SPARK-4297 [BUILD] Build warning fixes omnibus

There are a number of warnings generated in a normal, successful build right now. They're mostly Java unchecked cast warnings, which can be suppressed. But there's a grab bag of other Scala language warnings and so on that can all be easily fixed. The forthcoming PR fixes about 90% of the build warnings I see now.

Author: Sean Owen <sowen@cloudera.com>

Closes #3157 from srowen/SPARK-4297 and squashes the following commits:

8c9e469 [Sean Owen] Suppress unchecked cast warnings, and several other build warning fixes

7 files changed, 26 insertions, 18 deletions

diff --git a/sql/core/src/main/java/org/apache/spark/sql/api/java/UserDefinedType.java b/sql/core/src/main/java/org/apache/spark/sql/api/java/UserDefinedType.java
index b751847b46..f0d079d25b 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/api/java/UserDefinedType.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/api/java/UserDefinedType.java
@@ -35,6 +35,7 @@ public abstract class UserDefinedType<UserType> extends DataType implements Seri
   public boolean equals(Object o) {
     if (this == o) return true;
     if (o == null || getClass() != o.getClass()) return false;
+    @SuppressWarnings("unchecked")
     UserDefinedType<UserType> that = (UserDefinedType<UserType>) o;
     return this.sqlType().equals(that.sqlType());
   }
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/parquet/ParquetTypes.scala b/sql/core/src/main/scala/org/apache/spark/sql/parquet/ParquetTypes.scala
index 0e6fb57d57..97447871a1 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/parquet/ParquetTypes.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/parquet/ParquetTypes.scala
@@ -24,8 +24,8 @@ import scala.util.Try
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.{FileSystem, Path}
 import org.apache.hadoop.mapreduce.Job
-import org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter
 
+import parquet.format.converter.ParquetMetadataConverter
 import parquet.hadoop.{ParquetFileReader, Footer, ParquetFileWriter}
 import parquet.hadoop.metadata.{ParquetMetadata, FileMetaData}
 import parquet.hadoop.util.ContextUtil
@@ -458,7 +458,7 @@ private[parquet] object ParquetTypesConverter extends Logging {
       // ... and fallback to "_metadata" if no such file exists (which implies the Parquet file is
       // empty, thus normally the "_metadata" file is expected to be fairly small).
       .orElse(children.find(_.getPath.getName == ParquetFileWriter.PARQUET_METADATA_FILE))
-      .map(ParquetFileReader.readFooter(conf, _))
+      .map(ParquetFileReader.readFooter(conf, _, ParquetMetadataConverter.NO_FILTER))
       .getOrElse(
         throw new IllegalArgumentException(s"Could not find Parquet metadata at path $path"))
   }
diff --git a/sql/core/src/test/java/org/apache/spark/sql/api/java/JavaRowSuite.java b/sql/core/src/test/java/org/apache/spark/sql/api/java/JavaRowSuite.java
index bc5cd66482..2b5812159d 100644
--- a/sql/core/src/test/java/org/apache/spark/sql/api/java/JavaRowSuite.java
+++ b/sql/core/src/test/java/org/apache/spark/sql/api/java/JavaRowSuite.java
@@ -141,6 +141,7 @@ public class JavaRowSuite {
       doubleValue, stringValue, timestampValue, null);
 
     // Complex array
+    @SuppressWarnings("unchecked")
     List<Map<String, Long>> arrayOfMaps = Arrays.asList(simpleMap);
     List<Row> arrayOfRows = Arrays.asList(simpleStruct);
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala
index e40d034ce4..691c4b3828 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala
@@ -24,6 +24,8 @@ import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.dsl._
 import org.apache.spark.sql.test.TestSQLContext._
 
+import scala.language.postfixOps
+
 class DslQuerySuite extends QueryTest {
   import org.apache.spark.sql.TestData._
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/parquet/ParquetQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/parquet/ParquetQuerySuite.scala
index 074855389d..a5fe2e8da2 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/parquet/ParquetQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/parquet/ParquetQuerySuite.scala
@@ -17,6 +17,8 @@
 
 package org.apache.spark.sql.parquet
 
+import scala.reflect.ClassTag
+
 import org.apache.hadoop.fs.{FileSystem, Path}
 import org.apache.hadoop.mapreduce.Job
 import org.scalatest.{BeforeAndAfterAll, FunSuiteLike}
@@ -459,11 +461,17 @@ class ParquetQuerySuite extends QueryTest with FunSuiteLike with BeforeAndAfterA
   }
 
   test("make RecordFilter for simple predicates") {
-    def checkFilter[T <: FilterPredicate](predicate: Expression, defined: Boolean = true): Unit = {
+    def checkFilter[T <: FilterPredicate : ClassTag](
+        predicate: Expression,
+        defined: Boolean = true): Unit = {
       val filter = ParquetFilters.createFilter(predicate)
       if (defined) {
         assert(filter.isDefined)
-        assert(filter.get.isInstanceOf[T])
+        val tClass = implicitly[ClassTag[T]].runtimeClass
+        val filterGet = filter.get
+        assert(
+          tClass.isInstance(filterGet),
+          s"$filterGet of type ${filterGet.getClass} is not an instance of $tClass")
       } else {
         assert(filter.isEmpty)
       }
@@ -484,7 +492,7 @@ class ParquetQuerySuite extends QueryTest with FunSuiteLike with BeforeAndAfterA
 
     checkFilter[Operators.And]('a.int === 1 && 'a.int < 4)
     checkFilter[Operators.Or]('a.int === 1 || 'a.int < 4)
-    checkFilter[Operators.Not](!('a.int === 1))
+    checkFilter[Operators.NotEq[Integer]](!('a.int === 1))
 
     checkFilter('a.int > 'b.int, defined = false)
     checkFilter(('a.int > 'b.int) && ('a.int > 'b.int), defined = false)
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/parquet/FakeParquetSerDe.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/parquet/FakeParquetSerDe.scala
index abed299cd9..2a16c9d1a2 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/parquet/FakeParquetSerDe.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/parquet/FakeParquetSerDe.scala
@@ -32,7 +32,7 @@ import org.apache.hadoop.io.Writable
  * when "spark.sql.hive.convertMetastoreParquet" is set to true.
  */
 @deprecated("No code should depend on FakeParquetHiveSerDe as it is only intended as a " +
-            "placeholder in the Hive MetaStore")
+            "placeholder in the Hive MetaStore", "1.2.0")
 class FakeParquetSerDe extends SerDe {
   override def getObjectInspector: ObjectInspector = new ObjectInspector {
     override def getCategory: Category = Category.PRIMITIVE
diff --git a/sql/hive/src/test/java/org/apache/spark/sql/hive/execution/UDFListListInt.java b/sql/hive/src/test/java/org/apache/spark/sql/hive/execution/UDFListListInt.java
index d2d39a8c4d..808e2986d3 100644
--- a/sql/hive/src/test/java/org/apache/spark/sql/hive/execution/UDFListListInt.java
+++ b/sql/hive/src/test/java/org/apache/spark/sql/hive/execution/UDFListListInt.java
@@ -23,25 +23,21 @@ import java.util.List;
 
 public class UDFListListInt extends UDF {
   /**
-   *
    * @param obj
-   *   SQL schema: array<struct<x: int, y: int, z: int>>
-   *   Java Type: List<List<Integer>>
-   * @return
+   *   SQL schema: array&lt;struct&lt;x: int, y: int, z: int&gt;&gt;
+   *   Java Type: List&lt;List&lt;Integer&gt;&gt;
    */
+  @SuppressWarnings("unchecked")
   public long evaluate(Object obj) {
     if (obj == null) {
-      return 0l;
+      return 0L;
     }
-    List<List> listList = (List<List>) obj;
+    List<List<?>> listList = (List<List<?>>) obj;
     long retVal = 0;
-    for (List aList : listList) {
-      @SuppressWarnings("unchecked")
-      List<Object> list = (List<Object>) aList;
-      @SuppressWarnings("unchecked")
-      Integer someInt = (Integer) list.get(1);
+    for (List<?> aList : listList) {
+      Number someInt = (Number) aList.get(1);
       try {
-        retVal += (long) (someInt.intValue());
+        retVal += someInt.longValue();
       } catch (NullPointerException e) {
         System.out.println(e);
       }