;) {
+        // Optimize for interior runs of ASCII bytes.
+        // TODO(nathanmittler): Consider checking 8 bytes at a time after some threshold?
+        // Maybe after seeing a few in a row that are ASCII, go back to fast mode?
+        int byte1 = 0;
+        for (; remaining > 0 && (byte1 = UNSAFE.getByte(bytes, offset++)) >= 0; --remaining) {
+        }
+        if (remaining == 0) {
+          return COMPLETE;
+        }
+        remaining--;
+
+        // If we're here byte1 is not ASCII. Only need to handle 2-4 byte forms.
+        if (byte1 < (byte) 0xE0) {
+          // Two-byte form (110xxxxx 10xxxxxx)
+          if (remaining == 0) {
+            // Incomplete sequence
+            return byte1;
+          }
+          remaining--;
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // Three-byte form (1110xxxx 10xxxxxx 10xxxxxx)
+          if (remaining < 2) {
+            // Incomplete sequence
+            return unsafeIncompleteStateFor(bytes, byte1, offset, remaining);
+          }
+          remaining -= 2;
+
+          final int byte2;
+          if ((byte2 = UNSAFE.getByte(bytes, offset++)) > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // check for illegal surrogate codepoints
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // Four-byte form (1110xxxx 10xxxxxx 10xxxxxx 10xxxxxx)
+          if (remaining < 3) {
+            // Incomplete sequence
+            return unsafeIncompleteStateFor(bytes, byte1, offset, remaining);
+          }
+          remaining -= 3;
+
+          final int byte2;
+          if ((byte2 = UNSAFE.getByte(bytes, offset++)) > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF
+              // byte4 trailing-byte test
+              || UNSAFE.getByte(bytes, offset++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+    }
+
+    private static int partialIsValidUtf8(long address, int remaining) {
+      // Skip past ASCII characters as quickly as possible.
+      final int skipped = unsafeEstimateConsecutiveAscii(address, remaining);
+      address += skipped;
+      remaining -= skipped;
+
+      for (;;) {
+        // Optimize for interior runs of ASCII bytes.
+        // TODO(nathanmittler): Consider checking 8 bytes at a time after some threshold?
+        // Maybe after seeing a few in a row that are ASCII, go back to fast mode?
+        int byte1 = 0;
+        for (; remaining > 0 && (byte1 = UNSAFE.getByte(address++)) >= 0; --remaining) {
+        }
+        if (remaining == 0) {
+          return COMPLETE;
+        }
+        remaining--;
+
+        if (byte1 < (byte) 0xE0) {
+          // Two-byte form
+
+          if (remaining == 0) {
+            // Incomplete sequence
+            return byte1;
+          }
+          remaining--;
+
+          // Simultaneously checks for illegal trailing-byte in
+          // leading position and overlong 2-byte form.
+          if (byte1 < (byte) 0xC2 || UNSAFE.getByte(address++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else if (byte1 < (byte) 0xF0) {
+          // Three-byte form
+
+          if (remaining < 2) {
+            // Incomplete sequence
+            return unsafeIncompleteStateFor(address, byte1, remaining);
+          }
+          remaining -= 2;
+
+          final byte byte2 = UNSAFE.getByte(address++);
+          if (byte2 > (byte) 0xBF
+              // overlong? 5 most significant bits must not all be zero
+              || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
+              // check for illegal surrogate codepoints
+              || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
+              // byte3 trailing-byte test
+              || UNSAFE.getByte(address++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        } else {
+          // Four-byte form
+
+          if (remaining < 3) {
+            // Incomplete sequence
+            return unsafeIncompleteStateFor(address, byte1, remaining);
+          }
+          remaining -= 3;
+
+          final byte byte2 = UNSAFE.getByte(address++);
+          if (byte2 > (byte) 0xBF
+              // Check that 1 <= plane <= 16.  Tricky optimized form of:
+              // if (byte1 > (byte) 0xF4 ||
+              //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+              //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+              || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
+              // byte3 trailing-byte test
+              || UNSAFE.getByte(address++) > (byte) 0xBF
+              // byte4 trailing-byte test
+              || UNSAFE.getByte(address++) > (byte) 0xBF) {
+            return MALFORMED;
+          }
+        }
+      }
+    }
+
+    private static int unsafeIncompleteStateFor(byte[] bytes, int byte1, long offset,
+        int remaining) {
+      switch (remaining) {
+        case 0: {
+          return incompleteStateFor(byte1);
+        }
+        case 1: {
+          return incompleteStateFor(byte1, UNSAFE.getByte(bytes, offset));
+        }
+        case 2: {
+          return incompleteStateFor(byte1, UNSAFE.getByte(bytes, offset),
+              UNSAFE.getByte(bytes, offset + 1));
+        }
+        default: {
+          throw new AssertionError();
+        }
+      }
+    }
+
+    private static int unsafeIncompleteStateFor(long address, final int byte1, int remaining) {
+      switch (remaining) {
+        case 0: {
+          return incompleteStateFor(byte1);
+        }
+        case 1: {
+          return incompleteStateFor(byte1, UNSAFE.getByte(address));
+        }
+        case 2: {
+          return incompleteStateFor(byte1, UNSAFE.getByte(address), UNSAFE.getByte(address + 1));
+        }
+        default: {
+          throw new AssertionError();
+        }
+      }
+    }
+
+    /**
+     * Gets the field with the given name within the class, or {@code null} if not found. If
+     * found, the field is made accessible.
+     */
+    private static Field field(Class<?> clazz, String fieldName) {
+      Field field;
+      try {
+        field = clazz.getDeclaredField(fieldName);
+        field.setAccessible(true);
+      } catch (Throwable t) {
+        // Failed to access the fields.
+        field = null;
+      }
+      logger.log(Level.FINEST, "{0}.{1}: {2}",
+          new Object[] {clazz.getName(), fieldName, (field != null ? "available" : "unavailable")});
+      return field;
+    }
+
+    /**
+     * Returns the offset of the provided field, or {@code -1} if {@code sun.misc.Unsafe} is not
+     * available.
+     */
+    private static long fieldOffset(Field field) {
+      return field == null || UNSAFE == null ? -1 : UNSAFE.objectFieldOffset(field);
+    }
+
+    /**
+     * Get the base offset for byte arrays, or {@code -1} if {@code sun.misc.Unsafe} is not
+     * available.
+     */
+    private static <T> int byteArrayBaseOffset() {
+      return UNSAFE == null ? -1 : UNSAFE.arrayBaseOffset(byte[].class);
+    }
+
+    /**
+     * Gets the offset of the {@code address} field of the given direct {@link ByteBuffer}.
+     */
+    private static long addressOffset(ByteBuffer buffer) {
+      return UNSAFE.getLong(buffer, BUFFER_ADDRESS_OFFSET);
+    }
+
+    /**
+     * Gets the {@code sun.misc.Unsafe} instance, or {@code null} if not available on this
+     * platform.
+     */
+    private static sun.misc.Unsafe getUnsafe() {
+      sun.misc.Unsafe unsafe = null;
+      try {
+        unsafe = AccessController.doPrivileged(new PrivilegedExceptionAction<sun.misc.Unsafe>() {
+          @Override
+          public sun.misc.Unsafe run() throws Exception {
+            Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
+
+            // Check that this platform supports all of the required unsafe methods.
+            checkRequiredMethods(k);
+
+            for (Field f : k.getDeclaredFields()) {
+              f.setAccessible(true);
+              Object x = f.get(null);
+              if (k.isInstance(x)) {
+                return k.cast(x);
+              }
+            }
+            // The sun.misc.Unsafe field does not exist.
+            return null;
+          }
+        });
+      } catch (Throwable e) {
+        // Catching Throwable here due to the fact that Google AppEngine raises NoClassDefFoundError
+        // for Unsafe.
+      }
+
+      logger.log(Level.FINEST, "sun.misc.Unsafe: {}",
+          unsafe != null ? "available" : "unavailable");
+      return unsafe;
+    }
+
+    /**
+     * Verifies that all required methods of {@code sun.misc.Unsafe} are available on this platform.
+     */
+    private static void checkRequiredMethods(Class<sun.misc.Unsafe> clazz)
+        throws NoSuchMethodException, SecurityException {
+      // Needed for Unsafe byte[] access
+      clazz.getMethod("arrayBaseOffset", Class.class);
+      clazz.getMethod("getByte", Object.class, long.class);
+      clazz.getMethod("putByte", Object.class, long.class, byte.class);
+      clazz.getMethod("getLong", Object.class, long.class);
+
+      // Needed for Unsafe Direct ByteBuffer access
+      clazz.getMethod("objectFieldOffset", Field.class);
+      clazz.getMethod("getByte", long.class);
+      clazz.getMethod("getLong", Object.class, long.class);
+      clazz.getMethod("putByte", long.class, byte.class);
+      clazz.getMethod("getLong", long.class);
+    }
+  }
+
+  private Utf8() {}
+}
diff --git a/java/src/main/java/com/google/protobuf/WireFormat.java b/java/core/src/main/java/com/google/protobuf/WireFormat.java
index 8dbe1ae3..6a58b081 100644
--- a/java/src/main/java/com/google/protobuf/WireFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/WireFormat.java
@@ -116,16 +116,24 @@ public final class WireFormat {
     FIXED32 (JavaType.INT        , WIRETYPE_FIXED32         ),
     BOOL    (JavaType.BOOLEAN    , WIRETYPE_VARINT          ),
     STRING  (JavaType.STRING     , WIRETYPE_LENGTH_DELIMITED) {
-      public boolean isPackable() { return false; }
+      @Override
+      public boolean isPackable() {
+        return false; }
     },
     GROUP   (JavaType.MESSAGE    , WIRETYPE_START_GROUP     ) {
-      public boolean isPackable() { return false; }
+      @Override
+      public boolean isPackable() {
+        return false; }
     },
     MESSAGE (JavaType.MESSAGE    , WIRETYPE_LENGTH_DELIMITED) {
-      public boolean isPackable() { return false; }
+      @Override
+      public boolean isPackable() {
+        return false; }
     },
     BYTES   (JavaType.BYTE_STRING, WIRETYPE_LENGTH_DELIMITED) {
-      public boolean isPackable() { return false; }
+      @Override
+      public boolean isPackable() {
+        return false; }
     },
     UINT32  (JavaType.INT        , WIRETYPE_VARINT          ),
     ENUM    (JavaType.ENUM       , WIRETYPE_VARINT          ),
@@ -170,18 +178,21 @@ public final class WireFormat {
   enum Utf8Validation {
     /** Eagerly parses to String; silently accepts invalid UTF8 bytes. */
     LOOSE {
+      @Override
       Object readString(CodedInputStream input) throws IOException {
         return input.readString();
       }
     },
     /** Eagerly parses to String; throws an IOException on invalid bytes. */
     STRICT {
+      @Override
       Object readString(CodedInputStream input) throws IOException {
         return input.readStringRequireUtf8();
       }
     },
     /** Keep data as ByteString; validation/conversion to String is lazy. */
     LAZY {
+      @Override
       Object readString(CodedInputStream input) throws IOException {
         return input.readBytes();
       }
diff --git a/java/src/test/java/com/google/protobuf/AbstractMessageTest.java b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
index d964ef59..7dc9fc15 100644
--- a/java/src/test/java/com/google/protobuf/AbstractMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
@@ -40,7 +40,6 @@ import protobuf_unittest.UnittestProto.TestPackedTypes;
 import protobuf_unittest.UnittestProto.TestRequired;
 import protobuf_unittest.UnittestProto.TestRequiredForeign;
 import protobuf_unittest.UnittestProto.TestUnpackedTypes;
-
 import junit.framework.TestCase;
 
 import java.util.Map;
@@ -65,35 +64,44 @@ public class AbstractMessageTest extends TestCase {
       this.wrappedMessage = wrappedMessage;
     }
 
+    @Override
     public Descriptors.Descriptor getDescriptorForType() {
       return wrappedMessage.getDescriptorForType();
     }
+    @Override
     public AbstractMessageWrapper getDefaultInstanceForType() {
       return new AbstractMessageWrapper(
         wrappedMessage.getDefaultInstanceForType());
     }
+    @Override
     public Map<Descriptors.FieldDescriptor, Object> getAllFields() {
       return wrappedMessage.getAllFields();
     }
+    @Override
     public boolean hasField(Descriptors.FieldDescriptor field) {
       return wrappedMessage.hasField(field);
     }
+    @Override
     public Object getField(Descriptors.FieldDescriptor field) {
       return wrappedMessage.getField(field);
     }
+    @Override
     public int getRepeatedFieldCount(Descriptors.FieldDescriptor field) {
       return wrappedMessage.getRepeatedFieldCount(field);
     }
-    public Object getRepeatedField(
-        Descriptors.FieldDescriptor field, int index) {
+    @Override
+    public Object getRepeatedField(Descriptors.FieldDescriptor field, int index) {
       return wrappedMessage.getRepeatedField(field, index);
     }
+    @Override
     public UnknownFieldSet getUnknownFields() {
       return wrappedMessage.getUnknownFields();
     }
+    @Override
     public Builder newBuilderForType() {
       return new Builder(wrappedMessage.newBuilderForType());
     }
+    @Override
     public Builder toBuilder() {
       return new Builder(wrappedMessage.toBuilder());
     }
@@ -105,65 +113,80 @@ public class AbstractMessageTest extends TestCase {
         this.wrappedBuilder = wrappedBuilder;
       }
 
+      @Override
       public AbstractMessageWrapper build() {
         return new AbstractMessageWrapper(wrappedBuilder.build());
       }
+      @Override
       public AbstractMessageWrapper buildPartial() {
         return new AbstractMessageWrapper(wrappedBuilder.buildPartial());
       }
+      @Override
       public Builder clone() {
         return new Builder(wrappedBuilder.clone());
       }
+      @Override
       public boolean isInitialized() {
         return clone().buildPartial().isInitialized();
       }
+      @Override
       public Descriptors.Descriptor getDescriptorForType() {
         return wrappedBuilder.getDescriptorForType();
       }
+      @Override
       public AbstractMessageWrapper getDefaultInstanceForType() {
         return new AbstractMessageWrapper(
           wrappedBuilder.getDefaultInstanceForType());
       }
+      @Override
       public Map<Descriptors.FieldDescriptor, Object> getAllFields() {
         return wrappedBuilder.getAllFields();
       }
+      @Override
       public Builder newBuilderForField(Descriptors.FieldDescriptor field) {
         return new Builder(wrappedBuilder.newBuilderForField(field));
       }
+      @Override
       public boolean hasField(Descriptors.FieldDescriptor field) {
         return wrappedBuilder.hasField(field);
       }
+      @Override
       public Object getField(Descriptors.FieldDescriptor field) {
         return wrappedBuilder.getField(field);
       }
+      @Override
       public Builder setField(Descriptors.FieldDescriptor field, Object value) {
         wrappedBuilder.setField(field, value);
         return this;
       }
+      @Override
       public Builder clearField(Descriptors.FieldDescriptor field) {
         wrappedBuilder.clearField(field);
         return this;
       }
+      @Override
       public int getRepeatedFieldCount(Descriptors.FieldDescriptor field) {
         return wrappedBuilder.getRepeatedFieldCount(field);
       }
-      public Object getRepeatedField(
-          Descriptors.FieldDescriptor field, int index) {
+      @Override
+      public Object getRepeatedField(Descriptors.FieldDescriptor field, int index) {
         return wrappedBuilder.getRepeatedField(field, index);
       }
-      public Builder setRepeatedField(Descriptors.FieldDescriptor field,
-                                      int index, Object value) {
+      @Override
+      public Builder setRepeatedField(Descriptors.FieldDescriptor field, int index, Object value) {
         wrappedBuilder.setRepeatedField(field, index, value);
         return this;
       }
-      public Builder addRepeatedField(
-          Descriptors.FieldDescriptor field, Object value) {
+      @Override
+      public Builder addRepeatedField(Descriptors.FieldDescriptor field, Object value) {
         wrappedBuilder.addRepeatedField(field, value);
         return this;
       }
+      @Override
       public UnknownFieldSet getUnknownFields() {
         return wrappedBuilder.getUnknownFields();
       }
+      @Override
       public Builder setUnknownFields(UnknownFieldSet unknownFields) {
         wrappedBuilder.setUnknownFields(unknownFields);
         return this;
@@ -173,6 +196,7 @@ public class AbstractMessageTest extends TestCase {
         return wrappedBuilder.getFieldBuilder(field);
       }
     }
+    @Override
     public Parser<? extends Message> getParserForType() {
       return wrappedMessage.getParserForType();
     }
diff --git a/java/src/test/java/com/google/protobuf/AnyTest.java b/java/core/src/test/java/com/google/protobuf/AnyTest.java
index e169f69d..cf91ed91 100644
--- a/java/src/test/java/com/google/protobuf/AnyTest.java
+++ b/java/core/src/test/java/com/google/protobuf/AnyTest.java
@@ -75,6 +75,51 @@ public class AnyTest extends TestCase {
     }
   }
 
+  public void testCustomTypeUrls() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+
+    TestAny container = TestAny.newBuilder()
+        .setValue(Any.pack(message, "xxx.com")).build();
+
+    assertEquals(
+        "xxx.com/" + TestAllTypes.getDescriptor().getFullName(),
+        container.getValue().getTypeUrl());
+
+    assertTrue(container.getValue().is(TestAllTypes.class));
+    assertFalse(container.getValue().is(TestAny.class));
+
+    TestAllTypes result = container.getValue().unpack(TestAllTypes.class);
+    TestUtil.assertAllFieldsSet(result);
+
+    container = TestAny.newBuilder()
+        .setValue(Any.pack(message, "yyy.com/")).build();
+
+    assertEquals(
+        "yyy.com/" + TestAllTypes.getDescriptor().getFullName(),
+        container.getValue().getTypeUrl());
+
+    assertTrue(container.getValue().is(TestAllTypes.class));
+    assertFalse(container.getValue().is(TestAny.class));
+
+    result = container.getValue().unpack(TestAllTypes.class);
+    TestUtil.assertAllFieldsSet(result);
+
+    container = TestAny.newBuilder()
+        .setValue(Any.pack(message, "")).build();
+
+    assertEquals(
+        "/" + TestAllTypes.getDescriptor().getFullName(),
+        container.getValue().getTypeUrl());
+
+    assertTrue(container.getValue().is(TestAllTypes.class));
+    assertFalse(container.getValue().is(TestAny.class));
+
+    result = container.getValue().unpack(TestAllTypes.class);
+    TestUtil.assertAllFieldsSet(result);
+  }
+
   public void testCachedUnpackResult() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TestUtil.setAllFields(builder);
diff --git a/java/src/test/java/com/google/protobuf/BooleanArrayListTest.java b/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java
index df89c263..24b96c60 100644
--- a/java/src/test/java/com/google/protobuf/BooleanArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java
@@ -73,20 +73,6 @@ public class BooleanArrayListTest extends TestCase {
     assertImmutable(list);
   }
   
-  public void testCopyConstructor() {
-    BooleanArrayList copy = new BooleanArrayList(TERTIARY_LIST);
-    assertEquals(TERTIARY_LIST, copy);
-
-    copy = new BooleanArrayList(BooleanArrayList.emptyList());
-    assertEquals(BooleanArrayList.emptyList(), copy);
-    
-    copy = new BooleanArrayList(asList(false, false, true));
-    assertEquals(asList(false, false, true), copy);
-
-    copy = new BooleanArrayList(Collections.<Boolean>emptyList());
-    assertEquals(BooleanArrayList.emptyList(), copy);
-  }
-  
   public void testModificationWithIteration() {
     list.addAll(asList(true, false, false, true));
     Iterator<Boolean> iterator = list.iterator();
@@ -310,10 +296,6 @@ public class BooleanArrayListTest extends TestCase {
   }
   
   private void assertImmutable(BooleanArrayList list) {
-    if (list.contains(1)) {
-      throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
-    }
-    
     try {
       list.add(false);
       fail();
@@ -413,7 +395,7 @@ public class BooleanArrayListTest extends TestCase {
     }
     
     try {
-      list.removeAll(Collections.singleton(1));
+      list.removeAll(Collections.singleton(Boolean.TRUE));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
@@ -434,7 +416,7 @@ public class BooleanArrayListTest extends TestCase {
     }
     
     try {
-      list.retainAll(Collections.singleton(1));
+      list.retainAll(Collections.singleton(Boolean.TRUE));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
diff --git a/java/src/test/java/com/google/protobuf/BoundedByteStringTest.java b/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java
index 447e6ef3..db10ee74 100644
--- a/java/src/test/java/com/google/protobuf/BoundedByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java
@@ -37,7 +37,6 @@ import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.UnsupportedEncodingException;
 
-
 /**
  * This class tests {@link BoundedByteString}, which extends {@link LiteralByteString},
  * by inheriting the tests from {@link LiteralByteStringTest}.  The only method which
@@ -62,7 +61,7 @@ public class BoundedByteStringTest extends LiteralByteStringTest {
   @Override
   public void testToString() throws UnsupportedEncodingException {
     String testString = "I love unicode \u1234\u5678 characters";
-    LiteralByteString unicode = new LiteralByteString(testString.getBytes(Internal.UTF_8));
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
     ByteString chopped = unicode.substring(2, unicode.size() - 6);
     assertEquals(classUnderTest + ".substring() must have the expected type",
         classUnderTest, getActualClassName(chopped));
@@ -73,9 +72,9 @@ public class BoundedByteStringTest extends LiteralByteStringTest {
   }
 
   @Override
-  public void testCharsetToString() throws UnsupportedEncodingException {
+  public void testCharsetToString() {
     String testString = "I love unicode \u1234\u5678 characters";
-    LiteralByteString unicode = new LiteralByteString(testString.getBytes(Internal.UTF_8));
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
     ByteString chopped = unicode.substring(2, unicode.size() - 6);
     assertEquals(classUnderTest + ".substring() must have the expected type",
         classUnderTest, getActualClassName(chopped));
diff --git a/java/core/src/test/java/com/google/protobuf/ByteBufferWriterTest.java b/java/core/src/test/java/com/google/protobuf/ByteBufferWriterTest.java
new file mode 100644
index 00000000..cbe742e5
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ByteBufferWriterTest.java
@@ -0,0 +1,81 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Random;
+
+/**
+ * Tests for {@link ByteBufferWriter}.
+ */
+public class ByteBufferWriterTest extends TestCase {
+
+  public void testHeapBuffer() throws IOException {
+    // Test a small and large buffer.
+    testWrite(ByteBuffer.allocate(100));
+    testWrite(ByteBuffer.allocate(1024 * 100));
+  }
+
+  public void testDirectBuffer() throws IOException {
+    // Test a small and large buffer.
+    testWrite(ByteBuffer.allocateDirect(100));
+    testWrite(ByteBuffer.allocateDirect(1024 * 100));
+  }
+
+  private void testWrite(ByteBuffer buffer) throws IOException {
+    fillRandom(buffer);
+    ByteArrayOutputStream os = new ByteArrayOutputStream(buffer.remaining());
+    ByteBufferWriter.write(buffer, os);
+    assertEquals(0, buffer.position());
+    assertTrue(Arrays.equals(toArray(buffer), os.toByteArray()));
+  }
+
+  private void fillRandom(ByteBuffer buf) {
+    byte[] bytes = new byte[buf.remaining()];
+    new Random().nextBytes(bytes);
+    buf.put(bytes);
+    buf.flip();
+    return;
+  }
+
+  private byte[] toArray(ByteBuffer buf) {
+    int originalPosition = buf.position();
+    byte[] bytes = new byte[buf.remaining()];
+    buf.get(bytes);
+    buf.position(originalPosition);
+    return bytes;
+  }
+}
diff --git a/java/src/test/java/com/google/protobuf/ByteStringTest.java b/java/core/src/test/java/com/google/protobuf/ByteStringTest.java
index 8af5dcde..ad9f266e 100644
--- a/java/src/test/java/com/google/protobuf/ByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ByteStringTest.java
@@ -39,7 +39,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.io.UnsupportedEncodingException;
+import java.lang.reflect.Field;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
@@ -129,7 +129,7 @@ public class ByteStringTest extends TestCase {
         isArrayRange(byteString.toByteArray(), bytes, 500, bytes.length - 500));
   }
 
-  public void testCopyFrom_StringEncoding() throws UnsupportedEncodingException {
+  public void testCopyFrom_StringEncoding() {
     String testString = "I love unicode \u1234\u5678 characters";
     ByteString byteString = ByteString.copyFrom(testString, UTF_16);
     byte[] testBytes = testString.getBytes(UTF_16);
@@ -137,7 +137,7 @@ public class ByteStringTest extends TestCase {
         isArrayRange(byteString.toByteArray(), testBytes, 0, testBytes.length));
   }
 
-  public void testCopyFrom_Utf8() throws UnsupportedEncodingException {
+  public void testCopyFrom_Utf8() {
     String testString = "I love unicode \u1234\u5678 characters";
     ByteString byteString = ByteString.copyFromUtf8(testString);
     byte[] testBytes = testString.getBytes(Internal.UTF_8);
@@ -154,6 +154,7 @@ public class ByteStringTest extends TestCase {
         isArrayRange(byteString.toByteArray(), testBytes, 0, testBytes.length));
     // Call copyFrom on an iteration that's not a collection
     ByteString byteStringAlt = ByteString.copyFrom(new Iterable<ByteString>() {
+      @Override
       public Iterator<ByteString> iterator() {
         return pieces.iterator();
       }
@@ -399,7 +400,7 @@ public class ByteStringTest extends TestCase {
     }
   }
 
-  public void testToStringUtf8() throws UnsupportedEncodingException {
+  public void testToStringUtf8() {
     String testString = "I love unicode \u1234\u5678 characters";
     byte[] testBytes = testString.getBytes(Internal.UTF_8);
     ByteString byteString = ByteString.copyFrom(testBytes);
@@ -419,7 +420,7 @@ public class ByteStringTest extends TestCase {
 
   // Test newOutput() using a variety of buffer sizes and a variety of (fixed)
   // write sizes
-  public void testNewOutput_ArrayWrite() throws IOException {
+  public void testNewOutput_ArrayWrite() {
     byte[] bytes = getTestBytes();
     int length = bytes.length;
     int[] bufferSizes = {128, 256, length / 2, length - 1, length, length + 1,
@@ -442,7 +443,7 @@ public class ByteStringTest extends TestCase {
 
   // Test newOutput() using a variety of buffer sizes, but writing all the
   // characters using write(byte);
-  public void testNewOutput_WriteChar() throws IOException {
+  public void testNewOutput_WriteChar() {
     byte[] bytes = getTestBytes();
     int length = bytes.length;
     int[] bufferSizes = {0, 1, 128, 256, length / 2,
@@ -461,7 +462,7 @@ public class ByteStringTest extends TestCase {
 
   // Test newOutput() in which we write the bytes using a variety of methods
   // and sizes, and in which we repeatedly call toByteString() in the middle.
-  public void testNewOutput_Mixed() throws IOException {
+  public void testNewOutput_Mixed() {
     Random rng = new Random(1);
     byte[] bytes = getTestBytes();
     int length = bytes.length;
@@ -494,7 +495,7 @@ public class ByteStringTest extends TestCase {
     }
   }
 
-  public void testNewOutputEmpty() throws IOException {
+  public void testNewOutputEmpty() {
     // Make sure newOutput() correctly builds empty byte strings
     ByteString byteString = ByteString.newOutput().toByteString();
     assertEquals(ByteString.EMPTY, byteString);
@@ -655,11 +656,11 @@ public class ByteStringTest extends TestCase {
     // trees of empty leaves, to make a string that will fail this test.
     for (int i = 1; i < duo.size(); ++i) {
       assertTrue("Substrings of size() < 2 must not be RopeByteStrings",
-          duo.substring(i - 1, i) instanceof LiteralByteString);
+          duo.substring(i - 1, i) instanceof ByteString.LeafByteString);
     }
     for (int i = 1; i < quintet.size(); ++i) {
       assertTrue("Substrings of size() < 2 must not be RopeByteStrings",
-          quintet.substring(i - 1, i) instanceof LiteralByteString);
+          quintet.substring(i - 1, i) instanceof ByteString.LeafByteString);
     }
   }
 
@@ -724,7 +725,7 @@ public class ByteStringTest extends TestCase {
     }
     data1[1] = (byte) 11;
     // Test LiteralByteString.writeTo(OutputStream,int,int)
-    LiteralByteString left = new LiteralByteString(data1);
+    ByteString left = ByteString.wrap(data1);
     byte[] result = substringUsingWriteTo(left, 1, 1);
     assertEquals(1, result.length);
     assertEquals((byte) 11, result[0]);
@@ -733,7 +734,7 @@ public class ByteStringTest extends TestCase {
     for (int i = 0; i < data1.length; i++) {
       data2[i] = (byte) 2;
     }
-    LiteralByteString right = new LiteralByteString(data2);
+    ByteString right = ByteString.wrap(data2);
     // Concatenate two ByteStrings to create a RopeByteString.
     ByteString root = left.concat(right);
     // Make sure we are actually testing a RopeByteString with a simple tree
@@ -757,4 +758,17 @@ public class ByteStringTest extends TestCase {
     assertEquals((byte) 2, result[dataSize - dataSize / 2]);
     assertEquals((byte) 2, result[dataSize - 1]);
   }
+  
+  /**
+   * Tests ByteString uses Arrays based byte copier when running under Hotstop VM.
+   */
+  public void testByteArrayCopier() throws Exception {
+    Field field = ByteString.class.getDeclaredField("byteArrayCopier");
+    field.setAccessible(true);
+    Object byteArrayCopier = field.get(null);
+    assertNotNull(byteArrayCopier);
+    assertTrue(
+        byteArrayCopier.toString(),
+        byteArrayCopier.getClass().getSimpleName().endsWith("ArraysByteArrayCopier"));
+  }
 }
diff --git a/java/src/test/java/com/google/protobuf/CheckUtf8Test.java b/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java
index 3d6381c9..cc65d19a 100644
--- a/java/src/test/java/com/google/protobuf/CheckUtf8Test.java
+++ b/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java
@@ -34,6 +34,7 @@ import proto2_test_check_utf8.TestCheckUtf8.BytesWrapper;
 import proto2_test_check_utf8.TestCheckUtf8.StringWrapper;
 import proto2_test_check_utf8_size.TestCheckUtf8Size.BytesWrapperSize;
 import proto2_test_check_utf8_size.TestCheckUtf8Size.StringWrapperSize;
+
 import junit.framework.TestCase;
 
 /**
diff --git a/java/src/test/java/com/google/protobuf/CodedInputStreamTest.java b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
index 18d8142c..ca940ced 100644
--- a/java/src/test/java/com/google/protobuf/CodedInputStreamTest.java
+++ b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
@@ -81,10 +81,12 @@ public class CodedInputStreamTest extends TestCase {
       this.blockSize = blockSize;
     }
 
+    @Override
     public int read(byte[] b) throws IOException {
       return super.read(b, 0, Math.min(b.length, blockSize));
     }
 
+    @Override
     public int read(byte[] b, int off, int len) throws IOException {
       return super.read(b, off, Math.min(len, blockSize));
     }
@@ -547,6 +549,56 @@ public class CodedInputStreamTest extends TestCase {
     }
   }
 
+  public void testReadString() throws Exception {
+    String lorem = "Lorem ipsum dolor sit amet ";
+    StringBuilder builder = new StringBuilder();
+    for (int i = 0; i < 4096; i += lorem.length()) {
+      builder.append(lorem);
+    }
+    lorem = builder.toString().substring(0, 4096);
+    byte[] bytes = lorem.getBytes("UTF-8");
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput, bytes.length);
+
+    int tag = WireFormat.makeTag(1, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+    output.writeRawVarint32(tag);
+    output.writeRawVarint32(bytes.length);
+    output.writeRawBytes(bytes);
+    output.flush();
+
+    CodedInputStream input =
+        CodedInputStream.newInstance(
+            new ByteArrayInputStream(rawOutput.toByteString().toByteArray()));
+    assertEquals(tag, input.readTag());
+    String text = input.readString();
+    assertEquals(lorem, text);
+  }
+
+  public void testReadStringRequireUtf8() throws Exception {
+    String lorem = "Lorem ipsum dolor sit amet ";
+    StringBuilder builder = new StringBuilder();
+    for (int i = 0; i < 4096; i += lorem.length()) {
+      builder.append(lorem);
+    }
+    lorem = builder.toString().substring(0, 4096);
+    byte[] bytes = lorem.getBytes("UTF-8");
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput, bytes.length);
+
+    int tag = WireFormat.makeTag(1, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+    output.writeRawVarint32(tag);
+    output.writeRawVarint32(bytes.length);
+    output.writeRawBytes(bytes);
+    output.flush();
+
+    CodedInputStream input =
+        CodedInputStream.newInstance(
+            new ByteArrayInputStream(rawOutput.toByteString().toByteArray()));
+    assertEquals(tag, input.readTag());
+    String text = input.readStringRequireUtf8();
+    assertEquals(lorem, text);
+  }
+
   /**
    * Tests that if we readString invalid UTF-8 bytes, no exception
    * is thrown.  Instead, the invalid bytes are replaced with the Unicode
diff --git a/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java b/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
new file mode 100644
index 00000000..33aa4357
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
@@ -0,0 +1,776 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.CodedOutputStream.OutOfSpaceException;
+import protobuf_unittest.UnittestProto.SparseEnumMessage;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestProto.TestSparseEnum;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Unit test for {@link CodedOutputStream}.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class CodedOutputStreamTest extends TestCase {
+  private interface Coder {
+    CodedOutputStream stream();
+
+    byte[] toByteArray();
+
+    OutputType getOutputType();
+  }
+
+  private static final class OutputStreamCoder implements Coder {
+    private final CodedOutputStream stream;
+    private final ByteArrayOutputStream output;
+
+    OutputStreamCoder(int size) {
+      output = new ByteArrayOutputStream();
+      stream = CodedOutputStream.newInstance(output, size);
+    }
+
+    @Override
+    public CodedOutputStream stream() {
+      return stream;
+    }
+
+    @Override
+    public byte[] toByteArray() {
+      return output.toByteArray();
+    }
+
+    @Override
+    public OutputType getOutputType() {
+      return OutputType.STREAM;
+    }
+  }
+
+  private static final class ArrayCoder implements Coder {
+    private final CodedOutputStream stream;
+    private final byte[] bytes;
+
+    ArrayCoder(int size) {
+      bytes = new byte[size];
+      stream = CodedOutputStream.newInstance(bytes);
+    }
+
+    @Override
+    public CodedOutputStream stream() {
+      return stream;
+    }
+
+    @Override
+    public byte[] toByteArray() {
+      return Arrays.copyOf(bytes, stream.getTotalBytesWritten());
+    }
+
+    @Override
+    public OutputType getOutputType() {
+      return OutputType.ARRAY;
+    }
+  }
+
+  private static final class NioHeapCoder implements Coder {
+    private final CodedOutputStream stream;
+    private final ByteBuffer buffer;
+    private final int initialPosition;
+
+    NioHeapCoder(int size) {
+      this(size, 0);
+    }
+
+    NioHeapCoder(int size, int initialPosition) {
+      this.initialPosition = initialPosition;
+      buffer = ByteBuffer.allocate(size);
+      buffer.position(initialPosition);
+      stream = CodedOutputStream.newInstance(buffer);
+    }
+
+    @Override
+    public CodedOutputStream stream() {
+      return stream;
+    }
+
+    @Override
+    public byte[] toByteArray() {
+      ByteBuffer dup = buffer.duplicate();
+      dup.position(initialPosition);
+      dup.limit(buffer.position());
+
+      byte[] bytes = new byte[dup.remaining()];
+      dup.get(bytes);
+      return bytes;
+    }
+
+    @Override
+    public OutputType getOutputType() {
+      return OutputType.NIO_HEAP;
+    }
+  }
+
+  private static final class NioDirectCoder implements Coder {
+    private final int initialPosition;
+    private final CodedOutputStream stream;
+    private final ByteBuffer buffer;
+
+    NioDirectCoder(int size) {
+      this(size, 0);
+    }
+
+    NioDirectCoder(int size, int initialPosition) {
+      this.initialPosition = initialPosition;
+      buffer = ByteBuffer.allocateDirect(size);
+      buffer.position(initialPosition);
+      stream = CodedOutputStream.newInstance(buffer);
+    }
+
+    @Override
+    public CodedOutputStream stream() {
+      return stream;
+    }
+
+    @Override
+    public byte[] toByteArray() {
+      ByteBuffer dup = buffer.duplicate();
+      dup.position(initialPosition);
+      dup.limit(buffer.position());
+
+      byte[] bytes = new byte[dup.remaining()];
+      dup.get(bytes);
+      return bytes;
+    }
+
+    @Override
+    public OutputType getOutputType() {
+      return OutputType.NIO_DIRECT;
+    }
+  }
+
+  private enum OutputType {
+    ARRAY() {
+      @Override
+      Coder newCoder(int size) {
+        return new ArrayCoder(size);
+      }
+    },
+    NIO_HEAP() {
+      @Override
+      Coder newCoder(int size) {
+        return new NioHeapCoder(size);
+      }
+    },
+    NIO_DIRECT() {
+      @Override
+      Coder newCoder(int size) {
+        return new NioDirectCoder(size);
+      }
+    },
+    STREAM() {
+      @Override
+      Coder newCoder(int size) {
+        return new OutputStreamCoder(size);
+      }
+    };
+
+    abstract Coder newCoder(int size);
+  }
+
+  /** Checks that invariants are maintained for varint round trip input and output. */
+  public void testVarintRoundTrips() throws Exception {
+    for (OutputType outputType : OutputType.values()) {
+      assertVarintRoundTrip(outputType, 0L);
+      for (int bits = 0; bits < 64; bits++) {
+        long value = 1L << bits;
+        assertVarintRoundTrip(outputType, value);
+        assertVarintRoundTrip(outputType, value + 1);
+        assertVarintRoundTrip(outputType, value - 1);
+        assertVarintRoundTrip(outputType, -value);
+      }
+    }
+  }
+
+  /** Tests writeRawVarint32() and writeRawVarint64(). */
+  public void testWriteVarint() throws Exception {
+    assertWriteVarint(bytes(0x00), 0);
+    assertWriteVarint(bytes(0x01), 1);
+    assertWriteVarint(bytes(0x7f), 127);
+    // 14882
+    assertWriteVarint(bytes(0xa2, 0x74), (0x22 << 0) | (0x74 << 7));
+    // 2961488830
+    assertWriteVarint(
+        bytes(0xbe, 0xf7, 0x92, 0x84, 0x0b),
+        (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) | (0x0bL << 28));
+
+    // 64-bit
+    // 7256456126
+    assertWriteVarint(
+        bytes(0xbe, 0xf7, 0x92, 0x84, 0x1b),
+        (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) | (0x1bL << 28));
+    // 41256202580718336
+    assertWriteVarint(
+        bytes(0x80, 0xe6, 0xeb, 0x9c, 0xc3, 0xc9, 0xa4, 0x49),
+        (0x00 << 0) | (0x66 << 7) | (0x6b << 14) | (0x1c << 21) | (0x43L << 28) | (0x49L << 35)
+        | (0x24L << 42) | (0x49L << 49));
+    // 11964378330978735131
+    assertWriteVarint(
+        bytes(0x9b, 0xa8, 0xf9, 0xc2, 0xbb, 0xd6, 0x80, 0x85, 0xa6, 0x01),
+        (0x1b << 0) | (0x28 << 7) | (0x79 << 14) | (0x42 << 21) | (0x3bL << 28) | (0x56L << 35)
+        | (0x00L << 42) | (0x05L << 49) | (0x26L << 56) | (0x01L << 63));
+  }
+
+  /** Tests writeRawLittleEndian32() and writeRawLittleEndian64(). */
+  public void testWriteLittleEndian() throws Exception {
+    assertWriteLittleEndian32(bytes(0x78, 0x56, 0x34, 0x12), 0x12345678);
+    assertWriteLittleEndian32(bytes(0xf0, 0xde, 0xbc, 0x9a), 0x9abcdef0);
+
+    assertWriteLittleEndian64(
+        bytes(0xf0, 0xde, 0xbc, 0x9a, 0x78, 0x56, 0x34, 0x12), 0x123456789abcdef0L);
+    assertWriteLittleEndian64(
+        bytes(0x78, 0x56, 0x34, 0x12, 0xf0, 0xde, 0xbc, 0x9a), 0x9abcdef012345678L);
+  }
+
+  /** Test encodeZigZag32() and encodeZigZag64(). */
+  public void testEncodeZigZag() throws Exception {
+    assertEquals(0, CodedOutputStream.encodeZigZag32(0));
+    assertEquals(1, CodedOutputStream.encodeZigZag32(-1));
+    assertEquals(2, CodedOutputStream.encodeZigZag32(1));
+    assertEquals(3, CodedOutputStream.encodeZigZag32(-2));
+    assertEquals(0x7FFFFFFE, CodedOutputStream.encodeZigZag32(0x3FFFFFFF));
+    assertEquals(0x7FFFFFFF, CodedOutputStream.encodeZigZag32(0xC0000000));
+    assertEquals(0xFFFFFFFE, CodedOutputStream.encodeZigZag32(0x7FFFFFFF));
+    assertEquals(0xFFFFFFFF, CodedOutputStream.encodeZigZag32(0x80000000));
+
+    assertEquals(0, CodedOutputStream.encodeZigZag64(0));
+    assertEquals(1, CodedOutputStream.encodeZigZag64(-1));
+    assertEquals(2, CodedOutputStream.encodeZigZag64(1));
+    assertEquals(3, CodedOutputStream.encodeZigZag64(-2));
+    assertEquals(0x000000007FFFFFFEL, CodedOutputStream.encodeZigZag64(0x000000003FFFFFFFL));
+    assertEquals(0x000000007FFFFFFFL, CodedOutputStream.encodeZigZag64(0xFFFFFFFFC0000000L));
+    assertEquals(0x00000000FFFFFFFEL, CodedOutputStream.encodeZigZag64(0x000000007FFFFFFFL));
+    assertEquals(0x00000000FFFFFFFFL, CodedOutputStream.encodeZigZag64(0xFFFFFFFF80000000L));
+    assertEquals(0xFFFFFFFFFFFFFFFEL, CodedOutputStream.encodeZigZag64(0x7FFFFFFFFFFFFFFFL));
+    assertEquals(0xFFFFFFFFFFFFFFFFL, CodedOutputStream.encodeZigZag64(0x8000000000000000L));
+
+    // Some easier-to-verify round-trip tests.  The inputs (other than 0, 1, -1)
+    // were chosen semi-randomly via keyboard bashing.
+    assertEquals(0, CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(0)));
+    assertEquals(1, CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(1)));
+    assertEquals(-1, CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(-1)));
+    assertEquals(14927, CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(14927)));
+    assertEquals(-3612, CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(-3612)));
+
+    assertEquals(0, CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(0)));
+    assertEquals(1, CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(1)));
+    assertEquals(-1, CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-1)));
+    assertEquals(14927, CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(14927)));
+    assertEquals(-3612, CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-3612)));
+
+    assertEquals(
+        856912304801416L,
+        CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(856912304801416L)));
+    assertEquals(
+        -75123905439571256L,
+        CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-75123905439571256L)));
+  }
+
+  /** Tests writing a whole message with every field type. */
+  public void testWriteWholeMessage() throws Exception {
+    final byte[] expectedBytes = TestUtil.getGoldenMessage().toByteArray();
+    TestAllTypes message = TestUtil.getAllSet();
+
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(message.getSerializedSize());
+      message.writeTo(coder.stream());
+      coder.stream().flush();
+      byte[] rawBytes = coder.toByteArray();
+      assertEqualBytes(outputType, expectedBytes, rawBytes);
+    }
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize < 256; blockSize *= 2) {
+      Coder coder = OutputType.STREAM.newCoder(blockSize);
+      message.writeTo(coder.stream());
+      coder.stream().flush();
+      assertEqualBytes(OutputType.STREAM, expectedBytes, coder.toByteArray());
+    }
+  }
+
+  /**
+   * Tests writing a whole message with every packed field type. Ensures the
+   * wire format of packed fields is compatible with C++.
+   */
+  public void testWriteWholePackedFieldsMessage() throws Exception {
+    byte[] expectedBytes = TestUtil.getGoldenPackedFieldsMessage().toByteArray();
+    TestPackedTypes message = TestUtil.getPackedSet();
+
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(message.getSerializedSize());
+      message.writeTo(coder.stream());
+      coder.stream().flush();
+      byte[] rawBytes = coder.toByteArray();
+      assertEqualBytes(outputType, expectedBytes, rawBytes);
+    }
+  }
+
+  /**
+   * Test writing a message containing a negative enum value. This used to
+   * fail because the size was not properly computed as a sign-extended varint.
+   */
+  public void testWriteMessageWithNegativeEnumValue() throws Exception {
+    SparseEnumMessage message =
+        SparseEnumMessage.newBuilder().setSparseEnum(TestSparseEnum.SPARSE_E).build();
+    assertTrue(message.getSparseEnum().getNumber() < 0);
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(message.getSerializedSize());
+      message.writeTo(coder.stream());
+      coder.stream().flush();
+      byte[] rawBytes = coder.toByteArray();
+      SparseEnumMessage message2 = SparseEnumMessage.parseFrom(rawBytes);
+      assertEquals(TestSparseEnum.SPARSE_E, message2.getSparseEnum());
+    }
+  }
+
+  /** Test getTotalBytesWritten() */
+  public void testGetTotalBytesWritten() throws Exception {
+    Coder coder = OutputType.STREAM.newCoder(4 * 1024);
+
+    // Write some some bytes (more than the buffer can hold) and verify that totalWritten
+    // is correct.
+    byte[] value = "abcde".getBytes(Internal.UTF_8);
+    for (int i = 0; i < 1024; ++i) {
+      coder.stream().writeRawBytes(value, 0, value.length);
+    }
+    assertEquals(value.length * 1024, coder.stream().getTotalBytesWritten());
+
+    // Now write an encoded string.
+    String string =
+        "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
+    // Ensure we take the slower fast path.
+    assertTrue(CodedOutputStream.computeUInt32SizeNoTag(string.length())
+        != CodedOutputStream.computeUInt32SizeNoTag(string.length() * Utf8.MAX_BYTES_PER_CHAR));
+
+    coder.stream().writeStringNoTag(string);
+    int stringSize = CodedOutputStream.computeStringSizeNoTag(string);
+
+    // Verify that the total bytes written is correct
+    assertEquals((value.length * 1024) + stringSize, coder.stream().getTotalBytesWritten());
+  }
+
+  // TODO(dweis): Write a comprehensive test suite for CodedOutputStream that covers more than just
+  //    this case.
+  public void testWriteStringNoTag_fastpath() throws Exception {
+    int bufferSize = 153;
+    String threeBytesPer = "\u0981";
+    String string = threeBytesPer;
+    for (int i = 0; i < 50; i++) {
+      string += threeBytesPer;
+    }
+    // These checks ensure we will tickle the slower fast path.
+    assertEquals(1, CodedOutputStream.computeUInt32SizeNoTag(string.length()));
+    assertEquals(
+        2, CodedOutputStream.computeUInt32SizeNoTag(string.length() * Utf8.MAX_BYTES_PER_CHAR));
+    assertEquals(bufferSize, string.length() * Utf8.MAX_BYTES_PER_CHAR);
+
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(bufferSize + 2);
+      coder.stream().writeStringNoTag(string);
+      coder.stream().flush();
+    }
+  }
+
+  public void testWriteToByteBuffer() throws Exception {
+    final int bufferSize = 16 * 1024;
+    ByteBuffer buffer = ByteBuffer.allocate(bufferSize);
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(buffer);
+    // Write raw bytes into the ByteBuffer.
+    final int length1 = 5000;
+    for (int i = 0; i < length1; i++) {
+      codedStream.writeRawByte((byte) 1);
+    }
+    final int length2 = 8 * 1024;
+    byte[] data = new byte[length2];
+    for (int i = 0; i < length2; i++) {
+      data[i] = (byte) 2;
+    }
+    codedStream.writeRawBytes(data);
+    final int length3 = bufferSize - length1 - length2;
+    for (int i = 0; i < length3; i++) {
+      codedStream.writeRawByte((byte) 3);
+    }
+    codedStream.flush();
+
+    // Check that data is correctly written to the ByteBuffer.
+    assertEquals(0, buffer.remaining());
+    buffer.flip();
+    for (int i = 0; i < length1; i++) {
+      assertEquals((byte) 1, buffer.get());
+    }
+    for (int i = 0; i < length2; i++) {
+      assertEquals((byte) 2, buffer.get());
+    }
+    for (int i = 0; i < length3; i++) {
+      assertEquals((byte) 3, buffer.get());
+    }
+  }
+
+  public void testWriteByteBuffer() throws Exception {
+    byte[] value = "abcde".getBytes(Internal.UTF_8);
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(outputStream);
+    ByteBuffer byteBuffer = ByteBuffer.wrap(value, 0, 1);
+    // This will actually write 5 bytes into the CodedOutputStream as the
+    // ByteBuffer's capacity() is 5.
+    codedStream.writeRawBytes(byteBuffer);
+    // The above call shouldn't affect the ByteBuffer's state.
+    assertEquals(0, byteBuffer.position());
+    assertEquals(1, byteBuffer.limit());
+
+    // The correct way to write part of an array using ByteBuffer.
+    codedStream.writeRawBytes(ByteBuffer.wrap(value, 2, 1).slice());
+
+    codedStream.flush();
+    byte[] result = outputStream.toByteArray();
+    assertEquals(6, result.length);
+    for (int i = 0; i < 5; i++) {
+      assertEquals(value[i], result[i]);
+    }
+    assertEquals(value[2], result[5]);
+  }
+
+  public void testWriteByteArrayWithOffsets() throws Exception {
+    byte[] fullArray = bytes(0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88);
+    byte[] destination = new byte[4];
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(destination);
+    codedStream.writeByteArrayNoTag(fullArray, 2, 2);
+    assertEqualBytes(OutputType.ARRAY, bytes(0x02, 0x33, 0x44, 0x00), destination);
+    assertEquals(3, codedStream.getTotalBytesWritten());
+  }
+
+  public void testSerializeUtf8_MultipleSmallWrites() throws Exception {
+    final String source = "abcdefghijklmnopqrstuvwxyz";
+
+    // Generate the expected output if the source string is written 2 bytes at a time.
+    ByteArrayOutputStream expectedBytesStream = new ByteArrayOutputStream();
+    for (int pos = 0; pos < source.length(); pos += 2) {
+      String substr = source.substring(pos, pos + 2);
+      expectedBytesStream.write(2);
+      expectedBytesStream.write(substr.getBytes(Internal.UTF_8));
+    }
+    final byte[] expectedBytes = expectedBytesStream.toByteArray();
+
+    // For each output type, write the source string 2 bytes at a time and verify the output.
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(expectedBytes.length);
+      for (int pos = 0; pos < source.length(); pos += 2) {
+        String substr = source.substring(pos, pos + 2);
+        coder.stream().writeStringNoTag(substr);
+      }
+      coder.stream().flush();
+      assertEqualBytes(outputType, expectedBytes, coder.toByteArray());
+    }
+  }
+
+  public void testSerializeInvalidUtf8() throws Exception {
+    String[] invalidStrings = new String[] {newString(Character.MIN_HIGH_SURROGATE),
+        "foobar" + newString(Character.MIN_HIGH_SURROGATE), newString(Character.MIN_LOW_SURROGATE),
+        "foobar" + newString(Character.MIN_LOW_SURROGATE),
+        newString(Character.MIN_HIGH_SURROGATE, Character.MIN_HIGH_SURROGATE)};
+
+    CodedOutputStream outputWithStream = CodedOutputStream.newInstance(new ByteArrayOutputStream());
+    CodedOutputStream outputWithArray = CodedOutputStream.newInstance(new byte[10000]);
+    CodedOutputStream outputWithByteBuffer =
+        CodedOutputStream.newInstance(ByteBuffer.allocate(10000));
+    for (String s : invalidStrings) {
+      // TODO(dweis): These should all fail; instead they are corrupting data.
+      CodedOutputStream.computeStringSizeNoTag(s);
+      outputWithStream.writeStringNoTag(s);
+      outputWithArray.writeStringNoTag(s);
+      outputWithByteBuffer.writeStringNoTag(s);
+    }
+  }
+
+  // TODO(nathanmittler): This test can be deleted once we properly throw IOException while
+  // encoding invalid UTF-8 strings.
+  public void testSerializeInvalidUtf8FollowedByOutOfSpace() throws Exception {
+    final int notEnoughBytes = 4;
+    CodedOutputStream outputWithArray = CodedOutputStream.newInstance(new byte[notEnoughBytes]);
+    CodedOutputStream outputWithByteBuffer =
+        CodedOutputStream.newInstance(ByteBuffer.allocate(notEnoughBytes));
+
+    String invalidString = newString(Character.MIN_HIGH_SURROGATE, 'f', 'o', 'o', 'b', 'a', 'r');
+    try {
+      outputWithArray.writeStringNoTag(invalidString);
+      fail("Expected OutOfSpaceException");
+    } catch (OutOfSpaceException e) {
+      assertTrue(e.getCause() instanceof IndexOutOfBoundsException);
+    }
+    try {
+      outputWithByteBuffer.writeStringNoTag(invalidString);
+      fail("Expected OutOfSpaceException");
+    } catch (OutOfSpaceException e) {
+      assertTrue(e.getCause() instanceof IndexOutOfBoundsException);
+    }
+  }
+
+  /** Regression test for https://github.com/google/protobuf/issues/292 */
+  public void testCorrectExceptionThrowWhenEncodingStringsWithoutEnoughSpace() throws Exception {
+    String testCase = "Foooooooo";
+    assertEquals(
+        CodedOutputStream.computeUInt32SizeNoTag(testCase.length()),
+        CodedOutputStream.computeUInt32SizeNoTag(testCase.length() * 3));
+    assertEquals(11, CodedOutputStream.computeStringSize(1, testCase));
+    // Tag is one byte, varint describing string length is 1 byte, string length is 9 bytes.
+    // An array of size 1 will cause a failure when trying to write the varint.
+    for (OutputType outputType :
+        new OutputType[] {OutputType.ARRAY, OutputType.NIO_HEAP, OutputType.NIO_DIRECT}) {
+      for (int i = 0; i < 11; i++) {
+        Coder coder = outputType.newCoder(i);
+        try {
+          coder.stream().writeString(1, testCase);
+          fail("Should have thrown an out of space exception");
+        } catch (CodedOutputStream.OutOfSpaceException expected) {
+        }
+      }
+    }
+  }
+
+  public void testDifferentStringLengths() throws Exception {
+    // Test string serialization roundtrip using strings of the following lengths,
+    // with ASCII and Unicode characters requiring different UTF-8 byte counts per
+    // char, hence causing the length delimiter varint to sometimes require more
+    // bytes for the Unicode strings than the ASCII string of the same length.
+    int[] lengths = new int[] {
+        0,
+        1,
+        (1 << 4) - 1, // 1 byte for ASCII and Unicode
+        (1 << 7) - 1, // 1 byte for ASCII, 2 bytes for Unicode
+        (1 << 11) - 1, // 2 bytes for ASCII and Unicode
+        (1 << 14) - 1, // 2 bytes for ASCII, 3 bytes for Unicode
+        (1 << 17) - 1,
+        // 3 bytes for ASCII and Unicode
+    };
+    for (OutputType outputType : OutputType.values()) {
+      for (int i : lengths) {
+        testEncodingOfString(outputType, 'q', i); // 1 byte per char
+        testEncodingOfString(outputType, '\u07FF', i); // 2 bytes per char
+        testEncodingOfString(outputType, '\u0981', i); // 3 bytes per char
+      }
+    }
+  }
+
+  public void testNioEncodersWithInitialOffsets() throws Exception {
+    String value = "abc";
+    for (Coder coder : new Coder[] {new NioHeapCoder(10, 2), new NioDirectCoder(10, 2)}) {
+      coder.stream().writeStringNoTag(value);
+      coder.stream().flush();
+      assertEqualBytes(coder.getOutputType(), new byte[]{3, 'a', 'b', 'c'}, coder.toByteArray());
+    }
+  }
+
+  /**
+   * Parses the given bytes using writeRawLittleEndian32() and checks
+   * that the result matches the given value.
+   */
+  private static void assertWriteLittleEndian32(byte[] data, int value) throws Exception {
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(data.length);
+      coder.stream().writeFixed32NoTag(value);
+      coder.stream().flush();
+      assertEqualBytes(outputType, data, coder.toByteArray());
+    }
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      Coder coder = OutputType.STREAM.newCoder(blockSize);
+      coder.stream().writeFixed32NoTag(value);
+      coder.stream().flush();
+      assertEqualBytes(OutputType.STREAM, data, coder.toByteArray());
+    }
+  }
+
+  /**
+   * Parses the given bytes using writeRawLittleEndian64() and checks
+   * that the result matches the given value.
+   */
+  private static void assertWriteLittleEndian64(byte[] data, long value) throws Exception {
+    for (OutputType outputType : OutputType.values()) {
+      Coder coder = outputType.newCoder(data.length);
+      coder.stream().writeFixed64NoTag(value);
+      coder.stream().flush();
+      assertEqualBytes(outputType, data, coder.toByteArray());
+    }
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      Coder coder = OutputType.STREAM.newCoder(blockSize);
+      coder.stream().writeFixed64NoTag(value);
+      coder.stream().flush();
+      assertEqualBytes(OutputType.STREAM, data, coder.toByteArray());
+    }
+  }
+
+  private static String newString(char... chars) {
+    return new String(chars);
+  }
+
+  private static void testEncodingOfString(OutputType outputType, char c, int length)
+      throws Exception {
+    String fullString = fullString(c, length);
+    TestAllTypes testAllTypes = TestAllTypes.newBuilder().setOptionalString(fullString).build();
+    Coder coder = outputType.newCoder(testAllTypes.getSerializedSize());
+    testAllTypes.writeTo(coder.stream());
+    coder.stream().flush();
+    assertEquals(
+        "OuputType: " + outputType,
+        fullString,
+        TestAllTypes.parseFrom(coder.toByteArray()).getOptionalString());
+  }
+
+  private static String fullString(char c, int length) {
+    char[] result = new char[length];
+    Arrays.fill(result, c);
+    return new String(result);
+  }
+
+  /**
+   * Helper to construct a byte array from a bunch of bytes.  The inputs are
+   * actually ints so that I can use hex notation and not get stupid errors
+   * about precision.
+   */
+  private static byte[] bytes(int... bytesAsInts) {
+    byte[] bytes = new byte[bytesAsInts.length];
+    for (int i = 0; i < bytesAsInts.length; i++) {
+      bytes[i] = (byte) bytesAsInts[i];
+    }
+    return bytes;
+  }
+
+  /** Arrays.asList() does not work with arrays of primitives.  :( */
+  private static List<Byte> toList(byte[] bytes) {
+    List<Byte> result = new ArrayList<Byte>();
+    for (byte b : bytes) {
+      result.add(b);
+    }
+    return result;
+  }
+
+  private static void assertEqualBytes(OutputType outputType, byte[] a, byte[] b) {
+    assertEquals(outputType.name(), toList(a), toList(b));
+  }
+
+  /**
+   * Writes the given value using writeRawVarint32() and writeRawVarint64() and
+   * checks that the result matches the given bytes.
+   */
+  private static void assertWriteVarint(byte[] data, long value) throws Exception {
+    for (OutputType outputType : OutputType.values()) {
+      // Only test 32-bit write if the value fits into an int.
+      if (value == (int) value) {
+        Coder coder = outputType.newCoder(10);
+        coder.stream().writeUInt32NoTag((int) value);
+        coder.stream().flush();
+        assertEqualBytes(outputType, data, coder.toByteArray());
+
+        // Also try computing size.
+        assertEquals(data.length, CodedOutputStream.computeUInt32SizeNoTag((int) value));
+      }
+
+      {
+        Coder coder = outputType.newCoder(10);
+        coder.stream().writeUInt64NoTag(value);
+        coder.stream().flush();
+        assertEqualBytes(outputType, data, coder.toByteArray());
+
+        // Also try computing size.
+        assertEquals(data.length, CodedOutputStream.computeUInt64SizeNoTag(value));
+      }
+    }
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      // Only test 32-bit write if the value fits into an int.
+      if (value == (int) value) {
+        Coder coder = OutputType.STREAM.newCoder(blockSize);
+        coder.stream().writeUInt64NoTag((int) value);
+        coder.stream().flush();
+        assertEqualBytes(OutputType.STREAM, data, coder.toByteArray());
+
+        ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+        CodedOutputStream output = CodedOutputStream.newInstance(rawOutput, blockSize);
+        output.writeUInt32NoTag((int) value);
+        output.flush();
+        assertEqualBytes(OutputType.STREAM, data, rawOutput.toByteArray());
+      }
+
+      {
+        Coder coder = OutputType.STREAM.newCoder(blockSize);
+        coder.stream().writeUInt64NoTag(value);
+        coder.stream().flush();
+        assertEqualBytes(OutputType.STREAM, data, coder.toByteArray());
+      }
+    }
+  }
+
+  private static void assertVarintRoundTrip(OutputType outputType, long value) throws Exception {
+    {
+      Coder coder = outputType.newCoder(10);
+      coder.stream().writeUInt64NoTag(value);
+      coder.stream().flush();
+      byte[] bytes = coder.toByteArray();
+      assertEquals(
+          outputType.name(), bytes.length, CodedOutputStream.computeUInt64SizeNoTag(value));
+      CodedInputStream input = CodedInputStream.newInstance(new ByteArrayInputStream(bytes));
+      assertEquals(outputType.name(), value, input.readRawVarint64());
+    }
+
+    if (value == (int) value) {
+      Coder coder = outputType.newCoder(10);
+      coder.stream().writeUInt32NoTag((int) value);
+      coder.stream().flush();
+      byte[] bytes = coder.toByteArray();
+      assertEquals(
+          outputType.name(), bytes.length, CodedOutputStream.computeUInt32SizeNoTag((int) value));
+      CodedInputStream input = CodedInputStream.newInstance(new ByteArrayInputStream(bytes));
+      assertEquals(outputType.name(), value, input.readRawVarint32());
+    }
+  }
+}
diff --git a/java/src/test/java/com/google/protobuf/DeprecatedFieldTest.java b/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
index e7905f79..ce85ae2e 100644
--- a/java/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
@@ -36,6 +36,7 @@ import junit.framework.TestCase;
 
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
+
 /**
  * Test field deprecation
  * 
diff --git a/java/src/test/java/com/google/protobuf/DescriptorsTest.java b/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java
index 30da2487..ef89b389 100644
--- a/java/src/test/java/com/google/protobuf/DescriptorsTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java
@@ -59,7 +59,6 @@ import protobuf_unittest.UnittestProto.TestMultipleExtensionRanges;
 import protobuf_unittest.UnittestProto.TestRequired;
 import protobuf_unittest.UnittestProto.TestReservedFields;
 import protobuf_unittest.UnittestProto.TestService;
-
 import junit.framework.TestCase;
 
 import java.util.Arrays;
@@ -274,6 +273,15 @@ public class DescriptorsTest extends TestCase {
     assertFalse(repeatedField.isRequired());
     assertTrue(repeatedField.isRepeated());
   }
+  
+  public void testFieldDescriptorJsonName() throws Exception {
+    FieldDescriptor requiredField = TestRequired.getDescriptor().findFieldByName("a");
+    FieldDescriptor optionalField = TestAllTypes.getDescriptor().findFieldByName("optional_int32");
+    FieldDescriptor repeatedField = TestAllTypes.getDescriptor().findFieldByName("repeated_int32");
+    assertEquals("a", requiredField.getJsonName());
+    assertEquals("optionalInt32", optionalField.getJsonName());
+    assertEquals("repeatedInt32", repeatedField.getJsonName());
+  }
 
   public void testFieldDescriptorDefault() throws Exception {
     Descriptor d = TestAllTypes.getDescriptor();
@@ -564,6 +572,42 @@ public class DescriptorsTest extends TestCase {
     }
   }
 
+  public void testUnknownFieldsDenied() throws Exception {
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto")
+        .addMessageType(DescriptorProto.newBuilder()
+            .setName("Foo")
+            .addField(FieldDescriptorProto.newBuilder()
+                .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                .setTypeName("Bar")
+                .setName("bar")
+                .setNumber(1)))
+        .build();
+
+    try {
+      Descriptors.FileDescriptor.buildFrom(fooProto, new FileDescriptor[0]);
+      fail("DescriptorValidationException expected");
+    } catch (DescriptorValidationException e) {
+      assertTrue(e.getMessage().indexOf("Bar") != -1);
+      assertTrue(e.getMessage().indexOf("is not defined") != -1);
+    }
+  }
+
+  public void testUnknownFieldsAllowed() throws Exception {
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto")
+        .addDependency("bar.proto")
+        .addMessageType(DescriptorProto.newBuilder()
+            .setName("Foo")
+            .addField(FieldDescriptorProto.newBuilder()
+                .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                .setTypeName("Bar")
+                .setName("bar")
+                .setNumber(1)))
+        .build();
+    Descriptors.FileDescriptor.buildFrom(fooProto, new FileDescriptor[0], true);
+  }
+
   public void testHiddenDependency() throws Exception {
     FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
         .setName("bar.proto")
diff --git a/java/src/test/java/com/google/protobuf/DoubleArrayListTest.java b/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java
index e7a73d70..85b418c4 100644
--- a/java/src/test/java/com/google/protobuf/DoubleArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java
@@ -73,20 +73,6 @@ public class DoubleArrayListTest extends TestCase {
     assertImmutable(list);
   }
   
-  public void testCopyConstructor() {
-    DoubleArrayList copy = new DoubleArrayList(TERTIARY_LIST);
-    assertEquals(TERTIARY_LIST, copy);
-
-    copy = new DoubleArrayList(DoubleArrayList.emptyList());
-    assertEquals(DoubleArrayList.emptyList(), copy);
-    
-    copy = new DoubleArrayList(asList(1D, 2D, 3D));
-    assertEquals(asList(1D, 2D, 3D), copy);
-
-    copy = new DoubleArrayList(Collections.<Double>emptyList());
-    assertEquals(DoubleArrayList.emptyList(), copy);
-  }
-  
   public void testModificationWithIteration() {
     list.addAll(asList(1D, 2D, 3D, 4D));
     Iterator<Double> iterator = list.iterator();
@@ -310,7 +296,7 @@ public class DoubleArrayListTest extends TestCase {
   }
   
   private void assertImmutable(DoubleArrayList list) {
-    if (list.contains(1)) {
+    if (list.contains(1D)) {
       throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
     }
     
@@ -413,7 +399,7 @@ public class DoubleArrayListTest extends TestCase {
     }
     
     try {
-      list.removeAll(Collections.singleton(1));
+      list.removeAll(Collections.singleton(1D));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
@@ -434,7 +420,7 @@ public class DoubleArrayListTest extends TestCase {
     }
     
     try {
-      list.retainAll(Collections.singleton(1));
+      list.retainAll(Collections.singleton(1D));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
diff --git a/java/src/test/java/com/google/protobuf/DynamicMessageTest.java b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
index 55144e7c..8f3a74c1 100644
--- a/java/src/test/java/com/google/protobuf/DynamicMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
@@ -33,13 +33,13 @@ package com.google.protobuf;
 import com.google.protobuf.Descriptors.EnumDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
-
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllTypes;
 import protobuf_unittest.UnittestProto.TestEmptyMessage;
 import protobuf_unittest.UnittestProto.TestPackedTypes;
 
 import junit.framework.TestCase;
+
 import java.util.Arrays;
 
 /**
diff --git a/java/core/src/test/java/com/google/protobuf/EnumTest.java b/java/core/src/test/java/com/google/protobuf/EnumTest.java
new file mode 100644
index 00000000..14c7406b
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/EnumTest.java
@@ -0,0 +1,76 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.UnittestLite.ForeignEnumLite;
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import protobuf_unittest.UnittestProto.ForeignEnum;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+
+import junit.framework.TestCase;
+
+public class EnumTest extends TestCase {
+  
+  public void testForNumber() {
+    ForeignEnum e = ForeignEnum.forNumber(ForeignEnum.FOREIGN_BAR.getNumber());
+    assertEquals(ForeignEnum.FOREIGN_BAR, e);
+
+    e = ForeignEnum.forNumber(1000);
+    assertEquals(null, e);
+  }
+  
+  public void testForNumber_oneof() {
+    TestAllTypes.OneofFieldCase e = TestAllTypes.OneofFieldCase.forNumber(
+        TestAllTypes.OneofFieldCase.ONEOF_NESTED_MESSAGE.getNumber());
+    assertEquals(TestAllTypes.OneofFieldCase.ONEOF_NESTED_MESSAGE, e);
+
+    e = TestAllTypes.OneofFieldCase.forNumber(1000);
+    assertEquals(null, e);
+  }
+  
+  public void testForNumberLite() {
+    ForeignEnumLite e = ForeignEnumLite.forNumber(ForeignEnumLite.FOREIGN_LITE_BAR.getNumber());
+    assertEquals(ForeignEnumLite.FOREIGN_LITE_BAR, e);
+
+    e = ForeignEnumLite.forNumber(1000);
+    assertEquals(null, e);
+  }
+  
+  public void testForNumberLite_oneof() {
+    TestAllTypesLite.OneofFieldCase e = TestAllTypesLite.OneofFieldCase.forNumber(
+        TestAllTypesLite.OneofFieldCase.ONEOF_NESTED_MESSAGE.getNumber());
+    assertEquals(TestAllTypesLite.OneofFieldCase.ONEOF_NESTED_MESSAGE, e);
+
+    e = TestAllTypesLite.OneofFieldCase.forNumber(1000);
+    assertEquals(null, e);
+  }
+}
+
diff --git a/java/src/test/java/com/google/protobuf/FieldPresenceTest.java b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
index eaeec0b8..304cec4f 100644
--- a/java/src/test/java/com/google/protobuf/FieldPresenceTest.java
+++ b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
@@ -44,9 +44,9 @@ import junit.framework.TestCase;
  * non-message fields.
  */
 public class FieldPresenceTest extends TestCase {
-  private static boolean hasMethod(Class clazz, String name) {
+  private static boolean hasMethod(Class<?> clazz, String name) {
     try {
-      if (clazz.getMethod(name, new Class[]{}) != null) {
+      if (clazz.getMethod(name) != null) {
         return true;
       } else {
         return false;
@@ -56,90 +56,90 @@ public class FieldPresenceTest extends TestCase {
     }
   }
 
-  private static boolean isHasMethodRemoved(
-      Class classWithFieldPresence,
-      Class classWithoutFieldPresence,
+  private static void assertHasMethodRemoved(
+      Class<?> classWithFieldPresence,
+      Class<?> classWithoutFieldPresence,
       String camelName) {
-    return hasMethod(classWithFieldPresence, "get" + camelName)
-        && hasMethod(classWithFieldPresence, "has" + camelName)
-        && hasMethod(classWithoutFieldPresence, "get" + camelName)
-        && !hasMethod(classWithoutFieldPresence, "has" + camelName);
+    assertTrue(hasMethod(classWithFieldPresence, "get" + camelName));
+    assertTrue(hasMethod(classWithFieldPresence, "has" + camelName));
+    assertTrue(hasMethod(classWithoutFieldPresence, "get" + camelName));
+    assertFalse(hasMethod(classWithoutFieldPresence, "has" + camelName));
   }
 
   public void testHasMethod() {
     // Optional non-message fields don't have a hasFoo() method generated.
-    assertTrue(isHasMethodRemoved(
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OptionalInt32"));
-    assertTrue(isHasMethodRemoved(
+        "OptionalInt32");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OptionalString"));
-    assertTrue(isHasMethodRemoved(
+        "OptionalString");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OptionalBytes"));
-    assertTrue(isHasMethodRemoved(
+        "OptionalBytes");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OptionalNestedEnum"));
+        "OptionalNestedEnum");
 
-    assertTrue(isHasMethodRemoved(
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OptionalInt32"));
-    assertTrue(isHasMethodRemoved(
+        "OptionalInt32");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OptionalString"));
-    assertTrue(isHasMethodRemoved(
+        "OptionalString");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OptionalBytes"));
-    assertTrue(isHasMethodRemoved(
+        "OptionalBytes");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OptionalNestedEnum"));
+        "OptionalNestedEnum");
 
     // message fields still have the hasFoo() method generated.
     assertFalse(TestAllTypes.newBuilder().build().hasOptionalNestedMessage());
     assertFalse(TestAllTypes.newBuilder().hasOptionalNestedMessage());
 
     // oneof fields don't have hasFoo() methods (even for message types).
-    assertTrue(isHasMethodRemoved(
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OneofUint32"));
-    assertTrue(isHasMethodRemoved(
+        "OneofUint32");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OneofString"));
-    assertTrue(isHasMethodRemoved(
+        "OneofString");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OneofBytes"));
-    assertTrue(isHasMethodRemoved(
+        "OneofBytes");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.class,
         TestAllTypes.class,
-        "OneofNestedMessage"));
+        "OneofNestedMessage");
 
-    assertTrue(isHasMethodRemoved(
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OneofUint32"));
-    assertTrue(isHasMethodRemoved(
+        "OneofUint32");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OneofString"));
-    assertTrue(isHasMethodRemoved(
+        "OneofString");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OneofBytes"));
-    assertTrue(isHasMethodRemoved(
+        "OneofBytes");
+    assertHasMethodRemoved(
         UnittestProto.TestAllTypes.Builder.class,
         TestAllTypes.Builder.class,
-        "OneofNestedMessage"));
+        "OneofNestedMessage");
   }
 
   public void testOneofEquals() throws Exception {
@@ -232,24 +232,24 @@ public class FieldPresenceTest extends TestCase {
     assertTrue(message.hasField(optionalNestedEnumField));
     assertEquals(4, message.getAllFields().size());
   }
-  
+
   public void testMessageField() {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     assertFalse(builder.hasOptionalNestedMessage());
     assertFalse(builder.build().hasOptionalNestedMessage());
-    
+
     TestAllTypes.NestedMessage.Builder nestedBuilder =
         builder.getOptionalNestedMessageBuilder();
     assertTrue(builder.hasOptionalNestedMessage());
     assertTrue(builder.build().hasOptionalNestedMessage());
-    
+
     nestedBuilder.setValue(1);
     assertEquals(1, builder.build().getOptionalNestedMessage().getValue());
-    
+
     builder.clearOptionalNestedMessage();
     assertFalse(builder.hasOptionalNestedMessage());
     assertFalse(builder.build().hasOptionalNestedMessage());
-    
+
     // Unlike non-message fields, if we set a message field to its default value (i.e.,
     // default instance), the field should be seen as present.
     builder.setOptionalNestedMessage(TestAllTypes.NestedMessage.getDefaultInstance());
@@ -340,7 +340,7 @@ public class FieldPresenceTest extends TestCase {
     assertTrue(builder.buildPartial().isInitialized());
   }
 
-  
+
   // Test that unknown fields are dropped.
   public void testUnknownFields() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
@@ -348,7 +348,7 @@ public class FieldPresenceTest extends TestCase {
     builder.addRepeatedInt32(5678);
     TestAllTypes message = builder.build();
     ByteString data = message.toByteString();
-    
+
     TestOptionalFieldsOnly optionalOnlyMessage =
         TestOptionalFieldsOnly.parseFrom(data);
     // UnknownFieldSet should be empty.
@@ -360,7 +360,7 @@ public class FieldPresenceTest extends TestCase {
     // The repeated field is discarded because it's unknown to the optional-only
     // message.
     assertEquals(0, message.getRepeatedInt32Count());
-    
+
     DynamicMessage dynamicOptionalOnlyMessage =
         DynamicMessage.getDefaultInstance(
             TestOptionalFieldsOnly.getDescriptor())
diff --git a/java/src/test/java/com/google/protobuf/FloatArrayListTest.java b/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java
index 8f3e93dc..88a75743 100644
--- a/java/src/test/java/com/google/protobuf/FloatArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java
@@ -73,20 +73,6 @@ public class FloatArrayListTest extends TestCase {
     assertImmutable(list);
   }
   
-  public void testCopyConstructor() {
-    FloatArrayList copy = new FloatArrayList(TERTIARY_LIST);
-    assertEquals(TERTIARY_LIST, copy);
-
-    copy = new FloatArrayList(FloatArrayList.emptyList());
-    assertEquals(FloatArrayList.emptyList(), copy);
-    
-    copy = new FloatArrayList(asList(1F, 2F, 3F));
-    assertEquals(asList(1F, 2F, 3F), copy);
-
-    copy = new FloatArrayList(Collections.<Float>emptyList());
-    assertEquals(FloatArrayList.emptyList(), copy);
-  }
-  
   public void testModificationWithIteration() {
     list.addAll(asList(1F, 2F, 3F, 4F));
     Iterator<Float> iterator = list.iterator();
@@ -310,7 +296,7 @@ public class FloatArrayListTest extends TestCase {
   }
   
   private void assertImmutable(FloatArrayList list) {
-    if (list.contains(1)) {
+    if (list.contains(1F)) {
       throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
     }
     
@@ -413,7 +399,7 @@ public class FloatArrayListTest extends TestCase {
     }
     
     try {
-      list.removeAll(Collections.singleton(1));
+      list.removeAll(Collections.singleton(1F));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
@@ -434,7 +420,7 @@ public class FloatArrayListTest extends TestCase {
     }
     
     try {
-      list.retainAll(Collections.singleton(1));
+      list.retainAll(Collections.singleton(1F));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
diff --git a/java/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java b/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
index a92ba374..b7eaebf5 100644
--- a/java/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
+++ b/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
@@ -41,7 +41,7 @@ package com.google.protobuf;
  */
 public class ForceFieldBuildersPreRun implements Runnable {
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void run() {
     GeneratedMessage.enableAlwaysUseFieldBuildersForTesting();
   }
diff --git a/java/src/test/java/com/google/protobuf/GeneratedMessageTest.java b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
index 70812b95..a9b8b638 100644
--- a/java/src/test/java/com/google/protobuf/GeneratedMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
@@ -620,6 +620,21 @@ public class GeneratedMessageTest extends TestCase {
     TestUtil.assertExtensionsClear(TestAllExtensions.newBuilder().build());
   }
 
+  public void testUnsetRepeatedExtensionGetField() {
+    TestAllExtensions message = TestAllExtensions.getDefaultInstance();
+    Object value;
+
+    value = message.getField(UnittestProto.repeatedStringExtension.getDescriptor());
+    assertTrue(value instanceof List);
+    assertTrue(((List<?>) value).isEmpty());
+    assertIsUnmodifiable((List<?>) value);
+
+    value = message.getField(UnittestProto.repeatedNestedMessageExtension.getDescriptor());
+    assertTrue(value instanceof List);
+    assertTrue(((List<?>) value).isEmpty());
+    assertIsUnmodifiable((List<?>) value);
+  }
+
   public void testExtensionReflectionGetters() throws Exception {
     TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
     TestUtil.setAllExtensions(builder);
@@ -708,7 +723,7 @@ public class GeneratedMessageTest extends TestCase {
 
   public void testLiteExtensionMessageOrBuilder() throws Exception {
     TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
-    TestUtil.setAllExtensions(builder);
+    TestUtilLite.setAllExtensions(builder);
     TestUtil.assertAllExtensionsSet(builder);
 
     TestAllExtensionsLite message = builder.build();
@@ -717,8 +732,8 @@ public class GeneratedMessageTest extends TestCase {
 
   public void testLiteExtensionRepeatedSetters() throws Exception {
     TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
-    TestUtil.setAllExtensions(builder);
-    TestUtil.modifyRepeatedExtensions(builder);
+    TestUtilLite.setAllExtensions(builder);
+    TestUtilLite.modifyRepeatedExtensions(builder);
     TestUtil.assertRepeatedExtensionsModified(builder);
 
     TestAllExtensionsLite message = builder.build();
@@ -745,7 +760,7 @@ public class GeneratedMessageTest extends TestCase {
   }
 
   public void testLiteExtensionCopy() throws Exception {
-    TestAllExtensionsLite original = TestUtil.getAllLiteExtensionsSet();
+    TestAllExtensionsLite original = TestUtilLite.getAllLiteExtensionsSet();
     TestAllExtensionsLite copy =
         TestAllExtensionsLite.newBuilder(original).build();
     TestUtil.assertAllExtensionsSet(copy);
diff --git a/java/src/test/java/com/google/protobuf/IntArrayListTest.java b/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java
index 3733eb30..efb8f3e2 100644
--- a/java/src/test/java/com/google/protobuf/IntArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java
@@ -72,20 +72,6 @@ public class IntArrayListTest extends TestCase {
     list.makeImmutable();
     assertImmutable(list);
   }
-  
-  public void testCopyConstructor() {
-    IntArrayList copy = new IntArrayList(TERTIARY_LIST);
-    assertEquals(TERTIARY_LIST, copy);
-
-    copy = new IntArrayList(IntArrayList.emptyList());
-    assertEquals(IntArrayList.emptyList(), copy);
-    
-    copy = new IntArrayList(asList(1, 2, 3));
-    assertEquals(asList(1, 2, 3), copy);
-
-    copy = new IntArrayList(Collections.<Integer>emptyList());
-    assertEquals(IntArrayList.emptyList(), copy);
-  }
 
   public void testModificationWithIteration() {
     list.addAll(asList(1, 2, 3, 4));
diff --git a/java/src/test/java/com/google/protobuf/IsValidUtf8Test.java b/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java
index 8751baae..756049b4 100644
--- a/java/src/test/java/com/google/protobuf/IsValidUtf8Test.java
+++ b/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java
@@ -30,12 +30,18 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.IsValidUtf8TestUtil.DIRECT_NIO_FACTORY;
+import static com.google.protobuf.IsValidUtf8TestUtil.EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT;
+import static com.google.protobuf.IsValidUtf8TestUtil.EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT;
+import static com.google.protobuf.IsValidUtf8TestUtil.HEAP_NIO_FACTORY;
+import static com.google.protobuf.IsValidUtf8TestUtil.LITERAL_FACTORY;
+import static com.google.protobuf.IsValidUtf8TestUtil.testBytes;
+
+import com.google.protobuf.IsValidUtf8TestUtil.ByteStringFactory;
 import com.google.protobuf.IsValidUtf8TestUtil.Shard;
 
 import junit.framework.TestCase;
 
-import java.io.UnsupportedEncodingException;
-
 /**
  * Tests cases for {@link ByteString#isValidUtf8()}. This includes three
  * brute force tests that actually test every permutation of one byte, two byte,
@@ -51,31 +57,33 @@ import java.io.UnsupportedEncodingException;
  * @author martinrb@google.com (Martin Buchholz)
  */
 public class IsValidUtf8Test extends TestCase {
-
   /**
    * Tests that round tripping of all two byte permutations work.
    */
-  public void testIsValidUtf8_1Byte() throws UnsupportedEncodingException {
-    IsValidUtf8TestUtil.testBytes(1,
-        IsValidUtf8TestUtil.EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
+  public void testIsValidUtf8_1Byte() {
+    testBytes(LITERAL_FACTORY, 1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
+    testBytes(HEAP_NIO_FACTORY, 1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
+    testBytes(DIRECT_NIO_FACTORY, 1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
   }
 
   /**
    * Tests that round tripping of all two byte permutations work.
    */
-  public void testIsValidUtf8_2Bytes() throws UnsupportedEncodingException {
-    IsValidUtf8TestUtil.testBytes(2,
-        IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
+  public void testIsValidUtf8_2Bytes() {
+    testBytes(LITERAL_FACTORY, 2, IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
+    testBytes(HEAP_NIO_FACTORY, 2, IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
+    testBytes(DIRECT_NIO_FACTORY, 2, IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
   }
 
   /**
    * Tests that round tripping of all three byte permutations work.
    */
-  public void testIsValidUtf8_3Bytes() throws UnsupportedEncodingException {
+  public void testIsValidUtf8_3Bytes() {
     // Travis' OOM killer doesn't like this test
     if (System.getenv("TRAVIS") == null) {
-      IsValidUtf8TestUtil.testBytes(3,
-          IsValidUtf8TestUtil.EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
+      testBytes(LITERAL_FACTORY, 3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
+      testBytes(HEAP_NIO_FACTORY, 3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
+      testBytes(DIRECT_NIO_FACTORY, 3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
     }
   }
 
@@ -85,8 +93,7 @@ public class IsValidUtf8Test extends TestCase {
    * {@link IsValidUtf8FourByteTest} is used for full coverage. This method
    * tests specific four-byte cases.
    */
-  public void testIsValidUtf8_4BytesSamples()
-      throws UnsupportedEncodingException {
+  public void testIsValidUtf8_4BytesSamples() {
     // Valid 4 byte.
     assertValidUtf8(0xF0, 0xA4, 0xAD, 0xA2);
 
@@ -119,9 +126,7 @@ public class IsValidUtf8Test extends TestCase {
     assertTrue(asBytes("\u024B62\u024B62").isValidUtf8());
 
     // Mixed string
-    assertTrue(
-        asBytes("a\u020ac\u00a2b\\u024B62u020acc\u00a2de\u024B62")
-        .isValidUtf8());
+    assertTrue(asBytes("a\u020ac\u00a2b\\u024B62u020acc\u00a2de\u024B62").isValidUtf8());
 
     // Not a valid string
     assertInvalidUtf8(-1, 0, -1, 0);
@@ -135,36 +140,35 @@ public class IsValidUtf8Test extends TestCase {
     return realBytes;
   }
 
-  private ByteString toByteString(int... bytes) {
-    return ByteString.copyFrom(toByteArray(bytes));
-  }
-
-  private void assertValidUtf8(int[] bytes, boolean not) {
+  private void assertValidUtf8(ByteStringFactory factory, int[] bytes, boolean not) {
     byte[] realBytes = toByteArray(bytes);
     assertTrue(not ^ Utf8.isValidUtf8(realBytes));
     assertTrue(not ^ Utf8.isValidUtf8(realBytes, 0, bytes.length));
-    ByteString lit = ByteString.copyFrom(realBytes);
-    ByteString sub = lit.substring(0, bytes.length);
-    assertTrue(not ^ lit.isValidUtf8());
+    ByteString leaf = factory.newByteString(realBytes);
+    ByteString sub = leaf.substring(0, bytes.length);
+    assertTrue(not ^ leaf.isValidUtf8());
     assertTrue(not ^ sub.isValidUtf8());
     ByteString[] ropes = {
-      RopeByteString.newInstanceForTest(ByteString.EMPTY, lit),
-      RopeByteString.newInstanceForTest(ByteString.EMPTY, sub),
-      RopeByteString.newInstanceForTest(lit, ByteString.EMPTY),
-      RopeByteString.newInstanceForTest(sub, ByteString.EMPTY),
-      RopeByteString.newInstanceForTest(sub, lit)
-    };
+        RopeByteString.newInstanceForTest(ByteString.EMPTY, leaf),
+        RopeByteString.newInstanceForTest(ByteString.EMPTY, sub),
+        RopeByteString.newInstanceForTest(leaf, ByteString.EMPTY),
+        RopeByteString.newInstanceForTest(sub, ByteString.EMPTY),
+        RopeByteString.newInstanceForTest(sub, leaf)};
     for (ByteString rope : ropes) {
       assertTrue(not ^ rope.isValidUtf8());
     }
   }
 
   private void assertValidUtf8(int... bytes) {
-    assertValidUtf8(bytes, false);
+    assertValidUtf8(LITERAL_FACTORY, bytes, false);
+    assertValidUtf8(HEAP_NIO_FACTORY, bytes, false);
+    assertValidUtf8(DIRECT_NIO_FACTORY, bytes, false);
   }
 
   private void assertInvalidUtf8(int... bytes) {
-    assertValidUtf8(bytes, true);
+    assertValidUtf8(LITERAL_FACTORY, bytes, true);
+    assertValidUtf8(HEAP_NIO_FACTORY, bytes, true);
+    assertValidUtf8(DIRECT_NIO_FACTORY, bytes, true);
   }
 
   private static ByteString asBytes(String s) {
@@ -177,7 +181,6 @@ public class IsValidUtf8Test extends TestCase {
     for (Shard shard : IsValidUtf8TestUtil.FOUR_BYTE_SHARDS) {
       actual += shard.expected;
     }
-    assertEquals(IsValidUtf8TestUtil.EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT,
-        actual);
+    assertEquals(IsValidUtf8TestUtil.EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT, actual);
   }
 }
diff --git a/java/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java b/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
index 321669f3..16a808bf 100644
--- a/java/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
+++ b/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
@@ -30,9 +30,13 @@
 
 package com.google.protobuf;
 
-import static junit.framework.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
-import java.io.UnsupportedEncodingException;
+import java.lang.ref.SoftReference;
 import java.nio.ByteBuffer;
 import java.nio.CharBuffer;
 import java.nio.charset.CharsetDecoder;
@@ -52,64 +56,105 @@ import java.util.logging.Logger;
  * @author jonp@google.com (Jon Perlow)
  * @author martinrb@google.com (Martin Buchholz)
  */
-class IsValidUtf8TestUtil {
-  private static Logger logger = Logger.getLogger(
-      IsValidUtf8TestUtil.class.getName());
+final class IsValidUtf8TestUtil {
+  private static Logger logger = Logger.getLogger(IsValidUtf8TestUtil.class.getName());
+
+  private IsValidUtf8TestUtil() {}
+
+  static interface ByteStringFactory {
+    ByteString newByteString(byte[] bytes);
+  }
+
+  static final ByteStringFactory LITERAL_FACTORY = new ByteStringFactory() {
+    @Override
+    public ByteString newByteString(byte[] bytes) {
+      return ByteString.wrap(bytes);
+    }
+  };
+
+  static final ByteStringFactory HEAP_NIO_FACTORY = new ByteStringFactory() {
+    @Override
+    public ByteString newByteString(byte[] bytes) {
+      return new NioByteString(ByteBuffer.wrap(bytes));
+    }
+  };
+
+  private static ThreadLocal<SoftReference<ByteBuffer>> directBuffer =
+      new ThreadLocal<SoftReference<ByteBuffer>>();
+
+  /**
+   * Factory for direct {@link ByteBuffer} instances. To reduce direct memory usage, this
+   * uses a thread local direct buffer. This means that each call will overwrite the buffer's
+   * contents from the previous call, so the calling code must be careful not to continue using
+   * a buffer returned from a previous invocation.
+   */
+  static final ByteStringFactory DIRECT_NIO_FACTORY = new ByteStringFactory() {
+    @Override
+    public ByteString newByteString(byte[] bytes) {
+      SoftReference<ByteBuffer> ref = directBuffer.get();
+      ByteBuffer buffer = ref == null ? null : ref.get();
+      if (buffer == null || buffer.capacity() < bytes.length) {
+        buffer = ByteBuffer.allocateDirect(bytes.length);
+        directBuffer.set(new SoftReference<ByteBuffer>(buffer));
+      }
+      buffer.clear();
+      buffer.put(bytes);
+      buffer.flip();
+      return new NioByteString(buffer);
+    }
+  };
 
   // 128 - [chars 0x0000 to 0x007f]
-  static long ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x007f - 0x0000 + 1;
+  static final long ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x007f - 0x0000 + 1;
 
   // 128
-  static long EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT =
-      ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS;
+  static final long EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT = ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS;
 
   // 1920 [chars 0x0080 to 0x07FF]
-  static long TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x07FF - 0x0080 + 1;
+  static final long TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x07FF - 0x0080 + 1;
 
   // 18,304
-  static long EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT =
+  static final long EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT =
       // Both bytes are one byte characters
       (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 2) +
       // The possible number of two byte characters
       TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS;
 
   // 2048
-  static long THREE_BYTE_SURROGATES = 2 * 1024;
+  static final long THREE_BYTE_SURROGATES = 2 * 1024;
 
   // 61,440 [chars 0x0800 to 0xFFFF, minus surrogates]
-  static long THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS =
+  static final long THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS =
       0xFFFF - 0x0800 + 1 - THREE_BYTE_SURROGATES;
 
   // 2,650,112
-  static long EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT =
+  static final long EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT =
       // All one byte characters
       (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 3) +
       // One two byte character and a one byte character
-      2 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS *
-          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
-       // Three byte characters
+      2 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS * ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+      // Three byte characters
       THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS;
 
   // 1,048,576 [chars 0x10000L to 0x10FFFF]
-  static long FOUR_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x10FFFF - 0x10000L + 1;
+  static final long FOUR_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x10FFFF - 0x10000L + 1;
 
   // 289,571,839
-  static long EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT =
+  static final long EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT =
       // All one byte characters
       (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 4) +
       // One and three byte characters
-      2 * THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS *
-          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+      2 * THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS * ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
       // Two two byte characters
       TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS +
       // Permutations of one and two byte characters
-      3 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS *
-          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS *
-          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+      3 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS * ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS
+      * ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS
+      +
       // Four byte characters
       FOUR_BYTE_ROUNDTRIPPABLE_CHARACTERS;
 
-  static class Shard {
+  static final class Shard {
     final long index;
     final long start;
     final long lim;
@@ -138,7 +183,7 @@ class IsValidUtf8TestUtil {
 
     // 97-111 are all 2342912
     for (int i = 97; i <= 111; i++) {
-     expected[i] = 2342912;
+      expected[i] = 2342912;
     }
 
     // 113-117 are all 1048576
@@ -158,22 +203,18 @@ class IsValidUtf8TestUtil {
     return expected;
   }
 
-  static final List<Shard> FOUR_BYTE_SHARDS = generateFourByteShards(
-      128, FOUR_BYTE_SHARDS_EXPECTED_ROUNTRIPPABLES);
+  static final List<Shard> FOUR_BYTE_SHARDS =
+      generateFourByteShards(128, FOUR_BYTE_SHARDS_EXPECTED_ROUNTRIPPABLES);
 
 
-  private static List<Shard> generateFourByteShards(
-      int numShards, long[] expected) {
+  private static List<Shard> generateFourByteShards(int numShards, long[] expected) {
     assertEquals(numShards, expected.length);
     List<Shard> shards = new ArrayList<Shard>(numShards);
     long LIM = 1L << 32;
     long increment = LIM / numShards;
     assertTrue(LIM % numShards == 0);
     for (int i = 0; i < numShards; i++) {
-      shards.add(new Shard(i,
-          increment * i,
-          increment * (i + 1),
-          expected[i]));
+      shards.add(new Shard(i, increment * i, increment * (i + 1), expected[i]));
     }
     return shards;
   }
@@ -182,12 +223,12 @@ class IsValidUtf8TestUtil {
    * Helper to run the loop to test all the permutations for the number of bytes
    * specified.
    *
+   * @param factory the factory for {@link ByteString} instances.
    * @param numBytes the number of bytes in the byte array
    * @param expectedCount the expected number of roundtrippable permutations
    */
-  static void testBytes(int numBytes, long expectedCount)
-      throws UnsupportedEncodingException {
-    testBytes(numBytes, expectedCount, 0, -1);
+  static void testBytes(ByteStringFactory factory, int numBytes, long expectedCount) {
+    testBytes(factory, numBytes, expectedCount, 0, -1);
   }
 
   /**
@@ -195,14 +236,15 @@ class IsValidUtf8TestUtil {
    * specified. This overload is useful for debugging to get the loop to start
    * at a certain character.
    *
+   * @param factory the factory for {@link ByteString} instances.
    * @param numBytes the number of bytes in the byte array
    * @param expectedCount the expected number of roundtrippable permutations
    * @param start the starting bytes encoded as a long as big-endian
    * @param lim the limit of bytes to process encoded as a long as big-endian,
    *     or -1 to mean the max limit for numBytes
    */
-  static void testBytes(int numBytes, long expectedCount, long start, long lim)
-      throws UnsupportedEncodingException {
+  static void testBytes(
+      ByteStringFactory factory, int numBytes, long expectedCount, long start, long lim) {
     Random rnd = new Random();
     byte[] bytes = new byte[numBytes];
 
@@ -217,7 +259,7 @@ class IsValidUtf8TestUtil {
         bytes[bytes.length - i - 1] = (byte) tmpByteChar;
         tmpByteChar = tmpByteChar >> 8;
       }
-      ByteString bs = ByteString.copyFrom(bytes);
+      ByteString bs = factory.newByteString(bytes);
       boolean isRoundTrippable = bs.isValidUtf8();
       String s = new String(bytes, Internal.UTF_8);
       byte[] bytesReencoded = s.getBytes(Internal.UTF_8);
@@ -236,14 +278,15 @@ class IsValidUtf8TestUtil {
       int i = rnd.nextInt(numBytes);
       int j = rnd.nextInt(numBytes);
       if (j < i) {
-        int tmp = i; i = j; j = tmp;
+        int tmp = i;
+        i = j;
+        j = tmp;
       }
       int state1 = Utf8.partialIsValidUtf8(Utf8.COMPLETE, bytes, 0, i);
       int state2 = Utf8.partialIsValidUtf8(state1, bytes, i, j);
       int state3 = Utf8.partialIsValidUtf8(state2, bytes, j, numBytes);
       if (isRoundTrippable != (state3 == Utf8.COMPLETE)) {
-        System.out.printf("state=%04x %04x %04x i=%d j=%d%n",
-                          state1, state2, state3, i, j);
+        System.out.printf("state=%04x %04x %04x i=%d j=%d%n", state1, state2, state3, i, j);
         outputFailure(byteChar, bytes, bytesReencoded);
       }
       assertEquals(isRoundTrippable, (state3 == Utf8.COMPLETE));
@@ -251,36 +294,24 @@ class IsValidUtf8TestUtil {
       // Test ropes built out of small partial sequences
       ByteString rope = RopeByteString.newInstanceForTest(
           bs.substring(0, i),
-          RopeByteString.newInstanceForTest(
-              bs.substring(i, j),
-              bs.substring(j, numBytes)));
+          RopeByteString.newInstanceForTest(bs.substring(i, j), bs.substring(j, numBytes)));
       assertSame(RopeByteString.class, rope.getClass());
 
-      ByteString[] byteStrings = { bs, bs.substring(0, numBytes), rope };
+      ByteString[] byteStrings = {bs, bs.substring(0, numBytes), rope};
       for (ByteString x : byteStrings) {
-        assertEquals(isRoundTrippable,
-                     x.isValidUtf8());
-        assertEquals(state3,
-                     x.partialIsValidUtf8(Utf8.COMPLETE, 0, numBytes));
-
-        assertEquals(state1,
-                     x.partialIsValidUtf8(Utf8.COMPLETE, 0, i));
-        assertEquals(state1,
-                     x.substring(0, i).partialIsValidUtf8(Utf8.COMPLETE, 0, i));
-        assertEquals(state2,
-                     x.partialIsValidUtf8(state1, i, j - i));
-        assertEquals(state2,
-                     x.substring(i, j).partialIsValidUtf8(state1, 0, j - i));
-        assertEquals(state3,
-                     x.partialIsValidUtf8(state2, j, numBytes - j));
-        assertEquals(state3,
-                     x.substring(j, numBytes)
-                     .partialIsValidUtf8(state2, 0, numBytes - j));
+        assertEquals(isRoundTrippable, x.isValidUtf8());
+        assertEquals(state3, x.partialIsValidUtf8(Utf8.COMPLETE, 0, numBytes));
+
+        assertEquals(state1, x.partialIsValidUtf8(Utf8.COMPLETE, 0, i));
+        assertEquals(state1, x.substring(0, i).partialIsValidUtf8(Utf8.COMPLETE, 0, i));
+        assertEquals(state2, x.partialIsValidUtf8(state1, i, j - i));
+        assertEquals(state2, x.substring(i, j).partialIsValidUtf8(state1, 0, j - i));
+        assertEquals(state3, x.partialIsValidUtf8(state2, j, numBytes - j));
+        assertEquals(state3, x.substring(j, numBytes).partialIsValidUtf8(state2, 0, numBytes - j));
       }
 
       // ByteString reduplication should not affect its UTF-8 validity.
-      ByteString ropeADope =
-          RopeByteString.newInstanceForTest(bs, bs.substring(0, numBytes));
+      ByteString ropeADope = RopeByteString.newInstanceForTest(bs, bs.substring(0, numBytes));
       assertEquals(isRoundTrippable, ropeADope.isValidUtf8());
 
       if (isRoundTrippable) {
@@ -288,8 +319,7 @@ class IsValidUtf8TestUtil {
       }
       count++;
       if (byteChar != 0 && byteChar % 1000000L == 0) {
-        logger.info("Processed " + (byteChar / 1000000L) +
-            " million characters");
+        logger.info("Processed " + (byteChar / 1000000L) + " million characters");
       }
     }
     logger.info("Round tripped " + countRoundTripped + " of " + count);
@@ -303,25 +333,26 @@ class IsValidUtf8TestUtil {
    * actual String class, it's possible for incompatibilities to develop
    * (although unlikely).
    *
+   * @param factory the factory for {@link ByteString} instances.
    * @param numBytes the number of bytes in the byte array
    * @param expectedCount the expected number of roundtrippable permutations
    * @param start the starting bytes encoded as a long as big-endian
    * @param lim the limit of bytes to process encoded as a long as big-endian,
    *     or -1 to mean the max limit for numBytes
    */
-  void testBytesUsingByteBuffers(
-      int numBytes, long expectedCount, long start, long lim)
-      throws UnsupportedEncodingException {
-    CharsetDecoder decoder = Internal.UTF_8.newDecoder()
-        .onMalformedInput(CodingErrorAction.REPLACE)
-        .onUnmappableCharacter(CodingErrorAction.REPLACE);
-    CharsetEncoder encoder = Internal.UTF_8.newEncoder()
-        .onMalformedInput(CodingErrorAction.REPLACE)
-        .onUnmappableCharacter(CodingErrorAction.REPLACE);
+  static void testBytesUsingByteBuffers(
+      ByteStringFactory factory, int numBytes, long expectedCount, long start, long lim) {
+    CharsetDecoder decoder =
+        Internal.UTF_8.newDecoder()
+            .onMalformedInput(CodingErrorAction.REPLACE)
+            .onUnmappableCharacter(CodingErrorAction.REPLACE);
+    CharsetEncoder encoder =
+        Internal.UTF_8.newEncoder()
+            .onMalformedInput(CodingErrorAction.REPLACE)
+            .onUnmappableCharacter(CodingErrorAction.REPLACE);
     byte[] bytes = new byte[numBytes];
     int maxChars = (int) (decoder.maxCharsPerByte() * numBytes) + 1;
-    char[] charsDecoded =
-        new char[(int) (decoder.maxCharsPerByte() * numBytes) + 1];
+    char[] charsDecoded = new char[(int) (decoder.maxCharsPerByte() * numBytes) + 1];
     int maxBytes = (int) (encoder.maxBytesPerChar() * maxChars) + 1;
     byte[] bytesReencoded = new byte[maxBytes];
 
@@ -347,7 +378,7 @@ class IsValidUtf8TestUtil {
         bytes[bytes.length - i - 1] = (byte) tmpByteChar;
         tmpByteChar = tmpByteChar >> 8;
       }
-      boolean isRoundTrippable = ByteString.copyFrom(bytes).isValidUtf8();
+      boolean isRoundTrippable = factory.newByteString(bytes).isValidUtf8();
       CoderResult result = decoder.decode(bb, cb, true);
       assertFalse(result.isError());
       result = decoder.flush(cb);
@@ -382,8 +413,7 @@ class IsValidUtf8TestUtil {
         countRoundTripped++;
       }
       if (byteChar != 0 && byteChar % 1000000 == 0) {
-        logger.info("Processed " + (byteChar / 1000000) +
-            " million characters");
+        logger.info("Processed " + (byteChar / 1000000) + " million characters");
       }
     }
     logger.info("Round tripped " + countRoundTripped + " of " + count);
@@ -394,10 +424,9 @@ class IsValidUtf8TestUtil {
     outputFailure(byteChar, bytes, after, after.length);
   }
 
-  private static void outputFailure(long byteChar, byte[] bytes, byte[] after,
-      int len) {
-    fail("Failure: (" + Long.toHexString(byteChar) + ") " +
-        toHexString(bytes) + " => " + toHexString(after, len));
+  private static void outputFailure(long byteChar, byte[] bytes, byte[] after, int len) {
+    fail("Failure: (" + Long.toHexString(byteChar) + ") " + toHexString(bytes) + " => "
+        + toHexString(after, len));
   }
 
   private static String toHexString(byte[] b) {
@@ -416,5 +445,4 @@ class IsValidUtf8TestUtil {
     s.append("\"");
     return s.toString();
   }
-
 }
diff --git a/java/src/test/java/com/google/protobuf/LazyFieldLiteTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
index 211b5697..8d1de6dc 100644
--- a/java/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
@@ -36,9 +36,10 @@ import static protobuf_unittest.UnittestProto.optionalInt64Extension;
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllTypes;
 
-import java.io.IOException;
 import junit.framework.TestCase;
 
+import java.io.IOException;
+
 /**
  * Unit test for {@link LazyFieldLite}.
  *
diff --git a/java/src/test/java/com/google/protobuf/LazyFieldTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
index 2b900065..ce473ae9 100644
--- a/java/src/test/java/com/google/protobuf/LazyFieldTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
@@ -33,9 +33,10 @@ package com.google.protobuf;
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllTypes;
 
-import java.io.IOException;
 import junit.framework.TestCase;
 
+import java.io.IOException;
+
 /**
  * Unit test for {@link LazyField}.
  *
diff --git a/java/src/test/java/com/google/protobuf/LazyMessageLiteTest.java b/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
index afe0fffd..afe0fffd 100644
--- a/java/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
diff --git a/java/src/test/java/com/google/protobuf/LazyStringArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
index 0f42ac50..0f42ac50 100644
--- a/java/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
index 0ef414aa..0ef414aa 100644
--- a/java/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
diff --git a/java/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java b/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
index 035917c8..29e8d875 100644
--- a/java/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
@@ -33,6 +33,8 @@ package com.google.protobuf;
 import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Bar;
 import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.BarPrime;
 import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Foo;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestOneofEquals;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestRecursiveOneof;
 
 import junit.framework.TestCase;
 
@@ -83,6 +85,16 @@ public class LiteEqualsAndHashTest extends TestCase {
     assertFalse(bar.equals(barPrime));
   }
 
+  public void testOneofEquals() throws Exception {
+    TestOneofEquals.Builder builder = TestOneofEquals.newBuilder();
+    TestOneofEquals message1 = builder.build();
+    // Set message2's name field to default value. The two messages should be different when we
+    // check with the oneof case.
+    builder.setName("");
+    TestOneofEquals message2 = builder.build();
+    assertFalse(message1.equals(message2));
+  }
+
   public void testEqualsAndHashCodeWithUnknownFields() throws InvalidProtocolBufferException {
     Foo fooWithOnlyValue = Foo.newBuilder()
         .setValue(1)
@@ -105,4 +117,9 @@ public class LiteEqualsAndHashTest extends TestCase {
     assertFalse(o1.equals(o2));
     assertFalse(o1.hashCode() == o2.hashCode());
   }
+
+  public void testRecursiveHashcode() {
+    // This tests that we don't infinite loop.
+    TestRecursiveOneof.getDefaultInstance().hashCode();
+  }
 }
diff --git a/java/src/test/java/com/google/protobuf/LiteTest.java b/java/core/src/test/java/com/google/protobuf/LiteTest.java
index b1f298ff..88c3e0b2 100644
--- a/java/src/test/java/com/google/protobuf/LiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteTest.java
@@ -33,22 +33,31 @@ package com.google.protobuf;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 
+import com.google.protobuf.UnittestImportLite.ImportEnumLite;
+import com.google.protobuf.UnittestImportPublicLite.PublicImportMessageLite;
 import com.google.protobuf.UnittestLite;
 import com.google.protobuf.UnittestLite.ForeignEnumLite;
 import com.google.protobuf.UnittestLite.ForeignMessageLite;
 import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
 import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import com.google.protobuf.UnittestLite.TestAllTypesLite.NestedEnum;
 import com.google.protobuf.UnittestLite.TestAllTypesLite.NestedMessage;
 import com.google.protobuf.UnittestLite.TestAllTypesLite.OneofFieldCase;
 import com.google.protobuf.UnittestLite.TestAllTypesLite.OptionalGroup;
 import com.google.protobuf.UnittestLite.TestAllTypesLite.RepeatedGroup;
 import com.google.protobuf.UnittestLite.TestAllTypesLiteOrBuilder;
 import com.google.protobuf.UnittestLite.TestNestedExtensionLite;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Bar;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.BarPrime;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Foo;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestOneofEquals;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestRecursiveOneof;
 
 import junit.framework.TestCase;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.NotSerializableException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 
@@ -58,6 +67,7 @@ import java.io.ObjectOutputStream;
  * @author kenton@google.com Kenton Varda
  */
 public class LiteTest extends TestCase {
+  @Override
   public void setUp() throws Exception {
     // Test that nested extensions are initialized correctly even if the outer
     // class has not been accessed directly.  This was once a bug with lite
@@ -128,33 +138,7 @@ public class LiteTest extends TestCase {
     assertEquals(7, message2.getExtension(
         UnittestLite.optionalNestedMessageExtensionLite).getBb());
   }
-
-  public void testSerialize() throws Exception {
-    ByteArrayOutputStream baos = new ByteArrayOutputStream();
-    TestAllTypesLite expected =
-      TestAllTypesLite.newBuilder()
-                      .setOptionalInt32(123)
-                      .addRepeatedString("hello")
-                      .setOptionalNestedMessage(
-                          TestAllTypesLite.NestedMessage.newBuilder().setBb(7))
-                      .build();
-    ObjectOutputStream out = new ObjectOutputStream(baos);
-    try {
-      out.writeObject(expected);
-    } finally {
-      out.close();
-    }
-    ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
-    ObjectInputStream in = new ObjectInputStream(bais);
-    TestAllTypesLite actual = (TestAllTypesLite) in.readObject();
-    assertEquals(expected.getOptionalInt32(), actual.getOptionalInt32());
-    assertEquals(expected.getRepeatedStringCount(),
-        actual.getRepeatedStringCount());
-    assertEquals(expected.getRepeatedString(0),
-        actual.getRepeatedString(0));
-    assertEquals(expected.getOptionalNestedMessage().getBb(),
-        actual.getOptionalNestedMessage().getBb());
-  }
+  
   
   public void testClone() {
     TestAllTypesLite.Builder expected = TestAllTypesLite.newBuilder()
@@ -327,11 +311,9 @@ public class LiteTest extends TestCase {
     assertEquals(
         ForeignMessageLite.getDefaultInstance(),
         message.getOptionalForeignMessage());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property and
-    // ensure the property isn't set on foreignMessage.
-    assertEquals(3, builder.getOptionalForeignMessage().getC());
+    assertEquals(foreignMessageBuilder.build(), builder.getOptionalForeignMessage());
     messageAfterBuild = builder.build();
-    assertEquals(3, messageAfterBuild.getOptionalForeignMessage().getC());
+    assertEquals(foreignMessageBuilder.build(), messageAfterBuild.getOptionalForeignMessage());
     assertEquals(
         ForeignMessageLite.getDefaultInstance(),
         message.getOptionalForeignMessage());
@@ -339,7 +321,7 @@ public class LiteTest extends TestCase {
     assertEquals(
         ForeignMessageLite.getDefaultInstance(),
         builder.getOptionalForeignMessage());
-    assertEquals(3, messageAfterBuild.getOptionalForeignMessage().getC());
+    assertEquals(foreignMessageBuilder.build(), messageAfterBuild.getOptionalForeignMessage());
 
     message = builder.build();
     OptionalGroup optionalGroup = OptionalGroup.newBuilder()
@@ -364,17 +346,15 @@ public class LiteTest extends TestCase {
     builder.setOptionalGroup(optionalGroupBuilder);
     assertEquals(
         OptionalGroup.getDefaultInstance(), message.getOptionalGroup());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property and
-    // ensure the property isn't set on optionalGroup.
-    assertEquals(3, builder.getOptionalGroup().getA());
+    assertEquals(optionalGroupBuilder.build(), builder.getOptionalGroup());
     messageAfterBuild = builder.build();
-    assertEquals(3, messageAfterBuild.getOptionalGroup().getA());
+    assertEquals(optionalGroupBuilder.build(), messageAfterBuild.getOptionalGroup());
     assertEquals(
         OptionalGroup.getDefaultInstance(), message.getOptionalGroup());
     builder.clearOptionalGroup();
     assertEquals(
         OptionalGroup.getDefaultInstance(), builder.getOptionalGroup());
-    assertEquals(3, messageAfterBuild.getOptionalGroup().getA());
+    assertEquals(optionalGroupBuilder.build(), messageAfterBuild.getOptionalGroup());
 
     message = builder.build();
     builder.setOptionalInt32(1);
@@ -425,17 +405,16 @@ public class LiteTest extends TestCase {
     assertEquals(
         NestedMessage.getDefaultInstance(),
         message.getOptionalLazyMessage());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property.
-    assertEquals(3, builder.getOptionalLazyMessage().getBb());
+    assertEquals(nestedMessageBuilder.build(), builder.getOptionalLazyMessage());
     messageAfterBuild = builder.build();
-    assertEquals(3, messageAfterBuild.getOptionalLazyMessage().getBb());
+    assertEquals(nestedMessageBuilder.build(), messageAfterBuild.getOptionalLazyMessage());
     assertEquals(
         NestedMessage.getDefaultInstance(),
         message.getOptionalLazyMessage());
     builder.clearOptionalLazyMessage();
     assertEquals(
         NestedMessage.getDefaultInstance(), builder.getOptionalLazyMessage());
-    assertEquals(3, messageAfterBuild.getOptionalLazyMessage().getBb());
+    assertEquals(nestedMessageBuilder.build(), messageAfterBuild.getOptionalLazyMessage());
 
     message = builder.build();
     builder.setOptionalSfixed32(1);
@@ -1125,8 +1104,7 @@ public class LiteTest extends TestCase {
     assertEquals(0, message.getRepeatedForeignMessageCount());
     builder.setRepeatedForeignMessage(
         0, ForeignMessageLite.getDefaultInstance());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property.
-    assertEquals(3, messageAfterBuild.getRepeatedForeignMessage(0).getC());
+    assertEquals(foreignMessageBuilder.build(), messageAfterBuild.getRepeatedForeignMessage(0));
     assertEquals(
         ForeignMessageLite.getDefaultInstance(),
         builder.getRepeatedForeignMessage(0));
@@ -1139,8 +1117,7 @@ public class LiteTest extends TestCase {
     builder.setRepeatedForeignMessage(0, foreignMessageBuilder);
     assertEquals(
         foreignMessage, messageAfterBuild.getRepeatedForeignMessage(0));
-    // LITE_RUNTIME doesn't implement equals so we compare on a property.
-    assertEquals(3, builder.getRepeatedForeignMessage(0).getC());
+    assertEquals(foreignMessageBuilder.build(), builder.getRepeatedForeignMessage(0));
     builder.clearRepeatedForeignMessage();
 
     message = builder.build();
@@ -1173,9 +1150,7 @@ public class LiteTest extends TestCase {
     messageAfterBuild = builder.build();
     assertEquals(0, message.getRepeatedGroupCount());
     builder.setRepeatedGroup(0, RepeatedGroup.getDefaultInstance());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property and
-    // ensure the property isn't set on repeatedGroup.
-    assertEquals(3, messageAfterBuild.getRepeatedGroup(0).getA());
+    assertEquals(repeatedGroupBuilder.build(), messageAfterBuild.getRepeatedGroup(0));
     assertEquals(
         RepeatedGroup.getDefaultInstance(), builder.getRepeatedGroup(0));
     builder.clearRepeatedGroup();
@@ -1185,9 +1160,7 @@ public class LiteTest extends TestCase {
     messageAfterBuild = builder.build();
     assertEquals(0, message.getRepeatedGroupCount());
     builder.setRepeatedGroup(0, RepeatedGroup.getDefaultInstance());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property and
-    // ensure the property isn't set on repeatedGroup.
-    assertEquals(3, messageAfterBuild.getRepeatedGroup(0).getA());
+    assertEquals(repeatedGroupBuilder.build(), messageAfterBuild.getRepeatedGroup(0));
     assertEquals(
         RepeatedGroup.getDefaultInstance(), builder.getRepeatedGroup(0));
     builder.clearRepeatedGroup();
@@ -1235,9 +1208,7 @@ public class LiteTest extends TestCase {
     messageAfterBuild = builder.build();
     assertEquals(0, message.getRepeatedLazyMessageCount());
     builder.setRepeatedLazyMessage(0, NestedMessage.getDefaultInstance());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property and
-    // ensure the property isn't set on repeatedGroup.
-    assertEquals(3, messageAfterBuild.getRepeatedLazyMessage(0).getBb());
+    assertEquals(nestedMessageBuilder.build(), messageAfterBuild.getRepeatedLazyMessage(0));
     assertEquals(
         NestedMessage.getDefaultInstance(), builder.getRepeatedLazyMessage(0));
     builder.clearRepeatedLazyMessage();
@@ -1247,9 +1218,7 @@ public class LiteTest extends TestCase {
     messageAfterBuild = builder.build();
     assertEquals(0, message.getRepeatedLazyMessageCount());
     builder.setRepeatedLazyMessage(0, NestedMessage.getDefaultInstance());
-    // LITE_RUNTIME doesn't implement equals so we compare on a property and
-    // ensure the property isn't set on repeatedGroup.
-    assertEquals(3, messageAfterBuild.getRepeatedLazyMessage(0).getBb());
+    assertEquals(nestedMessageBuilder.build(), messageAfterBuild.getRepeatedLazyMessage(0));
     assertEquals(
         NestedMessage.getDefaultInstance(), builder.getRepeatedLazyMessage(0));
     builder.clearRepeatedLazyMessage();
@@ -1459,4 +1428,802 @@ public class LiteTest extends TestCase {
         11, (int) extendableMessage.getExtension(
             UnittestLite.optionalFixed32ExtensionLite));
   }
+
+  public void testToStringDefaultInstance() throws Exception {
+    assertToStringEquals("", TestAllTypesLite.getDefaultInstance());
+  }
+
+  public void testToStringPrimitives() throws Exception {
+    TestAllTypesLite proto = TestAllTypesLite.newBuilder()
+        .setOptionalInt32(1)
+        .setOptionalInt64(9223372036854775807L)
+        .build();
+    assertToStringEquals("optional_int32: 1\noptional_int64: 9223372036854775807", proto);
+
+    proto = TestAllTypesLite.newBuilder()
+        .setOptionalBool(true)
+        .setOptionalNestedEnum(TestAllTypesLite.NestedEnum.BAZ)
+        .build();
+    assertToStringEquals("optional_bool: true\noptional_nested_enum: BAZ", proto);
+
+    proto = TestAllTypesLite.newBuilder()
+        .setOptionalFloat(2.72f)
+        .setOptionalDouble(3.14)
+        .build();
+    assertToStringEquals("optional_double: 3.14\noptional_float: 2.72", proto);
+  }
+
+  public void testToStringStringFields() throws Exception {
+    TestAllTypesLite proto = TestAllTypesLite.newBuilder()
+        .setOptionalString("foo\"bar\nbaz\\")
+        .build();
+    assertToStringEquals("optional_string: \"foo\\\"bar\\nbaz\\\\\"", proto);
+
+    proto = TestAllTypesLite.newBuilder()
+        .setOptionalString("\u6587")
+        .build();
+    assertToStringEquals("optional_string: \"\\346\\226\\207\"", proto);
+  }
+
+  public void testToStringNestedMessage() throws Exception {
+    TestAllTypesLite proto = TestAllTypesLite.newBuilder()
+        .setOptionalNestedMessage(TestAllTypesLite.NestedMessage.getDefaultInstance())
+        .build();
+    assertToStringEquals("optional_nested_message {\n}", proto);
+
+    proto = TestAllTypesLite.newBuilder()
+        .setOptionalNestedMessage(
+            TestAllTypesLite.NestedMessage.newBuilder().setBb(7))
+        .build();
+    assertToStringEquals("optional_nested_message {\n  bb: 7\n}", proto);
+  }
+
+  public void testToStringRepeatedFields() throws Exception {
+    TestAllTypesLite proto = TestAllTypesLite.newBuilder()
+        .addRepeatedInt32(32)
+        .addRepeatedInt32(32)
+        .addRepeatedInt64(64)
+        .build();
+    assertToStringEquals("repeated_int32: 32\nrepeated_int32: 32\nrepeated_int64: 64", proto);
+
+    proto = TestAllTypesLite.newBuilder()
+        .addRepeatedLazyMessage(
+            TestAllTypesLite.NestedMessage.newBuilder().setBb(7))
+        .addRepeatedLazyMessage(
+            TestAllTypesLite.NestedMessage.newBuilder().setBb(8))
+        .build();
+    assertToStringEquals(
+        "repeated_lazy_message {\n  bb: 7\n}\nrepeated_lazy_message {\n  bb: 8\n}",
+        proto);
+  }
+
+  public void testToStringForeignFields() throws Exception {
+    TestAllTypesLite proto = TestAllTypesLite.newBuilder()
+        .setOptionalForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR)
+        .setOptionalForeignMessage(
+            ForeignMessageLite.newBuilder()
+            .setC(3))
+        .build();
+    assertToStringEquals(
+        "optional_foreign_enum: FOREIGN_LITE_BAR\noptional_foreign_message {\n  c: 3\n}",
+        proto);
+  }
+
+  public void testToStringExtensions() throws Exception {
+    TestAllExtensionsLite message = TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalInt32ExtensionLite, 123)
+        .addExtension(UnittestLite.repeatedStringExtensionLite, "spam")
+        .addExtension(UnittestLite.repeatedStringExtensionLite, "eggs")
+        .setExtension(UnittestLite.optionalNestedEnumExtensionLite,
+            TestAllTypesLite.NestedEnum.BAZ)
+        .setExtension(UnittestLite.optionalNestedMessageExtensionLite,
+            TestAllTypesLite.NestedMessage.newBuilder().setBb(7).build())
+        .build();
+    assertToStringEquals(
+        "[1]: 123\n[18] {\n  bb: 7\n}\n[21]: 3\n[44]: \"spam\"\n[44]: \"eggs\"",
+        message);
+  }
+
+  public void testToStringUnknownFields() throws Exception {
+    TestAllExtensionsLite messageWithExtensions = TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalInt32ExtensionLite, 123)
+        .addExtension(UnittestLite.repeatedStringExtensionLite, "spam")
+        .addExtension(UnittestLite.repeatedStringExtensionLite, "eggs")
+        .setExtension(UnittestLite.optionalNestedEnumExtensionLite,
+            TestAllTypesLite.NestedEnum.BAZ)
+        .setExtension(UnittestLite.optionalNestedMessageExtensionLite,
+            TestAllTypesLite.NestedMessage.newBuilder().setBb(7).build())
+        .build();
+    TestAllExtensionsLite messageWithUnknownFields = TestAllExtensionsLite.parseFrom(
+        messageWithExtensions.toByteArray());
+    assertToStringEquals(
+        "1: 123\n18: \"\\b\\a\"\n21: 3\n44: \"spam\"\n44: \"eggs\"",
+        messageWithUnknownFields);
+  }
+  
+  public void testToStringLazyMessage() throws Exception {
+    TestAllTypesLite message = TestAllTypesLite.newBuilder()
+        .setOptionalLazyMessage(NestedMessage.newBuilder().setBb(1).build())
+        .build();
+    assertToStringEquals("optional_lazy_message {\n  bb: 1\n}", message);
+  }
+  
+  public void testToStringGroup() throws Exception {
+    TestAllTypesLite message = TestAllTypesLite.newBuilder()
+        .setOptionalGroup(OptionalGroup.newBuilder().setA(1).build())
+        .build();
+    assertToStringEquals("optional_group {\n  a: 1\n}", message);
+  }
+  
+  public void testToStringOneof() throws Exception {
+    TestAllTypesLite message = TestAllTypesLite.newBuilder()
+        .setOneofString("hello")
+        .build();
+    assertToStringEquals("oneof_string: \"hello\"", message);
+  }
+
+  // Asserts that the toString() representation of the message matches the expected. This verifies
+  // the first line starts with a comment; but, does not factor in said comment as part of the
+  // comparison as it contains unstable addresses.
+  private static void assertToStringEquals(String expected, MessageLite message) {
+    String toString = message.toString();
+    assertEquals('#', toString.charAt(0));
+    if (toString.indexOf("\n") >= 0) {
+      toString = toString.substring(toString.indexOf("\n") + 1);
+    } else {
+      toString = "";
+    }
+    assertEquals(expected, toString);
+  }
+  
+  public void testParseLazy() throws Exception {
+    ByteString bb = TestAllTypesLite.newBuilder()
+        .setOptionalLazyMessage(NestedMessage.newBuilder()
+            .setBb(11)
+            .build())
+        .build().toByteString();
+    ByteString cc = TestAllTypesLite.newBuilder()
+        .setOptionalLazyMessage(NestedMessage.newBuilder()
+            .setCc(22)
+            .build())
+        .build().toByteString();
+    
+    ByteString concat = bb.concat(cc);
+    TestAllTypesLite message = TestAllTypesLite.parseFrom(concat);
+
+    assertEquals(11, message.getOptionalLazyMessage().getBb());
+    assertEquals(22L, message.getOptionalLazyMessage().getCc());
+  }
+  
+  public void testParseLazy_oneOf() throws Exception {
+    ByteString bb = TestAllTypesLite.newBuilder()
+        .setOneofLazyNestedMessage(NestedMessage.newBuilder()
+            .setBb(11)
+            .build())
+        .build().toByteString();
+    ByteString cc = TestAllTypesLite.newBuilder()
+        .setOneofLazyNestedMessage(NestedMessage.newBuilder()
+            .setCc(22)
+            .build())
+        .build().toByteString();
+    
+    ByteString concat = bb.concat(cc);
+    TestAllTypesLite message = TestAllTypesLite.parseFrom(concat);
+
+    assertEquals(11, message.getOneofLazyNestedMessage().getBb());
+    assertEquals(22L, message.getOneofLazyNestedMessage().getCc());
+  }
+
+  public void testMergeFromStream_repeatedField() throws Exception {
+    TestAllTypesLite.Builder builder = TestAllTypesLite.newBuilder()
+        .addRepeatedString("hello");
+    builder.mergeFrom(CodedInputStream.newInstance(builder.build().toByteArray()));
+
+    assertEquals(2, builder.getRepeatedStringCount());
+  }
+
+  public void testMergeFromStream_invalidBytes() throws Exception {
+    TestAllTypesLite.Builder builder = TestAllTypesLite.newBuilder()
+        .setDefaultBool(true);
+    try {
+      builder.mergeFrom(CodedInputStream.newInstance("Invalid bytes".getBytes(Internal.UTF_8)));
+      fail();
+    } catch (InvalidProtocolBufferException expected) {}
+  }
+  
+  public void testMergeFrom_sanity() throws Exception {
+    TestAllTypesLite one = TestUtilLite.getAllLiteSetBuilder().build();
+    byte[] bytes = one.toByteArray();
+    TestAllTypesLite two = TestAllTypesLite.parseFrom(bytes);
+    
+    one = one.toBuilder().mergeFrom(one).build();
+    two = two.toBuilder().mergeFrom(bytes).build();
+    assertEquals(one, two);
+    assertEquals(two, one);
+    assertEquals(one.hashCode(), two.hashCode());
+  }
+  
+  public void testEquals_notEqual() throws Exception {
+    TestAllTypesLite one = TestUtilLite.getAllLiteSetBuilder().build();
+    byte[] bytes = one.toByteArray();
+    TestAllTypesLite two = one.toBuilder().mergeFrom(one).mergeFrom(bytes).build();
+    
+    assertFalse(one.equals(two));
+    assertFalse(two.equals(one));
+    
+    assertFalse(one.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(one));
+    
+    TestAllTypesLite oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultBool(true)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultCord("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultCordBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultDouble(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultFixed32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultFixed64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultFloat(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultImportEnum(ImportEnumLite.IMPORT_LITE_BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultInt32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultInt64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultNestedEnum(NestedEnum.BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultSfixed32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultSfixed64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultSint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultSint64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultString("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultStringBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultStringPiece("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultStringPieceBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultUint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setDefaultUint64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedBool(true)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedCord("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedCordBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedDouble(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedFixed32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedFixed64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedFloat(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedImportEnum(ImportEnumLite.IMPORT_LITE_BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedInt32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedInt64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedNestedEnum(NestedEnum.BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedSfixed32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedSfixed64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedSint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedSint64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedString("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedStringBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedStringPiece("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedStringPieceBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedUint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedUint64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalBool(true)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalCord("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalCordBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalDouble(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalFixed32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalFixed64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalFloat(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalImportEnum(ImportEnumLite.IMPORT_LITE_BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalInt32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalInt64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalNestedEnum(NestedEnum.BAR)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalSfixed32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalSfixed64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalSint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalSint64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalString("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalStringBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalStringPiece("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalStringPieceBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalUint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalUint64(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOneofBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOneofLazyNestedMessage(NestedMessage.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOneofNestedMessage(NestedMessage.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOneofString("")
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOneofStringBytes(ByteString.EMPTY)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOneofUint32(0)
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalForeignMessage(ForeignMessageLite.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalGroup(OptionalGroup.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalPublicImportMessage(PublicImportMessageLite.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .setOptionalLazyMessage(NestedMessage.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+    oneFieldSet = TestAllTypesLite.newBuilder()
+        .addRepeatedLazyMessage(NestedMessage.getDefaultInstance())
+        .build();
+    assertFalse(oneFieldSet.equals(TestAllTypesLite.getDefaultInstance()));
+    assertFalse(TestAllTypesLite.getDefaultInstance().equals(oneFieldSet));
+  }
+
+  public void testEquals() throws Exception {
+    // Check that two identical objs are equal.
+    Foo foo1a = Foo.newBuilder()
+        .setValue(1)
+        .addBar(Bar.newBuilder().setName("foo1"))
+        .build();
+    Foo foo1b = Foo.newBuilder()
+        .setValue(1)
+        .addBar(Bar.newBuilder().setName("foo1"))
+        .build();
+    Foo foo2 = Foo.newBuilder()
+        .setValue(1)
+        .addBar(Bar.newBuilder().setName("foo2"))
+        .build();
+
+    // Check that equals is doing value rather than object equality.
+    assertEquals(foo1a, foo1b);
+    assertEquals(foo1a.hashCode(), foo1b.hashCode());
+
+    // Check that a diffeent object is not equal.
+    assertFalse(foo1a.equals(foo2));
+
+    // Check that two objects which have different types but the same field values are not
+    // considered to be equal.
+    Bar bar = Bar.newBuilder().setName("bar").build();
+    BarPrime barPrime = BarPrime.newBuilder().setName("bar").build();
+    assertFalse(bar.equals(barPrime));
+  }
+
+  public void testOneofEquals() throws Exception {
+    TestOneofEquals.Builder builder = TestOneofEquals.newBuilder();
+    TestOneofEquals message1 = builder.build();
+    // Set message2's name field to default value. The two messages should be different when we
+    // check with the oneof case.
+    builder.setName("");
+    TestOneofEquals message2 = builder.build();
+    assertFalse(message1.equals(message2));
+  }
+  
+  public void testEquals_sanity() throws Exception {
+    TestAllTypesLite one = TestUtilLite.getAllLiteSetBuilder().build();
+    TestAllTypesLite two = TestAllTypesLite.parseFrom(one.toByteArray());
+    assertEquals(one, two);
+    assertEquals(one.hashCode(), two.hashCode());
+    
+    assertEquals(
+        one.toBuilder().mergeFrom(two).build(),
+        two.toBuilder().mergeFrom(two.toByteArray()).build());
+  }
+
+  public void testEqualsAndHashCodeWithUnknownFields() throws InvalidProtocolBufferException {
+    Foo fooWithOnlyValue = Foo.newBuilder()
+        .setValue(1)
+        .build();
+
+    Foo fooWithValueAndExtension = fooWithOnlyValue.toBuilder()
+        .setValue(1)
+        .setExtension(Bar.fooExt, Bar.newBuilder()
+            .setName("name")
+            .build())
+        .build();
+
+    Foo fooWithValueAndUnknownFields = Foo.parseFrom(fooWithValueAndExtension.toByteArray());
+
+    assertEqualsAndHashCodeAreFalse(fooWithOnlyValue, fooWithValueAndUnknownFields);
+    assertEqualsAndHashCodeAreFalse(fooWithValueAndExtension, fooWithValueAndUnknownFields);
+  }
+  
+  // Test to ensure we avoid a class cast exception with oneofs.
+  public void testEquals_oneOfMessages() {
+    TestAllTypesLite mine = TestAllTypesLite.newBuilder()
+        .setOneofString("Hello")
+        .build();
+    
+    TestAllTypesLite other = TestAllTypesLite.newBuilder()
+        .setOneofNestedMessage(NestedMessage.getDefaultInstance())
+        .build();
+    
+    assertFalse(mine.equals(other));
+    assertFalse(other.equals(mine));
+  }
+
+  private void assertEqualsAndHashCodeAreFalse(Object o1, Object o2) {
+    assertFalse(o1.equals(o2));
+    assertFalse(o1.hashCode() == o2.hashCode());
+  }
+
+  public void testRecursiveHashcode() {
+    // This tests that we don't infinite loop.
+    TestRecursiveOneof.getDefaultInstance().hashCode();
+  }
 }
diff --git a/java/src/test/java/com/google/protobuf/LiteralByteStringTest.java b/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java
index 7dfda2ae..2e7792a8 100644
--- a/java/src/test/java/com/google/protobuf/LiteralByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java
@@ -47,9 +47,9 @@ import java.util.List;
 import java.util.NoSuchElementException;
 
 /**
- * Test {@link LiteralByteString} by setting up a reference string in {@link #setUp()}.
- * This class is designed to be extended for testing extensions of {@link LiteralByteString}
- * such as {@link BoundedByteString}, see {@link BoundedByteStringTest}.
+ * Test {@code LiteralByteString} by setting up a reference string in {@link #setUp()}.
+ * This class is designed to be extended for testing extensions of {@code LiteralByteString}
+ * such as {@code BoundedByteString}, see {@link BoundedByteStringTest}.
  *
  * @author carlanton@google.com (Carl Haverl)
  */
@@ -75,9 +75,7 @@ public class LiteralByteStringTest extends TestCase {
   }
 
   protected String getActualClassName(Object object) {
-    String actualClassName = object.getClass().getName();
-    actualClassName = actualClassName.substring(actualClassName.lastIndexOf('.') + 1);
-    return actualClassName;
+    return object.getClass().getSimpleName();
   }
 
   public void testByteAt() {
@@ -306,25 +304,75 @@ public class LiteralByteStringTest extends TestCase {
         Arrays.equals(referenceBytes, roundTripBytes));
   }
 
-  public void testWriteTo_mutating() throws IOException {
+  public void testWriteToShouldNotExposeInternalBufferToOutputStream() throws IOException {
     OutputStream os = new OutputStream() {
       @Override
       public void write(byte[] b, int off, int len) {
-        for (int x = 0; x < len; ++x) {
-          b[off + x] = (byte) 0;
-        }
+        Arrays.fill(b, off, off + len, (byte) 0);
       }
 
       @Override
       public void write(int b) {
-        // Purposefully left blank.
+        throw new UnsupportedOperationException();
       }
     };
 
     stringUnderTest.writeTo(os);
-    byte[] newBytes = stringUnderTest.toByteArray();
     assertTrue(classUnderTest + ".writeTo() must not grant access to underlying array",
-        Arrays.equals(referenceBytes, newBytes));
+        Arrays.equals(referenceBytes, stringUnderTest.toByteArray()));
+  }
+
+  public void testWriteToInternalShouldExposeInternalBufferToOutputStream() throws IOException {
+    OutputStream os = new OutputStream() {
+      @Override
+      public void write(byte[] b, int off, int len) {
+        Arrays.fill(b, off, off + len, (byte) 0);
+      }
+
+      @Override
+      public void write(int b) {
+        throw new UnsupportedOperationException();
+      }
+    };
+
+    stringUnderTest.writeToInternal(os, 0, stringUnderTest.size());
+    byte[] allZeros = new byte[stringUnderTest.size()];
+    assertTrue(classUnderTest + ".writeToInternal() must grant access to underlying array",
+        Arrays.equals(allZeros, stringUnderTest.toByteArray()));
+  }
+
+  public void testWriteToShouldExposeInternalBufferToByteOutput() throws IOException {
+    ByteOutput out = new ByteOutput() {
+      @Override
+      public void write(byte value) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void write(byte[] value, int offset, int length) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void writeLazy(byte[] value, int offset, int length) throws IOException {
+        Arrays.fill(value, offset, offset + length, (byte) 0);
+      }
+
+      @Override
+      public void write(ByteBuffer value) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void writeLazy(ByteBuffer value) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+    };
+
+    stringUnderTest.writeTo(out);
+    byte[] allZeros = new byte[stringUnderTest.size()];
+    assertTrue(classUnderTest + ".writeToInternal() must grant access to underlying array",
+        Arrays.equals(allZeros, stringUnderTest.toByteArray()));
   }
 
   public void testNewOutput() throws IOException {
@@ -350,14 +398,14 @@ public class LiteralByteStringTest extends TestCase {
 
   public void testToString() throws UnsupportedEncodingException {
     String testString = "I love unicode \u1234\u5678 characters";
-    LiteralByteString unicode = new LiteralByteString(testString.getBytes(Internal.UTF_8));
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
     String roundTripString = unicode.toString(UTF_8);
     assertEquals(classUnderTest + " unicode must match", testString, roundTripString);
   }
 
-  public void testCharsetToString() throws UnsupportedEncodingException {
+  public void testCharsetToString() {
     String testString = "I love unicode \u1234\u5678 characters";
-    LiteralByteString unicode = new LiteralByteString(testString.getBytes(Internal.UTF_8));
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
     String roundTripString = unicode.toString(Internal.UTF_8);
     assertEquals(classUnderTest + " unicode must match", testString, roundTripString);
   }
@@ -365,7 +413,7 @@ public class LiteralByteStringTest extends TestCase {
   public void testToString_returnsCanonicalEmptyString() {
     assertSame(classUnderTest + " must be the same string references",
         ByteString.EMPTY.toString(Internal.UTF_8),
-        new LiteralByteString(new byte[]{}).toString(Internal.UTF_8));
+        ByteString.wrap(new byte[]{}).toString(Internal.UTF_8));
   }
 
   public void testToString_raisesException() {
@@ -377,7 +425,7 @@ public class LiteralByteStringTest extends TestCase {
     }
 
     try {
-      new LiteralByteString(referenceBytes).toString("invalid");
+      ByteString.wrap(referenceBytes).toString("invalid");
       fail("Should have thrown an exception.");
     } catch (UnsupportedEncodingException expected) {
       // This is success
@@ -390,15 +438,15 @@ public class LiteralByteStringTest extends TestCase {
     assertFalse(classUnderTest + " must not equal the empty string",
         stringUnderTest.equals(ByteString.EMPTY));
     assertEquals(classUnderTest + " empty strings must be equal",
-        new LiteralByteString(new byte[]{}), stringUnderTest.substring(55, 55));
+        ByteString.wrap(new byte[]{}), stringUnderTest.substring(55, 55));
     assertEquals(classUnderTest + " must equal another string with the same value",
-        stringUnderTest, new LiteralByteString(referenceBytes));
+        stringUnderTest, ByteString.wrap(referenceBytes));
 
     byte[] mungedBytes = new byte[referenceBytes.length];
     System.arraycopy(referenceBytes, 0, mungedBytes, 0, referenceBytes.length);
     mungedBytes[mungedBytes.length - 5] = (byte) (mungedBytes[mungedBytes.length - 5] ^ 0xFF);
     assertFalse(classUnderTest + " must not equal every string with the same length",
-        stringUnderTest.equals(new LiteralByteString(mungedBytes)));
+        stringUnderTest.equals(ByteString.wrap(mungedBytes)));
   }
 
   public void testHashCode() {
diff --git a/java/src/test/java/com/google/protobuf/LongArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java
index 3a52ec7f..0a8f9ed2 100644
--- a/java/src/test/java/com/google/protobuf/LongArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java
@@ -73,20 +73,6 @@ public class LongArrayListTest extends TestCase {
     assertImmutable(list);
   }
   
-  public void testCopyConstructor() {
-    LongArrayList copy = new LongArrayList(TERTIARY_LIST);
-    assertEquals(TERTIARY_LIST, copy);
-
-    copy = new LongArrayList(LongArrayList.emptyList());
-    assertEquals(LongArrayList.emptyList(), copy);
-    
-    copy = new LongArrayList(asList(1L, 2L, 3L));
-    assertEquals(asList(1L, 2L, 3L), copy);
-
-    copy = new LongArrayList(Collections.<Long>emptyList());
-    assertEquals(LongArrayList.emptyList(), copy);
-  }
-  
   public void testModificationWithIteration() {
     list.addAll(asList(1L, 2L, 3L, 4L));
     Iterator<Long> iterator = list.iterator();
@@ -310,7 +296,7 @@ public class LongArrayListTest extends TestCase {
   }
   
   private void assertImmutable(LongArrayList list) {
-    if (list.contains(1)) {
+    if (list.contains(1L)) {
       throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
     }
     
@@ -413,7 +399,7 @@ public class LongArrayListTest extends TestCase {
     }
     
     try {
-      list.removeAll(Collections.singleton(1));
+      list.removeAll(Collections.singleton(1L));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
@@ -434,7 +420,7 @@ public class LongArrayListTest extends TestCase {
     }
     
     try {
-      list.retainAll(Collections.singleton(1));
+      list.retainAll(Collections.singleton(1L));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
diff --git a/java/src/test/java/com/google/protobuf/MapForProto2LiteTest.java b/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
index 3d8c9bc4..d79d0029 100644
--- a/java/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
@@ -432,7 +432,7 @@ public class MapForProto2LiteTest extends TestCase {
     assertEquals(1, messageWithUnknownEnums.getInt32ToInt32Field().get(1).intValue());
     assertEquals(54321, messageWithUnknownEnums.getInt32ToInt32Field().get(2).intValue());
   }
-  
+
 
   public void testIterationOrder() throws Exception {
     TestMap.Builder builder = TestMap.newBuilder();
diff --git a/java/src/test/java/com/google/protobuf/MapForProto2Test.java b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
index 1fa3cbdb..73154c0f 100644
--- a/java/src/test/java/com/google/protobuf/MapForProto2Test.java
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
@@ -36,7 +36,6 @@ import map_test.MapForProto2TestProto.TestMap.MessageValue;
 import map_test.MapForProto2TestProto.TestMap.MessageWithRequiredFields;
 import map_test.MapForProto2TestProto.TestRecursiveMap;
 import map_test.MapForProto2TestProto.TestUnknownEnumValue;
-
 import junit.framework.TestCase;
 
 import java.util.ArrayList;
diff --git a/java/src/test/java/com/google/protobuf/MapTest.java b/java/core/src/test/java/com/google/protobuf/MapTest.java
index 0e5c1284..1dc5787d 100644
--- a/java/src/test/java/com/google/protobuf/MapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapTest.java
@@ -37,7 +37,6 @@ import com.google.protobuf.Descriptors.FieldDescriptor;
 import map_test.MapTestProto.TestMap;
 import map_test.MapTestProto.TestMap.MessageValue;
 import map_test.MapTestProto.TestOnChangeEventPropagation;
-
 import junit.framework.TestCase;
 
 import java.util.ArrayList;
diff --git a/java/src/test/java/com/google/protobuf/MessageTest.java b/java/core/src/test/java/com/google/protobuf/MessageTest.java
index abcd3a1d..dcd1aba7 100644
--- a/java/src/test/java/com/google/protobuf/MessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MessageTest.java
@@ -30,11 +30,11 @@
 
 package com.google.protobuf;
 
-import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.ForeignMessage;
 import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
 import protobuf_unittest.UnittestProto.TestRequired;
 import protobuf_unittest.UnittestProto.TestRequiredForeign;
-import protobuf_unittest.UnittestProto.ForeignMessage;
 
 import junit.framework.TestCase;
 
diff --git a/java/src/test/java/com/google/protobuf/NestedBuildersTest.java b/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java
index 23653126..542e28c0 100644
--- a/java/src/test/java/com/google/protobuf/NestedBuildersTest.java
+++ b/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java
@@ -35,8 +35,8 @@ import protobuf_unittest.Wheel;
 
 import junit.framework.TestCase;
 
-import java.util.List;
 import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Test cases that exercise end-to-end use cases involving
diff --git a/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java b/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java
new file mode 100644
index 00000000..6be5b93c
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java
@@ -0,0 +1,620 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static com.google.protobuf.Internal.UTF_8;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.BufferOverflowException;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+/**
+ * Tests for {@link NioByteString}.
+ */
+public class NioByteStringTest extends TestCase {
+  private static final ByteString EMPTY = new NioByteString(ByteBuffer.wrap(new byte[0]));
+  private static final String CLASSNAME = NioByteString.class.getSimpleName();
+  private static final byte[] BYTES = ByteStringTest.getTestBytes(1234, 11337766L);
+  private static final int EXPECTED_HASH = ByteString.wrap(BYTES).hashCode();
+
+  private final ByteBuffer backingBuffer = ByteBuffer.wrap(BYTES.clone());
+  private final ByteString testString = new NioByteString(backingBuffer);
+
+  public void testExpectedType() {
+    String actualClassName = getActualClassName(testString);
+    assertEquals(CLASSNAME + " should match type exactly", CLASSNAME, actualClassName);
+  }
+
+  protected String getActualClassName(Object object) {
+    String actualClassName = object.getClass().getName();
+    actualClassName = actualClassName.substring(actualClassName.lastIndexOf('.') + 1);
+    return actualClassName;
+  }
+
+  public void testByteAt() {
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < BYTES.length; ++i) {
+      stillEqual = (BYTES[i] == testString.byteAt(i));
+    }
+    assertTrue(CLASSNAME + " must capture the right bytes", stillEqual);
+  }
+
+  public void testByteIterator() {
+    boolean stillEqual = true;
+    ByteString.ByteIterator iter = testString.iterator();
+    for (int i = 0; stillEqual && i < BYTES.length; ++i) {
+      stillEqual = (iter.hasNext() && BYTES[i] == iter.nextByte());
+    }
+    assertTrue(CLASSNAME + " must capture the right bytes", stillEqual);
+    assertFalse(CLASSNAME + " must have exhausted the itertor", iter.hasNext());
+
+    try {
+      iter.nextByte();
+      fail("Should have thrown an exception.");
+    } catch (NoSuchElementException e) {
+      // This is success
+    }
+  }
+
+  public void testByteIterable() {
+    boolean stillEqual = true;
+    int j = 0;
+    for (byte quantum : testString) {
+      stillEqual = (BYTES[j] == quantum);
+      ++j;
+    }
+    assertTrue(CLASSNAME + " must capture the right bytes as Bytes", stillEqual);
+    assertEquals(CLASSNAME + " iterable character count", BYTES.length, j);
+  }
+
+  public void testSize() {
+    assertEquals(CLASSNAME + " must have the expected size", BYTES.length,
+        testString.size());
+  }
+
+  public void testGetTreeDepth() {
+    assertEquals(CLASSNAME + " must have depth 0", 0, testString.getTreeDepth());
+  }
+
+  public void testIsBalanced() {
+    assertTrue(CLASSNAME + " is technically balanced", testString.isBalanced());
+  }
+
+  public void testCopyTo_ByteArrayOffsetLength() {
+    int destinationOffset = 50;
+    int length = 100;
+    byte[] destination = new byte[destinationOffset + length];
+    int sourceOffset = 213;
+    testString.copyTo(destination, sourceOffset, destinationOffset, length);
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < length; ++i) {
+      stillEqual = BYTES[i + sourceOffset] == destination[i + destinationOffset];
+    }
+    assertTrue(CLASSNAME + ".copyTo(4 arg) must give the expected bytes", stillEqual);
+  }
+
+  public void testCopyTo_ByteArrayOffsetLengthErrors() {
+    int destinationOffset = 50;
+    int length = 100;
+    byte[] destination = new byte[destinationOffset + length];
+
+    try {
+      // Copy one too many bytes
+      testString.copyTo(destination, testString.size() + 1 - length,
+          destinationOffset, length);
+      fail("Should have thrown an exception when copying too many bytes of a "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative sourceOffset
+      testString.copyTo(destination, -1, destinationOffset, length);
+      fail("Should have thrown an exception when given a negative sourceOffset in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative destinationOffset
+      testString.copyTo(destination, 0, -1, length);
+      fail("Should have thrown an exception when given a negative destinationOffset in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative size
+      testString.copyTo(destination, 0, 0, -1);
+      fail("Should have thrown an exception when given a negative size in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal too-large sourceOffset
+      testString.copyTo(destination, 2 * testString.size(), 0, length);
+      fail("Should have thrown an exception when the destinationOffset is too large in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal too-large destinationOffset
+      testString.copyTo(destination, 0, 2 * destination.length, length);
+      fail("Should have thrown an exception when the destinationOffset is too large in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+  }
+
+  public void testCopyTo_ByteBuffer() {
+    // Same length.
+    ByteBuffer myBuffer = ByteBuffer.allocate(BYTES.length);
+    testString.copyTo(myBuffer);
+    myBuffer.flip();
+    assertEquals(CLASSNAME + ".copyTo(ByteBuffer) must give back the same bytes",
+        backingBuffer, myBuffer);
+
+    // Target buffer bigger than required.
+    myBuffer = ByteBuffer.allocate(testString.size() + 1);
+    testString.copyTo(myBuffer);
+    myBuffer.flip();
+    assertEquals(backingBuffer, myBuffer);
+
+    // Target buffer has no space.
+    myBuffer = ByteBuffer.allocate(0);
+    try {
+      testString.copyTo(myBuffer);
+      fail("Should have thrown an exception when target ByteBuffer has insufficient capacity");
+    } catch (BufferOverflowException e) {
+      // Expected.
+    }
+
+    // Target buffer too small.
+    myBuffer = ByteBuffer.allocate(1);
+    try {
+      testString.copyTo(myBuffer);
+      fail("Should have thrown an exception when target ByteBuffer has insufficient capacity");
+    } catch (BufferOverflowException e) {
+      // Expected.
+    }
+  }
+
+  public void testMarkSupported() {
+    InputStream stream = testString.newInput();
+    assertTrue(CLASSNAME + ".newInput() must support marking", stream.markSupported());
+  }
+
+  public void testMarkAndReset() throws IOException {
+    int fraction = testString.size() / 3;
+
+    InputStream stream = testString.newInput();
+    stream.mark(testString.size()); // First, mark() the end.
+
+    skipFully(stream, fraction); // Skip a large fraction, but not all.
+    assertEquals(
+        CLASSNAME + ": after skipping to the 'middle', half the bytes are available",
+        (testString.size() - fraction), stream.available());
+    stream.reset();
+    assertEquals(
+        CLASSNAME + ": after resetting, all bytes are available",
+        testString.size(), stream.available());
+
+    skipFully(stream, testString.size()); // Skip to the end.
+    assertEquals(
+        CLASSNAME + ": after skipping to the end, no more bytes are available",
+        0, stream.available());
+  }
+
+  /**
+   * Discards {@code n} bytes of data from the input stream. This method
+   * will block until the full amount has been skipped. Does not close the
+   * stream.
+   * <p>Copied from com.google.common.io.ByteStreams to avoid adding dependency.
+   *
+   * @param in the input stream to read from
+   * @param n the number of bytes to skip
+   * @throws EOFException if this stream reaches the end before skipping all
+   *     the bytes
+   * @throws IOException if an I/O error occurs, or the stream does not
+   *     support skipping
+   */
+  static void skipFully(InputStream in, long n) throws IOException {
+    long toSkip = n;
+    while (n > 0) {
+      long amt = in.skip(n);
+      if (amt == 0) {
+        // Force a blocking read to avoid infinite loop
+        if (in.read() == -1) {
+          long skipped = toSkip - n;
+          throw new EOFException("reached end of stream after skipping "
+              + skipped + " bytes; " + toSkip + " bytes expected");
+        }
+        n--;
+      } else {
+        n -= amt;
+      }
+    }
+  }
+
+  public void testAsReadOnlyByteBuffer() {
+    ByteBuffer byteBuffer = testString.asReadOnlyByteBuffer();
+    byte[] roundTripBytes = new byte[BYTES.length];
+    assertTrue(byteBuffer.remaining() == BYTES.length);
+    assertTrue(byteBuffer.isReadOnly());
+    byteBuffer.get(roundTripBytes);
+    assertTrue(CLASSNAME + ".asReadOnlyByteBuffer() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testAsReadOnlyByteBufferList() {
+    List<ByteBuffer> byteBuffers = testString.asReadOnlyByteBufferList();
+    int bytesSeen = 0;
+    byte[] roundTripBytes = new byte[BYTES.length];
+    for (ByteBuffer byteBuffer : byteBuffers) {
+      int thisLength = byteBuffer.remaining();
+      assertTrue(byteBuffer.isReadOnly());
+      assertTrue(bytesSeen + thisLength <= BYTES.length);
+      byteBuffer.get(roundTripBytes, bytesSeen, thisLength);
+      bytesSeen += thisLength;
+    }
+    assertTrue(bytesSeen == BYTES.length);
+    assertTrue(CLASSNAME + ".asReadOnlyByteBufferTest() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testToByteArray() {
+    byte[] roundTripBytes = testString.toByteArray();
+    assertTrue(CLASSNAME + ".toByteArray() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testWriteTo() throws IOException {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    testString.writeTo(bos);
+    byte[] roundTripBytes = bos.toByteArray();
+    assertTrue(CLASSNAME + ".writeTo() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testWriteToShouldNotExposeInternalBufferToOutputStream() throws IOException {
+    OutputStream os = new OutputStream() {
+      @Override
+      public void write(byte[] b, int off, int len) {
+        Arrays.fill(b, off, off + len, (byte) 0);
+      }
+
+      @Override
+      public void write(int b) {
+        throw new UnsupportedOperationException();
+      }
+    };
+
+    byte[] original = Arrays.copyOf(BYTES, BYTES.length);
+    testString.writeTo(os);
+    assertTrue(CLASSNAME + ".writeTo() must NOT grant access to underlying buffer",
+        Arrays.equals(original, BYTES));
+  }
+
+  public void testWriteToInternalShouldExposeInternalBufferToOutputStream() throws IOException {
+    OutputStream os = new OutputStream() {
+      @Override
+      public void write(byte[] b, int off, int len) {
+        Arrays.fill(b, off, off + len, (byte) 0);
+      }
+
+      @Override
+      public void write(int b) {
+        throw new UnsupportedOperationException();
+      }
+    };
+
+    testString.writeToInternal(os, 0, testString.size());
+    byte[] allZeros = new byte[testString.size()];
+    assertTrue(CLASSNAME + ".writeToInternal() must grant access to underlying buffer",
+        Arrays.equals(allZeros, backingBuffer.array()));
+  }
+
+  public void testWriteToShouldExposeInternalBufferToByteOutput() throws IOException {
+    ByteOutput out = new ByteOutput() {
+      @Override
+      public void write(byte value) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void write(byte[] value, int offset, int length) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void writeLazy(byte[] value, int offset, int length) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void write(ByteBuffer value) throws IOException {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void writeLazy(ByteBuffer value) throws IOException {
+        Arrays.fill(value.array(), value.arrayOffset(), value.arrayOffset() + value.limit(),
+            (byte) 0);
+      }
+    };
+
+    testString.writeTo(out);
+    byte[] allZeros = new byte[testString.size()];
+    assertTrue(CLASSNAME + ".writeTo() must grant access to underlying buffer",
+        Arrays.equals(allZeros, backingBuffer.array()));
+  }
+
+  public void testNewOutput() throws IOException {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    ByteString.Output output = ByteString.newOutput();
+    testString.writeTo(output);
+    assertEquals("Output Size returns correct result",
+        output.size(), testString.size());
+    output.writeTo(bos);
+    assertTrue("Output.writeTo() must give back the same bytes",
+        Arrays.equals(BYTES, bos.toByteArray()));
+
+    // write the output stream to itself! This should cause it to double
+    output.writeTo(output);
+    assertEquals("Writing an output stream to itself is successful",
+        testString.concat(testString), output.toByteString());
+
+    output.reset();
+    assertEquals("Output.reset() resets the output", 0, output.size());
+    assertEquals("Output.reset() resets the output",
+        EMPTY, output.toByteString());
+  }
+
+  public void testToString() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = forString(testString);
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(CLASSNAME + " unicode must match", testString, roundTripString);
+  }
+
+  public void testCharsetToString() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = forString(testString);
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(CLASSNAME + " unicode must match", testString, roundTripString);
+  }
+
+  public void testToString_returnsCanonicalEmptyString() {
+    assertSame(CLASSNAME + " must be the same string references",
+        EMPTY.toString(UTF_8),
+        new NioByteString(ByteBuffer.wrap(new byte[0])).toString(UTF_8));
+  }
+
+  public void testToString_raisesException() {
+    try {
+      EMPTY.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+
+    try {
+      testString.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+  }
+
+  public void testEquals() {
+    assertEquals(CLASSNAME + " must not equal null", false, testString.equals(null));
+    assertEquals(CLASSNAME + " must equal self", testString, testString);
+    assertFalse(CLASSNAME + " must not equal the empty string",
+        testString.equals(EMPTY));
+    assertEquals(CLASSNAME + " empty strings must be equal",
+        EMPTY, testString.substring(55, 55));
+    assertEquals(CLASSNAME + " must equal another string with the same value",
+        testString, new NioByteString(backingBuffer));
+
+    byte[] mungedBytes = mungedBytes();
+    assertFalse(CLASSNAME + " must not equal every string with the same length",
+        testString.equals(new NioByteString(ByteBuffer.wrap(mungedBytes))));
+  }
+
+  public void testEqualsLiteralByteString() {
+    ByteString literal = ByteString.copyFrom(BYTES);
+    assertEquals(CLASSNAME + " must equal LiteralByteString with same value", literal,
+        testString);
+    assertEquals(CLASSNAME + " must equal LiteralByteString with same value", testString,
+        literal);
+    assertFalse(CLASSNAME + " must not equal the empty string",
+        testString.equals(ByteString.EMPTY));
+    assertEquals(CLASSNAME + " empty strings must be equal",
+        ByteString.EMPTY, testString.substring(55, 55));
+
+    literal = ByteString.copyFrom(mungedBytes());
+    assertFalse(CLASSNAME + " must not equal every LiteralByteString with the same length",
+        testString.equals(literal));
+    assertFalse(CLASSNAME + " must not equal every LiteralByteString with the same length",
+        literal.equals(testString));
+  }
+
+  public void testEqualsRopeByteString() {
+    ByteString p1 = ByteString.copyFrom(BYTES, 0, 5);
+    ByteString p2 = ByteString.copyFrom(BYTES, 5, BYTES.length - 5);
+    ByteString rope = p1.concat(p2);
+
+    assertEquals(CLASSNAME + " must equal RopeByteString with same value", rope,
+        testString);
+    assertEquals(CLASSNAME + " must equal RopeByteString with same value", testString,
+        rope);
+    assertFalse(CLASSNAME + " must not equal the empty string",
+        testString.equals(ByteString.EMPTY.concat(ByteString.EMPTY)));
+    assertEquals(CLASSNAME + " empty strings must be equal",
+        ByteString.EMPTY.concat(ByteString.EMPTY), testString.substring(55, 55));
+
+    byte[] mungedBytes = mungedBytes();
+    p1 = ByteString.copyFrom(mungedBytes, 0, 5);
+    p2 = ByteString.copyFrom(mungedBytes, 5, mungedBytes.length - 5);
+    rope = p1.concat(p2);
+    assertFalse(CLASSNAME + " must not equal every RopeByteString with the same length",
+        testString.equals(rope));
+    assertFalse(CLASSNAME + " must not equal every RopeByteString with the same length",
+        rope.equals(testString));
+  }
+
+  private byte[] mungedBytes() {
+    byte[] mungedBytes = new byte[BYTES.length];
+    System.arraycopy(BYTES, 0, mungedBytes, 0, BYTES.length);
+    mungedBytes[mungedBytes.length - 5] = (byte) (mungedBytes[mungedBytes.length - 5] ^ 0xFF);
+    return mungedBytes;
+  }
+
+  public void testHashCode() {
+    int hash = testString.hashCode();
+    assertEquals(CLASSNAME + " must have expected hashCode", EXPECTED_HASH, hash);
+  }
+
+  public void testPeekCachedHashCode() {
+    ByteString newString = new NioByteString(backingBuffer);
+    assertEquals(CLASSNAME + ".peekCachedHashCode() should return zero at first", 0,
+        newString.peekCachedHashCode());
+    newString.hashCode();
+    assertEquals(CLASSNAME + ".peekCachedHashCode should return zero at first",
+        EXPECTED_HASH, newString.peekCachedHashCode());
+  }
+
+  public void testPartialHash() {
+    // partialHash() is more strenuously tested elsewhere by testing hashes of substrings.
+    // This test would fail if the expected hash were 1.  It's not.
+    int hash = testString.partialHash(testString.size(), 0, testString.size());
+    assertEquals(CLASSNAME + ".partialHash() must yield expected hashCode",
+        EXPECTED_HASH, hash);
+  }
+
+  public void testNewInput() throws IOException {
+    InputStream input = testString.newInput();
+    assertEquals("InputStream.available() returns correct value",
+        testString.size(), input.available());
+    boolean stillEqual = true;
+    for (byte referenceByte : BYTES) {
+      int expectedInt = (referenceByte & 0xFF);
+      stillEqual = (expectedInt == input.read());
+    }
+    assertEquals("InputStream.available() returns correct value",
+        0, input.available());
+    assertTrue(CLASSNAME + " must give the same bytes from the InputStream", stillEqual);
+    assertEquals(CLASSNAME + " InputStream must now be exhausted", -1, input.read());
+  }
+
+  public void testNewInput_skip() throws IOException {
+    InputStream input = testString.newInput();
+    int stringSize = testString.size();
+    int nearEndIndex = stringSize * 2 / 3;
+    long skipped1 = input.skip(nearEndIndex);
+    assertEquals("InputStream.skip()", skipped1, nearEndIndex);
+    assertEquals("InputStream.available()",
+        stringSize - skipped1, input.available());
+    assertTrue("InputStream.mark() is available", input.markSupported());
+    input.mark(0);
+    assertEquals("InputStream.skip(), read()",
+        testString.byteAt(nearEndIndex) & 0xFF, input.read());
+    assertEquals("InputStream.available()",
+        stringSize - skipped1 - 1, input.available());
+    long skipped2 = input.skip(stringSize);
+    assertEquals("InputStream.skip() incomplete",
+        skipped2, stringSize - skipped1 - 1);
+    assertEquals("InputStream.skip(), no more input", 0, input.available());
+    assertEquals("InputStream.skip(), no more input", -1, input.read());
+    input.reset();
+    assertEquals("InputStream.reset() succeded",
+        stringSize - skipped1, input.available());
+    assertEquals("InputStream.reset(), read()",
+        testString.byteAt(nearEndIndex) & 0xFF, input.read());
+  }
+
+  public void testNewCodedInput() throws IOException {
+    CodedInputStream cis = testString.newCodedInput();
+    byte[] roundTripBytes = cis.readRawBytes(BYTES.length);
+    assertTrue(CLASSNAME + " must give the same bytes back from the CodedInputStream",
+        Arrays.equals(BYTES, roundTripBytes));
+    assertTrue(CLASSNAME + " CodedInputStream must now be exhausted", cis.isAtEnd());
+  }
+
+  /**
+   * Make sure we keep things simple when concatenating with empty. See also
+   * {@link ByteStringTest#testConcat_empty()}.
+   */
+  public void testConcat_empty() {
+    assertSame(CLASSNAME + " concatenated with empty must give " + CLASSNAME,
+        testString.concat(EMPTY), testString);
+    assertSame("empty concatenated with " + CLASSNAME + " must give " + CLASSNAME,
+        EMPTY.concat(testString), testString);
+  }
+
+  public void testJavaSerialization() throws Exception {
+    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    ObjectOutputStream oos = new ObjectOutputStream(out);
+    oos.writeObject(testString);
+    oos.close();
+    byte[] pickled = out.toByteArray();
+    InputStream in = new ByteArrayInputStream(pickled);
+    ObjectInputStream ois = new ObjectInputStream(in);
+    Object o = ois.readObject();
+    assertTrue("Didn't get a ByteString back", o instanceof ByteString);
+    assertEquals("Should get an equal ByteString back", testString, o);
+  }
+
+  private static ByteString forString(String str) {
+    return new NioByteString(ByteBuffer.wrap(str.getBytes(UTF_8)));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java b/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java
new file mode 100644
index 00000000..bf1f1d71
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java
@@ -0,0 +1,273 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import com.google.protobuf.DescriptorProtos.DescriptorProto;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Tests the exceptions thrown when parsing from a stream. The methods on the {@link Parser}
+ * interface are specified to only throw {@link InvalidProtocolBufferException}. But we really want
+ * to distinguish between invalid protos vs. actual I/O errors (like failures reading from a
+ * socket, etc.). So, when we're not using the parser directly, an {@link IOException} should be
+ * thrown where appropriate, instead of always an {@link InvalidProtocolBufferException}.
+ *
+ * @author jh@squareup.com (Joshua Humphries)
+ */
+@RunWith(JUnit4.class)
+public class ParseExceptionsTest {
+
+  private interface ParseTester {
+    DescriptorProto parse(InputStream in) throws IOException;
+  }
+
+  private byte serializedProto[];
+
+  private void setup() {
+    serializedProto = DescriptorProto.getDescriptor().toProto().toByteArray();
+  }
+
+  private void setupDelimited() {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    try {
+      DescriptorProto.getDescriptor().toProto().writeDelimitedTo(bos);
+    } catch (IOException e) {
+      fail("Exception not expected: " + e);
+    }
+    serializedProto = bos.toByteArray();
+  }
+
+  @Test public void message_parseFrom_InputStream() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.parseFrom(in);
+          }
+        });
+  }
+
+  @Test public void message_parseFrom_InputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.parseFrom(in, ExtensionRegistry.newInstance());
+          }
+        });
+  }
+
+  @Test public void message_parseFrom_CodedInputStream() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.parseFrom(CodedInputStream.newInstance(in));
+          }
+        });
+  }
+
+  @Test public void message_parseFrom_CodedInputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.parseFrom(
+                CodedInputStream.newInstance(in), ExtensionRegistry.newInstance());
+          }
+        });
+  }
+
+  @Test public void message_parseDelimitedFrom_InputStream() {
+    setupDelimited();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.parseDelimitedFrom(in);
+          }
+        });
+  }
+
+  @Test public void message_parseDelimitedFrom_InputStreamAndExtensionRegistry() {
+    setupDelimited();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.parseDelimitedFrom(in, ExtensionRegistry.newInstance());
+          }
+        });
+  }
+
+  @Test public void messageBuilder_mergeFrom_InputStream() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.newBuilder().mergeFrom(in).build();
+          }
+        });
+  }
+
+  @Test public void messageBuilder_mergeFrom_InputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.newBuilder()
+                .mergeFrom(in, ExtensionRegistry.newInstance())
+                .build();
+          }
+        });
+  }
+
+  @Test public void messageBuilder_mergeFrom_CodedInputStream() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.newBuilder().mergeFrom(CodedInputStream.newInstance(in)).build();
+          }
+        });
+  }
+
+  @Test public void messageBuilder_mergeFrom_CodedInputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            return DescriptorProto.newBuilder()
+                .mergeFrom(CodedInputStream.newInstance(in), ExtensionRegistry.newInstance())
+                .build();
+          }
+        });
+  }
+
+  @Test public void messageBuilder_mergeDelimitedFrom_InputStream() {
+    setupDelimited();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            DescriptorProto.Builder builder = DescriptorProto.newBuilder();
+            builder.mergeDelimitedFrom(in);
+            return builder.build();
+          }
+        });
+  }
+
+  @Test public void messageBuilder_mergeDelimitedFrom_InputStreamAndExtensionRegistry() {
+    setupDelimited();
+    verifyExceptions(
+        new ParseTester() {
+          @Override
+          public DescriptorProto parse(InputStream in) throws IOException {
+            DescriptorProto.Builder builder = DescriptorProto.newBuilder();
+            builder.mergeDelimitedFrom(in, ExtensionRegistry.newInstance());
+            return builder.build();
+          }
+        });
+  }
+
+  private void verifyExceptions(ParseTester parseTester) {
+    // No exception
+    try {
+      assertEquals(DescriptorProto.getDescriptor().toProto(),
+          parseTester.parse(new ByteArrayInputStream(serializedProto)));
+    } catch (IOException e) {
+      fail("No exception expected: " + e);
+    }
+
+    // IOException
+    try {
+      // using a "broken" stream that will throw part-way through reading the message
+      parseTester.parse(broken(new ByteArrayInputStream(serializedProto)));
+      fail("IOException expected but not thrown");
+    } catch (IOException e) {
+      assertFalse(e instanceof InvalidProtocolBufferException);
+    }
+
+    // InvalidProtocolBufferException
+    try {
+      // make the serialized proto invalid
+      for (int i = 0; i < 50; i++) {
+        serializedProto[i] = -1;
+      }
+      parseTester.parse(new ByteArrayInputStream(serializedProto));
+      fail("InvalidProtocolBufferException expected but not thrown");
+    } catch (IOException e) {
+      assertTrue(e instanceof InvalidProtocolBufferException);
+    }
+  }
+
+  private InputStream broken(InputStream i) {
+    return new FilterInputStream(i) {
+      int count = 0;
+
+      @Override public int read() throws IOException {
+        if (count++ >= 50) {
+          throw new IOException("I'm broken!");
+        }
+        return super.read();
+      }
+
+      @Override public int read(byte b[], int off, int len) throws IOException {
+        if ((count += len) >= 50) {
+          throw new IOException("I'm broken!");
+        }
+        return super.read(b, off, len);
+      }
+    };
+  }
+}
diff --git a/java/src/test/java/com/google/protobuf/ParserTest.java b/java/core/src/test/java/com/google/protobuf/ParserTest.java
index 5a92bacf..30842d2c 100644
--- a/java/src/test/java/com/google/protobuf/ParserTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ParserTest.java
@@ -33,15 +33,15 @@ package com.google.protobuf;
 import com.google.protobuf.UnittestLite.TestAllTypesLite;
 import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
 import com.google.protobuf.UnittestLite.TestParsingMergeLite;
+import protobuf_unittest.UnittestOptimizeFor;
 import protobuf_unittest.UnittestOptimizeFor.TestOptimizedForSize;
 import protobuf_unittest.UnittestOptimizeFor.TestRequiredOptimizedForSize;
-import protobuf_unittest.UnittestOptimizeFor;
+import protobuf_unittest.UnittestProto;
 import protobuf_unittest.UnittestProto.ForeignMessage;
 import protobuf_unittest.UnittestProto.TestAllTypes;
 import protobuf_unittest.UnittestProto.TestEmptyMessage;
 import protobuf_unittest.UnittestProto.TestParsingMerge;
 import protobuf_unittest.UnittestProto.TestRequired;
-import protobuf_unittest.UnittestProto;
 
 import junit.framework.TestCase;
 
@@ -179,16 +179,16 @@ public class ParserTest extends TestCase {
   public void testParseExtensions() throws Exception {
     assertRoundTripEquals(TestUtil.getAllExtensionsSet(),
                           TestUtil.getExtensionRegistry());
-    assertRoundTripEquals(TestUtil.getAllLiteExtensionsSet(),
-                          TestUtil.getExtensionRegistryLite());
+    assertRoundTripEquals(
+        TestUtilLite.getAllLiteExtensionsSet(), TestUtilLite.getExtensionRegistryLite());
   }
 
   public void testParsePacked() throws Exception {
     assertRoundTripEquals(TestUtil.getPackedSet());
     assertRoundTripEquals(TestUtil.getPackedExtensionsSet(),
                           TestUtil.getExtensionRegistry());
-    assertRoundTripEquals(TestUtil.getLitePackedExtensionsSet(),
-                          TestUtil.getExtensionRegistryLite());
+    assertRoundTripEquals(
+        TestUtilLite.getLitePackedExtensionsSet(), TestUtilLite.getExtensionRegistryLite());
   }
 
   public void testParseDelimitedTo() throws Exception {
@@ -198,8 +198,7 @@ public class ParserTest extends TestCase {
     normalMessage.writeDelimitedTo(output);
 
     // Write MessageLite with packed extension fields.
-    TestPackedExtensionsLite packedMessage =
-        TestUtil.getLitePackedExtensionsSet();
+    TestPackedExtensionsLite packedMessage = TestUtilLite.getLitePackedExtensionsSet();
     packedMessage.writeDelimitedTo(output);
 
     InputStream input = new ByteArrayInputStream(output.toByteArray());
@@ -208,8 +207,9 @@ public class ParserTest extends TestCase {
         normalMessage.getParserForType().parseDelimitedFrom(input));
     assertMessageEquals(
         packedMessage,
-        packedMessage.getParserForType().parseDelimitedFrom(
-            input, TestUtil.getExtensionRegistryLite()));
+        packedMessage
+            .getParserForType()
+            .parseDelimitedFrom(input, TestUtilLite.getExtensionRegistryLite()));
   }
 
   public void testParseUnknownFields() throws Exception {
diff --git a/java/src/test/java/com/google/protobuf/ProtobufArrayListTest.java b/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
index f9f5e9c7..3f45e226 100644
--- a/java/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
@@ -63,20 +63,6 @@ public class ProtobufArrayListTest extends TestCase {
     assertImmutable(ProtobufArrayList.<Integer>emptyList());
   }
   
-  public void testCopyConstructor() {
-    ProtobufArrayList<Integer> copy = new ProtobufArrayList<Integer>(TERTIARY_LIST);
-    assertEquals(TERTIARY_LIST, copy);
-
-    copy = new ProtobufArrayList<Integer>(IntArrayList.emptyList());
-    assertEquals(ProtobufArrayList.emptyList(), copy);
-    
-    copy = new ProtobufArrayList<Integer>(asList(1, 2, 3));
-    assertEquals(asList(1, 2, 3), copy);
-
-    copy = new ProtobufArrayList<Integer>(Collections.<Integer>emptyList());
-    assertEquals(ProtobufArrayList.emptyList(), copy);
-  }
-  
   public void testModificationWithIteration() {
     list.addAll(asList(1, 2, 3, 4));
     Iterator<Integer> iterator = list.iterator();
@@ -243,7 +229,7 @@ public class ProtobufArrayListTest extends TestCase {
     }
     
     try {
-      list.removeAll(Collections.<Double>emptyList());
+      list.removeAll(Collections.emptyList());
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
@@ -264,7 +250,7 @@ public class ProtobufArrayListTest extends TestCase {
     }
     
     try {
-      list.retainAll(Collections.<Double>emptyList());
+      list.retainAll(Collections.emptyList());
       fail();
     } catch (UnsupportedOperationException e) {
       // expected
diff --git a/java/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java b/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
index 49d52321..49d52321 100644
--- a/java/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
+++ b/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
diff --git a/java/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java b/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
index cc385599..dc56f2e9 100644
--- a/java/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
@@ -96,7 +96,7 @@ public class RopeByteStringSubstringTest extends LiteralByteStringTest {
   }
 
   @Override
-  public void testCharsetToString() throws UnsupportedEncodingException {
+  public void testCharsetToString() {
     String sourceString = "I love unicode \u1234\u5678 characters";
     ByteString sourceByteString = ByteString.copyFromUtf8(sourceString);
     int copies = 250;
diff --git a/java/src/test/java/com/google/protobuf/RopeByteStringTest.java b/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java
index 4ec3a409..4ec3a409 100644
--- a/java/src/test/java/com/google/protobuf/RopeByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java
diff --git a/java/src/test/java/com/google/protobuf/ServiceTest.java b/java/core/src/test/java/com/google/protobuf/ServiceTest.java
index ff980d66..b902737d 100644
--- a/java/src/test/java/com/google/protobuf/ServiceTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ServiceTest.java
@@ -35,22 +35,22 @@ import com.google.protobuf.Descriptors.MethodDescriptor;
 import google.protobuf.no_generic_services_test.UnittestNoGenericServices;
 import protobuf_unittest.MessageWithNoOuter;
 import protobuf_unittest.ServiceWithNoOuter;
-import protobuf_unittest.UnittestProto.TestAllTypes;
-import protobuf_unittest.UnittestProto.TestService;
-import protobuf_unittest.UnittestProto.FooRequest;
-import protobuf_unittest.UnittestProto.FooResponse;
 import protobuf_unittest.UnittestProto.BarRequest;
 import protobuf_unittest.UnittestProto.BarResponse;
+import protobuf_unittest.UnittestProto.FooRequest;
+import protobuf_unittest.UnittestProto.FooResponse;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestService;
+
+import junit.framework.TestCase;
 
 import org.easymock.classextension.EasyMock;
-import org.easymock.classextension.IMocksControl;
 import org.easymock.IArgumentMatcher;
+import org.easymock.classextension.IMocksControl;
 
 import java.util.HashSet;
 import java.util.Set;
 
-import junit.framework.TestCase;
-
 /**
  * Tests services and stubs.
  *
@@ -175,12 +175,14 @@ public class ServiceTest extends TestCase {
     MethodDescriptor fooMethod =
         ServiceWithNoOuter.getDescriptor().findMethodByName("Foo");
     MessageWithNoOuter request = MessageWithNoOuter.getDefaultInstance();
-    RpcCallback<Message> callback = new RpcCallback<Message>() {
-      public void run(Message parameter) {
-        // No reason this should be run.
-        fail();
-      }
-    };
+    RpcCallback<Message> callback =
+        new RpcCallback<Message>() {
+          @Override
+          public void run(Message parameter) {
+            // No reason this should be run.
+            fail();
+          }
+        };
     RpcCallback<TestAllTypes> specializedCallback =
         RpcUtil.specializeCallback(callback);
 
@@ -290,7 +292,9 @@ public class ServiceTest extends TestCase {
     public boolean isCalled() { return called; }
 
     public void reset() { called = false; }
-    public void run(Type message) { called = true; }
+    @Override
+    public void run(Type message) {
+      called = true; }
   }
 
   /** Implementation of the wrapsCallback() argument matcher. */
@@ -301,6 +305,7 @@ public class ServiceTest extends TestCase {
       this.callback = callback;
     }
 
+    @Override
     @SuppressWarnings("unchecked")
     public boolean matches(Object actual) {
       if (!(actual instanceof RpcCallback)) {
@@ -313,6 +318,7 @@ public class ServiceTest extends TestCase {
       return callback.isCalled();
     }
 
+    @Override
     public void appendTo(StringBuffer buffer) {
       buffer.append("wrapsCallback(mockCallback)");
     }
diff --git a/java/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java b/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
index 58b80007..58b80007 100644
--- a/java/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
+++ b/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
diff --git a/java/src/test/java/com/google/protobuf/SmallSortedMapTest.java b/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java
index 366086d3..e96ecd65 100644
--- a/java/src/test/java/com/google/protobuf/SmallSortedMapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java
@@ -56,14 +56,17 @@ public class SmallSortedMapTest extends TestCase {
       this.value = value;
     }
 
+    @Override
     public K getKey() {
       return key;
     }
 
+    @Override
     public V getValue() {
       return value;
     }
 
+    @Override
     public V setValue(V value) {
       V oldValue = this.value;
       this.value = value;
diff --git a/java/src/test/java/com/google/protobuf/TestBadIdentifiers.java b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
index 2c60fe0e..2c60fe0e 100644
--- a/java/src/test/java/com/google/protobuf/TestBadIdentifiers.java
+++ b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
diff --git a/java/src/test/java/com/google/protobuf/TestUtil.java b/java/core/src/test/java/com/google/protobuf/TestUtil.java
index 792e8665..08b2a76d 100644
--- a/java/src/test/java/com/google/protobuf/TestUtil.java
+++ b/java/core/src/test/java/com/google/protobuf/TestUtil.java
@@ -30,205 +30,200 @@
 
 package com.google.protobuf;
 
-import protobuf_unittest.UnittestProto;
-import com.google.protobuf.UnittestLite;
-
+import static com.google.protobuf.UnittestLite.defaultBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultCordExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultStringExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofStringExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalCordExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalForeignMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalGroupExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalLazyMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalPublicImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalStringExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.packedDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.packedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.packedInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedCordExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedForeignMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedGroupExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedLazyMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedStringExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedUint64ExtensionLite;
+import static protobuf_unittest.UnittestProto.OptionalGroup_extension;
+import static protobuf_unittest.UnittestProto.RepeatedGroup_extension;
+import static protobuf_unittest.UnittestProto.defaultBoolExtension;
+import static protobuf_unittest.UnittestProto.defaultBytesExtension;
+import static protobuf_unittest.UnittestProto.defaultCordExtension;
+import static protobuf_unittest.UnittestProto.defaultDoubleExtension;
+import static protobuf_unittest.UnittestProto.defaultFixed32Extension;
+import static protobuf_unittest.UnittestProto.defaultFixed64Extension;
+import static protobuf_unittest.UnittestProto.defaultFloatExtension;
+import static protobuf_unittest.UnittestProto.defaultForeignEnumExtension;
+import static protobuf_unittest.UnittestProto.defaultImportEnumExtension;
 // The static imports are to avoid 100+ char lines.  The following is roughly equivalent to
 // import static protobuf_unittest.UnittestProto.*;
 import static protobuf_unittest.UnittestProto.defaultInt32Extension;
 import static protobuf_unittest.UnittestProto.defaultInt64Extension;
-import static protobuf_unittest.UnittestProto.defaultUint32Extension;
-import static protobuf_unittest.UnittestProto.defaultUint64Extension;
-import static protobuf_unittest.UnittestProto.defaultSint32Extension;
-import static protobuf_unittest.UnittestProto.defaultSint64Extension;
-import static protobuf_unittest.UnittestProto.defaultFixed32Extension;
-import static protobuf_unittest.UnittestProto.defaultFixed64Extension;
+import static protobuf_unittest.UnittestProto.defaultNestedEnumExtension;
 import static protobuf_unittest.UnittestProto.defaultSfixed32Extension;
 import static protobuf_unittest.UnittestProto.defaultSfixed64Extension;
-import static protobuf_unittest.UnittestProto.defaultFloatExtension;
-import static protobuf_unittest.UnittestProto.defaultDoubleExtension;
-import static protobuf_unittest.UnittestProto.defaultBoolExtension;
+import static protobuf_unittest.UnittestProto.defaultSint32Extension;
+import static protobuf_unittest.UnittestProto.defaultSint64Extension;
 import static protobuf_unittest.UnittestProto.defaultStringExtension;
-import static protobuf_unittest.UnittestProto.defaultBytesExtension;
-import static protobuf_unittest.UnittestProto.defaultNestedEnumExtension;
-import static protobuf_unittest.UnittestProto.defaultForeignEnumExtension;
-import static protobuf_unittest.UnittestProto.defaultImportEnumExtension;
 import static protobuf_unittest.UnittestProto.defaultStringPieceExtension;
-import static protobuf_unittest.UnittestProto.defaultCordExtension;
-
-import static protobuf_unittest.UnittestProto.oneofUint32Extension;
+import static protobuf_unittest.UnittestProto.defaultUint32Extension;
+import static protobuf_unittest.UnittestProto.defaultUint64Extension;
+import static protobuf_unittest.UnittestProto.oneofBytesExtension;
 import static protobuf_unittest.UnittestProto.oneofNestedMessageExtension;
 import static protobuf_unittest.UnittestProto.oneofStringExtension;
-import static protobuf_unittest.UnittestProto.oneofBytesExtension;
-
-import static protobuf_unittest.UnittestProto.optionalInt32Extension;
-import static protobuf_unittest.UnittestProto.optionalInt64Extension;
-import static protobuf_unittest.UnittestProto.optionalUint32Extension;
-import static protobuf_unittest.UnittestProto.optionalUint64Extension;
-import static protobuf_unittest.UnittestProto.optionalSint32Extension;
-import static protobuf_unittest.UnittestProto.optionalSint64Extension;
-import static protobuf_unittest.UnittestProto.optionalFixed32Extension;
-import static protobuf_unittest.UnittestProto.optionalFixed64Extension;
-import static protobuf_unittest.UnittestProto.optionalSfixed32Extension;
-import static protobuf_unittest.UnittestProto.optionalSfixed64Extension;
-import static protobuf_unittest.UnittestProto.optionalFloatExtension;
-import static protobuf_unittest.UnittestProto.optionalDoubleExtension;
+import static protobuf_unittest.UnittestProto.oneofUint32Extension;
 import static protobuf_unittest.UnittestProto.optionalBoolExtension;
-import static protobuf_unittest.UnittestProto.optionalStringExtension;
 import static protobuf_unittest.UnittestProto.optionalBytesExtension;
-import static protobuf_unittest.UnittestProto.optionalGroupExtension;
 import static protobuf_unittest.UnittestProto.optionalCordExtension;
+import static protobuf_unittest.UnittestProto.optionalDoubleExtension;
+import static protobuf_unittest.UnittestProto.optionalFixed32Extension;
+import static protobuf_unittest.UnittestProto.optionalFixed64Extension;
+import static protobuf_unittest.UnittestProto.optionalFloatExtension;
 import static protobuf_unittest.UnittestProto.optionalForeignEnumExtension;
 import static protobuf_unittest.UnittestProto.optionalForeignMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalGroupExtension;
 import static protobuf_unittest.UnittestProto.optionalImportEnumExtension;
 import static protobuf_unittest.UnittestProto.optionalImportMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalInt32Extension;
+import static protobuf_unittest.UnittestProto.optionalInt64Extension;
+import static protobuf_unittest.UnittestProto.optionalLazyMessageExtension;
 import static protobuf_unittest.UnittestProto.optionalNestedEnumExtension;
 import static protobuf_unittest.UnittestProto.optionalNestedMessageExtension;
 import static protobuf_unittest.UnittestProto.optionalPublicImportMessageExtension;
-import static protobuf_unittest.UnittestProto.optionalLazyMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalSfixed32Extension;
+import static protobuf_unittest.UnittestProto.optionalSfixed64Extension;
+import static protobuf_unittest.UnittestProto.optionalSint32Extension;
+import static protobuf_unittest.UnittestProto.optionalSint64Extension;
+import static protobuf_unittest.UnittestProto.optionalStringExtension;
 import static protobuf_unittest.UnittestProto.optionalStringPieceExtension;
-
-import static protobuf_unittest.UnittestProto.repeatedInt32Extension;
-import static protobuf_unittest.UnittestProto.repeatedInt64Extension;
-import static protobuf_unittest.UnittestProto.repeatedUint32Extension;
-import static protobuf_unittest.UnittestProto.repeatedUint64Extension;
-import static protobuf_unittest.UnittestProto.repeatedSint32Extension;
-import static protobuf_unittest.UnittestProto.repeatedSint64Extension;
+import static protobuf_unittest.UnittestProto.optionalUint32Extension;
+import static protobuf_unittest.UnittestProto.optionalUint64Extension;
+import static protobuf_unittest.UnittestProto.packedBoolExtension;
+import static protobuf_unittest.UnittestProto.packedDoubleExtension;
+import static protobuf_unittest.UnittestProto.packedEnumExtension;
+import static protobuf_unittest.UnittestProto.packedFixed32Extension;
+import static protobuf_unittest.UnittestProto.packedFixed64Extension;
+import static protobuf_unittest.UnittestProto.packedFloatExtension;
+import static protobuf_unittest.UnittestProto.packedInt32Extension;
+import static protobuf_unittest.UnittestProto.packedInt64Extension;
+import static protobuf_unittest.UnittestProto.packedSfixed32Extension;
+import static protobuf_unittest.UnittestProto.packedSfixed64Extension;
+import static protobuf_unittest.UnittestProto.packedSint32Extension;
+import static protobuf_unittest.UnittestProto.packedSint64Extension;
+import static protobuf_unittest.UnittestProto.packedUint32Extension;
+import static protobuf_unittest.UnittestProto.packedUint64Extension;
+import static protobuf_unittest.UnittestProto.repeatedBoolExtension;
+import static protobuf_unittest.UnittestProto.repeatedBytesExtension;
+import static protobuf_unittest.UnittestProto.repeatedCordExtension;
+import static protobuf_unittest.UnittestProto.repeatedDoubleExtension;
 import static protobuf_unittest.UnittestProto.repeatedFixed32Extension;
 import static protobuf_unittest.UnittestProto.repeatedFixed64Extension;
-import static protobuf_unittest.UnittestProto.repeatedSfixed32Extension;
-import static protobuf_unittest.UnittestProto.repeatedSfixed64Extension;
 import static protobuf_unittest.UnittestProto.repeatedFloatExtension;
-import static protobuf_unittest.UnittestProto.repeatedDoubleExtension;
-import static protobuf_unittest.UnittestProto.repeatedBoolExtension;
-import static protobuf_unittest.UnittestProto.repeatedStringExtension;
-import static protobuf_unittest.UnittestProto.repeatedBytesExtension;
-import static protobuf_unittest.UnittestProto.repeatedGroupExtension;
-import static protobuf_unittest.UnittestProto.repeatedNestedMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedForeignEnumExtension;
 import static protobuf_unittest.UnittestProto.repeatedForeignMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedGroupExtension;
+import static protobuf_unittest.UnittestProto.repeatedImportEnumExtension;
 import static protobuf_unittest.UnittestProto.repeatedImportMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedInt32Extension;
+import static protobuf_unittest.UnittestProto.repeatedInt64Extension;
 import static protobuf_unittest.UnittestProto.repeatedLazyMessageExtension;
 import static protobuf_unittest.UnittestProto.repeatedNestedEnumExtension;
-import static protobuf_unittest.UnittestProto.repeatedForeignEnumExtension;
-import static protobuf_unittest.UnittestProto.repeatedImportEnumExtension;
+import static protobuf_unittest.UnittestProto.repeatedNestedMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedSfixed32Extension;
+import static protobuf_unittest.UnittestProto.repeatedSfixed64Extension;
+import static protobuf_unittest.UnittestProto.repeatedSint32Extension;
+import static protobuf_unittest.UnittestProto.repeatedSint64Extension;
+import static protobuf_unittest.UnittestProto.repeatedStringExtension;
 import static protobuf_unittest.UnittestProto.repeatedStringPieceExtension;
-import static protobuf_unittest.UnittestProto.repeatedCordExtension;
-
-import static protobuf_unittest.UnittestProto.OptionalGroup_extension;
-import static protobuf_unittest.UnittestProto.RepeatedGroup_extension;
-
-import static protobuf_unittest.UnittestProto.packedInt32Extension;
-import static protobuf_unittest.UnittestProto.packedInt64Extension;
-import static protobuf_unittest.UnittestProto.packedUint32Extension;
-import static protobuf_unittest.UnittestProto.packedUint64Extension;
-import static protobuf_unittest.UnittestProto.packedSint32Extension;
-import static protobuf_unittest.UnittestProto.packedSint64Extension;
-import static protobuf_unittest.UnittestProto.packedFixed32Extension;
-import static protobuf_unittest.UnittestProto.packedFixed64Extension;
-import static protobuf_unittest.UnittestProto.packedSfixed32Extension;
-import static protobuf_unittest.UnittestProto.packedSfixed64Extension;
-import static protobuf_unittest.UnittestProto.packedFloatExtension;
-import static protobuf_unittest.UnittestProto.packedDoubleExtension;
-import static protobuf_unittest.UnittestProto.packedBoolExtension;
-import static protobuf_unittest.UnittestProto.packedEnumExtension;
-
-import static com.google.protobuf.UnittestLite.defaultInt32ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultInt64ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultUint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultUint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultSint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultSint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultFixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultFixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultSfixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultSfixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultFloatExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultDoubleExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultBoolExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultStringExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultBytesExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultNestedEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultForeignEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultImportEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultStringPieceExtensionLite;
-import static com.google.protobuf.UnittestLite.defaultCordExtensionLite;
-
-import static com.google.protobuf.UnittestLite.oneofUint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.oneofNestedMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.oneofStringExtensionLite;
-import static com.google.protobuf.UnittestLite.oneofBytesExtensionLite;
-
-import static com.google.protobuf.UnittestLite.optionalInt32ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalInt64ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalUint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalUint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalSint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalSint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalFixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalFixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalSfixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalSfixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalFloatExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalDoubleExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalBoolExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalStringExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalBytesExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalGroupExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalNestedMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalForeignEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalForeignMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalImportEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalImportMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalNestedEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalPublicImportMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalLazyMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalStringPieceExtensionLite;
-import static com.google.protobuf.UnittestLite.optionalCordExtensionLite;
-
-import static com.google.protobuf.UnittestLite.repeatedInt32ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedInt64ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedUint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedUint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedSint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedSint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedFixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedFixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedSfixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedSfixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedFloatExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedDoubleExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedBoolExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedStringExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedBytesExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedGroupExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedNestedMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedForeignMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedImportMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedLazyMessageExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedNestedEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedForeignEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedImportEnumExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedStringPieceExtensionLite;
-import static com.google.protobuf.UnittestLite.repeatedCordExtensionLite;
-
-import static com.google.protobuf.UnittestLite.OptionalGroup_extension_lite;
-import static com.google.protobuf.UnittestLite.RepeatedGroup_extension_lite;
-
-import static com.google.protobuf.UnittestLite.packedInt32ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedInt64ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedUint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedUint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedSint32ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedSint64ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedFixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedFixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedSfixed32ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedSfixed64ExtensionLite;
-import static com.google.protobuf.UnittestLite.packedFloatExtensionLite;
-import static com.google.protobuf.UnittestLite.packedDoubleExtensionLite;
-import static com.google.protobuf.UnittestLite.packedBoolExtensionLite;
-import static com.google.protobuf.UnittestLite.packedEnumExtensionLite;
+import static protobuf_unittest.UnittestProto.repeatedUint32Extension;
+import static protobuf_unittest.UnittestProto.repeatedUint64Extension;
 
+import com.google.protobuf.UnittestImportLite.ImportEnumLite;
+import com.google.protobuf.UnittestLite.ForeignEnumLite;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLiteOrBuilder;
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+import com.google.protobuf.test.UnittestImport.ImportEnum;
+import com.google.protobuf.test.UnittestImport.ImportMessage;
+import com.google.protobuf.test.UnittestImportPublic.PublicImportMessage;
+import protobuf_unittest.UnittestProto;
+import protobuf_unittest.UnittestProto.ForeignEnum;
+import protobuf_unittest.UnittestProto.ForeignMessage;
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllExtensionsOrBuilder;
 import protobuf_unittest.UnittestProto.TestAllTypes;
@@ -237,21 +232,6 @@ import protobuf_unittest.UnittestProto.TestOneof2;
 import protobuf_unittest.UnittestProto.TestPackedExtensions;
 import protobuf_unittest.UnittestProto.TestPackedTypes;
 import protobuf_unittest.UnittestProto.TestUnpackedTypes;
-import protobuf_unittest.UnittestProto.ForeignMessage;
-import protobuf_unittest.UnittestProto.ForeignEnum;
-import com.google.protobuf.test.UnittestImport.ImportEnum;
-import com.google.protobuf.test.UnittestImport.ImportMessage;
-import com.google.protobuf.test.UnittestImportPublic.PublicImportMessage;
-
-import com.google.protobuf.UnittestLite.TestAllTypesLite;
-import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
-import com.google.protobuf.UnittestLite.TestAllExtensionsLiteOrBuilder;
-import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
-import com.google.protobuf.UnittestLite.ForeignMessageLite;
-import com.google.protobuf.UnittestLite.ForeignEnumLite;
-import com.google.protobuf.UnittestImportLite.ImportEnumLite;
-import com.google.protobuf.UnittestImportLite.ImportMessageLite;
-import com.google.protobuf.UnittestImportPublicLite.PublicImportMessageLite;
 
 import junit.framework.Assert;
 
@@ -309,12 +289,6 @@ public final class TestUtil {
     return builder.build();
   }
 
-  public static TestAllExtensionsLite getAllLiteExtensionsSet() {
-    TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
-    setAllExtensions(builder);
-    return builder.build();
-  }
-
   public static TestPackedTypes getPackedSet() {
     TestPackedTypes.Builder builder = TestPackedTypes.newBuilder();
     setPackedFields(builder);
@@ -333,13 +307,6 @@ public final class TestUtil {
     return builder.build();
   }
 
-  public static TestPackedExtensionsLite getLitePackedExtensionsSet() {
-    TestPackedExtensionsLite.Builder builder =
-        TestPackedExtensionsLite.newBuilder();
-    setPackedExtensions(builder);
-    return builder.build();
-  }
-
   /**
    * Set every field of {@code message} to the values expected by
    * {@code assertAllFieldsSet()}.
@@ -1229,23 +1196,13 @@ public final class TestUtil {
     return registry.getUnmodifiable();
   }
 
-  public static ExtensionRegistryLite getExtensionRegistryLite() {
-    ExtensionRegistryLite registry = ExtensionRegistryLite.newInstance();
-    registerAllExtensionsLite(registry);
-    return registry.getUnmodifiable();
-  }
-
   /**
    * Register all of {@code TestAllExtensions}'s extensions with the
    * given {@link ExtensionRegistry}.
    */
   public static void registerAllExtensions(ExtensionRegistry registry) {
     UnittestProto.registerAllExtensions(registry);
-    registerAllExtensionsLite(registry);
-  }
-
-  public static void registerAllExtensionsLite(ExtensionRegistryLite registry) {
-    UnittestLite.registerAllExtensions(registry);
+    TestUtilLite.registerAllExtensionsLite(registry);
   }
 
   /**
@@ -2039,195 +1996,6 @@ public final class TestUtil {
   // Lite extensions
 
   /**
-   * Set every field of {@code message} to the values expected by
-   * {@code assertAllExtensionsSet()}.
-   */
-  public static void setAllExtensions(TestAllExtensionsLite.Builder message) {
-    message.setExtension(optionalInt32ExtensionLite   , 101);
-    message.setExtension(optionalInt64ExtensionLite   , 102L);
-    message.setExtension(optionalUint32ExtensionLite  , 103);
-    message.setExtension(optionalUint64ExtensionLite  , 104L);
-    message.setExtension(optionalSint32ExtensionLite  , 105);
-    message.setExtension(optionalSint64ExtensionLite  , 106L);
-    message.setExtension(optionalFixed32ExtensionLite , 107);
-    message.setExtension(optionalFixed64ExtensionLite , 108L);
-    message.setExtension(optionalSfixed32ExtensionLite, 109);
-    message.setExtension(optionalSfixed64ExtensionLite, 110L);
-    message.setExtension(optionalFloatExtensionLite   , 111F);
-    message.setExtension(optionalDoubleExtensionLite  , 112D);
-    message.setExtension(optionalBoolExtensionLite    , true);
-    message.setExtension(optionalStringExtensionLite  , "115");
-    message.setExtension(optionalBytesExtensionLite   , toBytes("116"));
-
-    message.setExtension(optionalGroupExtensionLite,
-      OptionalGroup_extension_lite.newBuilder().setA(117).build());
-    message.setExtension(optionalNestedMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(118).build());
-    message.setExtension(optionalForeignMessageExtensionLite,
-      ForeignMessageLite.newBuilder().setC(119).build());
-    message.setExtension(optionalImportMessageExtensionLite,
-      ImportMessageLite.newBuilder().setD(120).build());
-    message.setExtension(optionalPublicImportMessageExtensionLite,
-      PublicImportMessageLite.newBuilder().setE(126).build());
-    message.setExtension(optionalLazyMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(127).build());
-
-    message.setExtension(optionalNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAZ);
-    message.setExtension(optionalForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
-    message.setExtension(optionalImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ);
-
-    message.setExtension(optionalStringPieceExtensionLite, "124");
-    message.setExtension(optionalCordExtensionLite, "125");
-
-    // -----------------------------------------------------------------
-
-    message.addExtension(repeatedInt32ExtensionLite   , 201);
-    message.addExtension(repeatedInt64ExtensionLite   , 202L);
-    message.addExtension(repeatedUint32ExtensionLite  , 203);
-    message.addExtension(repeatedUint64ExtensionLite  , 204L);
-    message.addExtension(repeatedSint32ExtensionLite  , 205);
-    message.addExtension(repeatedSint64ExtensionLite  , 206L);
-    message.addExtension(repeatedFixed32ExtensionLite , 207);
-    message.addExtension(repeatedFixed64ExtensionLite , 208L);
-    message.addExtension(repeatedSfixed32ExtensionLite, 209);
-    message.addExtension(repeatedSfixed64ExtensionLite, 210L);
-    message.addExtension(repeatedFloatExtensionLite   , 211F);
-    message.addExtension(repeatedDoubleExtensionLite  , 212D);
-    message.addExtension(repeatedBoolExtensionLite    , true);
-    message.addExtension(repeatedStringExtensionLite  , "215");
-    message.addExtension(repeatedBytesExtensionLite   , toBytes("216"));
-
-    message.addExtension(repeatedGroupExtensionLite,
-      RepeatedGroup_extension_lite.newBuilder().setA(217).build());
-    message.addExtension(repeatedNestedMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(218).build());
-    message.addExtension(repeatedForeignMessageExtensionLite,
-      ForeignMessageLite.newBuilder().setC(219).build());
-    message.addExtension(repeatedImportMessageExtensionLite,
-      ImportMessageLite.newBuilder().setD(220).build());
-    message.addExtension(repeatedLazyMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(227).build());
-
-    message.addExtension(repeatedNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAR);
-    message.addExtension(repeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAR);
-    message.addExtension(repeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAR);
-
-    message.addExtension(repeatedStringPieceExtensionLite, "224");
-    message.addExtension(repeatedCordExtensionLite, "225");
-
-    // Add a second one of each field.
-    message.addExtension(repeatedInt32ExtensionLite   , 301);
-    message.addExtension(repeatedInt64ExtensionLite   , 302L);
-    message.addExtension(repeatedUint32ExtensionLite  , 303);
-    message.addExtension(repeatedUint64ExtensionLite  , 304L);
-    message.addExtension(repeatedSint32ExtensionLite  , 305);
-    message.addExtension(repeatedSint64ExtensionLite  , 306L);
-    message.addExtension(repeatedFixed32ExtensionLite , 307);
-    message.addExtension(repeatedFixed64ExtensionLite , 308L);
-    message.addExtension(repeatedSfixed32ExtensionLite, 309);
-    message.addExtension(repeatedSfixed64ExtensionLite, 310L);
-    message.addExtension(repeatedFloatExtensionLite   , 311F);
-    message.addExtension(repeatedDoubleExtensionLite  , 312D);
-    message.addExtension(repeatedBoolExtensionLite    , false);
-    message.addExtension(repeatedStringExtensionLite  , "315");
-    message.addExtension(repeatedBytesExtensionLite   , toBytes("316"));
-
-    message.addExtension(repeatedGroupExtensionLite,
-      RepeatedGroup_extension_lite.newBuilder().setA(317).build());
-    message.addExtension(repeatedNestedMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(318).build());
-    message.addExtension(repeatedForeignMessageExtensionLite,
-      ForeignMessageLite.newBuilder().setC(319).build());
-    message.addExtension(repeatedImportMessageExtensionLite,
-      ImportMessageLite.newBuilder().setD(320).build());
-    message.addExtension(repeatedLazyMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(327).build());
-
-    message.addExtension(repeatedNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAZ);
-    message.addExtension(repeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
-    message.addExtension(repeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ);
-
-    message.addExtension(repeatedStringPieceExtensionLite, "324");
-    message.addExtension(repeatedCordExtensionLite, "325");
-
-    // -----------------------------------------------------------------
-
-    message.setExtension(defaultInt32ExtensionLite   , 401);
-    message.setExtension(defaultInt64ExtensionLite   , 402L);
-    message.setExtension(defaultUint32ExtensionLite  , 403);
-    message.setExtension(defaultUint64ExtensionLite  , 404L);
-    message.setExtension(defaultSint32ExtensionLite  , 405);
-    message.setExtension(defaultSint64ExtensionLite  , 406L);
-    message.setExtension(defaultFixed32ExtensionLite , 407);
-    message.setExtension(defaultFixed64ExtensionLite , 408L);
-    message.setExtension(defaultSfixed32ExtensionLite, 409);
-    message.setExtension(defaultSfixed64ExtensionLite, 410L);
-    message.setExtension(defaultFloatExtensionLite   , 411F);
-    message.setExtension(defaultDoubleExtensionLite  , 412D);
-    message.setExtension(defaultBoolExtensionLite    , false);
-    message.setExtension(defaultStringExtensionLite  , "415");
-    message.setExtension(defaultBytesExtensionLite   , toBytes("416"));
-
-    message.setExtension(defaultNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.FOO);
-    message.setExtension(defaultForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_FOO);
-    message.setExtension(defaultImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_FOO);
-
-    message.setExtension(defaultStringPieceExtensionLite, "424");
-    message.setExtension(defaultCordExtensionLite, "425");
-
-    message.setExtension(oneofUint32ExtensionLite, 601);
-    message.setExtension(oneofNestedMessageExtensionLite,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(602).build());
-    message.setExtension(oneofStringExtensionLite, "603");
-    message.setExtension(oneofBytesExtensionLite, toBytes("604"));
-  }
-
-  // -------------------------------------------------------------------
-
-  /**
-   * Modify the repeated extensions of {@code message} to contain the values
-   * expected by {@code assertRepeatedExtensionsModified()}.
-   */
-  public static void modifyRepeatedExtensions(
-      TestAllExtensionsLite.Builder message) {
-    message.setExtension(repeatedInt32ExtensionLite   , 1, 501);
-    message.setExtension(repeatedInt64ExtensionLite   , 1, 502L);
-    message.setExtension(repeatedUint32ExtensionLite  , 1, 503);
-    message.setExtension(repeatedUint64ExtensionLite  , 1, 504L);
-    message.setExtension(repeatedSint32ExtensionLite  , 1, 505);
-    message.setExtension(repeatedSint64ExtensionLite  , 1, 506L);
-    message.setExtension(repeatedFixed32ExtensionLite , 1, 507);
-    message.setExtension(repeatedFixed64ExtensionLite , 1, 508L);
-    message.setExtension(repeatedSfixed32ExtensionLite, 1, 509);
-    message.setExtension(repeatedSfixed64ExtensionLite, 1, 510L);
-    message.setExtension(repeatedFloatExtensionLite   , 1, 511F);
-    message.setExtension(repeatedDoubleExtensionLite  , 1, 512D);
-    message.setExtension(repeatedBoolExtensionLite    , 1, true);
-    message.setExtension(repeatedStringExtensionLite  , 1, "515");
-    message.setExtension(repeatedBytesExtensionLite   , 1, toBytes("516"));
-
-    message.setExtension(repeatedGroupExtensionLite, 1,
-      RepeatedGroup_extension_lite.newBuilder().setA(517).build());
-    message.setExtension(repeatedNestedMessageExtensionLite, 1,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(518).build());
-    message.setExtension(repeatedForeignMessageExtensionLite, 1,
-      ForeignMessageLite.newBuilder().setC(519).build());
-    message.setExtension(repeatedImportMessageExtensionLite, 1,
-      ImportMessageLite.newBuilder().setD(520).build());
-    message.setExtension(repeatedLazyMessageExtensionLite, 1,
-      TestAllTypesLite.NestedMessage.newBuilder().setBb(527).build());
-
-    message.setExtension(repeatedNestedEnumExtensionLite , 1, TestAllTypesLite.NestedEnum.FOO);
-    message.setExtension(repeatedForeignEnumExtensionLite, 1, ForeignEnumLite.FOREIGN_LITE_FOO);
-    message.setExtension(repeatedImportEnumExtensionLite , 1, ImportEnumLite.IMPORT_LITE_FOO);
-
-    message.setExtension(repeatedStringPieceExtensionLite, 1, "524");
-    message.setExtension(repeatedCordExtensionLite, 1, "525");
-  }
-
-  // -------------------------------------------------------------------
-
-  /**
    * Assert (using {@code junit.framework.Assert}} that all extensions of
    * {@code message} are set to the values assigned by {@code setAllExtensions}.
    */
@@ -2726,38 +2494,6 @@ public final class TestUtil {
     assertEqualsExactType("525", message.getExtension(repeatedCordExtensionLite, 1));
   }
 
-  public static void setPackedExtensions(TestPackedExtensionsLite.Builder message) {
-    message.addExtension(packedInt32ExtensionLite   , 601);
-    message.addExtension(packedInt64ExtensionLite   , 602L);
-    message.addExtension(packedUint32ExtensionLite  , 603);
-    message.addExtension(packedUint64ExtensionLite  , 604L);
-    message.addExtension(packedSint32ExtensionLite  , 605);
-    message.addExtension(packedSint64ExtensionLite  , 606L);
-    message.addExtension(packedFixed32ExtensionLite , 607);
-    message.addExtension(packedFixed64ExtensionLite , 608L);
-    message.addExtension(packedSfixed32ExtensionLite, 609);
-    message.addExtension(packedSfixed64ExtensionLite, 610L);
-    message.addExtension(packedFloatExtensionLite   , 611F);
-    message.addExtension(packedDoubleExtensionLite  , 612D);
-    message.addExtension(packedBoolExtensionLite    , true);
-    message.addExtension(packedEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAR);
-    // Add a second one of each field.
-    message.addExtension(packedInt32ExtensionLite   , 701);
-    message.addExtension(packedInt64ExtensionLite   , 702L);
-    message.addExtension(packedUint32ExtensionLite  , 703);
-    message.addExtension(packedUint64ExtensionLite  , 704L);
-    message.addExtension(packedSint32ExtensionLite  , 705);
-    message.addExtension(packedSint64ExtensionLite  , 706L);
-    message.addExtension(packedFixed32ExtensionLite , 707);
-    message.addExtension(packedFixed64ExtensionLite , 708L);
-    message.addExtension(packedSfixed32ExtensionLite, 709);
-    message.addExtension(packedSfixed64ExtensionLite, 710L);
-    message.addExtension(packedFloatExtensionLite   , 711F);
-    message.addExtension(packedDoubleExtensionLite  , 712D);
-    message.addExtension(packedBoolExtensionLite    , false);
-    message.addExtension(packedEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
-  }
-
   public static void assertPackedExtensionsSet(TestPackedExtensionsLite message) {
     Assert.assertEquals(2, message.getExtensionCount(packedInt32ExtensionLite   ));
     Assert.assertEquals(2, message.getExtensionCount(packedInt64ExtensionLite   ));
@@ -4109,7 +3845,7 @@ public final class TestUtil {
 
     private int invalidations;
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public void markDirty() {
       invalidations++;
     }
diff --git a/java/core/src/test/java/com/google/protobuf/TestUtilLite.java b/java/core/src/test/java/com/google/protobuf/TestUtilLite.java
new file mode 100644
index 00000000..8f33fa14
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/TestUtilLite.java
@@ -0,0 +1,559 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static com.google.protobuf.UnittestLite.OptionalGroup_extension_lite;
+import static com.google.protobuf.UnittestLite.RepeatedGroup_extension_lite;
+import static com.google.protobuf.UnittestLite.defaultBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultCordExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultStringExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofStringExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalCordExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalForeignMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalGroupExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalLazyMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalPublicImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalStringExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.packedDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.packedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.packedInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedCordExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedForeignMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedGroupExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedLazyMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedStringExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedUint64ExtensionLite;
+
+import com.google.protobuf.UnittestImportLite.ImportEnumLite;
+import com.google.protobuf.UnittestImportLite.ImportMessageLite;
+import com.google.protobuf.UnittestImportPublicLite.PublicImportMessageLite;
+import com.google.protobuf.UnittestLite.ForeignEnumLite;
+import com.google.protobuf.UnittestLite.ForeignMessageLite;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+
+/**
+ * Contains methods for setting fields of {@code TestAllTypesLite}, {@code TestAllExtensionsLite},
+ * and {@code TestPackedExtensionsLite}. This is analogous to the functionality in TestUtil.java but
+ * does not depend on the presence of any non-lite protos.
+ *
+ * <p>This code is not to be used outside of {@code com.google.protobuf} and
+ * subpackages.
+ */
+public final class TestUtilLite {
+  private TestUtilLite() {}
+
+  /** Helper to convert a String to ByteString. */
+  static ByteString toBytes(String str) {
+    return ByteString.copyFrom(str.getBytes(Internal.UTF_8));
+  }
+
+  /**
+   * Get a {@code TestAllTypesLite.Builder} with all fields set as they would be by
+   * {@link #setAllFields(TestAllTypesLite.Builder)}.
+   */
+  public static TestAllTypesLite.Builder getAllLiteSetBuilder() {
+    TestAllTypesLite.Builder builder = TestAllTypesLite.newBuilder();
+    setAllFields(builder);
+    return builder;
+  }
+
+  /**
+   * Get a {@code TestAllExtensionsLite} with all fields set as they would be by
+   * {@link #setAllExtensions(TestAllExtensionsLite.Builder)}.
+   */
+  public static TestAllExtensionsLite getAllLiteExtensionsSet() {
+    TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
+    setAllExtensions(builder);
+    return builder.build();
+  }
+
+  public static TestPackedExtensionsLite getLitePackedExtensionsSet() {
+    TestPackedExtensionsLite.Builder builder = TestPackedExtensionsLite.newBuilder();
+    setPackedExtensions(builder);
+    return builder.build();
+  }
+  
+  /**
+   * Set every field of {@code builder} to the values expected by
+   * {@code assertAllFieldsSet()}.
+   */
+  public static void setAllFields(TestAllTypesLite.Builder builder) {
+    builder.setOptionalInt32   (101);
+    builder.setOptionalInt64   (102);
+    builder.setOptionalUint32  (103);
+    builder.setOptionalUint64  (104);
+    builder.setOptionalSint32  (105);
+    builder.setOptionalSint64  (106);
+    builder.setOptionalFixed32 (107);
+    builder.setOptionalFixed64 (108);
+    builder.setOptionalSfixed32(109);
+    builder.setOptionalSfixed64(110);
+    builder.setOptionalFloat   (111);
+    builder.setOptionalDouble  (112);
+    builder.setOptionalBool    (true);
+    builder.setOptionalString  ("115");
+    builder.setOptionalBytes   (toBytes("116"));
+
+    builder.setOptionalGroup(
+        TestAllTypesLite.OptionalGroup.newBuilder().setA(117).build());
+    builder.setOptionalNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(118).build());
+    builder.setOptionalForeignMessage(
+        ForeignMessageLite.newBuilder().setC(119).build());
+    builder.setOptionalImportMessage(
+        ImportMessageLite.newBuilder().setD(120).build());
+    builder.setOptionalPublicImportMessage(
+        PublicImportMessageLite.newBuilder().setE(126).build());
+    builder.setOptionalLazyMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(127).build());
+
+    builder.setOptionalNestedEnum (TestAllTypesLite.NestedEnum.BAZ);
+    builder.setOptionalForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAZ);
+    builder.setOptionalImportEnum (ImportEnumLite.IMPORT_LITE_BAZ);
+
+    builder.setOptionalStringPiece("124");
+    builder.setOptionalCord("125");
+
+    // -----------------------------------------------------------------
+
+    builder.addRepeatedInt32   (201);
+    builder.addRepeatedInt64   (202);
+    builder.addRepeatedUint32  (203);
+    builder.addRepeatedUint64  (204);
+    builder.addRepeatedSint32  (205);
+    builder.addRepeatedSint64  (206);
+    builder.addRepeatedFixed32 (207);
+    builder.addRepeatedFixed64 (208);
+    builder.addRepeatedSfixed32(209);
+    builder.addRepeatedSfixed64(210);
+    builder.addRepeatedFloat   (211);
+    builder.addRepeatedDouble  (212);
+    builder.addRepeatedBool    (true);
+    builder.addRepeatedString  ("215");
+    builder.addRepeatedBytes   (toBytes("216"));
+
+    builder.addRepeatedGroup(
+        TestAllTypesLite.RepeatedGroup.newBuilder().setA(217).build());
+    builder.addRepeatedNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(218).build());
+    builder.addRepeatedForeignMessage(
+        ForeignMessageLite.newBuilder().setC(219).build());
+    builder.addRepeatedImportMessage(
+        ImportMessageLite.newBuilder().setD(220).build());
+    builder.addRepeatedLazyMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(227).build());
+
+    builder.addRepeatedNestedEnum (TestAllTypesLite.NestedEnum.BAR);
+    builder.addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR);
+    builder.addRepeatedImportEnum (ImportEnumLite.IMPORT_LITE_BAR);
+
+    builder.addRepeatedStringPiece("224");
+    builder.addRepeatedCord("225");
+
+    // Add a second one of each field.
+    builder.addRepeatedInt32   (301);
+    builder.addRepeatedInt64   (302);
+    builder.addRepeatedUint32  (303);
+    builder.addRepeatedUint64  (304);
+    builder.addRepeatedSint32  (305);
+    builder.addRepeatedSint64  (306);
+    builder.addRepeatedFixed32 (307);
+    builder.addRepeatedFixed64 (308);
+    builder.addRepeatedSfixed32(309);
+    builder.addRepeatedSfixed64(310);
+    builder.addRepeatedFloat   (311);
+    builder.addRepeatedDouble  (312);
+    builder.addRepeatedBool    (false);
+    builder.addRepeatedString  ("315");
+    builder.addRepeatedBytes   (toBytes("316"));
+
+    builder.addRepeatedGroup(
+        TestAllTypesLite.RepeatedGroup.newBuilder().setA(317).build());
+    builder.addRepeatedNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(318).build());
+    builder.addRepeatedForeignMessage(
+        ForeignMessageLite.newBuilder().setC(319).build());
+    builder.addRepeatedImportMessage(
+        ImportMessageLite.newBuilder().setD(320).build());
+    builder.addRepeatedLazyMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(327).build());
+
+    builder.addRepeatedNestedEnum (TestAllTypesLite.NestedEnum.BAZ);
+    builder.addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAZ);
+    builder.addRepeatedImportEnum (ImportEnumLite.IMPORT_LITE_BAZ);
+
+    builder.addRepeatedStringPiece("324");
+    builder.addRepeatedCord("325");
+
+    // -----------------------------------------------------------------
+
+    builder.setDefaultInt32   (401);
+    builder.setDefaultInt64   (402);
+    builder.setDefaultUint32  (403);
+    builder.setDefaultUint64  (404);
+    builder.setDefaultSint32  (405);
+    builder.setDefaultSint64  (406);
+    builder.setDefaultFixed32 (407);
+    builder.setDefaultFixed64 (408);
+    builder.setDefaultSfixed32(409);
+    builder.setDefaultSfixed64(410);
+    builder.setDefaultFloat   (411);
+    builder.setDefaultDouble  (412);
+    builder.setDefaultBool    (false);
+    builder.setDefaultString  ("415");
+    builder.setDefaultBytes   (toBytes("416"));
+
+    builder.setDefaultNestedEnum (TestAllTypesLite.NestedEnum.FOO);
+    builder.setDefaultForeignEnum(ForeignEnumLite.FOREIGN_LITE_FOO);
+    builder.setDefaultImportEnum (ImportEnumLite.IMPORT_LITE_FOO);
+
+    builder.setDefaultStringPiece("424");
+    builder.setDefaultCord("425");
+
+    builder.setOneofUint32(601);
+    builder.setOneofNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(602).build());
+    builder.setOneofString("603");
+    builder.setOneofBytes(toBytes("604"));
+  }
+
+  /**
+   * Get an unmodifiable {@link ExtensionRegistryLite} containing all the
+   * extensions of {@code TestAllExtensionsLite}.
+   */
+  public static ExtensionRegistryLite getExtensionRegistryLite() {
+    ExtensionRegistryLite registry = ExtensionRegistryLite.newInstance();
+    registerAllExtensionsLite(registry);
+    return registry.getUnmodifiable();
+  }
+
+  /**
+   * Register all of {@code TestAllExtensionsLite}'s extensions with the
+   * given {@link ExtensionRegistryLite}.
+   */
+  public static void registerAllExtensionsLite(ExtensionRegistryLite registry) {
+    UnittestLite.registerAllExtensions(registry);
+  }
+
+  // ===================================================================
+  // Lite extensions
+
+  /**
+   * Set every field of {@code message} to the values expected by
+   * {@code assertAllExtensionsSet()}.
+   */
+  public static void setAllExtensions(TestAllExtensionsLite.Builder message) {
+    message.setExtension(optionalInt32ExtensionLite   , 101);
+    message.setExtension(optionalInt64ExtensionLite   , 102L);
+    message.setExtension(optionalUint32ExtensionLite  , 103);
+    message.setExtension(optionalUint64ExtensionLite  , 104L);
+    message.setExtension(optionalSint32ExtensionLite  , 105);
+    message.setExtension(optionalSint64ExtensionLite  , 106L);
+    message.setExtension(optionalFixed32ExtensionLite , 107);
+    message.setExtension(optionalFixed64ExtensionLite , 108L);
+    message.setExtension(optionalSfixed32ExtensionLite, 109);
+    message.setExtension(optionalSfixed64ExtensionLite, 110L);
+    message.setExtension(optionalFloatExtensionLite   , 111F);
+    message.setExtension(optionalDoubleExtensionLite  , 112D);
+    message.setExtension(optionalBoolExtensionLite    , true);
+    message.setExtension(optionalStringExtensionLite  , "115");
+    message.setExtension(optionalBytesExtensionLite   , toBytes("116"));
+
+    message.setExtension(optionalGroupExtensionLite,
+      OptionalGroup_extension_lite.newBuilder().setA(117).build());
+    message.setExtension(optionalNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(118).build());
+    message.setExtension(optionalForeignMessageExtensionLite,
+      ForeignMessageLite.newBuilder().setC(119).build());
+    message.setExtension(optionalImportMessageExtensionLite,
+      ImportMessageLite.newBuilder().setD(120).build());
+    message.setExtension(optionalPublicImportMessageExtensionLite,
+      PublicImportMessageLite.newBuilder().setE(126).build());
+    message.setExtension(optionalLazyMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(127).build());
+
+    message.setExtension(optionalNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAZ);
+    message.setExtension(optionalForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
+    message.setExtension(optionalImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ);
+
+    message.setExtension(optionalStringPieceExtensionLite, "124");
+    message.setExtension(optionalCordExtensionLite, "125");
+
+    // -----------------------------------------------------------------
+
+    message.addExtension(repeatedInt32ExtensionLite   , 201);
+    message.addExtension(repeatedInt64ExtensionLite   , 202L);
+    message.addExtension(repeatedUint32ExtensionLite  , 203);
+    message.addExtension(repeatedUint64ExtensionLite  , 204L);
+    message.addExtension(repeatedSint32ExtensionLite  , 205);
+    message.addExtension(repeatedSint64ExtensionLite  , 206L);
+    message.addExtension(repeatedFixed32ExtensionLite , 207);
+    message.addExtension(repeatedFixed64ExtensionLite , 208L);
+    message.addExtension(repeatedSfixed32ExtensionLite, 209);
+    message.addExtension(repeatedSfixed64ExtensionLite, 210L);
+    message.addExtension(repeatedFloatExtensionLite   , 211F);
+    message.addExtension(repeatedDoubleExtensionLite  , 212D);
+    message.addExtension(repeatedBoolExtensionLite    , true);
+    message.addExtension(repeatedStringExtensionLite  , "215");
+    message.addExtension(repeatedBytesExtensionLite   , toBytes("216"));
+
+    message.addExtension(repeatedGroupExtensionLite,
+      RepeatedGroup_extension_lite.newBuilder().setA(217).build());
+    message.addExtension(repeatedNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(218).build());
+    message.addExtension(repeatedForeignMessageExtensionLite,
+      ForeignMessageLite.newBuilder().setC(219).build());
+    message.addExtension(repeatedImportMessageExtensionLite,
+      ImportMessageLite.newBuilder().setD(220).build());
+    message.addExtension(repeatedLazyMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(227).build());
+
+    message.addExtension(repeatedNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAR);
+    message.addExtension(repeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAR);
+    message.addExtension(repeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAR);
+
+    message.addExtension(repeatedStringPieceExtensionLite, "224");
+    message.addExtension(repeatedCordExtensionLite, "225");
+
+    // Add a second one of each field.
+    message.addExtension(repeatedInt32ExtensionLite   , 301);
+    message.addExtension(repeatedInt64ExtensionLite   , 302L);
+    message.addExtension(repeatedUint32ExtensionLite  , 303);
+    message.addExtension(repeatedUint64ExtensionLite  , 304L);
+    message.addExtension(repeatedSint32ExtensionLite  , 305);
+    message.addExtension(repeatedSint64ExtensionLite  , 306L);
+    message.addExtension(repeatedFixed32ExtensionLite , 307);
+    message.addExtension(repeatedFixed64ExtensionLite , 308L);
+    message.addExtension(repeatedSfixed32ExtensionLite, 309);
+    message.addExtension(repeatedSfixed64ExtensionLite, 310L);
+    message.addExtension(repeatedFloatExtensionLite   , 311F);
+    message.addExtension(repeatedDoubleExtensionLite  , 312D);
+    message.addExtension(repeatedBoolExtensionLite    , false);
+    message.addExtension(repeatedStringExtensionLite  , "315");
+    message.addExtension(repeatedBytesExtensionLite   , toBytes("316"));
+
+    message.addExtension(repeatedGroupExtensionLite,
+      RepeatedGroup_extension_lite.newBuilder().setA(317).build());
+    message.addExtension(repeatedNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(318).build());
+    message.addExtension(repeatedForeignMessageExtensionLite,
+      ForeignMessageLite.newBuilder().setC(319).build());
+    message.addExtension(repeatedImportMessageExtensionLite,
+      ImportMessageLite.newBuilder().setD(320).build());
+    message.addExtension(repeatedLazyMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(327).build());
+
+    message.addExtension(repeatedNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAZ);
+    message.addExtension(repeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
+    message.addExtension(repeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ);
+
+    message.addExtension(repeatedStringPieceExtensionLite, "324");
+    message.addExtension(repeatedCordExtensionLite, "325");
+
+    // -----------------------------------------------------------------
+
+    message.setExtension(defaultInt32ExtensionLite   , 401);
+    message.setExtension(defaultInt64ExtensionLite   , 402L);
+    message.setExtension(defaultUint32ExtensionLite  , 403);
+    message.setExtension(defaultUint64ExtensionLite  , 404L);
+    message.setExtension(defaultSint32ExtensionLite  , 405);
+    message.setExtension(defaultSint64ExtensionLite  , 406L);
+    message.setExtension(defaultFixed32ExtensionLite , 407);
+    message.setExtension(defaultFixed64ExtensionLite , 408L);
+    message.setExtension(defaultSfixed32ExtensionLite, 409);
+    message.setExtension(defaultSfixed64ExtensionLite, 410L);
+    message.setExtension(defaultFloatExtensionLite   , 411F);
+    message.setExtension(defaultDoubleExtensionLite  , 412D);
+    message.setExtension(defaultBoolExtensionLite    , false);
+    message.setExtension(defaultStringExtensionLite  , "415");
+    message.setExtension(defaultBytesExtensionLite   , toBytes("416"));
+
+    message.setExtension(defaultNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.FOO);
+    message.setExtension(defaultForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_FOO);
+    message.setExtension(defaultImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_FOO);
+
+    message.setExtension(defaultStringPieceExtensionLite, "424");
+    message.setExtension(defaultCordExtensionLite, "425");
+
+    message.setExtension(oneofUint32ExtensionLite, 601);
+    message.setExtension(oneofNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(602).build());
+    message.setExtension(oneofStringExtensionLite, "603");
+    message.setExtension(oneofBytesExtensionLite, toBytes("604"));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Modify the repeated extensions of {@code message} to contain the values
+   * expected by {@code assertRepeatedExtensionsModified()}.
+   */
+  public static void modifyRepeatedExtensions(
+      TestAllExtensionsLite.Builder message) {
+    message.setExtension(repeatedInt32ExtensionLite   , 1, 501);
+    message.setExtension(repeatedInt64ExtensionLite   , 1, 502L);
+    message.setExtension(repeatedUint32ExtensionLite  , 1, 503);
+    message.setExtension(repeatedUint64ExtensionLite  , 1, 504L);
+    message.setExtension(repeatedSint32ExtensionLite  , 1, 505);
+    message.setExtension(repeatedSint64ExtensionLite  , 1, 506L);
+    message.setExtension(repeatedFixed32ExtensionLite , 1, 507);
+    message.setExtension(repeatedFixed64ExtensionLite , 1, 508L);
+    message.setExtension(repeatedSfixed32ExtensionLite, 1, 509);
+    message.setExtension(repeatedSfixed64ExtensionLite, 1, 510L);
+    message.setExtension(repeatedFloatExtensionLite   , 1, 511F);
+    message.setExtension(repeatedDoubleExtensionLite  , 1, 512D);
+    message.setExtension(repeatedBoolExtensionLite    , 1, true);
+    message.setExtension(repeatedStringExtensionLite  , 1, "515");
+    message.setExtension(repeatedBytesExtensionLite   , 1, toBytes("516"));
+
+    message.setExtension(repeatedGroupExtensionLite, 1,
+      RepeatedGroup_extension_lite.newBuilder().setA(517).build());
+    message.setExtension(repeatedNestedMessageExtensionLite, 1,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(518).build());
+    message.setExtension(repeatedForeignMessageExtensionLite, 1,
+      ForeignMessageLite.newBuilder().setC(519).build());
+    message.setExtension(repeatedImportMessageExtensionLite, 1,
+      ImportMessageLite.newBuilder().setD(520).build());
+    message.setExtension(repeatedLazyMessageExtensionLite, 1,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(527).build());
+
+    message.setExtension(repeatedNestedEnumExtensionLite , 1, TestAllTypesLite.NestedEnum.FOO);
+    message.setExtension(repeatedForeignEnumExtensionLite, 1, ForeignEnumLite.FOREIGN_LITE_FOO);
+    message.setExtension(repeatedImportEnumExtensionLite , 1, ImportEnumLite.IMPORT_LITE_FOO);
+
+    message.setExtension(repeatedStringPieceExtensionLite, 1, "524");
+    message.setExtension(repeatedCordExtensionLite, 1, "525");
+  }
+
+  public static void setPackedExtensions(TestPackedExtensionsLite.Builder message) {
+    message.addExtension(packedInt32ExtensionLite   , 601);
+    message.addExtension(packedInt64ExtensionLite   , 602L);
+    message.addExtension(packedUint32ExtensionLite  , 603);
+    message.addExtension(packedUint64ExtensionLite  , 604L);
+    message.addExtension(packedSint32ExtensionLite  , 605);
+    message.addExtension(packedSint64ExtensionLite  , 606L);
+    message.addExtension(packedFixed32ExtensionLite , 607);
+    message.addExtension(packedFixed64ExtensionLite , 608L);
+    message.addExtension(packedSfixed32ExtensionLite, 609);
+    message.addExtension(packedSfixed64ExtensionLite, 610L);
+    message.addExtension(packedFloatExtensionLite   , 611F);
+    message.addExtension(packedDoubleExtensionLite  , 612D);
+    message.addExtension(packedBoolExtensionLite    , true);
+    message.addExtension(packedEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAR);
+    // Add a second one of each field.
+    message.addExtension(packedInt32ExtensionLite   , 701);
+    message.addExtension(packedInt64ExtensionLite   , 702L);
+    message.addExtension(packedUint32ExtensionLite  , 703);
+    message.addExtension(packedUint64ExtensionLite  , 704L);
+    message.addExtension(packedSint32ExtensionLite  , 705);
+    message.addExtension(packedSint64ExtensionLite  , 706L);
+    message.addExtension(packedFixed32ExtensionLite , 707);
+    message.addExtension(packedFixed64ExtensionLite , 708L);
+    message.addExtension(packedSfixed32ExtensionLite, 709);
+    message.addExtension(packedSfixed64ExtensionLite, 710L);
+    message.addExtension(packedFloatExtensionLite   , 711F);
+    message.addExtension(packedDoubleExtensionLite  , 712D);
+    message.addExtension(packedBoolExtensionLite    , false);
+    message.addExtension(packedEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/TextFormatParseInfoTreeTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatParseInfoTreeTest.java
new file mode 100644
index 00000000..e338af21
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatParseInfoTreeTest.java
@@ -0,0 +1,182 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+
+import junit.framework.TestCase;
+
+/**
+ * Test @{link TextFormatParseInfoTree}.
+ */
+public class TextFormatParseInfoTreeTest extends TestCase {
+
+  private static final Descriptor DESCRIPTOR = TestAllTypes.getDescriptor();
+  private static final FieldDescriptor OPTIONAL_INT32 =
+      DESCRIPTOR.findFieldByName("optional_int32");
+  private static final FieldDescriptor OPTIONAL_BOOLEAN =
+      DESCRIPTOR.findFieldByName("optional_boolean");
+  private static final FieldDescriptor REPEATED_INT32 =
+      DESCRIPTOR.findFieldByName("repeated_int32");
+  private static final FieldDescriptor OPTIONAL_NESTED_MESSAGE =
+      DESCRIPTOR.findFieldByName("optional_nested_message");
+  private static final FieldDescriptor REPEATED_NESTED_MESSAGE =
+      DESCRIPTOR.findFieldByName("repeated_nested_message");
+  private static final FieldDescriptor FIELD_BB =
+      TestAllTypes.NestedMessage.getDescriptor().findFieldByName("bb");
+
+  private static final TextFormatParseLocation LOC0 = TextFormatParseLocation.create(1, 2);
+  private static final TextFormatParseLocation LOC1 = TextFormatParseLocation.create(2, 3);
+
+  private TextFormatParseInfoTree.Builder rootBuilder;
+
+  @Override
+  public void setUp() {
+    rootBuilder = TextFormatParseInfoTree.builder();
+  }
+
+  public void testBuildEmptyParseTree() {
+    TextFormatParseInfoTree tree = rootBuilder.build();
+    assertTrue(tree.getLocations(null).isEmpty());
+  }
+
+  public void testGetLocationReturnsSingleLocation() {
+    rootBuilder.setLocation(OPTIONAL_INT32, LOC0);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    assertEquals(LOC0, root.getLocation(OPTIONAL_INT32, 0));
+    assertEquals(1, root.getLocations(OPTIONAL_INT32).size());
+    }
+
+  public void testGetLocationsReturnsNoParseLocationsForUnknownField() {
+    assertTrue(rootBuilder.build().getLocations(OPTIONAL_INT32).isEmpty());
+    rootBuilder.setLocation(OPTIONAL_BOOLEAN, LOC0);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    assertTrue(root.getLocations(OPTIONAL_INT32).isEmpty());
+    assertEquals(LOC0, root.getLocations(OPTIONAL_BOOLEAN).get(0));
+  }
+
+  public void testGetLocationThrowsIllegalArgumentExceptionForUnknownField() {
+    rootBuilder.setLocation(REPEATED_INT32, LOC0);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    try {
+      root.getNestedTree(OPTIONAL_INT32, 0);
+      fail("Did not detect unknown field");
+    } catch (IllegalArgumentException expected) {
+      // pass
+    }
+  }
+
+  public void testGetLocationThrowsIllegalArgumentExceptionForInvalidIndex() {
+    TextFormatParseInfoTree root = rootBuilder.setLocation(OPTIONAL_INT32, LOC0).build();
+    try {
+      root.getLocation(OPTIONAL_INT32, 1);
+      fail("Invalid index not detected");
+    } catch (IllegalArgumentException expected) {
+      // pass
+    }
+    try {
+      root.getLocation(OPTIONAL_INT32, -1);
+      fail("Negative index not detected");
+    } catch (IllegalArgumentException expected) {
+      // pass
+    }
+  }
+
+  public void testGetLocationsReturnsMultipleLocations() {
+    rootBuilder.setLocation(REPEATED_INT32, LOC0);
+    rootBuilder.setLocation(REPEATED_INT32, LOC1);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    assertEquals(LOC0, root.getLocation(REPEATED_INT32, 0));
+    assertEquals(LOC1, root.getLocation(REPEATED_INT32, 1));
+    assertEquals(2, root.getLocations(REPEATED_INT32).size());
+  }
+
+  public void testGetNestedTreeThrowsIllegalArgumentExceptionForUnknownField() {
+    rootBuilder.setLocation(REPEATED_INT32, LOC0);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    try {
+      root.getNestedTree(OPTIONAL_NESTED_MESSAGE, 0);
+      fail("Did not detect unknown field");
+    } catch (IllegalArgumentException expected) {
+      // pass
+    }
+  }
+
+  public void testGetNestedTreesReturnsNoParseInfoTreesForUnknownField() {
+    rootBuilder.setLocation(REPEATED_INT32, LOC0);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    assertTrue(root.getNestedTrees(OPTIONAL_NESTED_MESSAGE).isEmpty());
+  }
+
+  public void testGetNestedTreeThrowsIllegalArgumentExceptionForInvalidIndex() {
+    rootBuilder.setLocation(REPEATED_INT32, LOC0);
+    rootBuilder.getBuilderForSubMessageField(OPTIONAL_NESTED_MESSAGE);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    try {
+      root.getNestedTree(OPTIONAL_NESTED_MESSAGE, 1);
+      fail("Submessage index that is too large not detected");
+    } catch (IllegalArgumentException expected) {
+      // pass
+    }
+    try {
+      rootBuilder.build().getNestedTree(OPTIONAL_NESTED_MESSAGE, -1);
+      fail("Invalid submessage index (-1) not detected");
+    } catch (IllegalArgumentException expected) {
+      // pass
+    }
+  }
+
+  public void testGetNestedTreesReturnsSingleTree() {
+    rootBuilder.getBuilderForSubMessageField(OPTIONAL_NESTED_MESSAGE);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    assertEquals(1, root.getNestedTrees(OPTIONAL_NESTED_MESSAGE).size());
+    TextFormatParseInfoTree subtree = root.getNestedTrees(OPTIONAL_NESTED_MESSAGE).get(0);
+    assertNotNull(subtree);
+  }
+
+  public void testGetNestedTreesReturnsMultipleTrees() {
+    TextFormatParseInfoTree.Builder subtree1Builder =
+        rootBuilder.getBuilderForSubMessageField(REPEATED_NESTED_MESSAGE);
+    subtree1Builder.getBuilderForSubMessageField(FIELD_BB);
+    subtree1Builder.getBuilderForSubMessageField(FIELD_BB);
+    TextFormatParseInfoTree.Builder subtree2Builder =
+        rootBuilder.getBuilderForSubMessageField(REPEATED_NESTED_MESSAGE);
+    subtree2Builder.getBuilderForSubMessageField(FIELD_BB);
+    TextFormatParseInfoTree root = rootBuilder.build();
+    assertEquals(2, root.getNestedTrees(REPEATED_NESTED_MESSAGE).size());
+    assertEquals(
+        2, root.getNestedTrees(REPEATED_NESTED_MESSAGE).get(0).getNestedTrees(FIELD_BB).size());
+    assertEquals(
+        1, root.getNestedTrees(REPEATED_NESTED_MESSAGE).get(1).getNestedTrees(FIELD_BB).size());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/TextFormatParseLocationTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatParseLocationTest.java
new file mode 100644
index 00000000..c42bfa6e
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatParseLocationTest.java
@@ -0,0 +1,86 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+/**
+ * Test @{link TextFormatParseLocation}.
+ */
+public class TextFormatParseLocationTest extends TestCase {
+
+  public void testCreateEmpty() {
+    TextFormatParseLocation location = TextFormatParseLocation.create(-1, -1);
+    assertEquals(TextFormatParseLocation.EMPTY, location);
+  }
+
+  public void testCreate() {
+    TextFormatParseLocation location = TextFormatParseLocation.create(2, 1);
+    assertEquals(2, location.getLine());
+    assertEquals(1, location.getColumn());
+  }
+
+  public void testCreateThrowsIllegalArgumentExceptionForInvalidIndex() {
+    try {
+      TextFormatParseLocation.create(-1, 0);
+      fail("Should throw IllegalArgumentException if line is less than 0");
+    } catch (IllegalArgumentException unused) {
+      // pass
+    }
+    try {
+      TextFormatParseLocation.create(0, -1);
+      fail("Should throw, column < 0");
+    } catch (IllegalArgumentException unused) {
+      // pass
+    }
+  }
+
+  public void testHashCode() {
+    TextFormatParseLocation loc0 = TextFormatParseLocation.create(2, 1);
+    TextFormatParseLocation loc1 = TextFormatParseLocation.create(2, 1);
+
+    assertEquals(loc0.hashCode(), loc1.hashCode());
+    assertEquals(
+        TextFormatParseLocation.EMPTY.hashCode(), TextFormatParseLocation.EMPTY.hashCode());
+  }
+
+  public void testEquals() {
+    TextFormatParseLocation loc0 = TextFormatParseLocation.create(2, 1);
+    TextFormatParseLocation loc1 = TextFormatParseLocation.create(1, 2);
+    TextFormatParseLocation loc2 = TextFormatParseLocation.create(2, 2);
+    TextFormatParseLocation loc3 = TextFormatParseLocation.create(2, 1);
+
+    assertEquals(loc0, loc3);
+    assertNotSame(loc0, loc1);
+    assertNotSame(loc0, loc2);
+    assertNotSame(loc1, loc2);
+  }
+}
diff --git a/java/src/test/java/com/google/protobuf/TextFormatTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
index 1df4fad7..63c17cd0 100644
--- a/java/src/test/java/com/google/protobuf/TextFormatTest.java
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
@@ -30,6 +30,7 @@
 
 package com.google.protobuf;
 
+import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.TextFormat.Parser.SingularOverwritePolicy;
 import protobuf_unittest.UnittestMset.TestMessageSetExtension1;
@@ -45,6 +46,7 @@ import proto2_wireformat_unittest.UnittestMsetWireFormat.TestMessageSet;
 import junit.framework.TestCase;
 
 import java.io.StringReader;
+import java.util.List;
 
 /**
  * Test case for {@link TextFormat}.
@@ -568,6 +570,16 @@ public class TextFormatTest extends TestCase {
     assertEquals(kEscapeTestString,
       TextFormat.unescapeText(kEscapeTestStringEscaped));
 
+    // Invariant
+    assertEquals("hello",
+        TextFormat.escapeBytes(bytes("hello")));
+    assertEquals("hello",
+        TextFormat.escapeText("hello"));
+    assertEquals(bytes("hello"),
+        TextFormat.unescapeBytes("hello"));
+    assertEquals("hello",
+        TextFormat.unescapeText("hello"));
+
     // Unicode handling.
     assertEquals("\\341\\210\\264", TextFormat.escapeText("\u1234"));
     assertEquals("\\341\\210\\264",
@@ -763,11 +775,14 @@ public class TextFormatTest extends TestCase {
   public void testParseBoolean() throws Exception {
     String goodText =
         "repeated_bool: t  repeated_bool : 0\n" +
-        "repeated_bool :f repeated_bool:1";
+        "repeated_bool :f repeated_bool:1\n" +
+        "repeated_bool: False repeated_bool: True";
     String goodTextCanonical =
         "repeated_bool: true\n" +
         "repeated_bool: false\n" +
         "repeated_bool: false\n" +
+        "repeated_bool: true\n" +
+        "repeated_bool: false\n" +
         "repeated_bool: true\n";
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge(goodText, builder);
@@ -811,7 +826,6 @@ public class TextFormatTest extends TestCase {
 
   private void assertPrintFieldValue(String expect, Object value,
       String fieldName) throws Exception {
-    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     StringBuilder sb = new StringBuilder();
     TextFormat.printFieldValue(
         TestAllTypes.getDescriptor().findFieldByName(fieldName),
@@ -1018,4 +1032,98 @@ public class TextFormatTest extends TestCase {
     assertFalse(oneof.hasFooString());
     assertTrue(oneof.hasFooInt());
   }
+
+  // =======================================================================
+  // test location information
+
+  public void testParseInfoTreeBuilding() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    TextFormatParseInfoTree.Builder treeBuilder = TextFormatParseInfoTree.builder();
+    // Set to allow unknown fields
+    TextFormat.Parser parser =
+        TextFormat.Parser.newBuilder()
+            .setParseInfoTreeBuilder(treeBuilder)
+            .build();
+
+    final String stringData =
+        "optional_int32: 1\n"
+        + "optional_int64: 2\n"
+        + "  optional_double: 2.4\n"
+        + "repeated_int32: 5\n"
+        + "repeated_int32: 10\n"
+        + "optional_nested_message <\n"
+        + "  bb: 78\n"
+        + ">\n"
+        + "repeated_nested_message <\n"
+        + "  bb: 79\n"
+        + ">\n"
+        + "repeated_nested_message <\n"
+        + "  bb: 80\n"
+        + ">";
+
+    parser.merge(stringData, builder);
+    TextFormatParseInfoTree tree = treeBuilder.build();
+
+    // Verify that the tree has the correct positions.
+    assertLocation(tree, descriptor, "optional_int32", 0, 0, 0);
+    assertLocation(tree, descriptor, "optional_int64", 0, 1, 0);
+    assertLocation(tree, descriptor, "optional_double", 0, 2, 2);
+
+    assertLocation(tree, descriptor, "repeated_int32", 0, 3, 0);
+    assertLocation(tree, descriptor, "repeated_int32", 1, 4, 0);
+
+    assertLocation(tree, descriptor, "optional_nested_message", 0, 5, 0);
+    assertLocation(tree, descriptor, "repeated_nested_message", 0, 8, 0);
+    assertLocation(tree, descriptor, "repeated_nested_message", 1, 11, 0);
+
+    // Check for fields not set. For an invalid field, the location returned should be -1, -1.
+    assertLocation(tree, descriptor, "repeated_int64", 0, -1, -1);
+    assertLocation(tree, descriptor, "repeated_int32", 6, -1, -1);
+
+    // Verify inside the nested message.
+    FieldDescriptor nestedField = descriptor.findFieldByName("optional_nested_message");
+
+    TextFormatParseInfoTree nestedTree = tree.getNestedTrees(nestedField).get(0);
+    assertLocation(nestedTree, nestedField.getMessageType(), "bb", 0, 6, 2);
+
+    // Verify inside another nested message.
+    nestedField = descriptor.findFieldByName("repeated_nested_message");
+    nestedTree = tree.getNestedTrees(nestedField).get(0);
+    assertLocation(nestedTree, nestedField.getMessageType(), "bb", 0, 9, 2);
+
+    nestedTree = tree.getNestedTrees(nestedField).get(1);
+    assertLocation(nestedTree, nestedField.getMessageType(), "bb", 0, 12, 2);
+
+    // Verify a NULL tree for an unknown nested field.
+    try {
+      tree.getNestedTree(nestedField, 2);
+      fail("unknown nested field should throw");
+    } catch (IllegalArgumentException unused) {
+      // pass
+    }
+  }
+
+  private void assertLocation(
+      TextFormatParseInfoTree tree,
+      final Descriptor descriptor,
+      final String fieldName,
+      int index,
+      int line,
+      int column) {
+    List<TextFormatParseLocation> locs = tree.getLocations(descriptor.findFieldByName(fieldName));
+    if (index < locs.size()) {
+      TextFormatParseLocation location = locs.get(index);
+      TextFormatParseLocation expected = TextFormatParseLocation.create(line, column);
+      assertEquals(expected, location);
+    } else if (line != -1 && column != -1) {
+      fail(
+          String.format(
+              "Tree/descriptor/fieldname did not contain index %d, line %d column %d expected",
+              index,
+              line,
+              column));
+    }
+  }
 }
diff --git a/java/src/test/java/com/google/protobuf/UnknownEnumValueTest.java b/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
index 8f45976f..8f45976f 100644
--- a/java/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
diff --git a/java/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
index dc987379..573cd665 100644
--- a/java/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
@@ -47,46 +47,6 @@ import java.io.IOException;
  * @author dweis@google.com (Daniel Weis)
  */
 public class UnknownFieldSetLiteTest extends TestCase {
-
-  public void testNoDataIsDefaultInstance() {
-    assertSame(
-        UnknownFieldSetLite.getDefaultInstance(),
-        UnknownFieldSetLite.newBuilder()
-            .build());
-  }
-  
-  public void testBuilderReuse() throws IOException {
-    UnknownFieldSetLite.Builder builder = UnknownFieldSetLite.newBuilder();
-    builder.mergeVarintField(10, 2);
-    builder.build();
-
-    try {
-      builder.build();
-      fail();
-    } catch (UnsupportedOperationException e) {
-      // Expected.
-    }
-
-    try {
-      builder.mergeFieldFrom(0, CodedInputStream.newInstance(new byte[0]));
-      fail();
-    } catch (UnsupportedOperationException e) {
-      // Expected.
-    }
-
-    try {
-      builder.mergeVarintField(5, 1);
-      fail();
-    } catch (UnsupportedOperationException e) {
-      // Expected.
-    }
-  }
-
-  public void testBuilderReuse_empty() {
-    UnknownFieldSetLite.Builder builder = UnknownFieldSetLite.newBuilder();
-    builder.build();
-    builder.build();
-  }
   
   public void testDefaultInstance() {
     UnknownFieldSetLite unknownFields = UnknownFieldSetLite.getDefaultInstance();
diff --git a/java/src/test/java/com/google/protobuf/UnknownFieldSetTest.java b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
index 8c9dcafe..32380f70 100644
--- a/java/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
@@ -50,6 +50,7 @@ import java.util.Map;
  * @author kenton@google.com (Kenton Varda)
  */
 public class UnknownFieldSetTest extends TestCase {
+  @Override
   public void setUp() throws Exception {
     descriptor = TestAllTypes.getDescriptor();
     allFields = TestUtil.getAllSet();
diff --git a/java/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java b/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
index b1c75fc3..b1c75fc3 100644
--- a/java/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
diff --git a/java/src/test/java/com/google/protobuf/WellKnownTypesTest.java b/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java
index 982e200f..982e200f 100644
--- a/java/src/test/java/com/google/protobuf/WellKnownTypesTest.java
+++ b/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java
diff --git a/java/src/test/java/com/google/protobuf/WireFormatTest.java b/java/core/src/test/java/com/google/protobuf/WireFormatTest.java
index 0175005d..e66b371c 100644
--- a/java/src/test/java/com/google/protobuf/WireFormatTest.java
+++ b/java/core/src/test/java/com/google/protobuf/WireFormatTest.java
@@ -30,12 +30,11 @@
 
 package com.google.protobuf;
 
-import junit.framework.TestCase;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.util.List;
-
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+import protobuf_unittest.UnittestMset.RawMessageSet;
+import protobuf_unittest.UnittestMset.TestMessageSetExtension1;
+import protobuf_unittest.UnittestMset.TestMessageSetExtension2;
 import protobuf_unittest.UnittestProto;
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllTypes;
@@ -44,12 +43,13 @@ import protobuf_unittest.UnittestProto.TestOneof2;
 import protobuf_unittest.UnittestProto.TestOneofBackwardsCompatible;
 import protobuf_unittest.UnittestProto.TestPackedExtensions;
 import protobuf_unittest.UnittestProto.TestPackedTypes;
-import protobuf_unittest.UnittestMset.RawMessageSet;
-import protobuf_unittest.UnittestMset.TestMessageSetExtension1;
-import protobuf_unittest.UnittestMset.TestMessageSetExtension2;
 import proto2_wireformat_unittest.UnittestMsetWireFormat.TestMessageSet;
-import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
-import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.util.List;
 
 /**
  * Tests related to parsing and serialization.
@@ -132,7 +132,7 @@ public class WireFormatTest extends TestCase {
     // so if we serialize a TestAllExtensions then parse it as TestAllTypes
     // it should work.
 
-    TestAllExtensionsLite message = TestUtil.getAllLiteExtensionsSet();
+    TestAllExtensionsLite message = TestUtilLite.getAllLiteExtensionsSet();
     ByteString rawBytes = message.toByteString();
     assertEquals(rawBytes.size(), message.getSerializedSize());
 
@@ -144,7 +144,7 @@ public class WireFormatTest extends TestCase {
   public void testSerializePackedExtensionsLite() throws Exception {
     // TestPackedTypes and TestPackedExtensions should have compatible wire
     // formats; check that they serialize to the same string.
-    TestPackedExtensionsLite message = TestUtil.getLitePackedExtensionsSet();
+    TestPackedExtensionsLite message = TestUtilLite.getLitePackedExtensionsSet();
     ByteString rawBytes = message.toByteString();
 
     TestPackedTypes message2 = TestUtil.getPackedSet();
@@ -190,7 +190,7 @@ public class WireFormatTest extends TestCase {
     TestAllTypes message = TestUtil.getAllSet();
     ByteString rawBytes = message.toByteString();
 
-    ExtensionRegistryLite registry_lite = TestUtil.getExtensionRegistryLite();
+    ExtensionRegistryLite registry_lite = TestUtilLite.getExtensionRegistryLite();
 
     TestAllExtensionsLite message2 =
       TestAllExtensionsLite.parseFrom(rawBytes, registry_lite);
@@ -208,10 +208,10 @@ public class WireFormatTest extends TestCase {
 
   public void testParsePackedExtensionsLite() throws Exception {
     // Ensure that packed extensions can be properly parsed.
-    TestPackedExtensionsLite message = TestUtil.getLitePackedExtensionsSet();
+    TestPackedExtensionsLite message = TestUtilLite.getLitePackedExtensionsSet();
     ByteString rawBytes = message.toByteString();
 
-    ExtensionRegistryLite registry = TestUtil.getExtensionRegistryLite();
+    ExtensionRegistryLite registry = TestUtilLite.getExtensionRegistryLite();
 
     TestPackedExtensionsLite message2 =
         TestPackedExtensionsLite.parseFrom(rawBytes, registry);
diff --git a/java/src/test/java/com/google/protobuf/any_test.proto b/java/core/src/test/proto/com/google/protobuf/any_test.proto
index 80173d8a..80173d8a 100644
--- a/java/src/test/java/com/google/protobuf/any_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/any_test.proto
diff --git a/java/src/test/java/com/google/protobuf/field_presence_test.proto b/java/core/src/test/proto/com/google/protobuf/field_presence_test.proto
index 8f3ca8c6..8f3ca8c6 100644
--- a/java/src/test/java/com/google/protobuf/field_presence_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/field_presence_test.proto
diff --git a/java/src/test/java/com/google/protobuf/lazy_fields_lite.proto b/java/core/src/test/proto/com/google/protobuf/lazy_fields_lite.proto
index 5580f72d..5580f72d 100644
--- a/java/src/test/java/com/google/protobuf/lazy_fields_lite.proto
+++ b/java/core/src/test/proto/com/google/protobuf/lazy_fields_lite.proto
diff --git a/java/src/test/java/com/google/protobuf/lite_equals_and_hash.proto b/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
index 86837250..6eef42c5 100644
--- a/java/src/test/java/com/google/protobuf/lite_equals_and_hash.proto
+++ b/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
@@ -34,11 +34,15 @@ syntax = "proto2";
 
 package protobuf_unittest.lite_equals_and_hash;
 
-// This proto definition is used to test that java_generate_equals_and_hash
-// works correctly with the LITE_RUNTIME.
-option java_generate_equals_and_hash = true;
 option optimize_for = LITE_RUNTIME;
 
+message TestOneofEquals {
+  oneof oneof_field {
+    string name = 1;
+    int32 value = 2;
+  }
+}
+
 message Foo {
   optional int32 value = 1;
   repeated Bar bar = 2;
@@ -70,3 +74,8 @@ extend Foo {
   }
 }
 
+message TestRecursiveOneof {
+  oneof Foo {
+    TestRecursiveOneof r = 1;
+  }
+}
diff --git a/java/src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_lite_test.proto
index d5418f28..d5418f28 100644
--- a/java/src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_lite_test.proto
diff --git a/java/src/test/java/com/google/protobuf/map_for_proto2_test.proto b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_test.proto
index a9be5166..a9be5166 100644
--- a/java/src/test/java/com/google/protobuf/map_for_proto2_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_test.proto
diff --git a/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto b/java/core/src/test/proto/com/google/protobuf/map_initialization_order_test.proto
index b02ac599..b02ac599 100644
--- a/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_initialization_order_test.proto
diff --git a/java/src/test/java/com/google/protobuf/map_test.proto b/java/core/src/test/proto/com/google/protobuf/map_test.proto
index 2f7709be..2280ac03 100644
--- a/java/src/test/java/com/google/protobuf/map_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_test.proto
@@ -36,7 +36,6 @@ option java_package = "map_test";
 option java_outer_classname = "MapTestProto";
 option java_generate_equals_and_hash = true;
 
-
 message TestMap {
   message MessageValue {
     int32 value = 1;
diff --git a/java/src/test/java/com/google/protobuf/multiple_files_test.proto b/java/core/src/test/proto/com/google/protobuf/multiple_files_test.proto
index 92790506..92790506 100644
--- a/java/src/test/java/com/google/protobuf/multiple_files_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/multiple_files_test.proto
diff --git a/java/src/test/java/com/google/protobuf/nested_builders_test.proto b/java/core/src/test/proto/com/google/protobuf/nested_builders_test.proto
index a5dd66d8..a5dd66d8 100644
--- a/java/src/test/java/com/google/protobuf/nested_builders_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/nested_builders_test.proto
diff --git a/java/src/test/java/com/google/protobuf/nested_extension.proto b/java/core/src/test/proto/com/google/protobuf/nested_extension.proto
index 704e649e..704e649e 100644
--- a/java/src/test/java/com/google/protobuf/nested_extension.proto
+++ b/java/core/src/test/proto/com/google/protobuf/nested_extension.proto
diff --git a/java/src/test/java/com/google/protobuf/nested_extension_lite.proto b/java/core/src/test/proto/com/google/protobuf/nested_extension_lite.proto
index a95c38b2..a95c38b2 100644
--- a/java/src/test/java/com/google/protobuf/nested_extension_lite.proto
+++ b/java/core/src/test/proto/com/google/protobuf/nested_extension_lite.proto
diff --git a/java/src/test/java/com/google/protobuf/non_nested_extension.proto b/java/core/src/test/proto/com/google/protobuf/non_nested_extension.proto
index 31fac552..31fac552 100644
--- a/java/src/test/java/com/google/protobuf/non_nested_extension.proto
+++ b/java/core/src/test/proto/com/google/protobuf/non_nested_extension.proto
diff --git a/java/src/test/java/com/google/protobuf/non_nested_extension_lite.proto b/java/core/src/test/proto/com/google/protobuf/non_nested_extension_lite.proto
index 37c369ed..37c369ed 100644
--- a/java/src/test/java/com/google/protobuf/non_nested_extension_lite.proto
+++ b/java/core/src/test/proto/com/google/protobuf/non_nested_extension_lite.proto
diff --git a/java/src/test/java/com/google/protobuf/outer_class_name_test.proto b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test.proto
index 42083681..42083681 100644
--- a/java/src/test/java/com/google/protobuf/outer_class_name_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test.proto
diff --git a/java/src/test/java/com/google/protobuf/outer_class_name_test2.proto b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test2.proto
index 3e5956b0..3e5956b0 100644
--- a/java/src/test/java/com/google/protobuf/outer_class_name_test2.proto
+++ b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test2.proto
diff --git a/java/src/test/java/com/google/protobuf/outer_class_name_test3.proto b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test3.proto
index 74a8ba3c..74a8ba3c 100644
--- a/java/src/test/java/com/google/protobuf/outer_class_name_test3.proto
+++ b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test3.proto
diff --git a/java/src/test/java/com/google/protobuf/test_bad_identifiers.proto b/java/core/src/test/proto/com/google/protobuf/test_bad_identifiers.proto
index 8c37c03c..2b1f65e4 100644
--- a/java/src/test/java/com/google/protobuf/test_bad_identifiers.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_bad_identifiers.proto
@@ -45,7 +45,6 @@ option java_package = "com.google.protobuf";
 option java_outer_classname = "TestBadIdentifiersProto";
 option java_generate_equals_and_hash = true;
 
-
 message TestMessage {
   optional string cached_size = 1;
   optional string serialized_size = 2;
diff --git a/java/src/test/java/com/google/protobuf/test_check_utf8.proto b/java/core/src/test/proto/com/google/protobuf/test_check_utf8.proto
index 119c1dcb..119c1dcb 100644
--- a/java/src/test/java/com/google/protobuf/test_check_utf8.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_check_utf8.proto
diff --git a/java/src/test/java/com/google/protobuf/test_check_utf8_size.proto b/java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto
index f06d76d6..f06d76d6 100644
--- a/java/src/test/java/com/google/protobuf/test_check_utf8_size.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto
diff --git a/java/src/test/java/com/google/protobuf/test_custom_options.proto b/java/core/src/test/proto/com/google/protobuf/test_custom_options.proto
index f8efd455..f8efd455 100644
--- a/java/src/test/java/com/google/protobuf/test_custom_options.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_custom_options.proto
diff --git a/java/src/test/java/com/google/protobuf/test_extra_interfaces.proto b/java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto
index 645f57b4..645f57b4 100644
--- a/java/src/test/java/com/google/protobuf/test_extra_interfaces.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto
diff --git a/java/lite/generate-sources-build.xml b/java/lite/generate-sources-build.xml
new file mode 100644
index 00000000..89c21c13
--- /dev/null
+++ b/java/lite/generate-sources-build.xml
@@ -0,0 +1,20 @@
+<project name="generate-sources">
+    <echo message="Running protoc ..."/>
+    <mkdir dir="${generated.sources.lite.dir}"/>
+    <exec executable="${protoc}">
+        <arg value="--java_out=lite:${generated.sources.lite.dir}"/>
+        <arg value="--proto_path=${protobuf.source.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/any.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/api.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/descriptor.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/duration.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/empty.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/field_mask.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/source_context.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/struct.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/timestamp.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/type.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/wrappers.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/compiler/plugin.proto"/>
+    </exec>
+</project>
diff --git a/java/lite/generate-test-sources-build.xml b/java/lite/generate-test-sources-build.xml
new file mode 100644
index 00000000..cdd1ee89
--- /dev/null
+++ b/java/lite/generate-test-sources-build.xml
@@ -0,0 +1,43 @@
+<project name="generate-test-sources">
+    <mkdir dir="${generated.testsources.lite.dir}"/>
+    <exec executable="${protoc}">
+        <arg value="--java_out=lite:${generated.testsources.lite.dir}"/>
+        <arg value="--proto_path=${protobuf.source.dir}"/>
+        <arg value="--proto_path=${test.proto.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_public.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_mset.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_mset_wire_format.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_optimize_for.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_custom_options.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_public_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_lite_imports_nonlite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_enormous_descriptor.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_no_generic_services.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_well_known_types.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/lazy_fields_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/lite_equals_and_hash.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/multiple_files_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_builders_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_extension.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_extension_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/non_nested_extension.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/non_nested_extension_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test2.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test3.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_bad_identifiers.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_check_utf8.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_check_utf8_size.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_custom_options.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/any_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/field_presence_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_for_proto2_lite_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_for_proto2_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_initialization_order_test.proto"/>
+    </exec>
+</project>
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
new file mode 100644
index 00000000..c403dc09
--- /dev/null
+++ b/java/lite/pom.xml
@@ -0,0 +1,156 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-parent</artifactId>
+    <version>3.0.0-beta-3</version>
+  </parent>
+
+  <artifactId>protobuf-lite</artifactId>
+  <packaging>bundle</packaging>
+
+  <name>Protocol Buffers [Lite]</name>
+  <description>A trimmed-down version of the Protocol Buffers library.</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymock</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymockclassextension</artifactId>
+    </dependency>
+  </dependencies>
+
+  <properties>
+    <core.root>../core</core.root>
+    <test.proto.dir>${core.root}/src/test/proto</test.proto.dir>
+  </properties>
+
+  <build>
+    <sourceDirectory>${core.root}/src/main/java</sourceDirectory>
+    <testSourceDirectory>${core.root}/src/test/java</testSourceDirectory>
+
+    <plugins>
+      <!-- Use Antrun plugin to generate sources with protoc -->
+      <plugin>
+        <artifactId>maven-antrun-plugin</artifactId>
+        <executions>
+          <!-- Generate core protos -->
+          <execution>
+            <id>generate-sources</id>
+            <phase>generate-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="generate-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+
+          <!-- Generate the test protos -->
+          <execution>
+            <id>generate-test-sources</id>
+            <phase>generate-test-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="generate-test-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+
+      <!-- Only compile a subset of the files -->
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <generatedSourcesDirectory>${generated.sources.lite.dir}</generatedSourcesDirectory>
+          <generatedTestSourcesDirectory>${generated.testsources.lite.dir}</generatedTestSourcesDirectory>
+          <includes>
+            <include>**/AbstractMessageLite.java</include>
+            <include>**/AbstractParser.java</include>
+            <include>**/AbstractProtobufList.java</include>
+            <include>**/BooleanArrayList.java</include>
+            <include>**/ByteString.java</include>
+            <include>**/CodedInputStream.java</include>
+            <include>**/CodedOutputStream.java</include>
+            <include>**/DoubleArrayList.java</include>
+            <include>**/ExtensionLite.java</include>
+            <include>**/ExtensionRegistryLite.java</include>
+            <include>**/FieldSet.java</include>
+            <include>**/FloatArrayList.java</include>
+            <include>**/GeneratedMessageLite.java</include>
+            <include>**/IntArrayList.java</include>
+            <include>**/Internal.java</include>
+            <include>**/InvalidProtocolBufferException.java</include>
+            <include>**/LazyFieldLite.java</include>
+            <include>**/LazyStringArrayList.java</include>
+            <include>**/LazyStringList.java</include>
+            <include>**/LongArrayList.java</include>
+            <include>**/MapEntryLite.java</include>
+            <include>**/MapFieldLite.java</include>
+            <include>**/MessageLite.java</include>
+            <include>**/MessageLiteOrBuilder.java</include>
+            <include>**/MessageLiteToString.java</include>
+            <include>**/MutabilityOracle.java</include>
+            <include>**/NioByteString.java</include>
+            <include>**/Parser.java</include>
+            <include>**/ProtobufArrayList.java</include>
+            <include>**/ProtocolStringList.java</include>
+            <include>**/RopeByteString.java</include>
+            <include>**/SmallSortedMap.java</include>
+            <include>**/TextFormatEscaper.java</include>
+            <include>**/UninitializedMessageException.java</include>
+            <include>**/UnknownFieldSetLite.java</include>
+            <include>**/UnmodifiableLazyStringList.java</include>
+            <include>**/UnsafeByteOperations.java</include>
+            <include>**/Utf8.java</include>
+            <include>**/WireFormat.java</include>
+          </includes>
+          <testIncludes>
+            <testInclude>**/*Lite.java</testInclude>
+            <testInclude>**/BooleanArrayListTest.java</testInclude>
+            <testInclude>**/DoubleArrayListTest.java</testInclude>
+            <testInclude>**/FloatArrayListTest.java</testInclude>
+            <testInclude>**/IntArrayListTest.java</testInclude>
+            <testInclude>**/LazyMessageLiteTest.java</testInclude>
+            <testInclude>**/LiteTest.java</testInclude>
+            <testInclude>**/LongArrayListTest.java</testInclude>
+            <testInclude>**/NioByteStringTest.java</testInclude>
+            <testInclude>**/ProtobufArrayListTest.java</testInclude>
+            <testInclude>**/UnknownFieldSetLiteTest.java</testInclude>
+          </testIncludes>
+        </configuration>
+      </plugin>
+
+      <!-- OSGI bundle configuration -->
+      <plugin>
+        <groupId>org.apache.felix</groupId>
+        <artifactId>maven-bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <instructions>
+            <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
+            <Bundle-SymbolicName>com.google.protobuf</Bundle-SymbolicName>
+            <Export-Package>com.google.${project.artifactId};version=${project.version}</Export-Package>
+          </instructions>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>
diff --git a/java/pom.xml b/java/pom.xml
index 8b81b645..7a1a91f8 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -8,17 +8,35 @@
     <artifactId>google</artifactId>
     <version>1</version>
   </parent>
+
   <groupId>com.google.protobuf</groupId>
-  <artifactId>protobuf-java</artifactId>
-  <version>3.0.0-beta-1</version>
-  <packaging>bundle</packaging>
-  <name>Protocol Buffer Java API</name>
+  <artifactId>protobuf-parent</artifactId>
+  <version>3.0.0-beta-3</version>
+  <packaging>pom</packaging>
+
+  <name>Protocol Buffers [Parent]</name>
+  <inceptionYear>2008</inceptionYear>
+  <url>https://developers.google.com/protocol-buffers/</url>
   <description>
     Protocol Buffers are a way of encoding structured data in an efficient yet
     extensible format.
   </description>
-  <inceptionYear>2008</inceptionYear>
-  <url>https://developers.google.com/protocol-buffers/</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+
+    <!-- These are relative to the submodules -->
+    <protobuf.basedir>${project.basedir}/../..</protobuf.basedir>
+    <protobuf.source.dir>${protobuf.basedir}/src</protobuf.source.dir>
+    <protoc>${protobuf.source.dir}/protoc</protoc>
+    <test.proto.dir>src/test/proto</test.proto.dir>
+    <generated.sources.dir>${project.build.directory}/generated-sources</generated.sources.dir>
+    <generated.testsources.dir>${project.build.directory}/generated-test-sources</generated.testsources.dir>
+    <generated.sources.lite.dir>${project.build.directory}/generated-sources-lite</generated.sources.lite.dir>
+    <generated.testsources.lite.dir>${project.build.directory}/generated-test-sources-lite</generated.testsources.lite.dir>
+  </properties>
+
   <licenses>
     <license>
       <name>New BSD license</name>
@@ -26,215 +44,116 @@
       <distribution>repo</distribution>
     </license>
   </licenses>
+
   <scm>
     <url>https://github.com/google/protobuf</url>
-    <connection>
-      scm:git:https://github.com/google/protobuf.git
-    </connection>
+    <connection>scm:git:https://github.com/google/protobuf.git</connection>
   </scm>
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>4.4</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.easymock</groupId>
-      <artifactId>easymock</artifactId>
-      <version>2.2</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.easymock</groupId>
-      <artifactId>easymockclassextension</artifactId>
-      <version>2.2.1</version>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+
+  <distributionManagement>
+    <snapshotRepository>
+      <id>sonatype-nexus-staging</id>
+      <url>https://oss.sonatype.org/content/repositories/snapshots</url>
+    </snapshotRepository>
+    <repository>
+      <id>sonatype-nexus-staging</id>
+      <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
+    </repository>
+  </distributionManagement>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>junit</groupId>
+        <artifactId>junit</artifactId>
+        <version>4.12</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>org.easymock</groupId>
+        <artifactId>easymock</artifactId>
+        <version>2.2</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>org.easymock</groupId>
+        <artifactId>easymockclassextension</artifactId>
+        <version>2.2.1</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>com.google.guava</groupId>
+        <artifactId>guava</artifactId>
+        <version>18.0</version>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
   <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration>
-          <source>1.5</source>
-          <target>1.5</target>
-        </configuration>
-      </plugin>
-      <plugin>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <configuration>
-          <includes>
-            <include>**/*Test.java</include>
-          </includes>
-        </configuration>
-      </plugin>
-      <plugin>
-        <artifactId>maven-antrun-plugin</artifactId>
-        <executions>
-          <execution>
-            <id>generate-sources</id>
-            <phase>generate-sources</phase>
-            <configuration>
-              <tasks>
-                <mkdir dir="target/generated-sources" />
-                <exec executable="../src/protoc">
-                  <arg value="--java_out=target/generated-sources" />
-                  <arg value="--proto_path=../src" />
-                  <arg value="../src/google/protobuf/any.proto" />
-                  <arg value="../src/google/protobuf/api.proto" />
-                  <arg value="../src/google/protobuf/descriptor.proto" />
-                  <arg value="../src/google/protobuf/duration.proto" />
-                  <arg value="../src/google/protobuf/empty.proto" />
-                  <arg value="../src/google/protobuf/field_mask.proto" />
-                  <arg value="../src/google/protobuf/source_context.proto" />
-                  <arg value="../src/google/protobuf/struct.proto" />
-                  <arg value="../src/google/protobuf/timestamp.proto" />
-                  <arg value="../src/google/protobuf/type.proto" />
-                  <arg value="../src/google/protobuf/wrappers.proto" />
-                </exec>
-              </tasks>
-              <sourceRoot>target/generated-sources</sourceRoot>
-            </configuration>
-            <goals>
-              <goal>run</goal>
-            </goals>
-          </execution>
-          <execution>
-            <id>generate-test-sources</id>
-            <phase>generate-test-sources</phase>
-            <configuration>
-              <tasks>
-                <mkdir dir="target/generated-test-sources" />
-                <exec executable="../src/protoc">
-                  <arg value="--java_out=target/generated-test-sources" />
-                  <arg value="--proto_path=../src" />
-                  <arg value="--proto_path=src/test/java" />
-                  <arg value="../src/google/protobuf/unittest.proto" />
-                  <arg value="../src/google/protobuf/unittest_import.proto" />
-                  <arg value="../src/google/protobuf/unittest_import_public.proto" />
-                  <arg value="../src/google/protobuf/unittest_mset.proto" />
-                  <arg value="../src/google/protobuf/unittest_mset_wire_format.proto" />
-                  <arg value="src/test/java/com/google/protobuf/lazy_fields_lite.proto" />
-                  <arg value="src/test/java/com/google/protobuf/lite_equals_and_hash.proto" />
-                  <arg
-                    value="src/test/java/com/google/protobuf/multiple_files_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/nested_builders_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/nested_extension.proto" />
-                  <arg value="src/test/java/com/google/protobuf/nested_extension_lite.proto" />
-                  <arg value="src/test/java/com/google/protobuf/non_nested_extension.proto" />
-                  <arg value="src/test/java/com/google/protobuf/non_nested_extension_lite.proto" />
-                  <arg value="src/test/java/com/google/protobuf/outer_class_name_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/outer_class_name_test2.proto" />
-                  <arg value="src/test/java/com/google/protobuf/outer_class_name_test3.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_bad_identifiers.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_check_utf8.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_check_utf8_size.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_custom_options.proto" />
-                  <arg
-                    value="../src/google/protobuf/unittest_optimize_for.proto" />
-                  <arg
-                    value="../src/google/protobuf/unittest_custom_options.proto" />
-                  <arg value="../src/google/protobuf/unittest_lite.proto" />
-                  <arg value="../src/google/protobuf/unittest_import_lite.proto" />
-                  <arg value="../src/google/protobuf/unittest_import_public_lite.proto" />
-                  <arg value="../src/google/protobuf/unittest_lite_imports_nonlite.proto" />
-                  <arg value="../src/google/protobuf/unittest_enormous_descriptor.proto" />
-                  <arg value="../src/google/protobuf/unittest_no_generic_services.proto" />
-                  <arg value="../src/google/protobuf/unittest_well_known_types.proto" />
-                  <arg value="src/test/java/com/google/protobuf/any_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/field_presence_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_for_proto2_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_initialization_order_test.proto" />
-                </exec>
-              </tasks>
-              <testSourceRoot>target/generated-test-sources</testSourceRoot>
-            </configuration>
-            <goals>
-              <goal>run</goal>
-            </goals>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>org.apache.felix</groupId>
-        <artifactId>maven-bundle-plugin</artifactId>
-        <extensions>true</extensions>
-        <configuration>
-          <instructions>
-            <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
-            <Bundle-SymbolicName>com.google.protobuf</Bundle-SymbolicName>
-            <Export-Package>com.google.protobuf;version=3.0.0-beta-1</Export-Package>
-          </instructions>
-        </configuration>
-      </plugin>
-    </plugins>
-    <resources>
-      <resource>
-        <directory>../src</directory>
-        <includes>
-          <include>google/protobuf/any.proto</include>
-          <include>google/protobuf/api.proto</include>
-          <include>google/protobuf/descriptor.proto</include>
-          <include>google/protobuf/duration.proto</include>
-          <include>google/protobuf/empty.proto</include>
-          <include>google/protobuf/field_mask.proto</include>
-          <include>google/protobuf/source_context.proto</include>
-          <include>google/protobuf/struct.proto</include>
-          <include>google/protobuf/timestamp.proto</include>
-          <include>google/protobuf/type.proto</include>
-          <include>google/protobuf/wrappers.proto</include>
-        </includes>
-      </resource>
-    </resources>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.3</version>
+          <configuration>
+            <source>1.6</source>
+            <target>1.6</target>
+          </configuration>
+        </plugin>
+        <plugin>
+          <artifactId>maven-source-plugin</artifactId>
+          <version>2.4</version>
+          <executions>
+            <execution>
+              <id>attach-sources</id>
+              <goals>
+                <goal>jar-no-fork</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
+        <plugin>
+          <artifactId>maven-javadoc-plugin</artifactId>
+          <version>2.10.3</version>
+          <executions>
+            <execution>
+              <id>attach-javadocs</id>
+              <goals>
+                <goal>jar</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
+        <plugin>
+          <artifactId>maven-jar-plugin</artifactId>
+          <version>2.6</version>
+        </plugin>
+        <plugin>
+          <groupId>org.codehaus.mojo</groupId>
+          <artifactId>build-helper-maven-plugin</artifactId>
+          <version>1.10</version>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.felix</groupId>
+          <artifactId>maven-bundle-plugin</artifactId>
+          <version>3.0.1</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-antrun-plugin</artifactId>
+          <version>1.8</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
   </build>
+
   <profiles>
     <profile>
       <id>release</id>
-      <distributionManagement>
-        <snapshotRepository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/content/repositories/snapshots</url>
-        </snapshotRepository>
-        <repository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
-        </repository>
-      </distributionManagement>
       <build>
         <plugins>
           <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-source-plugin</artifactId>
-            <version>2.2.1</version>
-            <executions>
-              <execution>
-                <id>attach-sources</id>
-                <goals>
-                  <goal>jar-no-fork</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-javadoc-plugin</artifactId>
-            <version>2.9.1</version>
-            <executions>
-              <execution>
-                <id>attach-javadocs</id>
-                <goals>
-                  <goal>jar</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-gpg-plugin</artifactId>
-            <version>1.5</version>
+            <version>1.6</version>
             <executions>
               <execution>
                 <id>sign-artifacts</id>
@@ -248,93 +167,23 @@
           <plugin>
             <groupId>org.sonatype.plugins</groupId>
             <artifactId>nexus-staging-maven-plugin</artifactId>
-            <version>1.6.3</version>
+            <version>1.6.6</version>
             <extensions>true</extensions>
             <configuration>
-               <serverId>sonatype-nexus-staging</serverId>
-               <nexusUrl>https://oss.sonatype.org/</nexusUrl>
-               <autoReleaseAfterClose>false</autoReleaseAfterClose>
-            </configuration>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
-    <profile>
-      <id>lite</id>
-      <build>
-        <plugins>
-          <plugin>
-            <artifactId>maven-compiler-plugin</artifactId>
-            <configuration>
-              <includes>
-                <include>**/AbstractMessageLite.java</include>
-                <include>**/AbstractParser.java</include>
-                <include>**/AbstractProtobufList.java</include>
-                <include>**/BoundedByteString.java</include>
-                <include>**/BooleanArrayList.java</include>
-                <include>**/ByteString.java</include>
-                <include>**/CodedInputStream.java</include>
-                <include>**/CodedOutputStream.java</include>
-                <include>**/DoublerrayList.java</include>
-                <include>**/ExtensionLite.java</include>
-                <include>**/ExtensionRegistryLite.java</include>
-                <include>**/FieldSet.java</include>
-                <include>**/FloatArrayList.java</include>
-                <include>**/GeneratedMessageLite.java</include>
-                <include>**/IntArrayList.java</include>
-                <include>**/Internal.java</include>
-                <include>**/InvalidProtocolBufferException.java</include>
-                <include>**/LazyFieldLite.java</include>
-                <include>**/LazyStringArrayList.java</include>
-                <include>**/LazyStringList.java</include>
-                <include>**/LiteralByteString.java</include>
-                <include>**/LongArrayList.java</include>
-                <include>**/MapEntryLite.java</include>
-                <include>**/MapFieldLite.java</include>
-                <include>**/MessageLite.java</include>
-                <include>**/MessageLiteOrBuilder.java</include>
-                <include>**/MutabilityOracle.java</include>
-                <include>**/Parser.java</include>
-                <include>**/ProtobufArrayList.java</include>
-                <include>**/ProtocolStringList.java</include>
-                <include>**/RopeByteString.java</include>
-                <include>**/SmallSortedMap.java</include>
-                <include>**/UninitializedMessageException.java</include>
-                <include>**/UnknownFieldSetLite.java</include>
-                <include>**/UnmodifiableLazyStringList.java</include>
-                <include>**/Utf8.java</include>
-                <include>**/WireFormat.java</include>
-              </includes>
-              <testIncludes>
-                <testInclude>**/*Lite.java</testInclude>
-                <testInclude>**/BooleanArrayListTest.java</testInclude>
-                <testInclude>**/DoubleArrayListTest.java</testInclude>
-                <testInclude>**/FloatArrayListTest.java</testInclude>
-                <testInclude>**/IntArrayListTest.java</testInclude>
-                <testInclude>**/LazyMessageLiteTest.java</testInclude>
-                <testInclude>**/LiteTest.java</testInclude>
-                <testInclude>**/LongArrayListTest.java</testInclude>
-                <testInclude>**/ProtobufArrayListTest.java</testInclude>
-                <testInclude>**/UnknownFieldSetLiteTest.java</testInclude>
-              </testIncludes>
-            </configuration>
-          </plugin>
-          <plugin>
-            <artifactId>maven-surefire-plugin</artifactId>
-            <configuration>
-              <includes>
-                <include>**/*Test.java</include>
-              </includes>
-            </configuration>
-          </plugin>
-          <plugin>
-            <artifactId>maven-jar-plugin</artifactId>
-            <configuration>
-              <classifier>lite</classifier>
+              <serverId>sonatype-nexus-staging</serverId>
+              <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+              <autoReleaseAfterClose>false</autoReleaseAfterClose>
             </configuration>
           </plugin>
         </plugins>
       </build>
     </profile>
   </profiles>
+
+  <modules>
+    <module>core</module>
+    <module>lite</module>
+    <module>util</module>
+  </modules>
+
 </project>
diff --git a/java/src/main/java/com/google/protobuf/BoundedByteString.java b/java/src/main/java/com/google/protobuf/BoundedByteString.java
deleted file mode 100644
index b4c3fb1b..00000000
--- a/java/src/main/java/com/google/protobuf/BoundedByteString.java
+++ /dev/null
@@ -1,180 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-import java.io.IOException;
-import java.io.InvalidObjectException;
-import java.io.ObjectInputStream;
-import java.util.NoSuchElementException;
-
-/**
- * This class is used to represent the substring of a {@link ByteString} over a
- * single byte array. In terms of the public API of {@link ByteString}, you end
- * up here by calling {@link ByteString#copyFrom(byte[])} followed by {@link
- * ByteString#substring(int, int)}.
- *
- * <p>This class contains most of the overhead involved in creating a substring
- * from a {@link LiteralByteString}.  The overhead involves some range-checking
- * and two extra fields.
- *
- * @author carlanton@google.com (Carl Haverl)
- */
-class BoundedByteString extends LiteralByteString {
-
-  private final int bytesOffset;
-  private final int bytesLength;
-
-  /**
-   * Creates a {@code BoundedByteString} backed by the sub-range of given array,
-   * without copying.
-   *
-   * @param bytes  array to wrap
-   * @param offset index to first byte to use in bytes
-   * @param length number of bytes to use from bytes
-   * @throws IllegalArgumentException if {@code offset < 0}, {@code length < 0},
-   *                                  or if {@code offset + length >
-   *                                  bytes.length}.
-   */
-  BoundedByteString(byte[] bytes, int offset, int length) {
-    super(bytes);
-    if (offset < 0) {
-      throw new IllegalArgumentException("Offset too small: " + offset);
-    }
-    if (length < 0) {
-      throw new IllegalArgumentException("Length too small: " + offset);
-    }
-    if ((long) offset + length > bytes.length) {
-      throw new IllegalArgumentException(
-          "Offset+Length too large: " + offset + "+" + length);
-    }
-
-    this.bytesOffset = offset;
-    this.bytesLength = length;
-  }
-
-  /**
-   * Gets the byte at the given index.
-   * Throws {@link ArrayIndexOutOfBoundsException}
-   * for backwards-compatibility reasons although it would more properly be
-   * {@link IndexOutOfBoundsException}.
-   *
-   * @param index index of byte
-   * @return the value
-   * @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size
-   */
-  @Override
-  public byte byteAt(int index) {
-    // We must check the index ourselves as we cannot rely on Java array index
-    // checking for substrings.
-    if (index < 0) {
-      throw new ArrayIndexOutOfBoundsException("Index too small: " + index);
-    }
-    if (index >= size()) {
-      throw new ArrayIndexOutOfBoundsException(
-          "Index too large: " + index + ", " + size());
-    }
-
-    return bytes[bytesOffset + index];
-  }
-
-  @Override
-  public int size() {
-    return bytesLength;
-  }
-
-  @Override
-  protected int getOffsetIntoBytes() {
-    return bytesOffset;
-  }
-
-  // =================================================================
-  // ByteString -> byte[]
-
-  @Override
-  protected void copyToInternal(byte[] target, int sourceOffset, 
-      int targetOffset, int numberToCopy) {
-    System.arraycopy(bytes, getOffsetIntoBytes() + sourceOffset, target,
-        targetOffset, numberToCopy);
-  }
-
-  // =================================================================
-  // Serializable
-
-  private static final long serialVersionUID = 1L;
-
-  Object writeReplace() {
-    return new LiteralByteString(toByteArray());
-  }
-
-  private void readObject(ObjectInputStream in) throws IOException {
-    throw new InvalidObjectException(
-        "BoundedByteStream instances are not to be serialized directly");
-  }
-
-  // =================================================================
-  // ByteIterator
-
-  @Override
-  public ByteIterator iterator() {
-    return new BoundedByteIterator();
-  }
-
-  private class BoundedByteIterator implements ByteIterator {
-
-    private int position;
-    private final int limit;
-
-    private BoundedByteIterator() {
-      position = getOffsetIntoBytes();
-      limit = position + size();
-    }
-
-    public boolean hasNext() {
-      return (position < limit);
-    }
-
-    public Byte next() {
-      // Boxing calls Byte.valueOf(byte), which does not instantiate.
-      return nextByte();
-    }
-
-    public byte nextByte() {
-      if (position >= limit) {
-        throw new NoSuchElementException();
-      }
-      return bytes[position++];
-    }
-
-    public void remove() {
-      throw new UnsupportedOperationException();
-    }
-  }
-}
diff --git a/java/src/main/java/com/google/protobuf/CodedOutputStream.java b/java/src/main/java/com/google/protobuf/CodedOutputStream.java
deleted file mode 100644
index 291bd20a..00000000
--- a/java/src/main/java/com/google/protobuf/CodedOutputStream.java
+++ /dev/null
@@ -1,1385 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-import com.google.protobuf.Utf8.UnpairedSurrogateException;
-
-import java.io.IOException;
-import java.io.OutputStream;
-import java.nio.ByteBuffer;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-/**
- * Encodes and writes protocol message fields.
- *
- * <p>This class contains two kinds of methods:  methods that write specific
- * protocol message constructs and field types (e.g. {@link #writeTag} and
- * {@link #writeInt32}) and methods that write low-level values (e.g.
- * {@link #writeRawVarint32} and {@link #writeRawBytes}).  If you are
- * writing encoded protocol messages, you should use the former methods, but if
- * you are writing some other format of your own design, use the latter.
- *
- * <p>This class is totally unsynchronized.
- *
- * @author kneton@google.com Kenton Varda
- */
-public final class CodedOutputStream {
-  
-  private static final Logger logger = Logger.getLogger(CodedOutputStream.class.getName());
-
-  // TODO(dweis): Consider migrating to a ByteBuffer.
-  private final byte[] buffer;
-  private final int limit;
-  private int position;
-  private int totalBytesWritten = 0;
-
-  private final OutputStream output;
-
-  /**
-   * The buffer size used in {@link #newInstance(OutputStream)}.
-   */
-  public static final int DEFAULT_BUFFER_SIZE = 4096;
-
-  /**
-   * Returns the buffer size to efficiently write dataLength bytes to this
-   * CodedOutputStream. Used by AbstractMessageLite.
-   *
-   * @return the buffer size to efficiently write dataLength bytes to this
-   *         CodedOutputStream.
-   */
-  static int computePreferredBufferSize(int dataLength) {
-    if (dataLength > DEFAULT_BUFFER_SIZE) return DEFAULT_BUFFER_SIZE;
-    return dataLength;
-  }
-
-  private CodedOutputStream(final byte[] buffer, final int offset,
-                            final int length) {
-    output = null;
-    this.buffer = buffer;
-    position = offset;
-    limit = offset + length;
-  }
-
-  private CodedOutputStream(final OutputStream output, final byte[] buffer) {
-    this.output = output;
-    this.buffer = buffer;
-    position = 0;
-    limit = buffer.length;
-  }
-
-  /**
-   * Create a new {@code CodedOutputStream} wrapping the given
-   * {@code OutputStream}.
-   */
-  public static CodedOutputStream newInstance(final OutputStream output) {
-    return newInstance(output, DEFAULT_BUFFER_SIZE);
-  }
-
-  /**
-   * Create a new {@code CodedOutputStream} wrapping the given
-   * {@code OutputStream} with a given buffer size.
-   */
-  public static CodedOutputStream newInstance(final OutputStream output,
-      final int bufferSize) {
-    return new CodedOutputStream(output, new byte[bufferSize]);
-  }
-
-  /**
-   * Create a new {@code CodedOutputStream} that writes directly to the given
-   * byte array.  If more bytes are written than fit in the array,
-   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
-   * array is faster than writing to an {@code OutputStream}.  See also
-   * {@link ByteString#newCodedBuilder}.
-   */
-  public static CodedOutputStream newInstance(final byte[] flatArray) {
-    return newInstance(flatArray, 0, flatArray.length);
-  }
-
-  /**
-   * Create a new {@code CodedOutputStream} that writes directly to the given
-   * byte array slice.  If more bytes are written than fit in the slice,
-   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
-   * array is faster than writing to an {@code OutputStream}.  See also
-   * {@link ByteString#newCodedBuilder}.
-   */
-  public static CodedOutputStream newInstance(final byte[] flatArray,
-                                              final int offset,
-                                              final int length) {
-    return new CodedOutputStream(flatArray, offset, length);
-  }
-
-  /**
-   * Create a new {@code CodedOutputStream} that writes to the given ByteBuffer.
-   */
-  public static CodedOutputStream newInstance(ByteBuffer byteBuffer) {
-    return newInstance(byteBuffer, DEFAULT_BUFFER_SIZE);
-  }
-
-  /**
-   * Create a new {@code CodedOutputStream} that writes to the given ByteBuffer.
-   */
-  public static CodedOutputStream newInstance(ByteBuffer byteBuffer,
-      int bufferSize) {
-    return newInstance(new ByteBufferOutputStream(byteBuffer), bufferSize);
-  }
-
-  private static class ByteBufferOutputStream extends OutputStream {
-    private final ByteBuffer byteBuffer;
-    public ByteBufferOutputStream(ByteBuffer byteBuffer) {
-      this.byteBuffer = byteBuffer;
-    }
-
-    @Override
-    public void write(int b) throws IOException {
-      byteBuffer.put((byte) b);
-    }
-
-    @Override
-    public void write(byte[] data, int offset, int length) throws IOException {
-      byteBuffer.put(data, offset, length);
-    }
-  }
-
-  // -----------------------------------------------------------------
-
-  /** Write a {@code double} field, including tag, to the stream. */
-  public void writeDouble(final int fieldNumber, final double value)
-                          throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
-    writeDoubleNoTag(value);
-  }
-
-  /** Write a {@code float} field, including tag, to the stream. */
-  public void writeFloat(final int fieldNumber, final float value)
-                         throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
-    writeFloatNoTag(value);
-  }
-
-  /** Write a {@code uint64} field, including tag, to the stream. */
-  public void writeUInt64(final int fieldNumber, final long value)
-                          throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeUInt64NoTag(value);
-  }
-
-  /** Write an {@code int64} field, including tag, to the stream. */
-  public void writeInt64(final int fieldNumber, final long value)
-                         throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeInt64NoTag(value);
-  }
-
-  /** Write an {@code int32} field, including tag, to the stream. */
-  public void writeInt32(final int fieldNumber, final int value)
-                         throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeInt32NoTag(value);
-  }
-
-  /** Write a {@code fixed64} field, including tag, to the stream. */
-  public void writeFixed64(final int fieldNumber, final long value)
-                           throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
-    writeFixed64NoTag(value);
-  }
-
-  /** Write a {@code fixed32} field, including tag, to the stream. */
-  public void writeFixed32(final int fieldNumber, final int value)
-                           throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
-    writeFixed32NoTag(value);
-  }
-
-  /** Write a {@code bool} field, including tag, to the stream. */
-  public void writeBool(final int fieldNumber, final boolean value)
-                        throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeBoolNoTag(value);
-  }
-
-  /** Write a {@code string} field, including tag, to the stream. */
-  public void writeString(final int fieldNumber, final String value)
-                          throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
-    writeStringNoTag(value);
-  }
-
-  /** Write a {@code group} field, including tag, to the stream. */
-  public void writeGroup(final int fieldNumber, final MessageLite value)
-                         throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_START_GROUP);
-    writeGroupNoTag(value);
-    writeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP);
-  }
-
-
-  /**
-   * Write a group represented by an {@link UnknownFieldSet}.
-   *
-   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
-   *             call {@link #writeGroup}.
-   */
-  @Deprecated
-  public void writeUnknownGroup(final int fieldNumber,
-                                final MessageLite value)
-                                throws IOException {
-    writeGroup(fieldNumber, value);
-  }
-
-  /** Write an embedded message field, including tag, to the stream. */
-  public void writeMessage(final int fieldNumber, final MessageLite value)
-                           throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
-    writeMessageNoTag(value);
-  }
-
-
-  /** Write a {@code bytes} field, including tag, to the stream. */
-  public void writeBytes(final int fieldNumber, final ByteString value)
-                         throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
-    writeBytesNoTag(value);
-  }
-
-  /** Write a {@code bytes} field, including tag, to the stream. */
-  public void writeByteArray(final int fieldNumber, final byte[] value)
-                             throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
-    writeByteArrayNoTag(value);
-  }
-
-  /** Write a {@code bytes} field, including tag, to the stream. */
-  public void writeByteArray(final int fieldNumber,
-                             final byte[] value,
-                             final int offset,
-                             final int length)
-                             throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
-    writeByteArrayNoTag(value, offset, length);
-  }
-
-  /**
-   * Write a {@code bytes} field, including tag, to the stream.
-   * This method will write all content of the ByteBuffer regardless of the
-   * current position and limit (i.e., the number of bytes to be written is
-   * value.capacity(), not value.remaining()). Furthermore, this method doesn't
-   * alter the state of the passed-in ByteBuffer. Its position, limit, mark,
-   * etc. will remain unchanged. If you only want to write the remaining bytes
-   * of a ByteBuffer, you can call
-   * {@code writeByteBuffer(fieldNumber, byteBuffer.slice())}.
-   */
-  public void writeByteBuffer(final int fieldNumber, final ByteBuffer value)
-      throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
-    writeByteBufferNoTag(value);
-  }
-
-  /** Write a {@code uint32} field, including tag, to the stream. */
-  public void writeUInt32(final int fieldNumber, final int value)
-                          throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeUInt32NoTag(value);
-  }
-
-  /**
-   * Write an enum field, including tag, to the stream.  Caller is responsible
-   * for converting the enum value to its numeric value.
-   */
-  public void writeEnum(final int fieldNumber, final int value)
-                        throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeEnumNoTag(value);
-  }
-
-  /** Write an {@code sfixed32} field, including tag, to the stream. */
-  public void writeSFixed32(final int fieldNumber, final int value)
-                            throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
-    writeSFixed32NoTag(value);
-  }
-
-  /** Write an {@code sfixed64} field, including tag, to the stream. */
-  public void writeSFixed64(final int fieldNumber, final long value)
-                            throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
-    writeSFixed64NoTag(value);
-  }
-
-  /** Write an {@code sint32} field, including tag, to the stream. */
-  public void writeSInt32(final int fieldNumber, final int value)
-                          throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeSInt32NoTag(value);
-  }
-
-  /** Write an {@code sint64} field, including tag, to the stream. */
-  public void writeSInt64(final int fieldNumber, final long value)
-                          throws IOException {
-    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
-    writeSInt64NoTag(value);
-  }
-
-  /**
-   * Write a MessageSet extension field to the stream.  For historical reasons,
-   * the wire format differs from normal fields.
-   */
-  public void writeMessageSetExtension(final int fieldNumber,
-                                       final MessageLite value)
-                                       throws IOException {
-    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
-    writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
-    writeMessage(WireFormat.MESSAGE_SET_MESSAGE, value);
-    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
-  }
-
-  /**
-   * Write an unparsed MessageSet extension field to the stream.  For
-   * historical reasons, the wire format differs from normal fields.
-   */
-  public void writeRawMessageSetExtension(final int fieldNumber,
-                                          final ByteString value)
-                                          throws IOException {
-    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
-    writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
-    writeBytes(WireFormat.MESSAGE_SET_MESSAGE, value);
-    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
-  }
-
-  // -----------------------------------------------------------------
-
-  /** Write a {@code double} field to the stream. */
-  public void writeDoubleNoTag(final double value) throws IOException {
-    writeRawLittleEndian64(Double.doubleToRawLongBits(value));
-  }
-
-  /** Write a {@code float} field to the stream. */
-  public void writeFloatNoTag(final float value) throws IOException {
-    writeRawLittleEndian32(Float.floatToRawIntBits(value));
-  }
-
-  /** Write a {@code uint64} field to the stream. */
-  public void writeUInt64NoTag(final long value) throws IOException {
-    writeRawVarint64(value);
-  }
-
-  /** Write an {@code int64} field to the stream. */
-  public void writeInt64NoTag(final long value) throws IOException {
-    writeRawVarint64(value);
-  }
-
-  /** Write an {@code int32} field to the stream. */
-  public void writeInt32NoTag(final int value) throws IOException {
-    if (value >= 0) {
-      writeRawVarint32(value);
-    } else {
-      // Must sign-extend.
-      writeRawVarint64(value);
-    }
-  }
-
-  /** Write a {@code fixed64} field to the stream. */
-  public void writeFixed64NoTag(final long value) throws IOException {
-    writeRawLittleEndian64(value);
-  }
-
-  /** Write a {@code fixed32} field to the stream. */
-  public void writeFixed32NoTag(final int value) throws IOException {
-    writeRawLittleEndian32(value);
-  }
-
-  /** Write a {@code bool} field to the stream. */
-  public void writeBoolNoTag(final boolean value) throws IOException {
-    writeRawByte(value ? 1 : 0);
-  }
-
-  /** Write a {@code string} field to the stream. */
-  // TODO(dweis): Document behavior on ill-formed UTF-16 input.
-  public void writeStringNoTag(final String value) throws IOException {
-    try {
-      efficientWriteStringNoTag(value);
-    } catch (UnpairedSurrogateException e) {
-      logger.log(Level.WARNING, 
-          "Converting ill-formed UTF-16. Your Protocol Buffer will not round trip correctly!", e);
-      inefficientWriteStringNoTag(value);
-    }
-  }
-
-  /** Write a {@code string} field to the stream. */
-  private void inefficientWriteStringNoTag(final String value) throws IOException {
-    // Unfortunately there does not appear to be any way to tell Java to encode
-    // UTF-8 directly into our buffer, so we have to let it create its own byte
-    // array and then copy.
-    // TODO(dweis): Consider using nio Charset methods instead.
-    final byte[] bytes = value.getBytes(Internal.UTF_8);
-    writeRawVarint32(bytes.length);
-    writeRawBytes(bytes);
-  }
-
-  /**
-   * Write a {@code string} field to the stream efficiently. If the {@code string} is malformed,
-   * this method rolls back its changes and throws an {@link UnpairedSurrogateException} with the
-   * intent that the caller will catch and retry with {@link #inefficientWriteStringNoTag(String)}.
-   * 
-   * @param value the string to write to the stream
-   * 
-   * @throws UnpairedSurrogateException when {@code value} is ill-formed UTF-16. 
-   */
-  private void efficientWriteStringNoTag(final String value) throws IOException {
-    // UTF-8 byte length of the string is at least its UTF-16 code unit length (value.length()),
-    // and at most 3 times of it. We take advantage of this in both branches below.
-    final int maxLength = value.length() * Utf8.MAX_BYTES_PER_CHAR;
-    final int maxLengthVarIntSize = computeRawVarint32Size(maxLength);
-
-    // If we are streaming and the potential length is too big to fit in our buffer, we take the
-    // slower path. Otherwise, we're good to try the fast path.
-    if (output != null && maxLengthVarIntSize + maxLength > limit - position) {
-      // Allocate a byte[] that we know can fit the string and encode into it. String.getBytes()
-      // does the same internally and then does *another copy* to return a byte[] of exactly the
-      // right size. We can skip that copy and just writeRawBytes up to the actualLength of the
-      // UTF-8 encoded bytes.
-      final byte[] encodedBytes = new byte[maxLength];
-      int actualLength = Utf8.encode(value, encodedBytes, 0, maxLength);
-      writeRawVarint32(actualLength);
-      writeRawBytes(encodedBytes, 0, actualLength);
-    } else {
-      // Optimize for the case where we know this length results in a constant varint length as this
-      // saves a pass for measuring the length of the string.
-      final int minLengthVarIntSize = computeRawVarint32Size(value.length());
-      int oldPosition = position;
-      final int length;
-      try {
-        if (minLengthVarIntSize == maxLengthVarIntSize) {
-          position = oldPosition + minLengthVarIntSize;
-          int newPosition = Utf8.encode(value, buffer, position, limit - position);
-          // Since this class is stateful and tracks the position, we rewind and store the state,
-          // prepend the length, then reset it back to the end of the string.
-          position = oldPosition;
-          length = newPosition - oldPosition - minLengthVarIntSize;
-          writeRawVarint32(length);
-          position = newPosition;
-        } else {
-          length = Utf8.encodedLength(value);
-          writeRawVarint32(length);
-          position = Utf8.encode(value, buffer, position, limit - position);
-        }
-      } catch (UnpairedSurrogateException e) {
-        // Be extra careful and restore the original position for retrying the write with the less
-        // efficient path.
-        position = oldPosition;
-        throw e;
-      } catch (ArrayIndexOutOfBoundsException e) {
-        throw new OutOfSpaceException(e);
-      }
-      totalBytesWritten += length;
-    }
-  }
-
-  /** Write a {@code group} field to the stream. */
-  public void writeGroupNoTag(final MessageLite value) throws IOException {
-    value.writeTo(this);
-  }
-
-
-  /**
-   * Write a group represented by an {@link UnknownFieldSet}.
-   *
-   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
-   *             call {@link #writeGroupNoTag}.
-   */
-  @Deprecated
-  public void writeUnknownGroupNoTag(final MessageLite value)
-      throws IOException {
-    writeGroupNoTag(value);
-  }
-
-  /** Write an embedded message field to the stream. */
-  public void writeMessageNoTag(final MessageLite value) throws IOException {
-    writeRawVarint32(value.getSerializedSize());
-    value.writeTo(this);
-  }
-
-
-  /** Write a {@code bytes} field to the stream. */
-  public void writeBytesNoTag(final ByteString value) throws IOException {
-    writeRawVarint32(value.size());
-    writeRawBytes(value);
-  }
-
-  /** Write a {@code bytes} field to the stream. */
-  public void writeByteArrayNoTag(final byte[] value) throws IOException {
-    writeRawVarint32(value.length);
-    writeRawBytes(value);
-  }
-
-  /** Write a {@code bytes} field to the stream. */
-  public void writeByteArrayNoTag(final byte[] value,
-                                  final int offset,
-                                  final int length) throws IOException {
-    writeRawVarint32(length);
-    writeRawBytes(value, offset, length);
-  }
-
-  /**
-   * Write a {@code bytes} field to the stream.  This method will write all
-   * content of the ByteBuffer regardless of the current position and limit
-   * (i.e., the number of bytes to be written is value.capacity(), not
-   * value.remaining()). Furthermore, this method doesn't alter the state of
-   * the passed-in ByteBuffer. Its position, limit, mark, etc. will remain
-   * unchanged. If you only want to write the remaining bytes of a ByteBuffer,
-   * you can call {@code writeByteBufferNoTag(byteBuffer.slice())}.
-   */
-  public void writeByteBufferNoTag(final ByteBuffer value) throws IOException {
-    writeRawVarint32(value.capacity());
-    writeRawBytes(value);
-  }
-
-  /** Write a {@code uint32} field to the stream. */
-  public void writeUInt32NoTag(final int value) throws IOException {
-    writeRawVarint32(value);
-  }
-
-  /**
-   * Write an enum field to the stream.  Caller is responsible
-   * for converting the enum value to its numeric value.
-   */
-  public void writeEnumNoTag(final int value) throws IOException {
-    writeInt32NoTag(value);
-  }
-
-  /** Write an {@code sfixed32} field to the stream. */
-  public void writeSFixed32NoTag(final int value) throws IOException {
-    writeRawLittleEndian32(value);
-  }
-
-  /** Write an {@code sfixed64} field to the stream. */
-  public void writeSFixed64NoTag(final long value) throws IOException {
-    writeRawLittleEndian64(value);
-  }
-
-  /** Write an {@code sint32} field to the stream. */
-  public void writeSInt32NoTag(final int value) throws IOException {
-    writeRawVarint32(encodeZigZag32(value));
-  }
-
-  /** Write an {@code sint64} field to the stream. */
-  public void writeSInt64NoTag(final long value) throws IOException {
-    writeRawVarint64(encodeZigZag64(value));
-  }
-
-  // =================================================================
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code double} field, including tag.
-   */
-  public static int computeDoubleSize(final int fieldNumber,
-                                      final double value) {
-    return computeTagSize(fieldNumber) + computeDoubleSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code float} field, including tag.
-   */
-  public static int computeFloatSize(final int fieldNumber, final float value) {
-    return computeTagSize(fieldNumber) + computeFloatSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code uint64} field, including tag.
-   */
-  public static int computeUInt64Size(final int fieldNumber, final long value) {
-    return computeTagSize(fieldNumber) + computeUInt64SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code int64} field, including tag.
-   */
-  public static int computeInt64Size(final int fieldNumber, final long value) {
-    return computeTagSize(fieldNumber) + computeInt64SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code int32} field, including tag.
-   */
-  public static int computeInt32Size(final int fieldNumber, final int value) {
-    return computeTagSize(fieldNumber) + computeInt32SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code fixed64} field, including tag.
-   */
-  public static int computeFixed64Size(final int fieldNumber,
-                                       final long value) {
-    return computeTagSize(fieldNumber) + computeFixed64SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code fixed32} field, including tag.
-   */
-  public static int computeFixed32Size(final int fieldNumber,
-                                       final int value) {
-    return computeTagSize(fieldNumber) + computeFixed32SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bool} field, including tag.
-   */
-  public static int computeBoolSize(final int fieldNumber,
-                                    final boolean value) {
-    return computeTagSize(fieldNumber) + computeBoolSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code string} field, including tag.
-   */
-  public static int computeStringSize(final int fieldNumber,
-                                      final String value) {
-    return computeTagSize(fieldNumber) + computeStringSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code group} field, including tag.
-   */
-  public static int computeGroupSize(final int fieldNumber,
-                                     final MessageLite value) {
-    return computeTagSize(fieldNumber) * 2 + computeGroupSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code group} field represented by an {@code UnknownFieldSet}, including
-   * tag.
-   *
-   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
-   *             call {@link #computeGroupSize}.
-   */
-  @Deprecated
-  public static int computeUnknownGroupSize(final int fieldNumber,
-                                            final MessageLite value) {
-    return computeGroupSize(fieldNumber, value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * embedded message field, including tag.
-   */
-  public static int computeMessageSize(final int fieldNumber,
-                                       final MessageLite value) {
-    return computeTagSize(fieldNumber) + computeMessageSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bytes} field, including tag.
-   */
-  public static int computeBytesSize(final int fieldNumber,
-                                     final ByteString value) {
-    return computeTagSize(fieldNumber) + computeBytesSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bytes} field, including tag.
-   */
-  public static int computeByteArraySize(final int fieldNumber,
-                                         final byte[] value) {
-    return computeTagSize(fieldNumber) + computeByteArraySizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bytes} field, including tag.
-   */
-  public static int computeByteBufferSize(final int fieldNumber,
-                                         final ByteBuffer value) {
-    return computeTagSize(fieldNumber) + computeByteBufferSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * embedded message in lazy field, including tag.
-   */
-  public static int computeLazyFieldSize(final int fieldNumber,
-                                         final LazyFieldLite value) {
-    return computeTagSize(fieldNumber) + computeLazyFieldSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code uint32} field, including tag.
-   */
-  public static int computeUInt32Size(final int fieldNumber, final int value) {
-    return computeTagSize(fieldNumber) + computeUInt32SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * enum field, including tag.  Caller is responsible for converting the
-   * enum value to its numeric value.
-   */
-  public static int computeEnumSize(final int fieldNumber, final int value) {
-    return computeTagSize(fieldNumber) + computeEnumSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sfixed32} field, including tag.
-   */
-  public static int computeSFixed32Size(final int fieldNumber,
-                                        final int value) {
-    return computeTagSize(fieldNumber) + computeSFixed32SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sfixed64} field, including tag.
-   */
-  public static int computeSFixed64Size(final int fieldNumber,
-                                        final long value) {
-    return computeTagSize(fieldNumber) + computeSFixed64SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sint32} field, including tag.
-   */
-  public static int computeSInt32Size(final int fieldNumber, final int value) {
-    return computeTagSize(fieldNumber) + computeSInt32SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sint64} field, including tag.
-   */
-  public static int computeSInt64Size(final int fieldNumber, final long value) {
-    return computeTagSize(fieldNumber) + computeSInt64SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * MessageSet extension to the stream.  For historical reasons,
-   * the wire format differs from normal fields.
-   */
-  public static int computeMessageSetExtensionSize(
-      final int fieldNumber, final MessageLite value) {
-    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2 +
-           computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber) +
-           computeMessageSize(WireFormat.MESSAGE_SET_MESSAGE, value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * unparsed MessageSet extension field to the stream.  For
-   * historical reasons, the wire format differs from normal fields.
-   */
-  public static int computeRawMessageSetExtensionSize(
-      final int fieldNumber, final ByteString value) {
-    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2 +
-           computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber) +
-           computeBytesSize(WireFormat.MESSAGE_SET_MESSAGE, value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * lazily parsed MessageSet extension field to the stream.  For
-   * historical reasons, the wire format differs from normal fields.
-   */
-  public static int computeLazyFieldMessageSetExtensionSize(
-      final int fieldNumber, final LazyFieldLite value) {
-    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2 +
-           computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber) +
-           computeLazyFieldSize(WireFormat.MESSAGE_SET_MESSAGE, value);
-  }
-
-  // -----------------------------------------------------------------
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code double} field, including tag.
-   */
-  public static int computeDoubleSizeNoTag(final double value) {
-    return LITTLE_ENDIAN_64_SIZE;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code float} field, including tag.
-   */
-  public static int computeFloatSizeNoTag(final float value) {
-    return LITTLE_ENDIAN_32_SIZE;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code uint64} field, including tag.
-   */
-  public static int computeUInt64SizeNoTag(final long value) {
-    return computeRawVarint64Size(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code int64} field, including tag.
-   */
-  public static int computeInt64SizeNoTag(final long value) {
-    return computeRawVarint64Size(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code int32} field, including tag.
-   */
-  public static int computeInt32SizeNoTag(final int value) {
-    if (value >= 0) {
-      return computeRawVarint32Size(value);
-    } else {
-      // Must sign-extend.
-      return 10;
-    }
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code fixed64} field.
-   */
-  public static int computeFixed64SizeNoTag(final long value) {
-    return LITTLE_ENDIAN_64_SIZE;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code fixed32} field.
-   */
-  public static int computeFixed32SizeNoTag(final int value) {
-    return LITTLE_ENDIAN_32_SIZE;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bool} field.
-   */
-  public static int computeBoolSizeNoTag(final boolean value) {
-    return 1;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code string} field.
-   */
-  public static int computeStringSizeNoTag(final String value) {
-    int length;
-    try {
-      length = Utf8.encodedLength(value);
-    } catch (UnpairedSurrogateException e) {
-      // TODO(dweis): Consider using nio Charset methods instead.
-      final byte[] bytes = value.getBytes(Internal.UTF_8);
-      length = bytes.length;
-    }
-
-    return computeRawVarint32Size(length) + length;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code group} field.
-   */
-  public static int computeGroupSizeNoTag(final MessageLite value) {
-    return value.getSerializedSize();
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code group} field represented by an {@code UnknownFieldSet}, including
-   * tag.
-   *
-   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
-   *             call {@link #computeUnknownGroupSizeNoTag}.
-   */
-  @Deprecated
-  public static int computeUnknownGroupSizeNoTag(final MessageLite value) {
-    return computeGroupSizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an embedded
-   * message field.
-   */
-  public static int computeMessageSizeNoTag(final MessageLite value) {
-    final int size = value.getSerializedSize();
-    return computeRawVarint32Size(size) + size;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an embedded
-   * message stored in lazy field.
-   */
-  public static int computeLazyFieldSizeNoTag(final LazyFieldLite value) {
-    final int size = value.getSerializedSize();
-    return computeRawVarint32Size(size) + size;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bytes} field.
-   */
-  public static int computeBytesSizeNoTag(final ByteString value) {
-    return computeRawVarint32Size(value.size()) +
-           value.size();
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bytes} field.
-   */
-  public static int computeByteArraySizeNoTag(final byte[] value) {
-    return computeRawVarint32Size(value.length) + value.length;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code bytes} field.
-   */
-  public static int computeByteBufferSizeNoTag(final ByteBuffer value) {
-    return computeRawVarint32Size(value.capacity()) + value.capacity();
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a
-   * {@code uint32} field.
-   */
-  public static int computeUInt32SizeNoTag(final int value) {
-    return computeRawVarint32Size(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an enum field.
-   * Caller is responsible for converting the enum value to its numeric value.
-   */
-  public static int computeEnumSizeNoTag(final int value) {
-    return computeInt32SizeNoTag(value);
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sfixed32} field.
-   */
-  public static int computeSFixed32SizeNoTag(final int value) {
-    return LITTLE_ENDIAN_32_SIZE;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sfixed64} field.
-   */
-  public static int computeSFixed64SizeNoTag(final long value) {
-    return LITTLE_ENDIAN_64_SIZE;
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sint32} field.
-   */
-  public static int computeSInt32SizeNoTag(final int value) {
-    return computeRawVarint32Size(encodeZigZag32(value));
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode an
-   * {@code sint64} field.
-   */
-  public static int computeSInt64SizeNoTag(final long value) {
-    return computeRawVarint64Size(encodeZigZag64(value));
-  }
-
-  // =================================================================
-
-  /**
-   * Internal helper that writes the current buffer to the output. The
-   * buffer position is reset to its initial value when this returns.
-   */
-  private void refreshBuffer() throws IOException {
-    if (output == null) {
-      // We're writing to a single buffer.
-      throw new OutOfSpaceException();
-    }
-
-    // Since we have an output stream, this is our buffer
-    // and buffer offset == 0
-    output.write(buffer, 0, position);
-    position = 0;
-  }
-
-  /**
-   * Flushes the stream and forces any buffered bytes to be written.  This
-   * does not flush the underlying OutputStream.
-   */
-  public void flush() throws IOException {
-    if (output != null) {
-      refreshBuffer();
-    }
-  }
-
-  /**
-   * If writing to a flat array, return the space left in the array.
-   * Otherwise, throws {@code UnsupportedOperationException}.
-   */
-  public int spaceLeft() {
-    if (output == null) {
-      return limit - position;
-    } else {
-      throw new UnsupportedOperationException(
-        "spaceLeft() can only be called on CodedOutputStreams that are " +
-        "writing to a flat array.");
-    }
-  }
-
-  /**
-   * Verifies that {@link #spaceLeft()} returns zero.  It's common to create
-   * a byte array that is exactly big enough to hold a message, then write to
-   * it with a {@code CodedOutputStream}.  Calling {@code checkNoSpaceLeft()}
-   * after writing verifies that the message was actually as big as expected,
-   * which can help catch bugs.
-   */
-  public void checkNoSpaceLeft() {
-    if (spaceLeft() != 0) {
-      throw new IllegalStateException(
-        "Did not write as much data as expected.");
-    }
-  }
-
-  /**
-   * If you create a CodedOutputStream around a simple flat array, you must
-   * not attempt to write more bytes than the array has space.  Otherwise,
-   * this exception will be thrown.
-   */
-  public static class OutOfSpaceException extends IOException {
-    private static final long serialVersionUID = -6947486886997889499L;
-
-    private static final String MESSAGE =
-        "CodedOutputStream was writing to a flat byte array and ran out of space.";
-
-    OutOfSpaceException() {
-      super(MESSAGE);
-    }
-
-    OutOfSpaceException(Throwable cause) {
-      super(MESSAGE, cause);
-    }
-  }
-
-  /**
-   * Get the total number of bytes successfully written to this stream.  The
-   * returned value is not guaranteed to be accurate if exceptions have been
-   * found in the middle of writing.
-   */
-  public int getTotalBytesWritten() {
-    return totalBytesWritten;
-  }
-
-  /** Write a single byte. */
-  public void writeRawByte(final byte value) throws IOException {
-    if (position == limit) {
-      refreshBuffer();
-    }
-
-    buffer[position++] = value;
-    ++totalBytesWritten;
-  }
-
-  /** Write a single byte, represented by an integer value. */
-  public void writeRawByte(final int value) throws IOException {
-    writeRawByte((byte) value);
-  }
-
-  /** Write a byte string. */
-  public void writeRawBytes(final ByteString value) throws IOException {
-    writeRawBytes(value, 0, value.size());
-  }
-
-  /** Write an array of bytes. */
-  public void writeRawBytes(final byte[] value) throws IOException {
-    writeRawBytes(value, 0, value.length);
-  }
-
-  /**
-   * Write a ByteBuffer. This method will write all content of the ByteBuffer
-   * regardless of the current position and limit (i.e., the number of bytes
-   * to be written is value.capacity(), not value.remaining()). Furthermore,
-   * this method doesn't alter the state of the passed-in ByteBuffer. Its
-   * position, limit, mark, etc. will remain unchanged. If you only want to
-   * write the remaining bytes of a ByteBuffer, you can call
-   * {@code writeRawBytes(byteBuffer.slice())}.
-   */
-  public void writeRawBytes(final ByteBuffer value) throws IOException {
-    if (value.hasArray()) {
-      writeRawBytes(value.array(), value.arrayOffset(), value.capacity());
-    } else {
-      ByteBuffer duplicated = value.duplicate();
-      duplicated.clear();
-      writeRawBytesInternal(duplicated);
-    }
-  }
-
-  /** Write a ByteBuffer that isn't backed by an array. */
-  private void writeRawBytesInternal(final ByteBuffer value)
-      throws IOException {
-    int length = value.remaining();
-    if (limit - position >= length) {
-      // We have room in the current buffer.
-      value.get(buffer, position, length);
-      position += length;
-      totalBytesWritten += length;
-    } else {
-      // Write extends past current buffer.  Fill the rest of this buffer and
-      // flush.
-      final int bytesWritten = limit - position;
-      value.get(buffer, position, bytesWritten);
-      length -= bytesWritten;
-      position = limit;
-      totalBytesWritten += bytesWritten;
-      refreshBuffer();
-
-      // Now deal with the rest.
-      // Since we have an output stream, this is our buffer
-      // and buffer offset == 0
-      while (length > limit) {
-        // Copy data into the buffer before writing it to OutputStream.
-        // TODO(xiaofeng): Introduce ZeroCopyOutputStream to avoid this copy.
-        value.get(buffer, 0, limit);
-        output.write(buffer, 0, limit);
-        length -= limit;
-        totalBytesWritten += limit;
-      }
-      value.get(buffer, 0, length);
-      position = length;
-      totalBytesWritten += length;
-    }
-  }
-
-  /** Write part of an array of bytes. */
-  public void writeRawBytes(final byte[] value, int offset, int length)
-                            throws IOException {
-    if (limit - position >= length) {
-      // We have room in the current buffer.
-      System.arraycopy(value, offset, buffer, position, length);
-      position += length;
-      totalBytesWritten += length;
-    } else {
-      // Write extends past current buffer.  Fill the rest of this buffer and
-      // flush.
-      final int bytesWritten = limit - position;
-      System.arraycopy(value, offset, buffer, position, bytesWritten);
-      offset += bytesWritten;
-      length -= bytesWritten;
-      position = limit;
-      totalBytesWritten += bytesWritten;
-      refreshBuffer();
-
-      // Now deal with the rest.
-      // Since we have an output stream, this is our buffer
-      // and buffer offset == 0
-      if (length <= limit) {
-        // Fits in new buffer.
-        System.arraycopy(value, offset, buffer, 0, length);
-        position = length;
-      } else {
-        // Write is very big.  Let's do it all at once.
-        output.write(value, offset, length);
-      }
-      totalBytesWritten += length;
-    }
-  }
-
-  /** Write part of a byte string. */
-  public void writeRawBytes(final ByteString value, int offset, int length)
-                            throws IOException {
-    if (limit - position >= length) {
-      // We have room in the current buffer.
-      value.copyTo(buffer, offset, position, length);
-      position += length;
-      totalBytesWritten += length;
-    } else {
-      // Write extends past current buffer.  Fill the rest of this buffer and
-      // flush.
-      final int bytesWritten = limit - position;
-      value.copyTo(buffer, offset, position, bytesWritten);
-      offset += bytesWritten;
-      length -= bytesWritten;
-      position = limit;
-      totalBytesWritten += bytesWritten;
-      refreshBuffer();
-
-      // Now deal with the rest.
-      // Since we have an output stream, this is our buffer
-      // and buffer offset == 0
-      if (length <= limit) {
-        // Fits in new buffer.
-        value.copyTo(buffer, offset, 0, length);
-        position = length;
-      } else {
-        value.writeTo(output, offset, length);
-      }
-      totalBytesWritten += length;
-    }
-  }
-
-  /** Encode and write a tag. */
-  public void writeTag(final int fieldNumber, final int wireType)
-                       throws IOException {
-    writeRawVarint32(WireFormat.makeTag(fieldNumber, wireType));
-  }
-
-  /** Compute the number of bytes that would be needed to encode a tag. */
-  public static int computeTagSize(final int fieldNumber) {
-    return computeRawVarint32Size(WireFormat.makeTag(fieldNumber, 0));
-  }
-
-  /**
-   * Encode and write a varint.  {@code value} is treated as
-   * unsigned, so it won't be sign-extended if negative.
-   */
-  public void writeRawVarint32(int value) throws IOException {
-    while (true) {
-      if ((value & ~0x7F) == 0) {
-        writeRawByte(value);
-        return;
-      } else {
-        writeRawByte((value & 0x7F) | 0x80);
-        value >>>= 7;
-      }
-    }
-  }
-
-  /**
-   * Compute the number of bytes that would be needed to encode a varint.
-   * {@code value} is treated as unsigned, so it won't be sign-extended if
-   * negative.
-   */
-  public static int computeRawVarint32Size(final int value) {
-    if ((value & (0xffffffff <<  7)) == 0) return 1;
-    if ((value & (0xffffffff << 14)) == 0) return 2;
-    if ((value & (0xffffffff << 21)) == 0) return 3;
-    if ((value & (0xffffffff << 28)) == 0) return 4;
-    return 5;
-  }
-
-  /** Encode and write a varint. */
-  public void writeRawVarint64(long value) throws IOException {
-    while (true) {
-      if ((value & ~0x7FL) == 0) {
-        writeRawByte((int)value);
-        return;
-      } else {
-        writeRawByte(((int)value & 0x7F) | 0x80);
-        value >>>= 7;
-      }
-    }
-  }
-
-  /** Compute the number of bytes that would be needed to encode a varint. */
-  public static int computeRawVarint64Size(final long value) {
-    if ((value & (0xffffffffffffffffL <<  7)) == 0) return 1;
-    if ((value & (0xffffffffffffffffL << 14)) == 0) return 2;
-    if ((value & (0xffffffffffffffffL << 21)) == 0) return 3;
-    if ((value & (0xffffffffffffffffL << 28)) == 0) return 4;
-    if ((value & (0xffffffffffffffffL << 35)) == 0) return 5;
-    if ((value & (0xffffffffffffffffL << 42)) == 0) return 6;
-    if ((value & (0xffffffffffffffffL << 49)) == 0) return 7;
-    if ((value & (0xffffffffffffffffL << 56)) == 0) return 8;
-    if ((value & (0xffffffffffffffffL << 63)) == 0) return 9;
-    return 10;
-  }
-
-  /** Write a little-endian 32-bit integer. */
-  public void writeRawLittleEndian32(final int value) throws IOException {
-    writeRawByte((value      ) & 0xFF);
-    writeRawByte((value >>  8) & 0xFF);
-    writeRawByte((value >> 16) & 0xFF);
-    writeRawByte((value >> 24) & 0xFF);
-  }
-
-  public static final int LITTLE_ENDIAN_32_SIZE = 4;
-
-  /** Write a little-endian 64-bit integer. */
-  public void writeRawLittleEndian64(final long value) throws IOException {
-    writeRawByte((int)(value      ) & 0xFF);
-    writeRawByte((int)(value >>  8) & 0xFF);
-    writeRawByte((int)(value >> 16) & 0xFF);
-    writeRawByte((int)(value >> 24) & 0xFF);
-    writeRawByte((int)(value >> 32) & 0xFF);
-    writeRawByte((int)(value >> 40) & 0xFF);
-    writeRawByte((int)(value >> 48) & 0xFF);
-    writeRawByte((int)(value >> 56) & 0xFF);
-  }
-
-  public static final int LITTLE_ENDIAN_64_SIZE = 8;
-
-  /**
-   * Encode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
-   * into values that can be efficiently encoded with varint.  (Otherwise,
-   * negative values must be sign-extended to 64 bits to be varint encoded,
-   * thus always taking 10 bytes on the wire.)
-   *
-   * @param n A signed 32-bit integer.
-   * @return An unsigned 32-bit integer, stored in a signed int because
-   *         Java has no explicit unsigned support.
-   */
-  public static int encodeZigZag32(final int n) {
-    // Note:  the right-shift must be arithmetic
-    return (n << 1) ^ (n >> 31);
-  }
-
-  /**
-   * Encode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
-   * into values that can be efficiently encoded with varint.  (Otherwise,
-   * negative values must be sign-extended to 64 bits to be varint encoded,
-   * thus always taking 10 bytes on the wire.)
-   *
-   * @param n A signed 64-bit integer.
-   * @return An unsigned 64-bit integer, stored in a signed int because
-   *         Java has no explicit unsigned support.
-   */
-  public static long encodeZigZag64(final long n) {
-    // Note:  the right-shift must be arithmetic
-    return (n << 1) ^ (n >> 63);
-  }
-}
diff --git a/java/src/main/java/com/google/protobuf/LiteralByteString.java b/java/src/main/java/com/google/protobuf/LiteralByteString.java
deleted file mode 100644
index c5a8512a..00000000
--- a/java/src/main/java/com/google/protobuf/LiteralByteString.java
+++ /dev/null
@@ -1,372 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.nio.ByteBuffer;
-import java.nio.charset.Charset;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.NoSuchElementException;
-
-/**
- * This class implements a {@link com.google.protobuf.ByteString} backed by a
- * single array of bytes, contiguous in memory. It supports substring by
- * pointing to only a sub-range of the underlying byte array, meaning that a
- * substring will reference the full byte-array of the string it's made from,
- * exactly as with {@link String}.
- *
- * @author carlanton@google.com (Carl Haverl)
- */
-class LiteralByteString extends ByteString {
-
-  private static final long serialVersionUID = 1L;
-
-  protected final byte[] bytes;
-
-  /**
-   * Creates a {@code LiteralByteString} backed by the given array, without
-   * copying.
-   *
-   * @param bytes array to wrap
-   */
-  LiteralByteString(byte[] bytes) {
-    this.bytes = bytes;
-  }
-
-  @Override
-  public byte byteAt(int index) {
-    // Unlike most methods in this class, this one is a direct implementation
-    // ignoring the potential offset because we need to do range-checking in the
-    // substring case anyway.
-    return bytes[index];
-  }
-
-  @Override
-  public int size() {
-    return bytes.length;
-  }
-
-  // =================================================================
-  // ByteString -> substring
-
-  @Override
-  public ByteString substring(int beginIndex, int endIndex) {
-    if (beginIndex < 0) {
-      throw new IndexOutOfBoundsException(
-          "Beginning index: " + beginIndex + " < 0");
-    }
-    if (endIndex > size()) {
-      throw new IndexOutOfBoundsException("End index: " + endIndex + " > " +
-          size());
-    }
-    int substringLength = endIndex - beginIndex;
-    if (substringLength < 0) {
-      throw new IndexOutOfBoundsException(
-          "Beginning index larger than ending index: " + beginIndex + ", "
-              + endIndex);
-    }
-
-    ByteString result;
-    if (substringLength == 0) {
-      result = ByteString.EMPTY;
-    } else {
-      result = new BoundedByteString(bytes, getOffsetIntoBytes() + beginIndex,
-          substringLength);
-    }
-    return result;
-  }
-
-  // =================================================================
-  // ByteString -> byte[]
-
-  @Override
-  protected void copyToInternal(byte[] target, int sourceOffset,
-      int targetOffset, int numberToCopy) {
-    // Optimized form, not for subclasses, since we don't call
-    // getOffsetIntoBytes() or check the 'numberToCopy' parameter.
-    System.arraycopy(bytes, sourceOffset, target, targetOffset, numberToCopy);
-  }
-
-  @Override
-  public void copyTo(ByteBuffer target) {
-    target.put(bytes, getOffsetIntoBytes(), size());  // Copies bytes
-  }
-
-  @Override
-  public ByteBuffer asReadOnlyByteBuffer() {
-    ByteBuffer byteBuffer =
-        ByteBuffer.wrap(bytes, getOffsetIntoBytes(), size());
-    return byteBuffer.asReadOnlyBuffer();
-  }
-
-  @Override
-  public List<ByteBuffer> asReadOnlyByteBufferList() {
-    // Return the ByteBuffer generated by asReadOnlyByteBuffer() as a singleton
-    List<ByteBuffer> result = new ArrayList<ByteBuffer>(1);
-    result.add(asReadOnlyByteBuffer());
-    return result;
- }
-
- @Override
-  public void writeTo(OutputStream outputStream) throws IOException {
-    outputStream.write(toByteArray());
-  }
-
-  @Override
-  void writeToInternal(OutputStream outputStream, int sourceOffset,
-      int numberToWrite) throws IOException {
-    outputStream.write(bytes, getOffsetIntoBytes() + sourceOffset,
-        numberToWrite);
-  }
-
-  @Override
-  protected String toStringInternal(Charset charset) {
-    return new String(bytes, getOffsetIntoBytes(), size(), charset);
-  }
-
-  // =================================================================
-  // UTF-8 decoding
-
-  @Override
-  public boolean isValidUtf8() {
-    int offset = getOffsetIntoBytes();
-    return Utf8.isValidUtf8(bytes, offset, offset + size());
-  }
-
-  @Override
-  protected int partialIsValidUtf8(int state, int offset, int length) {
-    int index = getOffsetIntoBytes() + offset;
-    return Utf8.partialIsValidUtf8(state, bytes, index, index + length);
-  }
-
-  // =================================================================
-  // equals() and hashCode()
-
-  @Override
-  public boolean equals(Object other) {
-    if (other == this) {
-      return true;
-    }
-    if (!(other instanceof ByteString)) {
-      return false;
-    }
-
-    if (size() != ((ByteString) other).size()) {
-      return false;
-    }
-    if (size() == 0) {
-      return true;
-    }
-
-    if (other instanceof LiteralByteString) {
-      LiteralByteString otherAsLiteral = (LiteralByteString) other;
-      // If we know the hash codes and they are not equal, we know the byte
-      // strings are not equal.
-      if (hash != 0
-          && otherAsLiteral.hash != 0
-          && hash != otherAsLiteral.hash) {
-        return false;
-      }
-
-      return equalsRange((LiteralByteString) other, 0, size());
-    } else if (other instanceof RopeByteString) {
-      return other.equals(this);
-    } else {
-      throw new IllegalArgumentException(
-          "Has a new type of ByteString been created? Found "
-              + other.getClass());
-    }
-  }
-
-  /**
-   * Check equality of the substring of given length of this object starting at
-   * zero with another {@code LiteralByteString} substring starting at offset.
-   *
-   * @param other  what to compare a substring in
-   * @param offset offset into other
-   * @param length number of bytes to compare
-   * @return true for equality of substrings, else false.
-   */
-  boolean equalsRange(LiteralByteString other, int offset, int length) {
-    if (length > other.size()) {
-      throw new IllegalArgumentException(
-          "Length too large: " + length + size());
-    }
-    if (offset + length > other.size()) {
-      throw new IllegalArgumentException(
-          "Ran off end of other: " + offset + ", " + length + ", " +
-              other.size());
-    }
-
-    byte[] thisBytes = bytes;
-    byte[] otherBytes = other.bytes;
-    int thisLimit = getOffsetIntoBytes() + length;
-    for (int thisIndex = getOffsetIntoBytes(), otherIndex =
-        other.getOffsetIntoBytes() + offset;
-        (thisIndex < thisLimit); ++thisIndex, ++otherIndex) {
-      if (thisBytes[thisIndex] != otherBytes[otherIndex]) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  /**
-   * Cached hash value.  Intentionally accessed via a data race, which
-   * is safe because of the Java Memory Model's "no out-of-thin-air values"
-   * guarantees for ints.
-   */
-  private int hash = 0;
-
-  /**
-   * Compute the hashCode using the traditional algorithm from {@link
-   * ByteString}.
-   *
-   * @return hashCode value
-   */
-  @Override
-  public int hashCode() {
-    int h = hash;
-
-    if (h == 0) {
-      int size = size();
-      h = partialHash(size, 0, size);
-      if (h == 0) {
-        h = 1;
-      }
-      hash = h;
-    }
-    return h;
-  }
-
-  @Override
-  protected int peekCachedHashCode() {
-    return hash;
-  }
-
-  @Override
-  protected int partialHash(int h, int offset, int length) {
-    return hashCode(h, bytes, getOffsetIntoBytes() + offset, length);
-  }
-
-  static int hashCode(int h, byte[] bytes, int offset, int length) {
-    for (int i = offset; i < offset + length; i++) {
-      h = h * 31 + bytes[i];
-    }
-    return h;
-  }
-
-  static int hashCode(byte[] bytes) {
-    int h = hashCode(bytes.length, bytes, 0, bytes.length);
-    return h == 0 ? 1 : h;
-  }
-
-  // =================================================================
-  // Input stream
-
-  @Override
-  public InputStream newInput() {
-    return new ByteArrayInputStream(bytes, getOffsetIntoBytes(),
-        size());  // No copy
-  }
-
-  @Override
-  public CodedInputStream newCodedInput() {
-    // We trust CodedInputStream not to modify the bytes, or to give anyone
-    // else access to them.
-    return CodedInputStream.newInstance(this);
-  }
-
-  // =================================================================
-  // ByteIterator
-
-  @Override
-  public ByteIterator iterator() {
-    return new LiteralByteIterator();
-  }
-
-  private class LiteralByteIterator implements ByteIterator {
-    private int position;
-    private final int limit;
-
-    private LiteralByteIterator() {
-      position = 0;
-      limit = size();
-    }
-
-    public boolean hasNext() {
-      return (position < limit);
-    }
-
-    public Byte next() {
-      // Boxing calls Byte.valueOf(byte), which does not instantiate.
-      return nextByte();
-    }
-
-    public byte nextByte() {
-      try {
-        return bytes[position++];
-      } catch (ArrayIndexOutOfBoundsException e) {
-        throw new NoSuchElementException(e.getMessage());
-      }
-    }
-
-    public void remove() {
-      throw new UnsupportedOperationException();
-    }
-  }
-
-  // =================================================================
-  // Internal methods
-
-  @Override
-  protected int getTreeDepth() {
-    return 0;
-  }
-
-  @Override
-  protected boolean isBalanced() {
-    return true;
-  }
-
-  /**
-   * Offset into {@code bytes[]} to use, non-zero for substrings.
-   *
-   * @return always 0 for this class
-   */
-  protected int getOffsetIntoBytes() {
-    return 0;
-  }
-}
diff --git a/java/src/main/java/com/google/protobuf/Utf8.java b/java/src/main/java/com/google/protobuf/Utf8.java
deleted file mode 100644
index 48c7e9e6..00000000
--- a/java/src/main/java/com/google/protobuf/Utf8.java
+++ /dev/null
@@ -1,481 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-/**
- * A set of low-level, high-performance static utility methods related
- * to the UTF-8 character encoding.  This class has no dependencies
- * outside of the core JDK libraries.
- *
- * <p>There are several variants of UTF-8.  The one implemented by
- * this class is the restricted definition of UTF-8 introduced in
- * Unicode 3.1, which mandates the rejection of "overlong" byte
- * sequences as well as rejection of 3-byte surrogate codepoint byte
- * sequences.  Note that the UTF-8 decoder included in Oracle's JDK
- * has been modified to also reject "overlong" byte sequences, but (as
- * of 2011) still accepts 3-byte surrogate codepoint byte sequences.
- *
- * <p>The byte sequences considered valid by this class are exactly
- * those that can be roundtrip converted to Strings and back to bytes
- * using the UTF-8 charset, without loss: <pre> {@code
- * Arrays.equals(bytes, new String(bytes, Internal.UTF_8).getBytes(Internal.UTF_8))
- * }</pre>
- *
- * <p>See the Unicode Standard,</br>
- * Table 3-6. <em>UTF-8 Bit Distribution</em>,</br>
- * Table 3-7. <em>Well Formed UTF-8 Byte Sequences</em>.
- *
- * <p>This class supports decoding of partial byte sequences, so that the
- * bytes in a complete UTF-8 byte sequences can be stored in multiple
- * segments.  Methods typically return {@link #MALFORMED} if the partial
- * byte sequence is definitely not well-formed, {@link #COMPLETE} if it is
- * well-formed in the absence of additional input, or if the byte sequence
- * apparently terminated in the middle of a character, an opaque integer
- * "state" value containing enough information to decode the character when
- * passed to a subsequent invocation of a partial decoding method.
- *
- * @author martinrb@google.com (Martin Buchholz)
- */
-final class Utf8 {
-  private Utf8() {}
-  
-  /**
-   * Maximum number of bytes per Java UTF-16 char in UTF-8.
-   * @see java.nio.charset.CharsetEncoder#maxBytesPerChar()
-   */
-  static final int MAX_BYTES_PER_CHAR = 3;
-
-  /**
-   * State value indicating that the byte sequence is well-formed and
-   * complete (no further bytes are needed to complete a character).
-   */
-  public static final int COMPLETE = 0;
-
-  /**
-   * State value indicating that the byte sequence is definitely not
-   * well-formed.
-   */
-  public static final int MALFORMED = -1;
-
-  // Other state values include the partial bytes of the incomplete
-  // character to be decoded in the simplest way: we pack the bytes
-  // into the state int in little-endian order.  For example:
-  //
-  // int state = byte1 ^ (byte2 << 8) ^ (byte3 << 16);
-  //
-  // Such a state is unpacked thus (note the ~ operation for byte2 to
-  // undo byte1's sign-extension bits):
-  //
-  // int byte1 = (byte) state;
-  // int byte2 = (byte) ~(state >> 8);
-  // int byte3 = (byte) (state >> 16);
-  //
-  // We cannot store a zero byte in the state because it would be
-  // indistinguishable from the absence of a byte.  But we don't need
-  // to, because partial bytes must always be negative.  When building
-  // a state, we ensure that byte1 is negative and subsequent bytes
-  // are valid trailing bytes.
-
-  /**
-   * Returns {@code true} if the given byte array is a well-formed
-   * UTF-8 byte sequence.
-   *
-   * <p>This is a convenience method, equivalent to a call to {@code
-   * isValidUtf8(bytes, 0, bytes.length)}.
-   */
-  public static boolean isValidUtf8(byte[] bytes) {
-    return isValidUtf8(bytes, 0, bytes.length);
-  }
-
-  /**
-   * Returns {@code true} if the given byte array slice is a
-   * well-formed UTF-8 byte sequence.  The range of bytes to be
-   * checked extends from index {@code index}, inclusive, to {@code
-   * limit}, exclusive.
-   *
-   * <p>This is a convenience method, equivalent to {@code
-   * partialIsValidUtf8(bytes, index, limit) == Utf8.COMPLETE}.
-   */
-  public static boolean isValidUtf8(byte[] bytes, int index, int limit) {
-    return partialIsValidUtf8(bytes, index, limit) == COMPLETE;
-  }
-
-  /**
-   * Tells whether the given byte array slice is a well-formed,
-   * malformed, or incomplete UTF-8 byte sequence.  The range of bytes
-   * to be checked extends from index {@code index}, inclusive, to
-   * {@code limit}, exclusive.
-   *
-   * @param state either {@link Utf8#COMPLETE} (if this is the initial decoding
-   * operation) or the value returned from a call to a partial decoding method
-   * for the previous bytes
-   *
-   * @return {@link #MALFORMED} if the partial byte sequence is
-   * definitely not well-formed, {@link #COMPLETE} if it is well-formed
-   * (no additional input needed), or if the byte sequence is
-   * "incomplete", i.e. apparently terminated in the middle of a character,
-   * an opaque integer "state" value containing enough information to
-   * decode the character when passed to a subsequent invocation of a
-   * partial decoding method.
-   */
-  public static int partialIsValidUtf8(
-      int state, byte[] bytes, int index, int limit) {
-    if (state != COMPLETE) {
-      // The previous decoding operation was incomplete (or malformed).
-      // We look for a well-formed sequence consisting of bytes from
-      // the previous decoding operation (stored in state) together
-      // with bytes from the array slice.
-      //
-      // We expect such "straddler characters" to be rare.
-
-      if (index >= limit) {  // No bytes? No progress.
-        return state;
-      }
-      int byte1 = (byte) state;
-      // byte1 is never ASCII.
-      if (byte1 < (byte) 0xE0) {
-        // two-byte form
-
-        // Simultaneously checks for illegal trailing-byte in
-        // leading position and overlong 2-byte form.
-        if (byte1 < (byte) 0xC2 ||
-            // byte2 trailing-byte test
-            bytes[index++] > (byte) 0xBF) {
-          return MALFORMED;
-        }
-      } else if (byte1 < (byte) 0xF0) {
-        // three-byte form
-
-        // Get byte2 from saved state or array
-        int byte2 = (byte) ~(state >> 8);
-        if (byte2 == 0) {
-          byte2 = bytes[index++];
-          if (index >= limit) {
-            return incompleteStateFor(byte1, byte2);
-          }
-        }
-        if (byte2 > (byte) 0xBF ||
-            // overlong? 5 most significant bits must not all be zero
-            (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0) ||
-            // illegal surrogate codepoint?
-            (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0) ||
-            // byte3 trailing-byte test
-            bytes[index++] > (byte) 0xBF) {
-          return MALFORMED;
-        }
-      } else {
-        // four-byte form
-
-        // Get byte2 and byte3 from saved state or array
-        int byte2 = (byte) ~(state >> 8);
-        int byte3 = 0;
-        if (byte2 == 0) {
-          byte2 = bytes[index++];
-          if (index >= limit) {
-            return incompleteStateFor(byte1, byte2);
-          }
-        } else {
-          byte3 = (byte) (state >> 16);
-        }
-        if (byte3 == 0) {
-          byte3 = bytes[index++];
-          if (index >= limit) {
-            return incompleteStateFor(byte1, byte2, byte3);
-          }
-        }
-
-        // If we were called with state == MALFORMED, then byte1 is 0xFF,
-        // which never occurs in well-formed UTF-8, and so we will return
-        // MALFORMED again below.
-
-        if (byte2 > (byte) 0xBF ||
-            // Check that 1 <= plane <= 16.  Tricky optimized form of:
-            // if (byte1 > (byte) 0xF4 ||
-            //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
-            //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
-            (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0 ||
-            // byte3 trailing-byte test
-            byte3 > (byte) 0xBF ||
-            // byte4 trailing-byte test
-             bytes[index++] > (byte) 0xBF) {
-          return MALFORMED;
-        }
-      }
-    }
-
-    return partialIsValidUtf8(bytes, index, limit);
-  }
-
-  /**
-   * Tells whether the given byte array slice is a well-formed,
-   * malformed, or incomplete UTF-8 byte sequence.  The range of bytes
-   * to be checked extends from index {@code index}, inclusive, to
-   * {@code limit}, exclusive.
-   *
-   * <p>This is a convenience method, equivalent to a call to {@code
-   * partialIsValidUtf8(Utf8.COMPLETE, bytes, index, limit)}.
-   *
-   * @return {@link #MALFORMED} if the partial byte sequence is
-   * definitely not well-formed, {@link #COMPLETE} if it is well-formed
-   * (no additional input needed), or if the byte sequence is
-   * "incomplete", i.e. apparently terminated in the middle of a character,
-   * an opaque integer "state" value containing enough information to
-   * decode the character when passed to a subsequent invocation of a
-   * partial decoding method.
-   */
-  public static int partialIsValidUtf8(
-      byte[] bytes, int index, int limit) {
-    // Optimize for 100% ASCII.
-    // Hotspot loves small simple top-level loops like this.
-    while (index < limit && bytes[index] >= 0) {
-      index++;
-    }
-
-    return (index >= limit) ? COMPLETE :
-        partialIsValidUtf8NonAscii(bytes, index, limit);
-  }
-
-  private static int partialIsValidUtf8NonAscii(
-      byte[] bytes, int index, int limit) {
-    for (;;) {
-      int byte1, byte2;
-
-      // Optimize for interior runs of ASCII bytes.
-      do {
-        if (index >= limit) {
-          return COMPLETE;
-        }
-      } while ((byte1 = bytes[index++]) >= 0);
-
-      if (byte1 < (byte) 0xE0) {
-        // two-byte form
-
-        if (index >= limit) {
-          return byte1;
-        }
-
-        // Simultaneously checks for illegal trailing-byte in
-        // leading position and overlong 2-byte form.
-        if (byte1 < (byte) 0xC2 ||
-            bytes[index++] > (byte) 0xBF) {
-          return MALFORMED;
-        }
-      } else if (byte1 < (byte) 0xF0) {
-        // three-byte form
-
-        if (index >= limit - 1) { // incomplete sequence
-          return incompleteStateFor(bytes, index, limit);
-        }
-        if ((byte2 = bytes[index++]) > (byte) 0xBF ||
-            // overlong? 5 most significant bits must not all be zero
-            (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0) ||
-            // check for illegal surrogate codepoints
-            (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0) ||
-            // byte3 trailing-byte test
-            bytes[index++] > (byte) 0xBF) {
-          return MALFORMED;
-        }
-      } else {
-        // four-byte form
-
-        if (index >= limit - 2) {  // incomplete sequence
-          return incompleteStateFor(bytes, index, limit);
-        }
-        if ((byte2 = bytes[index++]) > (byte) 0xBF ||
-            // Check that 1 <= plane <= 16.  Tricky optimized form of:
-            // if (byte1 > (byte) 0xF4 ||
-            //     byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
-            //     byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
-            (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0 ||
-            // byte3 trailing-byte test
-            bytes[index++] > (byte) 0xBF ||
-            // byte4 trailing-byte test
-            bytes[index++] > (byte) 0xBF) {
-          return MALFORMED;
-        }
-      }
-    }
-  }
-
-  private static int incompleteStateFor(int byte1) {
-    return (byte1 > (byte) 0xF4) ?
-        MALFORMED : byte1;
-  }
-
-  private static int incompleteStateFor(int byte1, int byte2) {
-    return (byte1 > (byte) 0xF4 ||
-            byte2 > (byte) 0xBF) ?
-        MALFORMED : byte1 ^ (byte2 << 8);
-  }
-
-  private static int incompleteStateFor(int byte1, int byte2, int byte3) {
-    return (byte1 > (byte) 0xF4 ||
-            byte2 > (byte) 0xBF ||
-            byte3 > (byte) 0xBF) ?
-        MALFORMED : byte1 ^ (byte2 << 8) ^ (byte3 << 16);
-  }
-
-  private static int incompleteStateFor(byte[] bytes, int index, int limit) {
-    int byte1 = bytes[index - 1];
-    switch (limit - index) {
-      case 0: return incompleteStateFor(byte1);
-      case 1: return incompleteStateFor(byte1, bytes[index]);
-      case 2: return incompleteStateFor(byte1, bytes[index], bytes[index + 1]);
-      default: throw new AssertionError();
-    }
-  }
-  
-
-  // These UTF-8 handling methods are copied from Guava's Utf8 class with a modification to throw
-  // a protocol buffer local exception. This exception is then caught in CodedOutputStream so it can
-  // fallback to more lenient behavior.
-  
-  static class UnpairedSurrogateException extends IllegalArgumentException {
-    
-    private UnpairedSurrogateException(int index, int length) {
-      super("Unpaired surrogate at index " + index + " of " + length);
-    }
-  }
-  
-  /**
-   * Returns the number of bytes in the UTF-8-encoded form of {@code sequence}. For a string,
-   * this method is equivalent to {@code string.getBytes(UTF_8).length}, but is more efficient in
-   * both time and space.
-   *
-   * @throws IllegalArgumentException if {@code sequence} contains ill-formed UTF-16 (unpaired
-   *     surrogates)
-   */
-  static int encodedLength(CharSequence sequence) {
-    // Warning to maintainers: this implementation is highly optimized.
-    int utf16Length = sequence.length();
-    int utf8Length = utf16Length;
-    int i = 0;
-
-    // This loop optimizes for pure ASCII.
-    while (i < utf16Length && sequence.charAt(i) < 0x80) {
-      i++;
-    }
-
-    // This loop optimizes for chars less than 0x800.
-    for (; i < utf16Length; i++) {
-      char c = sequence.charAt(i);
-      if (c < 0x800) {
-        utf8Length += ((0x7f - c) >>> 31);  // branch free!
-      } else {
-        utf8Length += encodedLengthGeneral(sequence, i);
-        break;
-      }
-    }
-
-    if (utf8Length < utf16Length) {
-      // Necessary and sufficient condition for overflow because of maximum 3x expansion
-      throw new IllegalArgumentException("UTF-8 length does not fit in int: "
-              + (utf8Length + (1L << 32)));
-    }
-    return utf8Length;
-  }
-
-  private static int encodedLengthGeneral(CharSequence sequence, int start) {
-    int utf16Length = sequence.length();
-    int utf8Length = 0;
-    for (int i = start; i < utf16Length; i++) {
-      char c = sequence.charAt(i);
-      if (c < 0x800) {
-        utf8Length += (0x7f - c) >>> 31; // branch free!
-      } else {
-        utf8Length += 2;
-        // jdk7+: if (Character.isSurrogate(c)) {
-        if (Character.MIN_SURROGATE <= c && c <= Character.MAX_SURROGATE) {
-          // Check that we have a well-formed surrogate pair.
-          int cp = Character.codePointAt(sequence, i);
-          if (cp < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
-            throw new UnpairedSurrogateException(i, utf16Length);
-          }
-          i++;
-        }
-      }
-    }
-    return utf8Length;
-  }
-
-  static int encode(CharSequence sequence, byte[] bytes, int offset, int length) {
-    int utf16Length = sequence.length();
-    int j = offset;
-    int i = 0;
-    int limit = offset + length;
-    // Designed to take advantage of
-    // https://wikis.oracle.com/display/HotSpotInternals/RangeCheckElimination
-    for (char c; i < utf16Length && i + j < limit && (c = sequence.charAt(i)) < 0x80; i++) {
-      bytes[j + i] = (byte) c;
-    }
-    if (i == utf16Length) {
-      return j + utf16Length;
-    }
-    j += i;
-    for (char c; i < utf16Length; i++) {
-      c = sequence.charAt(i);
-      if (c < 0x80 && j < limit) {
-        bytes[j++] = (byte) c;
-      } else if (c < 0x800 && j <= limit - 2) { // 11 bits, two UTF-8 bytes
-        bytes[j++] = (byte) ((0xF << 6) | (c >>> 6));
-        bytes[j++] = (byte) (0x80 | (0x3F & c));
-      } else if ((c < Character.MIN_SURROGATE || Character.MAX_SURROGATE < c) && j <= limit - 3) {
-        // Maximum single-char code point is 0xFFFF, 16 bits, three UTF-8 bytes
-        bytes[j++] = (byte) ((0xF << 5) | (c >>> 12));
-        bytes[j++] = (byte) (0x80 | (0x3F & (c >>> 6)));
-        bytes[j++] = (byte) (0x80 | (0x3F & c));
-      } else if (j <= limit - 4) {
-        // Minimum code point represented by a surrogate pair is 0x10000, 17 bits, four UTF-8 bytes
-        final char low;
-        if (i + 1 == sequence.length()
-                || !Character.isSurrogatePair(c, (low = sequence.charAt(++i)))) {
-          throw new UnpairedSurrogateException((i - 1), utf16Length);
-        }
-        int codePoint = Character.toCodePoint(c, low);
-        bytes[j++] = (byte) ((0xF << 4) | (codePoint >>> 18));
-        bytes[j++] = (byte) (0x80 | (0x3F & (codePoint >>> 12)));
-        bytes[j++] = (byte) (0x80 | (0x3F & (codePoint >>> 6)));
-        bytes[j++] = (byte) (0x80 | (0x3F & codePoint));
-      } else {
-        // If we are surrogates and we're not a surrogate pair, always throw an
-        // IllegalArgumentException instead of an ArrayOutOfBoundsException.
-        if ((Character.MIN_SURROGATE <= c && c <= Character.MAX_SURROGATE)
-            && (i + 1 == sequence.length()
-                || !Character.isSurrogatePair(c, sequence.charAt(i + 1)))) {
-          throw new UnpairedSurrogateException(i, utf16Length);
-        }
-        throw new ArrayIndexOutOfBoundsException("Failed writing " + c + " at index " + j);
-      }
-    }
-    return j;
-  }
-  // End Guava UTF-8 methods.
-}
diff --git a/java/src/test/java/com/google/protobuf/CodedOutputStreamTest.java b/java/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
deleted file mode 100644
index 360e759e..00000000
--- a/java/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
+++ /dev/null
@@ -1,509 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-import protobuf_unittest.UnittestProto.SparseEnumMessage;
-import protobuf_unittest.UnittestProto.TestAllTypes;
-import protobuf_unittest.UnittestProto.TestPackedTypes;
-import protobuf_unittest.UnittestProto.TestSparseEnum;
-
-import junit.framework.TestCase;
-
-import java.io.ByteArrayOutputStream;
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * Unit test for {@link CodedOutputStream}.
- *
- * @author kenton@google.com Kenton Varda
- */
-public class CodedOutputStreamTest extends TestCase {
-  /**
-   * Helper to construct a byte array from a bunch of bytes.  The inputs are
-   * actually ints so that I can use hex notation and not get stupid errors
-   * about precision.
-   */
-  private byte[] bytes(int... bytesAsInts) {
-    byte[] bytes = new byte[bytesAsInts.length];
-    for (int i = 0; i < bytesAsInts.length; i++) {
-      bytes[i] = (byte) bytesAsInts[i];
-    }
-    return bytes;
-  }
-
-  /** Arrays.asList() does not work with arrays of primitives.  :( */
-  private List<Byte> toList(byte[] bytes) {
-    List<Byte> result = new ArrayList<Byte>();
-    for (byte b : bytes) {
-      result.add(b);
-    }
-    return result;
-  }
-
-  private void assertEqualBytes(byte[] a, byte[] b) {
-    assertEquals(toList(a), toList(b));
-  }
-
-  /**
-   * Writes the given value using writeRawVarint32() and writeRawVarint64() and
-   * checks that the result matches the given bytes.
-   */
-  private void assertWriteVarint(byte[] data, long value) throws Exception {
-    // Only do 32-bit write if the value fits in 32 bits.
-    if ((value >>> 32) == 0) {
-      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-      CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
-      output.writeRawVarint32((int) value);
-      output.flush();
-      assertEqualBytes(data, rawOutput.toByteArray());
-
-      // Also try computing size.
-      assertEquals(data.length,
-                   CodedOutputStream.computeRawVarint32Size((int) value));
-    }
-
-    {
-      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-      CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
-      output.writeRawVarint64(value);
-      output.flush();
-      assertEqualBytes(data, rawOutput.toByteArray());
-
-      // Also try computing size.
-      assertEquals(data.length,
-                   CodedOutputStream.computeRawVarint64Size(value));
-    }
-
-    // Try different block sizes.
-    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
-      // Only do 32-bit write if the value fits in 32 bits.
-      if ((value >>> 32) == 0) {
-        ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-        CodedOutputStream output =
-          CodedOutputStream.newInstance(rawOutput, blockSize);
-        output.writeRawVarint32((int) value);
-        output.flush();
-        assertEqualBytes(data, rawOutput.toByteArray());
-      }
-
-      {
-        ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-        CodedOutputStream output =
-          CodedOutputStream.newInstance(rawOutput, blockSize);
-        output.writeRawVarint64(value);
-        output.flush();
-        assertEqualBytes(data, rawOutput.toByteArray());
-      }
-    }
-  }
-
-  /** Tests writeRawVarint32() and writeRawVarint64(). */
-  public void testWriteVarint() throws Exception {
-    assertWriteVarint(bytes(0x00), 0);
-    assertWriteVarint(bytes(0x01), 1);
-    assertWriteVarint(bytes(0x7f), 127);
-    // 14882
-    assertWriteVarint(bytes(0xa2, 0x74), (0x22 << 0) | (0x74 << 7));
-    // 2961488830
-    assertWriteVarint(bytes(0xbe, 0xf7, 0x92, 0x84, 0x0b),
-      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
-      (0x0bL << 28));
-
-    // 64-bit
-    // 7256456126
-    assertWriteVarint(bytes(0xbe, 0xf7, 0x92, 0x84, 0x1b),
-      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
-      (0x1bL << 28));
-    // 41256202580718336
-    assertWriteVarint(
-      bytes(0x80, 0xe6, 0xeb, 0x9c, 0xc3, 0xc9, 0xa4, 0x49),
-      (0x00 << 0) | (0x66 << 7) | (0x6b << 14) | (0x1c << 21) |
-      (0x43L << 28) | (0x49L << 35) | (0x24L << 42) | (0x49L << 49));
-    // 11964378330978735131
-    assertWriteVarint(
-      bytes(0x9b, 0xa8, 0xf9, 0xc2, 0xbb, 0xd6, 0x80, 0x85, 0xa6, 0x01),
-      (0x1b << 0) | (0x28 << 7) | (0x79 << 14) | (0x42 << 21) |
-      (0x3bL << 28) | (0x56L << 35) | (0x00L << 42) |
-      (0x05L << 49) | (0x26L << 56) | (0x01L << 63));
-  }
-
-  /**
-   * Parses the given bytes using writeRawLittleEndian32() and checks
-   * that the result matches the given value.
-   */
-  private void assertWriteLittleEndian32(byte[] data, int value)
-                                         throws Exception {
-    ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
-    output.writeRawLittleEndian32(value);
-    output.flush();
-    assertEqualBytes(data, rawOutput.toByteArray());
-
-    // Try different block sizes.
-    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
-      rawOutput = new ByteArrayOutputStream();
-      output = CodedOutputStream.newInstance(rawOutput, blockSize);
-      output.writeRawLittleEndian32(value);
-      output.flush();
-      assertEqualBytes(data, rawOutput.toByteArray());
-    }
-  }
-
-  /**
-   * Parses the given bytes using writeRawLittleEndian64() and checks
-   * that the result matches the given value.
-   */
-  private void assertWriteLittleEndian64(byte[] data, long value)
-                                         throws Exception {
-    ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
-    output.writeRawLittleEndian64(value);
-    output.flush();
-    assertEqualBytes(data, rawOutput.toByteArray());
-
-    // Try different block sizes.
-    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
-      rawOutput = new ByteArrayOutputStream();
-      output = CodedOutputStream.newInstance(rawOutput, blockSize);
-      output.writeRawLittleEndian64(value);
-      output.flush();
-      assertEqualBytes(data, rawOutput.toByteArray());
-    }
-  }
-
-  /** Tests writeRawLittleEndian32() and writeRawLittleEndian64(). */
-  public void testWriteLittleEndian() throws Exception {
-    assertWriteLittleEndian32(bytes(0x78, 0x56, 0x34, 0x12), 0x12345678);
-    assertWriteLittleEndian32(bytes(0xf0, 0xde, 0xbc, 0x9a), 0x9abcdef0);
-
-    assertWriteLittleEndian64(
-      bytes(0xf0, 0xde, 0xbc, 0x9a, 0x78, 0x56, 0x34, 0x12),
-      0x123456789abcdef0L);
-    assertWriteLittleEndian64(
-      bytes(0x78, 0x56, 0x34, 0x12, 0xf0, 0xde, 0xbc, 0x9a),
-      0x9abcdef012345678L);
-  }
-
-  /** Test encodeZigZag32() and encodeZigZag64(). */
-  public void testEncodeZigZag() throws Exception {
-    assertEquals(0, CodedOutputStream.encodeZigZag32( 0));
-    assertEquals(1, CodedOutputStream.encodeZigZag32(-1));
-    assertEquals(2, CodedOutputStream.encodeZigZag32( 1));
-    assertEquals(3, CodedOutputStream.encodeZigZag32(-2));
-    assertEquals(0x7FFFFFFE, CodedOutputStream.encodeZigZag32(0x3FFFFFFF));
-    assertEquals(0x7FFFFFFF, CodedOutputStream.encodeZigZag32(0xC0000000));
-    assertEquals(0xFFFFFFFE, CodedOutputStream.encodeZigZag32(0x7FFFFFFF));
-    assertEquals(0xFFFFFFFF, CodedOutputStream.encodeZigZag32(0x80000000));
-
-    assertEquals(0, CodedOutputStream.encodeZigZag64( 0));
-    assertEquals(1, CodedOutputStream.encodeZigZag64(-1));
-    assertEquals(2, CodedOutputStream.encodeZigZag64( 1));
-    assertEquals(3, CodedOutputStream.encodeZigZag64(-2));
-    assertEquals(0x000000007FFFFFFEL,
-                 CodedOutputStream.encodeZigZag64(0x000000003FFFFFFFL));
-    assertEquals(0x000000007FFFFFFFL,
-                 CodedOutputStream.encodeZigZag64(0xFFFFFFFFC0000000L));
-    assertEquals(0x00000000FFFFFFFEL,
-                 CodedOutputStream.encodeZigZag64(0x000000007FFFFFFFL));
-    assertEquals(0x00000000FFFFFFFFL,
-                 CodedOutputStream.encodeZigZag64(0xFFFFFFFF80000000L));
-    assertEquals(0xFFFFFFFFFFFFFFFEL,
-                 CodedOutputStream.encodeZigZag64(0x7FFFFFFFFFFFFFFFL));
-    assertEquals(0xFFFFFFFFFFFFFFFFL,
-                 CodedOutputStream.encodeZigZag64(0x8000000000000000L));
-
-    // Some easier-to-verify round-trip tests.  The inputs (other than 0, 1, -1)
-    // were chosen semi-randomly via keyboard bashing.
-    assertEquals(0,
-      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(0)));
-    assertEquals(1,
-      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(1)));
-    assertEquals(-1,
-      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(-1)));
-    assertEquals(14927,
-      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(14927)));
-    assertEquals(-3612,
-      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(-3612)));
-
-    assertEquals(0,
-      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(0)));
-    assertEquals(1,
-      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(1)));
-    assertEquals(-1,
-      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-1)));
-    assertEquals(14927,
-      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(14927)));
-    assertEquals(-3612,
-      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-3612)));
-
-    assertEquals(856912304801416L,
-      CodedOutputStream.encodeZigZag64(
-        CodedInputStream.decodeZigZag64(
-          856912304801416L)));
-    assertEquals(-75123905439571256L,
-      CodedOutputStream.encodeZigZag64(
-        CodedInputStream.decodeZigZag64(
-          -75123905439571256L)));
-  }
-
-  /** Tests writing a whole message with every field type. */
-  public void testWriteWholeMessage() throws Exception {
-    TestAllTypes message = TestUtil.getAllSet();
-
-    byte[] rawBytes = message.toByteArray();
-    assertEqualBytes(TestUtil.getGoldenMessage().toByteArray(), rawBytes);
-
-    // Try different block sizes.
-    for (int blockSize = 1; blockSize < 256; blockSize *= 2) {
-      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
-      CodedOutputStream output =
-        CodedOutputStream.newInstance(rawOutput, blockSize);
-      message.writeTo(output);
-      output.flush();
-      assertEqualBytes(rawBytes, rawOutput.toByteArray());
-    }
-  }
-
-  /** Tests writing a whole message with every packed field type. Ensures the
-   * wire format of packed fields is compatible with C++. */
-  public void testWriteWholePackedFieldsMessage() throws Exception {
-    TestPackedTypes message = TestUtil.getPackedSet();
-
-    byte[] rawBytes = message.toByteArray();
-    assertEqualBytes(TestUtil.getGoldenPackedFieldsMessage().toByteArray(),
-                     rawBytes);
-  }
-
-  /** Test writing a message containing a negative enum value. This used to
-   * fail because the size was not properly computed as a sign-extended varint.
-   */
-  public void testWriteMessageWithNegativeEnumValue() throws Exception {
-    SparseEnumMessage message = SparseEnumMessage.newBuilder()
-        .setSparseEnum(TestSparseEnum.SPARSE_E) .build();
-    assertTrue(message.getSparseEnum().getNumber() < 0);
-    byte[] rawBytes = message.toByteArray();
-    SparseEnumMessage message2 = SparseEnumMessage.parseFrom(rawBytes);
-    assertEquals(TestSparseEnum.SPARSE_E, message2.getSparseEnum());
-  }
-
-  /** Test getTotalBytesWritten() */
-  public void testGetTotalBytesWritten() throws Exception {
-    final int BUFFER_SIZE = 4 * 1024;
-    ByteArrayOutputStream outputStream = new ByteArrayOutputStream(BUFFER_SIZE);
-    CodedOutputStream codedStream = CodedOutputStream.newInstance(outputStream);
-    byte[] value = "abcde".getBytes(Internal.UTF_8);
-    for (int i = 0; i < 1024; ++i) {
-      codedStream.writeRawBytes(value, 0, value.length);
-    }
-    String string =
-        "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
-    // Ensure we take the slower fast path.
-    assertTrue(CodedOutputStream.computeRawVarint32Size(string.length())
-        != CodedOutputStream.computeRawVarint32Size(string.length() * Utf8.MAX_BYTES_PER_CHAR));
-    
-    codedStream.writeStringNoTag(string);
-    int stringSize = CodedOutputStream.computeStringSizeNoTag(string);
-    
-    // Make sure we have written more bytes than the buffer could hold. This is
-    // to make the test complete.
-    assertTrue(codedStream.getTotalBytesWritten() > BUFFER_SIZE);
-    
-    // Verify that the total bytes written is correct
-    assertEquals((value.length * 1024) + stringSize, codedStream.getTotalBytesWritten());
-  }
-  
-  // TODO(dweis): Write a comprehensive test suite for CodedOutputStream that covers more than just
-  //    this case.
-  public void testWriteStringNoTag_fastpath() throws Exception {
-    int bufferSize = 153;
-    String threeBytesPer = "\u0981";
-    String string = threeBytesPer;
-    for (int i = 0; i < 50; i++) {
-      string += threeBytesPer;
-    }
-    // These checks ensure we will tickle the slower fast path.
-    assertEquals(1, CodedOutputStream.computeRawVarint32Size(string.length()));
-    assertEquals(
-        2, CodedOutputStream.computeRawVarint32Size(string.length() * Utf8.MAX_BYTES_PER_CHAR));
-    assertEquals(bufferSize, string.length() * Utf8.MAX_BYTES_PER_CHAR);
-    
-    CodedOutputStream output =
-        CodedOutputStream.newInstance(ByteBuffer.allocate(bufferSize), bufferSize);
-    output.writeStringNoTag(string);
-  }
-
-  public void testWriteToByteBuffer() throws Exception {
-    final int bufferSize = 16 * 1024;
-    ByteBuffer buffer = ByteBuffer.allocate(bufferSize);
-    CodedOutputStream codedStream = CodedOutputStream.newInstance(buffer);
-    // Write raw bytes into the ByteBuffer.
-    final int length1 = 5000;
-    for (int i = 0; i < length1; i++) {
-      codedStream.writeRawByte((byte) 1);
-    }
-    final int length2 = 8 * 1024;
-    byte[] data = new byte[length2];
-    for (int i = 0; i < length2; i++) {
-      data[i] = (byte) 2;
-    }
-    codedStream.writeRawBytes(data);
-    final int length3 = bufferSize - length1 - length2;
-    for (int i = 0; i < length3; i++) {
-      codedStream.writeRawByte((byte) 3);
-    }
-    codedStream.flush();
-
-    // Check that data is correctly written to the ByteBuffer.
-    assertEquals(0, buffer.remaining());
-    buffer.flip();
-    for (int i = 0; i < length1; i++) {
-      assertEquals((byte) 1, buffer.get());
-    }
-    for (int i = 0; i < length2; i++) {
-      assertEquals((byte) 2, buffer.get());
-    }
-    for (int i = 0; i < length3; i++) {
-      assertEquals((byte) 3, buffer.get());
-    }
-  }
-
-  public void testWriteByteBuffer() throws Exception {
-    byte[] value = "abcde".getBytes(Internal.UTF_8);
-    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-    CodedOutputStream codedStream = CodedOutputStream.newInstance(outputStream);
-    ByteBuffer byteBuffer = ByteBuffer.wrap(value, 0, 1);
-    // This will actually write 5 bytes into the CodedOutputStream as the
-    // ByteBuffer's capacity() is 5.
-    codedStream.writeRawBytes(byteBuffer);
-    // The above call shouldn't affect the ByteBuffer's state.
-    assertEquals(0, byteBuffer.position());
-    assertEquals(1, byteBuffer.limit());
-
-    // The correct way to write part of an array using ByteBuffer.
-    codedStream.writeRawBytes(ByteBuffer.wrap(value, 2, 1).slice());
-
-    codedStream.flush();
-    byte[] result = outputStream.toByteArray();
-    assertEquals(6, result.length);
-    for (int i = 0; i < 5; i++) {
-      assertEquals(value[i], result[i]);
-    }
-    assertEquals(value[2], result[5]);
-  }
-
-  public void testWriteByteArrayWithOffsets() throws Exception {
-    byte[] fullArray = bytes(0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88);
-    byte[] destination = new byte[4];
-    CodedOutputStream codedStream = CodedOutputStream.newInstance(destination);
-    codedStream.writeByteArrayNoTag(fullArray, 2, 2);
-    assertEqualBytes(bytes(0x02, 0x33, 0x44, 0x00), destination);
-    assertEquals(3, codedStream.getTotalBytesWritten());
-  }
-  
-  public void testSerializeInvalidUtf8() throws Exception {
-    String[] invalidStrings = new String[] {
-        newString(Character.MIN_HIGH_SURROGATE),
-        "foobar" + newString(Character.MIN_HIGH_SURROGATE),
-        newString(Character.MIN_LOW_SURROGATE),
-        "foobar" + newString(Character.MIN_LOW_SURROGATE),
-        newString(Character.MIN_HIGH_SURROGATE, Character.MIN_HIGH_SURROGATE)
-    };
-    
-    CodedOutputStream outputWithStream = CodedOutputStream.newInstance(new ByteArrayOutputStream());
-    CodedOutputStream outputWithArray = CodedOutputStream.newInstance(new byte[10000]);
-    for (String s : invalidStrings) {
-      // TODO(dweis): These should all fail; instead they are corrupting data.
-      CodedOutputStream.computeStringSizeNoTag(s);
-      outputWithStream.writeStringNoTag(s);
-      outputWithArray.writeStringNoTag(s);
-    }
-  }
-  
-  private static String newString(char... chars) {
-    return new String(chars);
-  }
-
-  /** Regression test for https://github.com/google/protobuf/issues/292 */
-  public void testCorrectExceptionThrowWhenEncodingStringsWithoutEnoughSpace() throws Exception {
-    String testCase = "Foooooooo";
-    assertEquals(CodedOutputStream.computeRawVarint32Size(testCase.length()),
-        CodedOutputStream.computeRawVarint32Size(testCase.length() * 3));
-    assertEquals(11, CodedOutputStream.computeStringSize(1, testCase));
-    // Tag is one byte, varint describing string length is 1 byte, string length is 9 bytes.
-    // An array of size 1 will cause a failure when trying to write the varint.
-    for (int i = 0; i < 11; i++) {
-      CodedOutputStream output = CodedOutputStream.newInstance(new byte[i]);
-      try {
-        output.writeString(1, testCase);
-        fail("Should have thrown an out of space exception");
-      } catch (CodedOutputStream.OutOfSpaceException expected) {}
-    }
-  }
-  
-  public void testDifferentStringLengths() throws Exception {
-    // Test string serialization roundtrip using strings of the following lengths,
-    // with ASCII and Unicode characters requiring different UTF-8 byte counts per
-    // char, hence causing the length delimiter varint to sometimes require more
-    // bytes for the Unicode strings than the ASCII string of the same length.
-    int[] lengths = new int[] {
-            0,
-            1,
-            (1 << 4) - 1,  // 1 byte for ASCII and Unicode
-            (1 << 7) - 1,  // 1 byte for ASCII, 2 bytes for Unicode
-            (1 << 11) - 1, // 2 bytes for ASCII and Unicode
-            (1 << 14) - 1, // 2 bytes for ASCII, 3 bytes for Unicode
-            (1 << 17) - 1, // 3 bytes for ASCII and Unicode
-    };
-    for (int i : lengths) {
-      testEncodingOfString('q', i);      // 1 byte per char
-      testEncodingOfString('\u07FF', i); // 2 bytes per char
-      testEncodingOfString('\u0981', i); // 3 bytes per char
-    }
-  }
-
-  private void testEncodingOfString(char c, int length) throws Exception {
-    String fullString = fullString(c, length);
-    TestAllTypes testAllTypes = TestAllTypes.newBuilder()
-        .setOptionalString(fullString)
-        .build();
-    assertEquals(
-        fullString, TestAllTypes.parseFrom(testAllTypes.toByteArray()).getOptionalString());
-  }
-
-  private String fullString(char c, int length) {
-    char[] result = new char[length];
-    Arrays.fill(result, c);
-    return new String(result);
-  }
-}
diff --git a/java/util/pom.xml b/java/util/pom.xml
index 44a5662d..9236f907 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -4,110 +4,73 @@
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
-    <groupId>com.google</groupId>
-    <artifactId>google</artifactId>
-    <version>1</version>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-parent</artifactId>
+    <version>3.0.0-beta-3</version>
   </parent>
-  <groupId>com.google.protobuf</groupId>
+
   <artifactId>protobuf-java-util</artifactId>
-  <version>3.0.0-beta-1</version>
   <packaging>bundle</packaging>
-  <name>Protocol Buffer Java API</name>
-  <description>
-    Protocol Buffers are a way of encoding structured data in an efficient yet
-    extensible format.
-  </description>
-  <inceptionYear>2008</inceptionYear>
-  <url>https://developers.google.com/protocol-buffers/</url>
-  <licenses>
-    <license>
-      <name>New BSD license</name>
-      <url>http://www.opensource.org/licenses/bsd-license.php</url>
-      <distribution>repo</distribution>
-    </license>
-  </licenses>
-  <scm>
-    <url>https://github.com/google/protobuf</url>
-    <connection>
-      scm:git:https://github.com/google/protobuf.git
-    </connection>
-  </scm>
+
+  <name>Protocol Buffers [Util]</name>
+  <description>Utilities for Protocol Buffers</description>
+
   <dependencies>
     <dependency>
-      <groupId>com.google.protobuf</groupId>
+      <groupId>${project.groupId}</groupId>
       <artifactId>protobuf-java</artifactId>
-      <version>3.0.0-beta-1</version>
-      <scope>compile</scope>
+      <version>${project.version}</version>
     </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
-      <version>18.0</version>
-      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
       <version>2.3</version>
-      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>4.4</version>
-      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymock</artifactId>
-      <version>2.2</version>
-      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymockclassextension</artifactId>
-      <version>2.2.1</version>
-      <scope>test</scope>
     </dependency>
   </dependencies>
+
+  <properties>
+    <!-- Use the core proto dir so that we can call the core generation script -->
+    <test.proto.dir>../core/src/test/proto</test.proto.dir>
+  </properties>
+
   <build>
     <plugins>
       <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration>
-          <source>1.5</source>
-          <target>1.5</target>
-        </configuration>
-      </plugin>
-      <plugin>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <configuration>
-          <includes>
-            <include>**/*Test.java</include>
-            <include>../src/main/java/com/google/protobuf/TestUtil.java</include>
-          </includes>
-        </configuration>
-      </plugin>
-      <plugin>
         <artifactId>maven-antrun-plugin</artifactId>
         <executions>
+          <!-- Generate the test protos -->
           <execution>
             <id>generate-test-sources</id>
             <phase>generate-test-sources</phase>
             <configuration>
-              <tasks>
-                <mkdir dir="target/generated-test-sources" />
-                <exec executable="../../src/protoc">
-                  <arg value="--java_out=target/generated-test-sources" />
-                  <arg value="--proto_path=../../src" />
-                  <arg value="--proto_path=src/test/java" />
-                  <arg value="../../src/google/protobuf/unittest.proto" />
-                  <arg value="../../src/google/protobuf/unittest_import.proto" />
-                  <arg value="../../src/google/protobuf/unittest_import_public.proto" />
-                  <arg value="src/test/java/com/google/protobuf/util/json_test.proto" />
+              <target>
+                <!-- Generate all of the test protos from the core module -->
+                <ant antfile="../core/generate-test-sources-build.xml"/>
+
+                <!-- Generate additional test protos for this module -->
+                <exec executable="${protoc}">
+                  <arg value="--java_out=${generated.testsources.dir}" />
+                  <arg value="--proto_path=${protobuf.source.dir}" />
+                  <arg value="--proto_path=src/test/proto" />
+                  <arg value="src/test/proto/com/google/protobuf/util/json_test.proto" />
                 </exec>
-              </tasks>
-              <testSourceRoot>target/generated-test-sources</testSourceRoot>
+              </target>
             </configuration>
             <goals>
               <goal>run</goal>
@@ -115,6 +78,16 @@
           </execution>
         </executions>
       </plugin>
+
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <!-- Add the generated test sources to the build -->
+          <generatedTestSourcesDirectory>${generated.testsources.dir}</generatedTestSourcesDirectory>
+        </configuration>
+      </plugin>
+
+      <!-- Configure the OSGI bundle -->
       <plugin>
         <groupId>org.apache.felix</groupId>
         <artifactId>maven-bundle-plugin</artifactId>
@@ -123,80 +96,20 @@
           <instructions>
             <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
             <Bundle-SymbolicName>com.google.protobuf.util</Bundle-SymbolicName>
-            <Export-Package>com.google.protobuf.util;version=3.0.0-beta-1</Export-Package>
+            <Export-Package>com.google.protobuf.util;version=${project.version}</Export-Package>
           </instructions>
         </configuration>
       </plugin>
+
+      <!-- Configure the fat jar to include all dependencies -->
+      <plugin>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <configuration>
+          <descriptorRefs>
+            <descriptorRef>jar-with-dependencies</descriptorRef>
+          </descriptorRefs>
+        </configuration>
+      </plugin>
     </plugins>
   </build>
-  <profiles>
-    <profile>
-      <id>release</id>
-      <distributionManagement>
-        <snapshotRepository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/content/repositories/snapshots</url>
-        </snapshotRepository>
-        <repository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
-        </repository>
-      </distributionManagement>
-      <build>
-        <plugins>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-source-plugin</artifactId>
-            <version>2.2.1</version>
-            <executions>
-              <execution>
-                <id>attach-sources</id>
-                <goals>
-                  <goal>jar-no-fork</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-javadoc-plugin</artifactId>
-            <version>2.9.1</version>
-            <executions>
-              <execution>
-                <id>attach-javadocs</id>
-                <goals>
-                  <goal>jar</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-gpg-plugin</artifactId>
-            <version>1.5</version>
-            <executions>
-              <execution>
-                <id>sign-artifacts</id>
-                <phase>verify</phase>
-                <goals>
-                  <goal>sign</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.sonatype.plugins</groupId>
-            <artifactId>nexus-staging-maven-plugin</artifactId>
-            <version>1.6.3</version>
-            <extensions>true</extensions>
-            <configuration>
-               <serverId>sonatype-nexus-staging</serverId>
-               <nexusUrl>https://oss.sonatype.org/</nexusUrl>
-               <autoReleaseAfterClose>false</autoReleaseAfterClose>
-            </configuration>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
-  </profiles>
 </project>
diff --git a/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java b/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java
index dc2f4b84..668d65ab 100644
--- a/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java
+++ b/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java
@@ -60,10 +60,9 @@ import java.util.logging.Logger;
  * FieldMask in a message tree.
  */
 class FieldMaskTree {
-  private static final Logger logger =
-      Logger.getLogger(FieldMaskTree.class.getName());
-  
-  private static final String FIELD_PATH_SEPARATOR_REGEX = "\\."; 
+  private static final Logger logger = Logger.getLogger(FieldMaskTree.class.getName());
+
+  private static final String FIELD_PATH_SEPARATOR_REGEX = "\\.";
 
   private static class Node {
     public TreeMap<String, Node> children = new TreeMap<String, Node>();
@@ -73,12 +72,12 @@ class FieldMaskTree {
 
   /** Creates an empty FieldMaskTree. */
   public FieldMaskTree() {}
-  
+
   /** Creates a FieldMaskTree for a given FieldMask. */
   public FieldMaskTree(FieldMask mask) {
     mergeFromFieldMask(mask);
   }
-  
+
   @Override
   public String toString() {
     return FieldMaskUtil.toString(toFieldMask());
@@ -121,7 +120,7 @@ class FieldMaskTree {
     node.children.clear();
     return this;
   }
-  
+
   /**
    * Merges all field paths in a FieldMask into this tree.
    */
@@ -149,8 +148,7 @@ class FieldMaskTree {
       return;
     }
     for (Entry<String, Node> entry : node.children.entrySet()) {
-      String childPath = path.isEmpty()
-          ? entry.getKey() : path + "." + entry.getKey();
+      String childPath = path.isEmpty() ? entry.getKey() : path + "." + entry.getKey();
       getFieldPaths(entry.getValue(), childPath, paths);
     }
   }
@@ -193,11 +191,10 @@ class FieldMaskTree {
    * Merges all fields specified by this FieldMaskTree from {@code source} to
    * {@code destination}.
    */
-  public void merge(Message source, Message.Builder destination,
-      FieldMaskUtil.MergeOptions options) {
+  public void merge(
+      Message source, Message.Builder destination, FieldMaskUtil.MergeOptions options) {
     if (source.getDescriptorForType() != destination.getDescriptorForType()) {
-      throw new IllegalArgumentException(
-          "Cannot merge messages of different types.");
+      throw new IllegalArgumentException("Cannot merge messages of different types.");
     }
     if (root.children.isEmpty()) {
       return;
@@ -208,30 +205,41 @@ class FieldMaskTree {
   /** Merges all fields specified by a sub-tree from {@code source} to
    * {@code destination}.
    */
-  private void merge(Node node, String path, Message source,
-      Message.Builder destination, FieldMaskUtil.MergeOptions options) {
+  private void merge(
+      Node node,
+      String path,
+      Message source,
+      Message.Builder destination,
+      FieldMaskUtil.MergeOptions options) {
     assert source.getDescriptorForType() == destination.getDescriptorForType();
-    
+
     Descriptor descriptor = source.getDescriptorForType();
     for (Entry<String, Node> entry : node.children.entrySet()) {
-      FieldDescriptor field =
-          descriptor.findFieldByName(entry.getKey());
+      FieldDescriptor field = descriptor.findFieldByName(entry.getKey());
       if (field == null) {
-        logger.warning("Cannot find field \"" + entry.getKey()
-            + "\" in message type " + descriptor.getFullName());
+        logger.warning(
+            "Cannot find field \""
+                + entry.getKey()
+                + "\" in message type "
+                + descriptor.getFullName());
         continue;
       }
       if (!entry.getValue().children.isEmpty()) {
-        if (field.isRepeated()
-            || field.getJavaType() != FieldDescriptor.JavaType.MESSAGE) {
-          logger.warning("Field \"" + field.getFullName() + "\" is not a "
-              + "singluar message field and cannot have sub-fields.");
+        if (field.isRepeated() || field.getJavaType() != FieldDescriptor.JavaType.MESSAGE) {
+          logger.warning(
+              "Field \""
+                  + field.getFullName()
+                  + "\" is not a "
+                  + "singluar message field and cannot have sub-fields.");
           continue;
         }
-        String childPath = path.isEmpty()
-            ? entry.getKey() : path + "." + entry.getKey();
-        merge(entry.getValue(), childPath, (Message) source.getField(field),
-            destination.getFieldBuilder(field), options);
+        String childPath = path.isEmpty() ? entry.getKey() : path + "." + entry.getKey();
+        merge(
+            entry.getValue(),
+            childPath,
+            (Message) source.getField(field),
+            destination.getFieldBuilder(field),
+            options);
         continue;
       }
       if (field.isRepeated()) {
@@ -245,13 +253,22 @@ class FieldMaskTree {
       } else {
         if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
           if (options.replaceMessageFields()) {
-            destination.setField(field, source.getField(field));
+            if (!source.hasField(field)) {
+              destination.clearField(field);
+            } else {
+              destination.setField(field, source.getField(field));
+            }
           } else {
-            destination.getFieldBuilder(field).mergeFrom(
-                (Message) source.getField(field));
+            if (source.hasField(field)) {
+              destination.getFieldBuilder(field).mergeFrom((Message) source.getField(field));
+            }
           }
         } else {
-          destination.setField(field, source.getField(field));
+          if (source.hasField(field) || !options.replacePrimitiveFields()) {
+            destination.setField(field, source.getField(field));
+          } else {
+            destination.clearField(field);
+          }
         }
       }
     }
diff --git a/java/util/src/main/java/com/google/protobuf/util/FieldMaskUtil.java b/java/util/src/main/java/com/google/protobuf/util/FieldMaskUtil.java
index 7bf87858..96961521 100644
--- a/java/util/src/main/java/com/google/protobuf/util/FieldMaskUtil.java
+++ b/java/util/src/main/java/com/google/protobuf/util/FieldMaskUtil.java
@@ -30,6 +30,9 @@
 
 package com.google.protobuf.util;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.primitives.Ints;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.FieldMask;
@@ -37,7 +40,6 @@ import com.google.protobuf.Internal;
 import com.google.protobuf.Message;
 
 import java.util.Arrays;
-import java.util.List;
 
 /**
  * Utility helper functions to work with {@link com.google.protobuf.FieldMask}.
@@ -53,6 +55,7 @@ public class FieldMaskUtil {
    * Converts a FieldMask to a string.
    */
   public static String toString(FieldMask fieldMask) {
+    // TODO(xiaofeng): Consider using com.google.common.base.Joiner here instead.
     StringBuilder result = new StringBuilder();
     boolean first = true;
     for (String value : fieldMask.getPathsList()) {
@@ -74,6 +77,7 @@ public class FieldMaskUtil {
    * Parses from a string to a FieldMask.
    */
   public static FieldMask fromString(String value) {
+    // TODO(xiaofeng): Consider using com.google.common.base.Splitter here instead.
     return fromStringList(
         null, Arrays.asList(value.split(FIELD_PATH_SEPARATOR_REGEX)));
   }
@@ -83,8 +87,8 @@ public class FieldMaskUtil {
    * 
    * @throws IllegalArgumentException if any of the field path is invalid.
    */
-  public static FieldMask fromString(Class<? extends Message> type, String value)
-      throws IllegalArgumentException {
+  public static FieldMask fromString(Class<? extends Message> type, String value) {
+    // TODO(xiaofeng): Consider using com.google.common.base.Splitter here instead.
     return fromStringList(
         type, Arrays.asList(value.split(FIELD_PATH_SEPARATOR_REGEX)));
   }
@@ -94,9 +98,9 @@ public class FieldMaskUtil {
    *
    * @throws IllegalArgumentException if any of the field path is not valid.
    */
+  // TODO(xiaofeng): Consider renaming fromStrings()
   public static FieldMask fromStringList(
-      Class<? extends Message> type, List<String> paths)
-      throws IllegalArgumentException {
+      Class<? extends Message> type, Iterable<String> paths) {
     FieldMask.Builder builder = FieldMask.newBuilder();
     for (String path : paths) {
       if (path.isEmpty()) {
@@ -113,15 +117,74 @@ public class FieldMaskUtil {
   }
 
   /**
+   * Constructs a FieldMask from the passed field numbers.
+   *
+   * @throws IllegalArgumentException if any of the fields are invalid for the message.
+   */
+  public static FieldMask fromFieldNumbers(Class<? extends Message> type, int... fieldNumbers) {
+    return fromFieldNumbers(type, Ints.asList(fieldNumbers));
+  }
+
+  /**
+   * Constructs a FieldMask from the passed field numbers.
+   *
+   * @throws IllegalArgumentException if any of the fields are invalid for the message.
+   */
+  public static FieldMask fromFieldNumbers(
+      Class<? extends Message> type, Iterable<Integer> fieldNumbers) {
+    Descriptor descriptor = Internal.getDefaultInstance(type).getDescriptorForType();
+
+    FieldMask.Builder builder = FieldMask.newBuilder();
+    for (Integer fieldNumber : fieldNumbers) {
+      FieldDescriptor field = descriptor.findFieldByNumber(fieldNumber);
+      checkArgument(
+          field != null,
+          String.format("%s is not a valid field number for %s.", fieldNumber, type));
+      builder.addPaths(field.getName());
+    }
+    return builder.build();
+  }
+
+  /**
+   * Checks whether paths in a given fields mask are valid.
+   */
+  public static boolean isValid(Class<? extends Message> type, FieldMask fieldMask) {
+    Descriptor descriptor =
+        Internal.getDefaultInstance(type).getDescriptorForType();
+    
+    return isValid(descriptor, fieldMask);
+  }
+  
+  /**
+   * Checks whether paths in a given fields mask are valid.
+   */
+  public static boolean isValid(Descriptor descriptor, FieldMask fieldMask) {
+    for (String path : fieldMask.getPathsList()) {
+      if (!isValid(descriptor, path)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
    * Checks whether a given field path is valid.
    */
   public static boolean isValid(Class<? extends Message> type, String path) {
+    Descriptor descriptor =
+        Internal.getDefaultInstance(type).getDescriptorForType();
+    
+    return isValid(descriptor, path);
+  }
+
+  /**
+   * Checks whether paths in a given fields mask are valid.
+   */
+  public static boolean isValid(Descriptor descriptor, String path) {
     String[] parts = path.split(FIELD_SEPARATOR_REGEX);
     if (parts.length == 0) {
       return false;
     }
-    Descriptor descriptor =
-        Internal.getDefaultInstance(type).getDescriptorForType();
     for (String name : parts) {
       if (descriptor == null) {
         return false;
@@ -148,14 +211,19 @@ public class FieldMaskUtil {
   public static FieldMask normalize(FieldMask mask) {
     return new FieldMaskTree(mask).toFieldMask();
   }
-  
+
   /**
-   * Creates an union of two FieldMasks.
+   * Creates a union of two or more FieldMasks.
    */
-  public static FieldMask union(FieldMask mask1, FieldMask mask2) {
-    return new FieldMaskTree(mask1).mergeFromFieldMask(mask2).toFieldMask();
+  public static FieldMask union(
+      FieldMask firstMask, FieldMask secondMask, FieldMask... otherMasks) {
+    FieldMaskTree maskTree = new FieldMaskTree(firstMask).mergeFromFieldMask(secondMask);
+    for (FieldMask mask : otherMasks) {
+      maskTree.mergeFromFieldMask(mask);
+    }
+    return maskTree.toFieldMask();
   }
-  
+
   /**
    * Calculates the intersection of two FieldMasks.
    */
@@ -171,9 +239,12 @@ public class FieldMaskUtil {
   /**
    * Options to customize merging behavior.
    */
-  public static class MergeOptions {
+  public static final class MergeOptions {
     private boolean replaceMessageFields = false;
     private boolean replaceRepeatedFields = false;
+    // TODO(b/28277137): change the default behavior to always replace primitive fields after
+    // fixing all failing TAP tests.
+    private boolean replacePrimitiveFields = false;
 
     /**
      * Whether to replace message fields (i.e., discard existing content in
@@ -194,7 +265,23 @@ public class FieldMaskUtil {
     public boolean replaceRepeatedFields() {
       return replaceRepeatedFields;
     }
-    
+
+    /**
+     * Whether to replace primitive (non-repeated and non-message) fields in
+     * destination message fields with the source primitive fields (i.e., if the
+     * field is set in the source, the value is copied to the
+     * destination; if the field is unset in the source, the field is cleared
+     * from the destination) when merging.
+     *
+     * <p>Default behavior is to always set the value of the source primitive
+     * field to the destination primitive field, and if the source field is
+     * unset, the default value of the source field is copied to the
+     * destination.
+     */
+    public boolean replacePrimitiveFields() {
+      return replacePrimitiveFields;
+    }
+
     public void setReplaceMessageFields(boolean value) {
       replaceMessageFields = value;
     }
@@ -202,10 +289,15 @@ public class FieldMaskUtil {
     public void setReplaceRepeatedFields(boolean value) {
       replaceRepeatedFields = value;
     }
+
+    public void setReplacePrimitiveFields(boolean value) {
+      replacePrimitiveFields = value;
+    }
   }
-  
+
   /**
-   * Merges fields specified by a FieldMask from one message to another.
+   * Merges fields specified by a FieldMask from one message to another with the
+   * specified merge options.
    */
   public static void merge(FieldMask mask, Message source,
       Message.Builder destination, MergeOptions options) {
diff --git a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
index c9a39153..76f3437a 100644
--- a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
+++ b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
@@ -32,6 +32,7 @@ package com.google.protobuf.util;
 
 import com.google.common.io.BaseEncoding;
 import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonNull;
@@ -78,6 +79,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.logging.Logger;
 
 /**
@@ -99,7 +101,7 @@ public class JsonFormat {
    * Creates a {@link Printer} with default configurations.
    */
   public static Printer printer() {
-    return new Printer(TypeRegistry.getEmptyTypeRegistry());
+    return new Printer(TypeRegistry.getEmptyTypeRegistry(), false, false);
   }
   
   /**
@@ -107,9 +109,16 @@ public class JsonFormat {
    */
   public static class Printer {
     private final TypeRegistry registry;
-    
-    private Printer(TypeRegistry registry) {
+    private final boolean includingDefaultValueFields;
+    private final boolean preservingProtoFieldNames;
+
+    private Printer(
+        TypeRegistry registry,
+        boolean includingDefaultValueFields,
+        boolean preservingProtoFieldNames) {
       this.registry = registry;
+      this.includingDefaultValueFields = includingDefaultValueFields;
+      this.preservingProtoFieldNames = preservingProtoFieldNames;
     }
     
     /**
@@ -122,7 +131,27 @@ public class JsonFormat {
       if (this.registry != TypeRegistry.getEmptyTypeRegistry()) {
         throw new IllegalArgumentException("Only one registry is allowed.");
       }
-      return new Printer(registry);
+      return new Printer(registry, includingDefaultValueFields, preservingProtoFieldNames);
+    }
+
+    /**
+     * Creates a new {@link Printer} that will also print fields set to their
+     * defaults. Empty repeated fields and map fields will be printed as well.
+     * The new Printer clones all other configurations from the current
+     * {@link Printer}.
+     */
+    public Printer includingDefaultValueFields() {
+      return new Printer(registry, true, preservingProtoFieldNames);
+    }
+
+    /**
+     * Creates a new {@link Printer} that is configured to use the original proto
+     * field names as defined in the .proto file rather than converting them to
+     * lowerCamelCase. The new Printer clones all other configurations from the
+     * current {@link Printer}.
+     */
+    public Printer preservingProtoFieldNames() {
+      return new Printer(registry, includingDefaultValueFields, true);
     }
     
     /**
@@ -136,7 +165,8 @@ public class JsonFormat {
         throws IOException {
       // TODO(xiaofeng): Investigate the allocation overhead and optimize for
       // mobile.
-      new PrinterImpl(registry, output).print(message);
+      new PrinterImpl(registry, includingDefaultValueFields, preservingProtoFieldNames, output)
+          .print(message);
     }
 
     /**
@@ -298,7 +328,7 @@ public class JsonFormat {
 
       private void addFile(FileDescriptor file) {
         // Skip the file if it's already added.
-        if (files.contains(file.getName())) {
+        if (!files.add(file.getFullName())) {
           return;
         }
         for (FileDescriptor dependency : file.getDependencies()) {
@@ -397,16 +427,24 @@ public class JsonFormat {
    */
   private static final class PrinterImpl {
     private final TypeRegistry registry;
+    private final boolean includingDefaultValueFields;
+    private final boolean preservingProtoFieldNames;
     private final TextGenerator generator;
     // We use Gson to help handle string escapes.
     private final Gson gson;
 
     private static class GsonHolder {
-      private static final Gson DEFAULT_GSON = new Gson();
+      private static final Gson DEFAULT_GSON = new GsonBuilder().disableHtmlEscaping().create();
     }
 
-    PrinterImpl(TypeRegistry registry, Appendable jsonOutput) {
+    PrinterImpl(
+        TypeRegistry registry,
+        boolean includingDefaultValueFields,
+        boolean preservingProtoFieldNames,
+        Appendable jsonOutput) {
       this.registry = registry;
+      this.includingDefaultValueFields = includingDefaultValueFields;
+      this.preservingProtoFieldNames = preservingProtoFieldNames;
       this.generator = new TextGenerator(jsonOutput);
       this.gson = GsonHolder.DEFAULT_GSON;
     }
@@ -647,13 +685,23 @@ public class JsonFormat {
         generator.print("\"@type\": " + gson.toJson(typeUrl));
         printedField = true;
       }
-      for (Map.Entry<FieldDescriptor, Object> field
-          : message.getAllFields().entrySet()) {
-        // Skip unknown enum fields.
-        if (field.getValue() instanceof EnumValueDescriptor
-            && ((EnumValueDescriptor) field.getValue()).getIndex() == -1) {
-          continue;
+      Map<FieldDescriptor, Object> fieldsToPrint = null;
+      if (includingDefaultValueFields) {
+        fieldsToPrint = new TreeMap<FieldDescriptor, Object>();
+        for (FieldDescriptor field : message.getDescriptorForType().getFields()) {
+          if (field.isOptional()
+              && field.getJavaType() == FieldDescriptor.JavaType.MESSAGE
+              && !message.hasField(field)) {
+            // Always skip empty optional message fields. If not we will recurse indefinitely if
+            // a message has itself as a sub-field.
+            continue;
+          }
+          fieldsToPrint.put(field, message.getField(field));
         }
+      } else {
+        fieldsToPrint = message.getAllFields();
+      }
+      for (Map.Entry<FieldDescriptor, Object> field : fieldsToPrint.entrySet()) {
         if (printedField) {
           // Add line-endings for the previous field.
           generator.print(",\n");
@@ -673,7 +721,11 @@ public class JsonFormat {
 
     private void printField(FieldDescriptor field, Object value)
         throws IOException {
-      generator.print("\"" + fieldNameToCamelName(field.getName()) + "\": ");
+      if (preservingProtoFieldNames) {
+        generator.print("\"" + field.getName() + "\": ");
+      } else {
+        generator.print("\"" + field.getJsonName() + "\": ");
+      }
       if (field.isMapField()) {
         printMapFieldValue(field, value);
       } else if (field.isRepeated()) {
@@ -689,11 +741,6 @@ public class JsonFormat {
       generator.print("[");
       boolean printedElement = false;
       for (Object element : (List) value) {
-        // Skip unknown enum entries.
-        if (element instanceof EnumValueDescriptor
-            && ((EnumValueDescriptor) element).getIndex() == -1) {
-          continue;
-        }
         if (printedElement) {
           generator.print(", ");
         } else {
@@ -720,11 +767,6 @@ public class JsonFormat {
         Message entry = (Message) element;
         Object entryKey = entry.getField(keyField);
         Object entryValue = entry.getField(valueField);
-        // Skip unknown enum entries.
-        if (entryValue instanceof EnumValueDescriptor
-            && ((EnumValueDescriptor) entryValue).getIndex() == -1) {
-          continue;
-        }
         if (printedElement) {
           generator.print(",\n");
         } else {
@@ -871,8 +913,13 @@ public class JsonFormat {
               generator.print("\"");
             }
           } else {
-            generator.print(
-                "\"" + ((EnumValueDescriptor) value).getName() + "\"");
+            if (((EnumValueDescriptor) value).getIndex() == -1) {
+              generator.print(
+                  String.valueOf(((EnumValueDescriptor) value).getNumber()));
+            } else {
+              generator.print(
+                  "\"" + ((EnumValueDescriptor) value).getName() + "\"");
+            }
           }
           break;
 
@@ -905,48 +952,15 @@ public class JsonFormat {
     }
   }
   
-  private static final String TYPE_URL_PREFIX = "type.googleapis.com";
-  
+
   private static String getTypeName(String typeUrl)
       throws InvalidProtocolBufferException {
     String[] parts = typeUrl.split("/");
-    if (parts.length != 2 || !parts[0].equals(TYPE_URL_PREFIX)) {
+    if (parts.length == 1) {
       throw new InvalidProtocolBufferException(
           "Invalid type url found: " + typeUrl);
     }
-    return parts[1];
-  }
-
-  private static String fieldNameToCamelName(String name) {
-    StringBuilder result = new StringBuilder(name.length());
-    boolean isNextUpperCase = false;
-    for (int i = 0; i < name.length(); i++) {
-      Character ch = name.charAt(i);
-      if (Character.isLowerCase(ch)) {
-        if (isNextUpperCase) {
-          result.append(Character.toUpperCase(ch));
-        } else {
-          result.append(ch);
-        }
-        isNextUpperCase = false;
-      } else if (Character.isUpperCase(ch)) {
-        if (i == 0 && !isNextUpperCase) {
-          // Force first letter to lower-case unless explicitly told to
-          // capitalize it.
-          result.append(Character.toLowerCase(ch));
-        } else {
-          // Capital letters after the first are left as-is.
-          result.append(ch);
-        }
-        isNextUpperCase = false;
-      } else if (Character.isDigit(ch)) {
-        result.append(ch);
-        isNextUpperCase = true;
-      } else {
-        isNextUpperCase = true;
-      }
-    }
-    return result.toString();
+    return parts[parts.length - 1];
   }
   
   private static class ParserImpl {
@@ -1052,6 +1066,15 @@ public class JsonFormat {
           parser.mergeStruct(json, builder);
         }
       });
+      // Special-case ListValue.
+      parsers.put(ListValue.getDescriptor().getFullName(),
+          new WellKnownTypeParser() {
+        @Override
+        public void merge(ParserImpl parser, JsonElement json,
+            Message.Builder builder) throws InvalidProtocolBufferException {
+          parser.mergeListValue(json, builder);
+        }
+      });
       // Special-case Value.
       parsers.put(Value.getDescriptor().getFullName(),
           new WellKnownTypeParser() {
@@ -1085,7 +1108,8 @@ public class JsonFormat {
         Map<String, FieldDescriptor> fieldNameMap =
             new HashMap<String, FieldDescriptor>();
         for (FieldDescriptor field : descriptor.getFields()) {
-          fieldNameMap.put(fieldNameToCamelName(field.getName()), field);
+          fieldNameMap.put(field.getName(), field);
+          fieldNameMap.put(field.getJsonName(), field);
         }
         fieldNameMaps.put(descriptor, fieldNameMap);
         return fieldNameMap;
@@ -1198,6 +1222,16 @@ public class JsonFormat {
       }
       mergeMapField(field, json, builder);
     }
+
+    private void mergeListValue(JsonElement json, Message.Builder builder)
+        throws InvalidProtocolBufferException {
+      Descriptor descriptor = builder.getDescriptorForType();
+      FieldDescriptor field = descriptor.findFieldByName("values");
+      if (field == null) {
+        throw new InvalidProtocolBufferException("Invalid ListValue type.");
+      }
+      mergeRepeatedField(field, json, builder);
+    }
     
     private void mergeValue(JsonElement json, Message.Builder builder)
         throws InvalidProtocolBufferException {
@@ -1222,9 +1256,7 @@ public class JsonFormat {
       } else if (json instanceof JsonArray) {
         FieldDescriptor field = type.findFieldByName("list_value");
         Message.Builder listBuilder = builder.newBuilderForField(field);
-        FieldDescriptor listField =
-            listBuilder.getDescriptorForType().findFieldByName("values");
-        mergeRepeatedField(listField, json, listBuilder);
+        merge(json, listBuilder);
         builder.setField(field, listBuilder.build());
       } else {
         throw new IllegalStateException("Unexpected json data: " + json);
@@ -1244,7 +1276,25 @@ public class JsonFormat {
     
     private void mergeField(FieldDescriptor field, JsonElement json,
         Message.Builder builder) throws InvalidProtocolBufferException {
-      if (json instanceof JsonNull) {
+      if (field.isRepeated()) {
+        if (builder.getRepeatedFieldCount(field) > 0) {
+          throw new InvalidProtocolBufferException(
+              "Field " + field.getFullName() + " has already been set.");
+        }
+      } else {
+        if (builder.hasField(field)) {
+          throw new InvalidProtocolBufferException(
+              "Field " + field.getFullName() + " has already been set.");
+        }
+        if (field.getContainingOneof() != null
+            && builder.getOneofFieldDescriptor(field.getContainingOneof()) != null) {
+          FieldDescriptor other = builder.getOneofFieldDescriptor(field.getContainingOneof());
+          throw new InvalidProtocolBufferException(
+              "Cannot set field " + field.getFullName() + " because another field "
+              + other.getFullName() + " belonging to the same oneof has already been set ");
+        }
+      }
+      if (field.isRepeated() && json instanceof JsonNull) {
         // We allow "null" as value for all field types and treat it as if the
         // field is not present.
         return;
@@ -1282,7 +1332,8 @@ public class JsonFormat {
         Object value = parseFieldValue(
             valueField, entry.getValue(), entryBuilder);
         if (value == null) {
-          value = getDefaultValue(valueField, entryBuilder);
+          throw new InvalidProtocolBufferException(
+              "Map value cannot be null.");
         }
         entryBuilder.setField(keyField, key);
         entryBuilder.setField(valueField, value);
@@ -1341,7 +1392,8 @@ public class JsonFormat {
       for (int i = 0; i < array.size(); ++i) {
         Object value = parseFieldValue(field, array.get(i), builder);
         if (value == null) {
-          value = getDefaultValue(field, builder);
+          throw new InvalidProtocolBufferException(
+              "Repeated field elements cannot be null");
         }
         builder.addRepeatedField(field, value);
       }
@@ -1352,6 +1404,15 @@ public class JsonFormat {
       try {
         return Integer.parseInt(json.getAsString());
       } catch (Exception e) {
+        // Fall through.
+      }
+      // JSON doesn't distinguish between integer values and floating point values so "1" and
+      // "1.000" are treated as equal in JSON. For this reason we accept floating point values for
+      // integer fields as well as long as it actually is an integer (i.e., round(value) == value).
+      try {
+        BigDecimal value = new BigDecimal(json.getAsString());
+        return value.intValueExact();
+      } catch (Exception e) {
         throw new InvalidProtocolBufferException("Not an int32 value: " + json);
       }
     }
@@ -1361,7 +1422,16 @@ public class JsonFormat {
       try {
         return Long.parseLong(json.getAsString());
       } catch (Exception e) {
-        throw new InvalidProtocolBufferException("Not an int64 value: " + json);
+        // Fall through.
+      }
+      // JSON doesn't distinguish between integer values and floating point values so "1" and
+      // "1.000" are treated as equal in JSON. For this reason we accept floating point values for
+      // integer fields as well as long as it actually is an integer (i.e., round(value) == value).
+      try {
+        BigDecimal value = new BigDecimal(json.getAsString());
+        return value.longValueExact();
+      } catch (Exception e) {
+        throw new InvalidProtocolBufferException("Not an int32 value: " + json);
       }
     }
     
@@ -1377,6 +1447,21 @@ public class JsonFormat {
       } catch (InvalidProtocolBufferException e) {
         throw e;
       } catch (Exception e) {
+        // Fall through.
+      }
+      // JSON doesn't distinguish between integer values and floating point values so "1" and
+      // "1.000" are treated as equal in JSON. For this reason we accept floating point values for
+      // integer fields as well as long as it actually is an integer (i.e., round(value) == value).
+      try {
+        BigDecimal decimalValue = new BigDecimal(json.getAsString());
+        BigInteger value = decimalValue.toBigIntegerExact();
+        if (value.signum() < 0 || value.compareTo(new BigInteger("FFFFFFFF", 16)) > 0) {
+          throw new InvalidProtocolBufferException("Out of range uint32 value: " + json);
+        }
+        return value.intValue();
+      } catch (InvalidProtocolBufferException e) {
+        throw e;
+      } catch (Exception e) {
         throw new InvalidProtocolBufferException(
             "Not an uint32 value: " + json);
       }
@@ -1388,7 +1473,8 @@ public class JsonFormat {
     private long parseUint64(JsonElement json)
         throws InvalidProtocolBufferException {
       try {
-        BigInteger value = new BigInteger(json.getAsString());
+        BigDecimal decimalValue = new BigDecimal(json.getAsString());
+        BigInteger value = decimalValue.toBigIntegerExact();
         if (value.compareTo(BigInteger.ZERO) < 0
             || value.compareTo(MAX_UINT64) > 0) {
           throw new InvalidProtocolBufferException(
@@ -1488,7 +1574,12 @@ public class JsonFormat {
       return json.getAsString();
     }
     
-    private ByteString parseBytes(JsonElement json) {
+    private ByteString parseBytes(JsonElement json) throws InvalidProtocolBufferException {
+      String encoded = json.getAsString();
+      if (encoded.length() % 4 != 0) {
+        throw new InvalidProtocolBufferException(
+            "Bytes field is not encoded in standard BASE64 with paddings: " + encoded);
+      }
       return ByteString.copyFrom(
           BaseEncoding.base64().decode(json.getAsString()));
     }
@@ -1498,9 +1589,25 @@ public class JsonFormat {
       String value = json.getAsString();
       EnumValueDescriptor result = enumDescriptor.findValueByName(value);
       if (result == null) {
-        throw new InvalidProtocolBufferException(
-            "Invalid enum value: " + value + " for enum type: "
-            + enumDescriptor.getFullName());
+        // Try to interpret the value as a number.
+        try {
+          int numericValue = parseInt32(json);
+          if (enumDescriptor.getFile().getSyntax() == FileDescriptor.Syntax.PROTO3) {
+            result = enumDescriptor.findValueByNumberCreatingIfUnknown(numericValue);
+          } else {
+            result = enumDescriptor.findValueByNumber(numericValue);
+          }
+        } catch (InvalidProtocolBufferException e) {
+          // Fall through. This exception is about invalid int32 value we get from parseInt32() but
+          // that's not the exception we want the user to see. Since result == null, we will throw
+          // an exception later.
+        }
+        
+        if (result == null) {
+          throw new InvalidProtocolBufferException(
+              "Invalid enum value: " + value + " for enum type: "
+              + enumDescriptor.getFullName());
+        }
       }
       return result;
     }
diff --git a/java/util/src/main/java/com/google/protobuf/util/TimeUtil.java b/java/util/src/main/java/com/google/protobuf/util/TimeUtil.java
index 6e4b7c03..3033182a 100644
--- a/java/util/src/main/java/com/google/protobuf/util/TimeUtil.java
+++ b/java/util/src/main/java/com/google/protobuf/util/TimeUtil.java
@@ -58,8 +58,12 @@ public class TimeUtil {
   private static final long MILLIS_PER_SECOND = 1000;
   private static final long MICROS_PER_SECOND = 1000000;
 
-  private static final SimpleDateFormat timestampFormat =
-    createTimestampFormat();
+  private static final ThreadLocal<SimpleDateFormat> timestampFormat =
+      new ThreadLocal<SimpleDateFormat>() {
+        protected SimpleDateFormat initialValue() {
+          return createTimestampFormat();
+        }
+      };
 
   private static SimpleDateFormat createTimestampFormat() {
     SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
@@ -96,7 +100,7 @@ public class TimeUtil {
       throw new IllegalArgumentException("Timestamp is out of range.");
     }
     Date date = new Date(timestamp.getSeconds() * MILLIS_PER_SECOND);
-    result.append(timestampFormat.format(date));
+    result.append(timestampFormat.get().format(date));
     // Format the nanos part.
     if (timestamp.getNanos() < 0 || timestamp.getNanos() >= NANOS_PER_SECOND) {
       throw new IllegalArgumentException("Timestamp has invalid nanos value.");
@@ -147,7 +151,7 @@ public class TimeUtil {
       secondValue = timeValue.substring(0, pointPosition);
       nanoValue = timeValue.substring(pointPosition + 1);
     }
-    Date date = timestampFormat.parse(secondValue);
+    Date date = timestampFormat.get().parse(secondValue);
     long seconds = date.getTime() / MILLIS_PER_SECOND;
     int nanos = nanoValue.isEmpty() ? 0 : parseNanos(nanoValue);
     // Parse timezone offsets.
diff --git a/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java b/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java
index 3391f239..3ee0fc6e 100644
--- a/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java
@@ -61,19 +61,16 @@ public class FieldMaskTreeTest extends TestCase {
     tree.addFieldPath("bar");
     assertEquals("bar,foo", tree.toString());
   }
-  
+
   public void testMergeFromFieldMask() throws Exception {
-    FieldMaskTree tree = new FieldMaskTree(
-      FieldMaskUtil.fromString("foo,bar.baz,bar.quz"));
+    FieldMaskTree tree = new FieldMaskTree(FieldMaskUtil.fromString("foo,bar.baz,bar.quz"));
     assertEquals("bar.baz,bar.quz,foo", tree.toString());
-    tree.mergeFromFieldMask(
-      FieldMaskUtil.fromString("foo.bar,bar"));
+    tree.mergeFromFieldMask(FieldMaskUtil.fromString("foo.bar,bar"));
     assertEquals("bar,foo", tree.toString());
   }
-  
+
   public void testIntersectFieldPath() throws Exception {
-    FieldMaskTree tree = new FieldMaskTree(
-      FieldMaskUtil.fromString("foo,bar.baz,bar.quz"));
+    FieldMaskTree tree = new FieldMaskTree(FieldMaskUtil.fromString("foo,bar.baz,bar.quz"));
     FieldMaskTree result = new FieldMaskTree();
     // Empty path.
     tree.intersectFieldPath("", result);
@@ -96,16 +93,18 @@ public class FieldMaskTreeTest extends TestCase {
   }
 
   public void testMerge() throws Exception {
-    TestAllTypes value = TestAllTypes.newBuilder()
-        .setOptionalInt32(1234)
-        .setOptionalNestedMessage(NestedMessage.newBuilder().setBb(5678))
-        .addRepeatedInt32(4321)
-        .addRepeatedNestedMessage(NestedMessage.newBuilder().setBb(8765))
-        .build();
-    NestedTestAllTypes source = NestedTestAllTypes.newBuilder()
-        .setPayload(value)
-        .setChild(NestedTestAllTypes.newBuilder().setPayload(value))
-        .build();
+    TestAllTypes value =
+        TestAllTypes.newBuilder()
+            .setOptionalInt32(1234)
+            .setOptionalNestedMessage(NestedMessage.newBuilder().setBb(5678))
+            .addRepeatedInt32(4321)
+            .addRepeatedNestedMessage(NestedMessage.newBuilder().setBb(8765))
+            .build();
+    NestedTestAllTypes source =
+        NestedTestAllTypes.newBuilder()
+            .setPayload(value)
+            .setChild(NestedTestAllTypes.newBuilder().setPayload(value))
+            .build();
     // Now we have a message source with the following structure:
     //   [root] -+- payload -+- optional_int32
     //           |           +- optional_nested_message
@@ -116,114 +115,147 @@ public class FieldMaskTreeTest extends TestCase {
     //                                 +- optional_nested_message
     //                                 +- repeated_int32
     //                                 +- repeated_nested_message
-    
+
     FieldMaskUtil.MergeOptions options = new FieldMaskUtil.MergeOptions();
-    
+
     // Test merging each individual field.
     NestedTestAllTypes.Builder builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("payload.optional_int32")
-        .merge(source, builder, options);
+    new FieldMaskTree().addFieldPath("payload.optional_int32").merge(source, builder, options);
     NestedTestAllTypes.Builder expected = NestedTestAllTypes.newBuilder();
     expected.getPayloadBuilder().setOptionalInt32(1234);
     assertEquals(expected.build(), builder.build());
 
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("payload.optional_nested_message")
+    new FieldMaskTree()
+        .addFieldPath("payload.optional_nested_message")
         .merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
-    expected.getPayloadBuilder().setOptionalNestedMessage(
-        NestedMessage.newBuilder().setBb(5678));
+    expected.getPayloadBuilder().setOptionalNestedMessage(NestedMessage.newBuilder().setBb(5678));
     assertEquals(expected.build(), builder.build());
 
-
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("payload.repeated_int32")
-        .merge(source, builder, options);
+    new FieldMaskTree().addFieldPath("payload.repeated_int32").merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
     expected.getPayloadBuilder().addRepeatedInt32(4321);
     assertEquals(expected.build(), builder.build());
 
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("payload.repeated_nested_message")
+    new FieldMaskTree()
+        .addFieldPath("payload.repeated_nested_message")
         .merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
-    expected.getPayloadBuilder().addRepeatedNestedMessage(
-        NestedMessage.newBuilder().setBb(8765));
+    expected.getPayloadBuilder().addRepeatedNestedMessage(NestedMessage.newBuilder().setBb(8765));
     assertEquals(expected.build(), builder.build());
 
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("child.payload.optional_int32")
+    new FieldMaskTree()
+        .addFieldPath("child.payload.optional_int32")
         .merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
     expected.getChildBuilder().getPayloadBuilder().setOptionalInt32(1234);
     assertEquals(expected.build(), builder.build());
 
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("child.payload.optional_nested_message")
+    new FieldMaskTree()
+        .addFieldPath("child.payload.optional_nested_message")
         .merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
-    expected.getChildBuilder().getPayloadBuilder().setOptionalNestedMessage(
-        NestedMessage.newBuilder().setBb(5678));
+    expected
+        .getChildBuilder()
+        .getPayloadBuilder()
+        .setOptionalNestedMessage(NestedMessage.newBuilder().setBb(5678));
     assertEquals(expected.build(), builder.build());
 
-
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("child.payload.repeated_int32")
+    new FieldMaskTree()
+        .addFieldPath("child.payload.repeated_int32")
         .merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
     expected.getChildBuilder().getPayloadBuilder().addRepeatedInt32(4321);
     assertEquals(expected.build(), builder.build());
 
-
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("child.payload.repeated_nested_message")
+    new FieldMaskTree()
+        .addFieldPath("child.payload.repeated_nested_message")
         .merge(source, builder, options);
     expected = NestedTestAllTypes.newBuilder();
-    expected.getChildBuilder().getPayloadBuilder().addRepeatedNestedMessage(
-        NestedMessage.newBuilder().setBb(8765));
+    expected
+        .getChildBuilder()
+        .getPayloadBuilder()
+        .addRepeatedNestedMessage(NestedMessage.newBuilder().setBb(8765));
     assertEquals(expected.build(), builder.build());
-    
+
     // Test merging all fields.
     builder = NestedTestAllTypes.newBuilder();
-    new FieldMaskTree().addFieldPath("child").addFieldPath("payload")
-    .merge(source, builder, options);
+    new FieldMaskTree()
+        .addFieldPath("child")
+        .addFieldPath("payload")
+        .merge(source, builder, options);
     assertEquals(source, builder.build());
-    
+
     // Test repeated options.
     builder = NestedTestAllTypes.newBuilder();
     builder.getPayloadBuilder().addRepeatedInt32(1000);
-    new FieldMaskTree().addFieldPath("payload.repeated_int32")
-    .merge(source, builder, options);
+    new FieldMaskTree().addFieldPath("payload.repeated_int32").merge(source, builder, options);
     // Default behavior is to append repeated fields.
     assertEquals(2, builder.getPayload().getRepeatedInt32Count());
     assertEquals(1000, builder.getPayload().getRepeatedInt32(0));
     assertEquals(4321, builder.getPayload().getRepeatedInt32(1));
     // Change to replace repeated fields.
     options.setReplaceRepeatedFields(true);
-    new FieldMaskTree().addFieldPath("payload.repeated_int32")
-    .merge(source, builder, options);
+    new FieldMaskTree().addFieldPath("payload.repeated_int32").merge(source, builder, options);
     assertEquals(1, builder.getPayload().getRepeatedInt32Count());
     assertEquals(4321, builder.getPayload().getRepeatedInt32(0));
-    
+
     // Test message options.
     builder = NestedTestAllTypes.newBuilder();
     builder.getPayloadBuilder().setOptionalInt32(1000);
     builder.getPayloadBuilder().setOptionalUint32(2000);
-    new FieldMaskTree().addFieldPath("payload")
-      .merge(source, builder, options);
+    new FieldMaskTree().addFieldPath("payload").merge(source, builder, options);
     // Default behavior is to merge message fields.
     assertEquals(1234, builder.getPayload().getOptionalInt32());
     assertEquals(2000, builder.getPayload().getOptionalUint32());
-    
+
+    // Test merging unset message fields.
+    NestedTestAllTypes clearedSource = source.toBuilder().clearPayload().build();
+    builder = NestedTestAllTypes.newBuilder();
+    new FieldMaskTree().addFieldPath("payload").merge(clearedSource, builder, options);
+    assertEquals(false, builder.hasPayload());
+
     // Change to replace message fields.
     options.setReplaceMessageFields(true);
     builder = NestedTestAllTypes.newBuilder();
     builder.getPayloadBuilder().setOptionalInt32(1000);
     builder.getPayloadBuilder().setOptionalUint32(2000);
-    new FieldMaskTree().addFieldPath("payload")
-      .merge(source, builder, options);
+    new FieldMaskTree().addFieldPath("payload").merge(source, builder, options);
     assertEquals(1234, builder.getPayload().getOptionalInt32());
     assertEquals(0, builder.getPayload().getOptionalUint32());
+
+    // Test merging unset message fields.
+    builder = NestedTestAllTypes.newBuilder();
+    builder.getPayloadBuilder().setOptionalInt32(1000);
+    builder.getPayloadBuilder().setOptionalUint32(2000);
+    new FieldMaskTree().addFieldPath("payload").merge(clearedSource, builder, options);
+    assertEquals(false, builder.hasPayload());
+
+    // Test merging unset primitive fields.
+    builder = source.toBuilder();
+    builder.getPayloadBuilder().clearOptionalInt32();
+    NestedTestAllTypes sourceWithPayloadInt32Unset = builder.build();
+    builder = source.toBuilder();
+    new FieldMaskTree()
+        .addFieldPath("payload.optional_int32")
+        .merge(sourceWithPayloadInt32Unset, builder, options);
+    assertEquals(true, builder.getPayload().hasOptionalInt32());
+    assertEquals(0, builder.getPayload().getOptionalInt32());
+
+    // Change to clear unset primitive fields.
+    options.setReplacePrimitiveFields(true);
+    builder = source.toBuilder();
+    new FieldMaskTree()
+        .addFieldPath("payload.optional_int32")
+        .merge(sourceWithPayloadInt32Unset, builder, options);
+    assertEquals(true, builder.hasPayload());
+    assertEquals(false, builder.getPayload().hasOptionalInt32());
   }
 }
-
diff --git a/java/util/src/test/java/com/google/protobuf/util/FieldMaskUtilTest.java b/java/util/src/test/java/com/google/protobuf/util/FieldMaskUtilTest.java
index 67fbe0b1..194f7b9c 100644
--- a/java/util/src/test/java/com/google/protobuf/util/FieldMaskUtilTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/FieldMaskUtilTest.java
@@ -53,6 +53,21 @@ public class FieldMaskUtilTest extends TestCase {
         NestedTestAllTypes.class, "payload.nonexist"));
     
     assertTrue(FieldMaskUtil.isValid(
+        NestedTestAllTypes.class, FieldMaskUtil.fromString("payload")));
+    assertFalse(FieldMaskUtil.isValid(
+        NestedTestAllTypes.class, FieldMaskUtil.fromString("nonexist")));
+    assertFalse(FieldMaskUtil.isValid(
+        NestedTestAllTypes.class, FieldMaskUtil.fromString("payload,nonexist")));
+    
+    assertTrue(FieldMaskUtil.isValid(NestedTestAllTypes.getDescriptor(), "payload"));
+    assertFalse(FieldMaskUtil.isValid(NestedTestAllTypes.getDescriptor(), "nonexist"));
+    
+    assertTrue(FieldMaskUtil.isValid(
+        NestedTestAllTypes.getDescriptor(), FieldMaskUtil.fromString("payload")));
+    assertFalse(FieldMaskUtil.isValid(
+        NestedTestAllTypes.getDescriptor(), FieldMaskUtil.fromString("nonexist")));
+    
+    assertTrue(FieldMaskUtil.isValid(
         NestedTestAllTypes.class, "payload.optional_nested_message.bb"));
     // Repeated fields cannot have sub-paths.
     assertFalse(FieldMaskUtil.isValid(
@@ -74,7 +89,7 @@ public class FieldMaskUtilTest extends TestCase {
       addPaths("bar").addPaths("").build();
     assertEquals("foo,bar", FieldMaskUtil.toString(mask));
   }
-  
+
   public void testFromString() throws Exception {
     FieldMask mask = FieldMaskUtil.fromString("");
     assertEquals(0, mask.getPathsCount());
@@ -85,16 +100,16 @@ public class FieldMaskUtilTest extends TestCase {
     assertEquals(2, mask.getPathsCount());
     assertEquals("foo", mask.getPaths(0));
     assertEquals("bar.baz", mask.getPaths(1));
-    
+
     // Empty field paths are ignore.
     mask = FieldMaskUtil.fromString(",foo,,bar,");
     assertEquals(2, mask.getPathsCount());
     assertEquals("foo", mask.getPaths(0));
     assertEquals("bar", mask.getPaths(1));
-    
+
     // Check whether the field paths are valid if a class parameter is provided.
     mask = FieldMaskUtil.fromString(NestedTestAllTypes.class, ",payload");
-    
+
     try {
       mask = FieldMaskUtil.fromString(
           NestedTestAllTypes.class, "payload,nonexist");
@@ -103,6 +118,31 @@ public class FieldMaskUtilTest extends TestCase {
       // Expected.
     }
   }
+
+  public void testFromFieldNumbers() throws Exception {
+    FieldMask mask = FieldMaskUtil.fromFieldNumbers(TestAllTypes.class);
+    assertEquals(0, mask.getPathsCount());
+    mask =
+        FieldMaskUtil.fromFieldNumbers(
+            TestAllTypes.class, TestAllTypes.OPTIONAL_INT32_FIELD_NUMBER);
+    assertEquals(1, mask.getPathsCount());
+    assertEquals("optional_int32", mask.getPaths(0));
+    mask =
+        FieldMaskUtil.fromFieldNumbers(
+            TestAllTypes.class,
+            TestAllTypes.OPTIONAL_INT32_FIELD_NUMBER,
+            TestAllTypes.OPTIONAL_INT64_FIELD_NUMBER);
+    assertEquals(2, mask.getPathsCount());
+    assertEquals("optional_int32", mask.getPaths(0));
+    assertEquals("optional_int64", mask.getPaths(1));
+
+    try {
+      int invalidFieldNumber = 1000;
+      mask = FieldMaskUtil.fromFieldNumbers(TestAllTypes.class, invalidFieldNumber);
+      fail("Exception is expected.");
+    } catch (IllegalArgumentException expected) {
+    }
+  }
   
   public void testUnion() throws Exception {
     // Only test a simple case here and expect
@@ -112,6 +152,15 @@ public class FieldMaskUtilTest extends TestCase {
     FieldMask result = FieldMaskUtil.union(mask1, mask2);
     assertEquals("bar,foo", FieldMaskUtil.toString(result));
   }
+
+  public void testUnion_usingVarArgs() throws Exception {
+    FieldMask mask1 = FieldMaskUtil.fromString("foo");
+    FieldMask mask2 = FieldMaskUtil.fromString("foo.bar,bar.quz");
+    FieldMask mask3 = FieldMaskUtil.fromString("bar.quz");
+    FieldMask mask4 = FieldMaskUtil.fromString("bar");
+    FieldMask result = FieldMaskUtil.union(mask1, mask2, mask3, mask4);
+    assertEquals("bar,foo", FieldMaskUtil.toString(result));
+  }
   
   public void testIntersection() throws Exception {
     // Only test a simple case here and expect
diff --git a/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java b/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
index ddf5ad2a..d95b626c 100644
--- a/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
@@ -51,9 +51,11 @@ import com.google.protobuf.util.JsonTestProto.TestAllTypes;
 import com.google.protobuf.util.JsonTestProto.TestAllTypes.NestedEnum;
 import com.google.protobuf.util.JsonTestProto.TestAllTypes.NestedMessage;
 import com.google.protobuf.util.JsonTestProto.TestAny;
+import com.google.protobuf.util.JsonTestProto.TestCustomJsonName;
 import com.google.protobuf.util.JsonTestProto.TestDuration;
 import com.google.protobuf.util.JsonTestProto.TestFieldMask;
 import com.google.protobuf.util.JsonTestProto.TestMap;
+import com.google.protobuf.util.JsonTestProto.TestOneof;
 import com.google.protobuf.util.JsonTestProto.TestStruct;
 import com.google.protobuf.util.JsonTestProto.TestTimestamp;
 import com.google.protobuf.util.JsonTestProto.TestWrappers;
@@ -120,11 +122,11 @@ public class JsonFormatTest extends TestCase {
     builder.addRepeatedNestedEnum(NestedEnum.BAZ);
     builder.addRepeatedNestedMessageBuilder().setValue(200);
   }
-  
+
   private void assertRoundTripEquals(Message message) throws Exception {
     assertRoundTripEquals(message, TypeRegistry.getEmptyTypeRegistry());
   }
-  
+
   private void assertRoundTripEquals(Message message, TypeRegistry registry) throws Exception {
     JsonFormat.Printer printer = JsonFormat.printer().usingTypeRegistry(registry);
     JsonFormat.Parser parser = JsonFormat.parser().usingTypeRegistry(registry);
@@ -133,72 +135,69 @@ public class JsonFormatTest extends TestCase {
     Message parsedMessage = builder.build();
     assertEquals(message.toString(), parsedMessage.toString());
   }
-  
+
   private String toJsonString(Message message) throws IOException {
     return JsonFormat.printer().print(message);
   }
-  
+
   private void mergeFromJson(String json, Message.Builder builder) throws IOException {
     JsonFormat.parser().merge(json, builder);
   }
-  
+
   public void testAllFields() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     setAllFields(builder);
     TestAllTypes message = builder.build();
-    
-    assertEquals(        
-        "{\n"
-        + "  \"optionalInt32\": 1234,\n"
-        + "  \"optionalInt64\": \"1234567890123456789\",\n"
-        + "  \"optionalUint32\": 5678,\n"
-        + "  \"optionalUint64\": \"2345678901234567890\",\n"
-        + "  \"optionalSint32\": 9012,\n"
-        + "  \"optionalSint64\": \"3456789012345678901\",\n"
-        + "  \"optionalFixed32\": 3456,\n"
-        + "  \"optionalFixed64\": \"4567890123456789012\",\n"
-        + "  \"optionalSfixed32\": 7890,\n"
-        + "  \"optionalSfixed64\": \"5678901234567890123\",\n"
-        + "  \"optionalFloat\": 1.5,\n"
-        + "  \"optionalDouble\": 1.25,\n"
-        + "  \"optionalBool\": true,\n"
-        + "  \"optionalString\": \"Hello world!\",\n"
-        + "  \"optionalBytes\": \"AAEC\",\n"
-        + "  \"optionalNestedMessage\": {\n"
-        + "    \"value\": 100\n"
-        + "  },\n"
-        + "  \"optionalNestedEnum\": \"BAR\",\n"
-        + "  \"repeatedInt32\": [1234, 234],\n"
-        + "  \"repeatedInt64\": [\"1234567890123456789\", \"234567890123456789\"],\n"
-        + "  \"repeatedUint32\": [5678, 678],\n"
-        + "  \"repeatedUint64\": [\"2345678901234567890\", \"345678901234567890\"],\n"
-        + "  \"repeatedSint32\": [9012, 10],\n"
-        + "  \"repeatedSint64\": [\"3456789012345678901\", \"456789012345678901\"],\n"
-        + "  \"repeatedFixed32\": [3456, 456],\n"
-        + "  \"repeatedFixed64\": [\"4567890123456789012\", \"567890123456789012\"],\n"
-        + "  \"repeatedSfixed32\": [7890, 890],\n"
-        + "  \"repeatedSfixed64\": [\"5678901234567890123\", \"678901234567890123\"],\n"
-        + "  \"repeatedFloat\": [1.5, 11.5],\n"
-        + "  \"repeatedDouble\": [1.25, 11.25],\n"
-        + "  \"repeatedBool\": [true, true],\n"
-        + "  \"repeatedString\": [\"Hello world!\", \"ello world!\"],\n"
-        + "  \"repeatedBytes\": [\"AAEC\", \"AQI=\"],\n"
-        + "  \"repeatedNestedMessage\": [{\n"
-        + "    \"value\": 100\n"
-        + "  }, {\n"
-        + "    \"value\": 200\n"
-        + "  }],\n"
-        + "  \"repeatedNestedEnum\": [\"BAR\", \"BAZ\"]\n"
-        + "}",
+
+    assertEquals(
+        "{\n"
+            + "  \"optionalInt32\": 1234,\n"
+            + "  \"optionalInt64\": \"1234567890123456789\",\n"
+            + "  \"optionalUint32\": 5678,\n"
+            + "  \"optionalUint64\": \"2345678901234567890\",\n"
+            + "  \"optionalSint32\": 9012,\n"
+            + "  \"optionalSint64\": \"3456789012345678901\",\n"
+            + "  \"optionalFixed32\": 3456,\n"
+            + "  \"optionalFixed64\": \"4567890123456789012\",\n"
+            + "  \"optionalSfixed32\": 7890,\n"
+            + "  \"optionalSfixed64\": \"5678901234567890123\",\n"
+            + "  \"optionalFloat\": 1.5,\n"
+            + "  \"optionalDouble\": 1.25,\n"
+            + "  \"optionalBool\": true,\n"
+            + "  \"optionalString\": \"Hello world!\",\n"
+            + "  \"optionalBytes\": \"AAEC\",\n"
+            + "  \"optionalNestedMessage\": {\n"
+            + "    \"value\": 100\n"
+            + "  },\n"
+            + "  \"optionalNestedEnum\": \"BAR\",\n"
+            + "  \"repeatedInt32\": [1234, 234],\n"
+            + "  \"repeatedInt64\": [\"1234567890123456789\", \"234567890123456789\"],\n"
+            + "  \"repeatedUint32\": [5678, 678],\n"
+            + "  \"repeatedUint64\": [\"2345678901234567890\", \"345678901234567890\"],\n"
+            + "  \"repeatedSint32\": [9012, 10],\n"
+            + "  \"repeatedSint64\": [\"3456789012345678901\", \"456789012345678901\"],\n"
+            + "  \"repeatedFixed32\": [3456, 456],\n"
+            + "  \"repeatedFixed64\": [\"4567890123456789012\", \"567890123456789012\"],\n"
+            + "  \"repeatedSfixed32\": [7890, 890],\n"
+            + "  \"repeatedSfixed64\": [\"5678901234567890123\", \"678901234567890123\"],\n"
+            + "  \"repeatedFloat\": [1.5, 11.5],\n"
+            + "  \"repeatedDouble\": [1.25, 11.25],\n"
+            + "  \"repeatedBool\": [true, true],\n"
+            + "  \"repeatedString\": [\"Hello world!\", \"ello world!\"],\n"
+            + "  \"repeatedBytes\": [\"AAEC\", \"AQI=\"],\n"
+            + "  \"repeatedNestedMessage\": [{\n"
+            + "    \"value\": 100\n"
+            + "  }, {\n"
+            + "    \"value\": 200\n"
+            + "  }],\n"
+            + "  \"repeatedNestedEnum\": [\"BAR\", \"BAZ\"]\n"
+            + "}",
         toJsonString(message));
-    
+
     assertRoundTripEquals(message);
   }
-  
+
   public void testUnknownEnumValues() throws Exception {
-    // Unknown enum values will be dropped.
-    // TODO(xiaofeng): We may want to revisit this (whether we should omit
-    // unknown enum values).
     TestAllTypes message = TestAllTypes.newBuilder()
         .setOptionalNestedEnumValue(12345)
         .addRepeatedNestedEnumValue(12345)
@@ -206,21 +205,26 @@ public class JsonFormatTest extends TestCase {
         .build();
     assertEquals(
         "{\n"
-        + "  \"repeatedNestedEnum\": [\"FOO\"]\n"
+        + "  \"optionalNestedEnum\": 12345,\n"
+        + "  \"repeatedNestedEnum\": [12345, \"FOO\"]\n"
         + "}", toJsonString(message));
-    
+    assertRoundTripEquals(message);
+
     TestMap.Builder mapBuilder = TestMap.newBuilder();
     mapBuilder.getMutableInt32ToEnumMapValue().put(1, 0);
     mapBuilder.getMutableInt32ToEnumMapValue().put(2, 12345);
     TestMap mapMessage = mapBuilder.build();
     assertEquals(
-        "{\n" 
-        + "  \"int32ToEnumMap\": {\n" 
-        + "    \"1\": \"FOO\"\n" 
-        + "  }\n" 
-        + "}", toJsonString(mapMessage));
+        "{\n"
+            + "  \"int32ToEnumMap\": {\n"
+            + "    \"1\": \"FOO\",\n"
+            + "    \"2\": 12345\n"
+            + "  }\n"
+            + "}",
+        toJsonString(mapMessage));
+    assertRoundTripEquals(mapMessage);
   }
-  
+
   public void testSpecialFloatValues() throws Exception {
     TestAllTypes message = TestAllTypes.newBuilder()
         .addRepeatedFloat(Float.NaN)
@@ -235,10 +239,10 @@ public class JsonFormatTest extends TestCase {
         + "  \"repeatedFloat\": [\"NaN\", \"Infinity\", \"-Infinity\"],\n"
         + "  \"repeatedDouble\": [\"NaN\", \"Infinity\", \"-Infinity\"]\n"
         + "}", toJsonString(message));
-    
+
     assertRoundTripEquals(message);
   }
-  
+
   public void testParserAcceptStringForNumbericField() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     mergeFromJson(
@@ -262,7 +266,36 @@ public class JsonFormatTest extends TestCase {
     assertEquals(1.25, message.getOptionalDouble());
     assertEquals(true, message.getOptionalBool());
   }
-  
+
+  public void testParserAcceptFloatingPointValueForIntegerField() throws Exception {
+    // Test that numeric values like "1.000", "1e5" will also be accepted.
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    mergeFromJson(
+        "{\n"
+            + "  \"repeatedInt32\": [1.000, 1e5, \"1.000\", \"1e5\"],\n"
+            + "  \"repeatedUint32\": [1.000, 1e5, \"1.000\", \"1e5\"],\n"
+            + "  \"repeatedInt64\": [1.000, 1e5, \"1.000\", \"1e5\"],\n"
+            + "  \"repeatedUint64\": [1.000, 1e5, \"1.000\", \"1e5\"]\n"
+            + "}", builder);
+    int[] expectedValues = new int[]{1, 100000, 1, 100000};
+    assertEquals(4, builder.getRepeatedInt32Count());
+    assertEquals(4, builder.getRepeatedUint32Count());
+    assertEquals(4, builder.getRepeatedInt64Count());
+    assertEquals(4, builder.getRepeatedUint64Count());
+    for (int i = 0; i < 4; ++i) {
+      assertEquals(expectedValues[i], builder.getRepeatedInt32(i));
+      assertEquals(expectedValues[i], builder.getRepeatedUint32(i));
+      assertEquals(expectedValues[i], builder.getRepeatedInt64(i));
+      assertEquals(expectedValues[i], builder.getRepeatedUint64(i));
+    }
+
+    // Non-integers will still be rejected.
+    assertRejects("optionalInt32", "1.5");
+    assertRejects("optionalUint32", "1.5");
+    assertRejects("optionalInt64", "1.5");
+    assertRejects("optionalUint64", "1.5");
+  }
+
   private void assertRejects(String name, String value) {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     try {
@@ -280,24 +313,25 @@ public class JsonFormatTest extends TestCase {
       // Expected.
     }
   }
-  
+
   private void assertAccepts(String name, String value) throws IOException {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     // Both numeric form and string form are accepted.
     mergeFromJson("{\"" + name + "\":" + value + "}", builder);
+    builder.clear();
     mergeFromJson("{\"" + name + "\":\"" + value + "\"}", builder);
   }
-  
+
   public void testParserRejectOutOfRangeNumericValues() throws Exception {
     assertAccepts("optionalInt32", String.valueOf(Integer.MAX_VALUE));
     assertAccepts("optionalInt32", String.valueOf(Integer.MIN_VALUE));
     assertRejects("optionalInt32", String.valueOf(Integer.MAX_VALUE + 1L));
     assertRejects("optionalInt32", String.valueOf(Integer.MIN_VALUE - 1L));
-    
+
     assertAccepts("optionalUint32", String.valueOf(Integer.MAX_VALUE + 1L));
     assertRejects("optionalUint32", "123456789012345");
     assertRejects("optionalUint32", "-1");
-    
+
     BigInteger one = new BigInteger("1");
     BigInteger maxLong = new BigInteger(String.valueOf(Long.MAX_VALUE));
     BigInteger minLong = new BigInteger(String.valueOf(Long.MIN_VALUE));
@@ -318,7 +352,7 @@ public class JsonFormatTest extends TestCase {
     assertAccepts("optionalFloat", String.valueOf(-Float.MAX_VALUE));
     assertRejects("optionalFloat", String.valueOf(Double.MAX_VALUE));
     assertRejects("optionalFloat", String.valueOf(-Double.MAX_VALUE));
-    
+
     BigDecimal moreThanOne = new BigDecimal("1.000001");
     BigDecimal maxDouble = new BigDecimal(Double.MAX_VALUE);
     BigDecimal minDouble = new BigDecimal(-Double.MAX_VALUE);
@@ -327,7 +361,7 @@ public class JsonFormatTest extends TestCase {
     assertRejects("optionalDouble", maxDouble.multiply(moreThanOne).toString());
     assertRejects("optionalDouble", minDouble.multiply(moreThanOne).toString());
   }
-  
+
   public void testParserAcceptNull() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     mergeFromJson(
@@ -369,87 +403,77 @@ public class JsonFormatTest extends TestCase {
         + "}", builder);
     TestAllTypes message = builder.build();
     assertEquals(TestAllTypes.getDefaultInstance(), message);
-    
-    // Repeated field elements can also be null.
-    builder = TestAllTypes.newBuilder();
-    mergeFromJson(
-        "{\n"
-        + "  \"repeatedInt32\": [null, null],\n"
-        + "  \"repeatedInt64\": [null, null],\n"
-        + "  \"repeatedUint32\": [null, null],\n"
-        + "  \"repeatedUint64\": [null, null],\n"
-        + "  \"repeatedSint32\": [null, null],\n"
-        + "  \"repeatedSint64\": [null, null],\n"
-        + "  \"repeatedFixed32\": [null, null],\n"
-        + "  \"repeatedFixed64\": [null, null],\n"
-        + "  \"repeatedSfixed32\": [null, null],\n"
-        + "  \"repeatedSfixed64\": [null, null],\n"
-        + "  \"repeatedFloat\": [null, null],\n"
-        + "  \"repeatedDouble\": [null, null],\n"
-        + "  \"repeatedBool\": [null, null],\n"
-        + "  \"repeatedString\": [null, null],\n"
-        + "  \"repeatedBytes\": [null, null],\n"
-        + "  \"repeatedNestedMessage\": [null, null],\n"
-        + "  \"repeatedNestedEnum\": [null, null]\n"
-        + "}", builder);
-    message = builder.build();
-    // "null" elements will be parsed to default values.
-    assertEquals(2, message.getRepeatedInt32Count());
-    assertEquals(0, message.getRepeatedInt32(0));
-    assertEquals(0, message.getRepeatedInt32(1));
-    assertEquals(2, message.getRepeatedInt32Count());
-    assertEquals(0, message.getRepeatedInt32(0));
-    assertEquals(0, message.getRepeatedInt32(1));
-    assertEquals(2, message.getRepeatedInt64Count());
-    assertEquals(0, message.getRepeatedInt64(0));
-    assertEquals(0, message.getRepeatedInt64(1));
-    assertEquals(2, message.getRepeatedUint32Count());
-    assertEquals(0, message.getRepeatedUint32(0));
-    assertEquals(0, message.getRepeatedUint32(1));
-    assertEquals(2, message.getRepeatedUint64Count());
-    assertEquals(0, message.getRepeatedUint64(0));
-    assertEquals(0, message.getRepeatedUint64(1));
-    assertEquals(2, message.getRepeatedSint32Count());
-    assertEquals(0, message.getRepeatedSint32(0));
-    assertEquals(0, message.getRepeatedSint32(1));
-    assertEquals(2, message.getRepeatedSint64Count());
-    assertEquals(0, message.getRepeatedSint64(0));
-    assertEquals(0, message.getRepeatedSint64(1));
-    assertEquals(2, message.getRepeatedFixed32Count());
-    assertEquals(0, message.getRepeatedFixed32(0));
-    assertEquals(0, message.getRepeatedFixed32(1));
-    assertEquals(2, message.getRepeatedFixed64Count());
-    assertEquals(0, message.getRepeatedFixed64(0));
-    assertEquals(0, message.getRepeatedFixed64(1));
-    assertEquals(2, message.getRepeatedSfixed32Count());
-    assertEquals(0, message.getRepeatedSfixed32(0));
-    assertEquals(0, message.getRepeatedSfixed32(1));
-    assertEquals(2, message.getRepeatedSfixed64Count());
-    assertEquals(0, message.getRepeatedSfixed64(0));
-    assertEquals(0, message.getRepeatedSfixed64(1));
-    assertEquals(2, message.getRepeatedFloatCount());
-    assertEquals(0f, message.getRepeatedFloat(0));
-    assertEquals(0f, message.getRepeatedFloat(1));
-    assertEquals(2, message.getRepeatedDoubleCount());
-    assertEquals(0.0, message.getRepeatedDouble(0));
-    assertEquals(0.0, message.getRepeatedDouble(1));
-    assertEquals(2, message.getRepeatedBoolCount());
-    assertFalse(message.getRepeatedBool(0));
-    assertFalse(message.getRepeatedBool(1));
-    assertEquals(2, message.getRepeatedStringCount());
-    assertTrue(message.getRepeatedString(0).isEmpty());
-    assertTrue(message.getRepeatedString(1).isEmpty());
-    assertEquals(2, message.getRepeatedBytesCount());
-    assertTrue(message.getRepeatedBytes(0).isEmpty());
-    assertTrue(message.getRepeatedBytes(1).isEmpty());
-    assertEquals(2, message.getRepeatedNestedMessageCount());
-    assertEquals(NestedMessage.getDefaultInstance(), message.getRepeatedNestedMessage(0));
-    assertEquals(NestedMessage.getDefaultInstance(), message.getRepeatedNestedMessage(1));
-    assertEquals(2, message.getRepeatedNestedEnumCount());
-    assertEquals(0, message.getRepeatedNestedEnumValue(0));
-    assertEquals(0, message.getRepeatedNestedEnumValue(1));
-  }
-  
+
+    // Repeated field elements cannot be null.
+    try {
+      builder = TestAllTypes.newBuilder();
+      mergeFromJson(
+          "{\n"
+          + "  \"repeatedInt32\": [null, null],\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
+
+    try {
+      builder = TestAllTypes.newBuilder();
+      mergeFromJson(
+          "{\n"
+          + "  \"repeatedNestedMessage\": [null, null],\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
+  }
+
+  public void testParserRejectDuplicatedFields() throws Exception {
+    // TODO(xiaofeng): The parser we are currently using (GSON) will accept and keep the last
+    // one if multiple entries have the same name. This is not the desired behavior but it can
+    // only be fixed by using our own parser. Here we only test the cases where the names are
+    // different but still referring to the same field.
+
+    // Duplicated optional fields.
+    try {
+      TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+      mergeFromJson(
+          "{\n"
+              + "  \"optionalNestedMessage\": {},\n"
+              + "  \"optional_nested_message\": {}\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
+
+    // Duplicated repeated fields.
+    try {
+      TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+      mergeFromJson(
+          "{\n"
+          + "  \"repeatedNestedMessage\": [null, null],\n"
+          + "  \"repeated_nested_message\": [null, null]\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
+
+    // Duplicated oneof fields.
+    try {
+      TestOneof.Builder builder = TestOneof.newBuilder();
+      mergeFromJson(
+          "{\n"
+          + "  \"oneofInt32\": 1,\n"
+          + "  \"oneof_int32\": 2\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
+  }
+
   public void testMapFields() throws Exception {
     TestMap.Builder builder = TestMap.newBuilder();
     builder.getMutableInt32ToInt32Map().put(1, 10);
@@ -484,7 +508,7 @@ public class JsonFormatTest extends TestCase {
         8, NestedMessage.newBuilder().setValue(1234).build());
     builder.getMutableInt32ToEnumMap().put(9, NestedEnum.BAR);
     TestMap message = builder.build();
-    
+
     assertEquals(
         "{\n"
         + "  \"int32ToInt32Map\": {\n"
@@ -575,13 +599,13 @@ public class JsonFormatTest extends TestCase {
         + "  }\n"
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
-    
+
     // Test multiple entries.
     builder = TestMap.newBuilder();
     builder.getMutableInt32ToInt32Map().put(1, 2);
     builder.getMutableInt32ToInt32Map().put(3, 4);
     message = builder.build();
-    
+
     assertEquals(
         "{\n"
         + "  \"int32ToInt32Map\": {\n"
@@ -591,21 +615,33 @@ public class JsonFormatTest extends TestCase {
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
   }
-  
-  public void testMapNullValueIsDefault() throws Exception {
-    TestMap.Builder builder = TestMap.newBuilder();
-    mergeFromJson(
-        "{\n"
-        + "  \"int32ToInt32Map\": {\"1\": null},\n"
-        + "  \"int32ToMessageMap\": {\"2\": null}\n"
-        + "}", builder);
-    TestMap message = builder.build();
-    assertTrue(message.getInt32ToInt32Map().containsKey(1));
-    assertEquals(0, message.getInt32ToInt32Map().get(1).intValue());
-    assertTrue(message.getInt32ToMessageMap().containsKey(2));
-    assertEquals(0, message.getInt32ToMessageMap().get(2).getValue());
+
+  public void testMapNullValueIsRejected() throws Exception {
+    try {
+      TestMap.Builder builder = TestMap.newBuilder();
+      mergeFromJson(
+          "{\n"
+          + "  \"int32ToInt32Map\": {null: 1},\n"
+          + "  \"int32ToMessageMap\": {null: 2}\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
+
+    try {
+      TestMap.Builder builder = TestMap.newBuilder();
+      mergeFromJson(
+          "{\n"
+          + "  \"int32ToInt32Map\": {\"1\": null},\n"
+          + "  \"int32ToMessageMap\": {\"2\": null}\n"
+          + "}", builder);
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Exception expected.
+    }
   }
-  
+
   public void testParserAcceptNonQuotedObjectKey() throws Exception {
     TestMap.Builder builder = TestMap.newBuilder();
     mergeFromJson(
@@ -617,7 +653,7 @@ public class JsonFormatTest extends TestCase {
     assertEquals(2, message.getInt32ToInt32Map().get(1).intValue());
     assertEquals(3, message.getStringToInt32Map().get("hello").intValue());
   }
-  
+
   public void testWrappers() throws Exception {
     TestWrappers.Builder builder = TestWrappers.newBuilder();
     builder.getBoolValueBuilder().setValue(false);
@@ -630,7 +666,7 @@ public class JsonFormatTest extends TestCase {
     builder.getStringValueBuilder().setValue("");
     builder.getBytesValueBuilder().setValue(ByteString.EMPTY);
     TestWrappers message = builder.build();
-    
+
     assertEquals(
         "{\n"
         + "  \"int32Value\": 0,\n"
@@ -656,7 +692,7 @@ public class JsonFormatTest extends TestCase {
     builder.getStringValueBuilder().setValue("7");
     builder.getBytesValueBuilder().setValue(ByteString.copyFrom(new byte[]{8}));
     message = builder.build();
-    
+
     assertEquals(
         "{\n"
         + "  \"int32Value\": 1,\n"
@@ -671,43 +707,43 @@ public class JsonFormatTest extends TestCase {
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
   }
-  
+
   public void testTimestamp() throws Exception {
     TestTimestamp message = TestTimestamp.newBuilder()
         .setTimestampValue(TimeUtil.parseTimestamp("1970-01-01T00:00:00Z"))
         .build();
-    
+
     assertEquals(
         "{\n"
         + "  \"timestampValue\": \"1970-01-01T00:00:00Z\"\n"
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
   }
-  
+
   public void testDuration() throws Exception {
     TestDuration message = TestDuration.newBuilder()
         .setDurationValue(TimeUtil.parseDuration("12345s"))
         .build();
-    
+
     assertEquals(
         "{\n"
         + "  \"durationValue\": \"12345s\"\n"
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
   }
-  
+
   public void testFieldMask() throws Exception {
     TestFieldMask message = TestFieldMask.newBuilder()
         .setFieldMaskValue(FieldMaskUtil.fromString("foo.bar,baz"))
         .build();
-    
+
     assertEquals(
         "{\n"
         + "  \"fieldMaskValue\": \"foo.bar,baz\"\n"
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
   }
-  
+
   public void testStruct() throws Exception {
     // Build a struct with all possible values.
     TestStruct.Builder builder = TestStruct.newBuilder();
@@ -729,7 +765,7 @@ public class JsonFormatTest extends TestCase {
     structBuilder.getMutableFields().put(
         "list_value", Value.newBuilder().setListValue(listBuilder.build()).build());
     TestStruct message = builder.build();
-    
+
     assertEquals(
         "{\n"
         + "  \"structValue\": {\n"
@@ -743,12 +779,32 @@ public class JsonFormatTest extends TestCase {
         + "  }\n"
         + "}", toJsonString(message));
     assertRoundTripEquals(message);
+
+    builder = TestStruct.newBuilder();
+    builder.setValue(Value.newBuilder().setNullValueValue(0).build());
+    message = builder.build();
+    assertEquals(
+        "{\n"
+        + "  \"value\": null\n"
+        + "}", toJsonString(message));
+    assertRoundTripEquals(message);
+
+    builder = TestStruct.newBuilder();
+    listBuilder = builder.getListValueBuilder();
+    listBuilder.addValues(Value.newBuilder().setNumberValue(31831.125).build());
+    listBuilder.addValues(Value.newBuilder().setNullValueValue(0).build());
+    message = builder.build();
+    assertEquals(
+        "{\n"
+        + "  \"listValue\": [31831.125, null]\n"
+        + "}", toJsonString(message));
+    assertRoundTripEquals(message);
   }
-  
+
   public void testAnyFields() throws Exception {
     TestAllTypes content = TestAllTypes.newBuilder().setOptionalInt32(1234).build();
     TestAny message = TestAny.newBuilder().setAnyValue(Any.pack(content)).build();
-    
+
     // A TypeRegistry must be provided in order to convert Any types.
     try {
       toJsonString(message);
@@ -756,11 +812,11 @@ public class JsonFormatTest extends TestCase {
     } catch (IOException e) {
       // Expected.
     }
-    
+
     JsonFormat.TypeRegistry registry = JsonFormat.TypeRegistry.newBuilder()
         .add(TestAllTypes.getDescriptor()).build();
     JsonFormat.Printer printer = JsonFormat.printer().usingTypeRegistry(registry);
-    
+
     assertEquals(
         "{\n"
         + "  \"anyValue\": {\n"
@@ -769,8 +825,8 @@ public class JsonFormatTest extends TestCase {
         + "  }\n"
         + "}" , printer.print(message));
     assertRoundTripEquals(message, registry);
-    
-    
+
+
     // Well-known types have a special formatting when embedded in Any.
     //
     // 1. Any in Any.
@@ -784,7 +840,7 @@ public class JsonFormatTest extends TestCase {
         + "  }\n"
         + "}", printer.print(anyMessage));
     assertRoundTripEquals(anyMessage, registry);
-    
+
     // 2. Wrappers in Any.
     anyMessage = Any.pack(Int32Value.newBuilder().setValue(12345).build());
     assertEquals(
@@ -850,7 +906,7 @@ public class JsonFormatTest extends TestCase {
         + "  \"value\": \"AQI=\"\n"
         + "}", printer.print(anyMessage));
     assertRoundTripEquals(anyMessage, registry);
-    
+
     // 3. Timestamp in Any.
     anyMessage = Any.pack(TimeUtil.parseTimestamp("1969-12-31T23:59:59Z"));
     assertEquals(
@@ -859,7 +915,7 @@ public class JsonFormatTest extends TestCase {
         + "  \"value\": \"1969-12-31T23:59:59Z\"\n"
         + "}", printer.print(anyMessage));
     assertRoundTripEquals(anyMessage, registry);
-    
+
     // 4. Duration in Any
     anyMessage = Any.pack(TimeUtil.parseDuration("12345.10s"));
     assertEquals(
@@ -891,8 +947,17 @@ public class JsonFormatTest extends TestCase {
         + "  }\n"
         + "}", printer.print(anyMessage));
     assertRoundTripEquals(anyMessage, registry);
+    Value.Builder valueBuilder = Value.newBuilder();
+    valueBuilder.setNumberValue(1);
+    anyMessage = Any.pack(valueBuilder.build());
+    assertEquals(
+        "{\n"
+        + "  \"@type\": \"type.googleapis.com/google.protobuf.Value\",\n"
+        + "  \"value\": 1.0\n"
+        + "}", printer.print(anyMessage));
+    assertRoundTripEquals(anyMessage, registry);
   }
-  
+
   public void testParserMissingTypeUrl() throws Exception {
     try {
       Any.Builder builder = Any.newBuilder();
@@ -905,7 +970,7 @@ public class JsonFormatTest extends TestCase {
       // Expected.
     }
   }
-  
+
   public void testParserUnexpectedTypeUrl() throws Exception {
     try {
       TestAllTypes.Builder builder = TestAllTypes.newBuilder();
@@ -917,9 +982,9 @@ public class JsonFormatTest extends TestCase {
       fail("Exception is expected.");
     } catch (IOException e) {
       // Expected.
-    } 
+    }
   }
-  
+
   public void testParserRejectTrailingComma() throws Exception {
     try {
       TestAllTypes.Builder builder = TestAllTypes.newBuilder();
@@ -947,20 +1012,13 @@ public class JsonFormatTest extends TestCase {
     //   // Expected.
     // }
   }
-  
+
   public void testParserRejectInvalidBase64() throws Exception {
-    try {
-      TestAllTypes.Builder builder = TestAllTypes.newBuilder();
-      mergeFromJson(
-          "{\n"
-          + "  \"optionalBytes\": \"!@#$\"\n"
-          + "}", builder);
-      fail("Exception is expected.");
-    } catch (InvalidProtocolBufferException e) {
-      // Expected.
-    } 
+    assertRejects("optionalBytes", "!@#$");
+    // We use standard BASE64 with paddings.
+    assertRejects("optionalBytes", "AQI");
   }
-  
+
   public void testParserRejectInvalidEnumValue() throws Exception {
     try {
       TestAllTypes.Builder builder = TestAllTypes.newBuilder();
@@ -971,6 +1029,146 @@ public class JsonFormatTest extends TestCase {
       fail("Exception is expected.");
     } catch (InvalidProtocolBufferException e) {
       // Expected.
-    } 
+    }
+  }
+
+  public void testCustomJsonName() throws Exception {
+    TestCustomJsonName message = TestCustomJsonName.newBuilder().setValue(12345).build();
+    assertEquals("{\n" + "  \"@value\": 12345\n" + "}", JsonFormat.printer().print(message));
+    assertRoundTripEquals(message);
+  }
+
+  public void testDefaultGsonDoesNotHtmlEscape() throws Exception {
+    TestAllTypes message = TestAllTypes.newBuilder().setOptionalString("=").build();
+    assertEquals(
+        "{\n" + "  \"optionalString\": \"=\"" + "\n}", JsonFormat.printer().print(message));
+  }
+
+  public void testIncludingDefaultValueFields() throws Exception {
+    TestAllTypes message = TestAllTypes.getDefaultInstance();
+    assertEquals("{\n}", JsonFormat.printer().print(message));
+    assertEquals(
+        "{\n"
+            + "  \"optionalInt32\": 0,\n"
+            + "  \"optionalInt64\": \"0\",\n"
+            + "  \"optionalUint32\": 0,\n"
+            + "  \"optionalUint64\": \"0\",\n"
+            + "  \"optionalSint32\": 0,\n"
+            + "  \"optionalSint64\": \"0\",\n"
+            + "  \"optionalFixed32\": 0,\n"
+            + "  \"optionalFixed64\": \"0\",\n"
+            + "  \"optionalSfixed32\": 0,\n"
+            + "  \"optionalSfixed64\": \"0\",\n"
+            + "  \"optionalFloat\": 0.0,\n"
+            + "  \"optionalDouble\": 0.0,\n"
+            + "  \"optionalBool\": false,\n"
+            + "  \"optionalString\": \"\",\n"
+            + "  \"optionalBytes\": \"\",\n"
+            + "  \"optionalNestedEnum\": \"FOO\",\n"
+            + "  \"repeatedInt32\": [],\n"
+            + "  \"repeatedInt64\": [],\n"
+            + "  \"repeatedUint32\": [],\n"
+            + "  \"repeatedUint64\": [],\n"
+            + "  \"repeatedSint32\": [],\n"
+            + "  \"repeatedSint64\": [],\n"
+            + "  \"repeatedFixed32\": [],\n"
+            + "  \"repeatedFixed64\": [],\n"
+            + "  \"repeatedSfixed32\": [],\n"
+            + "  \"repeatedSfixed64\": [],\n"
+            + "  \"repeatedFloat\": [],\n"
+            + "  \"repeatedDouble\": [],\n"
+            + "  \"repeatedBool\": [],\n"
+            + "  \"repeatedString\": [],\n"
+            + "  \"repeatedBytes\": [],\n"
+            + "  \"repeatedNestedMessage\": [],\n"
+            + "  \"repeatedNestedEnum\": []\n"
+            + "}",
+        JsonFormat.printer().includingDefaultValueFields().print(message));
+
+    TestMap mapMessage = TestMap.getDefaultInstance();
+    assertEquals("{\n}", JsonFormat.printer().print(mapMessage));
+    assertEquals(
+        "{\n"
+            + "  \"int32ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"int64ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"uint32ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"uint64ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"sint32ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"sint64ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"fixed32ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"fixed64ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"sfixed32ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"sfixed64ToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"boolToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"stringToInt32Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToInt64Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToUint32Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToUint64Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToSint32Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToSint64Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToFixed32Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToFixed64Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToSfixed32Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToSfixed64Map\": {\n"
+            + "  },\n"
+            + "  \"int32ToFloatMap\": {\n"
+            + "  },\n"
+            + "  \"int32ToDoubleMap\": {\n"
+            + "  },\n"
+            + "  \"int32ToBoolMap\": {\n"
+            + "  },\n"
+            + "  \"int32ToStringMap\": {\n"
+            + "  },\n"
+            + "  \"int32ToBytesMap\": {\n"
+            + "  },\n"
+            + "  \"int32ToMessageMap\": {\n"
+            + "  },\n"
+            + "  \"int32ToEnumMap\": {\n"
+            + "  }\n"
+            + "}",
+        JsonFormat.printer().includingDefaultValueFields().print(mapMessage));
+  }
+
+  public void testPreservingProtoFieldNames() throws Exception {
+    TestAllTypes message = TestAllTypes.newBuilder().setOptionalInt32(12345).build();
+    assertEquals("{\n" + "  \"optionalInt32\": 12345\n" + "}", JsonFormat.printer().print(message));
+    assertEquals(
+        "{\n" + "  \"optional_int32\": 12345\n" + "}",
+        JsonFormat.printer().preservingProtoFieldNames().print(message));
+
+    // The json_name field option is ignored when configured to use original proto field names.
+    TestCustomJsonName messageWithCustomJsonName =
+        TestCustomJsonName.newBuilder().setValue(12345).build();
+    assertEquals(
+        "{\n" + "  \"value\": 12345\n" + "}",
+        JsonFormat.printer().preservingProtoFieldNames().print(messageWithCustomJsonName));
+
+    // Parsers accept both original proto field names and lowerCamelCase names.
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    JsonFormat.parser().merge("{\"optionalInt32\": 12345}", builder);
+    assertEquals(12345, builder.getOptionalInt32());
+    builder.clear();
+    JsonFormat.parser().merge("{\"optional_int32\": 54321}", builder);
+    assertEquals(54321, builder.getOptionalInt32());
   }
 }
diff --git a/java/util/src/test/java/com/google/protobuf/util/TimeUtilTest.java b/java/util/src/test/java/com/google/protobuf/util/TimeUtilTest.java
index fe5617e1..4c31b2b3 100644
--- a/java/util/src/test/java/com/google/protobuf/util/TimeUtilTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/TimeUtilTest.java
@@ -38,6 +38,8 @@ import junit.framework.TestCase;
 import org.junit.Assert;
 
 import java.text.ParseException;
+import java.util.ArrayList;
+import java.util.List;
 
 /** Unit tests for {@link TimeUtil}. */
 public class TimeUtilTest extends TestCase {
@@ -76,6 +78,71 @@ public class TimeUtilTest extends TestCase {
     assertEquals("1970-01-01T08:00:00.010Z", TimeUtil.toString(value));
   }
 
+  private volatile boolean stopParsingThreads = false;
+  private volatile String errorMessage = "";
+
+  private class ParseTimestampThread extends Thread {
+    private final String[] strings;
+    private final Timestamp[] values;
+    public ParseTimestampThread(String[] strings, Timestamp[] values) {
+      this.strings = strings;
+      this.values = values;
+    }
+
+    @Override
+    public void run() {
+      int index = 0;
+      while (!stopParsingThreads) {
+        Timestamp result;
+        try {
+          result = TimeUtil.parseTimestamp(strings[index]);
+        } catch (ParseException e) {
+          errorMessage = "Failed to parse timestamp: " + strings[index];
+          break;
+        }
+        if (result.getSeconds() != values[index].getSeconds()
+            || result.getNanos() != values[index].getNanos()) {
+          errorMessage = "Actual result: " + result.toString() + ", expected: "
+              + values[index].toString();
+          break;
+        }
+        index = (index + 1) % strings.length;
+      }
+    }
+  }
+
+  public void testTimestampConcurrentParsing() throws Exception {
+    String[] timestampStrings = new String[]{
+      "0001-01-01T00:00:00Z",
+      "9999-12-31T23:59:59.999999999Z",
+      "1970-01-01T00:00:00Z",
+      "1969-12-31T23:59:59.999Z",
+    };
+    Timestamp[] timestampValues = new Timestamp[timestampStrings.length];
+    for (int i = 0; i < timestampStrings.length; i++) {
+      timestampValues[i] = TimeUtil.parseTimestamp(timestampStrings[i]);
+    }
+
+    final int THREAD_COUNT = 16;
+    final int RUNNING_TIME = 5000;  // in milliseconds.
+    final List<Thread> threads = new ArrayList<Thread>();
+
+    stopParsingThreads = false;
+    errorMessage = "";
+    for (int i = 0; i < THREAD_COUNT; i++) {
+      Thread thread = new ParseTimestampThread(
+          timestampStrings, timestampValues);
+      thread.start();
+      threads.add(thread);
+    }
+    Thread.sleep(RUNNING_TIME);
+    stopParsingThreads = true;
+    for (Thread thread : threads) {
+      thread.join();
+    }
+    Assert.assertEquals("", errorMessage);
+  }
+
   public void testTimetampInvalidFormat() throws Exception {
     try {
       // Value too small.
diff --git a/java/util/src/test/java/com/google/protobuf/util/json_test.proto b/java/util/src/test/proto/com/google/protobuf/util/json_test.proto
index b2753af6..686edc42 100644
--- a/java/util/src/test/java/com/google/protobuf/util/json_test.proto
+++ b/java/util/src/test/proto/com/google/protobuf/util/json_test.proto
@@ -28,6 +28,36 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 syntax = "proto3";
 
 package json_test;
@@ -90,6 +120,13 @@ message TestAllTypes {
   repeated NestedEnum repeated_nested_enum = 51;
 }
 
+message TestOneof {
+  oneof oneof_field {
+    int32 oneof_int32 = 1;
+    TestAllTypes.NestedMessage oneof_nested_message = 2;
+  }
+}
+
 message TestMap {
   // Instead of testing all combinations (too many), we only make sure all
   // valid types have been used at least in one field as key and in one
@@ -151,8 +188,14 @@ message TestFieldMask {
 
 message TestStruct {
   google.protobuf.Struct struct_value = 1;
+  google.protobuf.Value value = 2;
+  google.protobuf.ListValue list_value = 3;
 }
 
 message TestAny {
   google.protobuf.Any any_value = 1;
 }
+
+message TestCustomJsonName {
+  int32 value = 1 [json_name = "@value"];
+}