[SPARK-4819] Remove Guava's "Optional" from public API

Replace Guava `Optional` with (an API clone of) Java 8 `java.util.Optional` (edit: and a clone of Guava `Optional`)

See also https://github.com/apache/spark/pull/10512

Author: Sean Owen <sowen@cloudera.com>

Closes #10513 from srowen/SPARK-4819.

2 files changed, 111 insertions, 29 deletions

diff --git a/core/src/test/java/org/apache/spark/JavaAPISuite.java b/core/src/test/java/org/apache/spark/JavaAPISuite.java
index 47382e4231..44d5cac7c2 100644
--- a/core/src/test/java/org/apache/spark/JavaAPISuite.java
+++ b/core/src/test/java/org/apache/spark/JavaAPISuite.java
@@ -21,7 +21,17 @@ import java.io.*;
 import java.nio.channels.FileChannel;
 import java.nio.ByteBuffer;
 import java.net.URI;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.*;
 
 import scala.Tuple2;
@@ -35,7 +45,6 @@ import com.google.common.collect.Iterators;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.base.Throwables;
-import com.google.common.base.Optional;
 import com.google.common.base.Charsets;
 import com.google.common.io.Files;
 import org.apache.hadoop.io.IntWritable;
@@ -49,7 +58,12 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.spark.api.java.*;
+import org.apache.spark.api.java.JavaDoubleRDD;
+import org.apache.spark.api.java.JavaFutureAction;
+import org.apache.spark.api.java.JavaPairRDD;
+import org.apache.spark.api.java.JavaRDD;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.api.java.Optional;
 import org.apache.spark.api.java.function.*;
 import org.apache.spark.input.PortableDataStream;
 import org.apache.spark.partial.BoundedDouble;
@@ -1785,32 +1799,6 @@ public class JavaAPISuite implements Serializable {
     Assert.assertTrue(future.isDone());
   }
 
-
-  /**
-   * Test for SPARK-3647. This test needs to use the maven-built assembly to trigger the issue,
-   * since that's the only artifact where Guava classes have been relocated.
-   */
-  @Test
-  public void testGuavaOptional() {
-    // Stop the context created in setUp() and start a local-cluster one, to force usage of the
-    // assembly.
-    sc.stop();
-    JavaSparkContext localCluster = new JavaSparkContext("local-cluster[1,1,1024]", "JavaAPISuite");
-    try {
-      JavaRDD<Integer> rdd1 = localCluster.parallelize(Arrays.asList(1, 2, null), 3);
-      JavaRDD<Optional<Integer>> rdd2 = rdd1.map(
-        new Function<Integer, Optional<Integer>>() {
-          @Override
-          public Optional<Integer> call(Integer i) {
-            return Optional.fromNullable(i);
-          }
-        });
-      rdd2.collect();
-    } finally {
-      localCluster.stop();
-    }
-  }
-
   static class Class1 {}
   static class Class2 {}
 
diff --git a/core/src/test/java/org/apache/spark/api/java/OptionalSuite.java b/core/src/test/java/org/apache/spark/api/java/OptionalSuite.java
new file mode 100644
index 0000000000..4b97c18198
--- /dev/null
+++ b/core/src/test/java/org/apache/spark/api/java/OptionalSuite.java
@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.api.java;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Tests {@link Optional}.
+ */
+public class OptionalSuite {
+
+  @Test
+  public void testEmpty() {
+    Assert.assertFalse(Optional.empty().isPresent());
+    Assert.assertNull(Optional.empty().orNull());
+    Assert.assertEquals("foo", Optional.empty().or("foo"));
+    Assert.assertEquals("foo", Optional.empty().orElse("foo"));
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void testEmptyGet() {
+    Optional.empty().get();
+  }
+
+  @Test
+  public void testAbsent() {
+    Assert.assertFalse(Optional.absent().isPresent());
+    Assert.assertNull(Optional.absent().orNull());
+    Assert.assertEquals("foo", Optional.absent().or("foo"));
+    Assert.assertEquals("foo", Optional.absent().orElse("foo"));
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void testAbsentGet() {
+    Optional.absent().get();
+  }
+
+  @Test
+  public void testOf() {
+    Assert.assertTrue(Optional.of(1).isPresent());
+    Assert.assertNotNull(Optional.of(1).orNull());
+    Assert.assertEquals(Integer.valueOf(1), Optional.of(1).get());
+    Assert.assertEquals(Integer.valueOf(1), Optional.of(1).or(2));
+    Assert.assertEquals(Integer.valueOf(1), Optional.of(1).orElse(2));
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void testOfWithNull() {
+    Optional.of(null);
+  }
+
+  @Test
+  public void testOfNullable() {
+    Assert.assertTrue(Optional.ofNullable(1).isPresent());
+    Assert.assertNotNull(Optional.ofNullable(1).orNull());
+    Assert.assertEquals(Integer.valueOf(1), Optional.ofNullable(1).get());
+    Assert.assertEquals(Integer.valueOf(1), Optional.ofNullable(1).or(2));
+    Assert.assertEquals(Integer.valueOf(1), Optional.ofNullable(1).orElse(2));
+    Assert.assertFalse(Optional.ofNullable(null).isPresent());
+    Assert.assertNull(Optional.ofNullable(null).orNull());
+    Assert.assertEquals(Integer.valueOf(2), Optional.<Integer>ofNullable(null).or(2));
+    Assert.assertEquals(Integer.valueOf(2), Optional.<Integer>ofNullable(null).orElse(2));
+  }
+
+  @Test
+  public void testFromNullable() {
+    Assert.assertTrue(Optional.fromNullable(1).isPresent());
+    Assert.assertNotNull(Optional.fromNullable(1).orNull());
+    Assert.assertEquals(Integer.valueOf(1), Optional.fromNullable(1).get());
+    Assert.assertEquals(Integer.valueOf(1), Optional.fromNullable(1).or(2));
+    Assert.assertEquals(Integer.valueOf(1), Optional.fromNullable(1).orElse(2));
+    Assert.assertFalse(Optional.fromNullable(null).isPresent());
+    Assert.assertNull(Optional.fromNullable(null).orNull());
+    Assert.assertEquals(Integer.valueOf(2), Optional.<Integer>fromNullable(null).or(2));
+    Assert.assertEquals(Integer.valueOf(2), Optional.<Integer>fromNullable(null).orElse(2));
+  }
+
+}