[SPARK-6428] Turn on explicit type checking for public methods.

This builds on my earlier pull requests and turns on the explicit type checking in scalastyle.

Author: Reynold Xin <rxin@databricks.com>

Closes #5342 from rxin/SPARK-6428 and squashes the following commits:

7b531ab [Reynold Xin] import ordering
2d9a8a5 [Reynold Xin] jl
e668b1c [Reynold Xin] override
9b9e119 [Reynold Xin] Parenthesis.
82e0cf5 [Reynold Xin] [SPARK-6428] Turn on explicit type checking for public methods.

2 files changed, 5 insertions, 5 deletions

diff --git a/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala b/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala
index 8d0f09933c..583823c90c 100644
--- a/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala
+++ b/tools/src/main/scala/org/apache/spark/tools/JavaAPICompletenessChecker.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.tools
 
-import java.lang.reflect.Method
+import java.lang.reflect.{Type, Method}
 
 import scala.collection.mutable.ArrayBuffer
 import scala.language.existentials
@@ -302,7 +302,7 @@ object JavaAPICompletenessChecker {
   private def isExcludedByInterface(method: Method): Boolean = {
     val excludedInterfaces =
       Set("org.apache.spark.Logging", "org.apache.hadoop.mapreduce.HadoopMapReduceUtil")
-    def toComparisionKey(method: Method) =
+    def toComparisionKey(method: Method): (Class[_], String, Type) =
       (method.getReturnType, method.getName, method.getGenericReturnType)
     val interfaces = method.getDeclaringClass.getInterfaces.filter { i =>
       excludedInterfaces.contains(i.getName)
diff --git a/tools/src/main/scala/org/apache/spark/tools/StoragePerfTester.scala b/tools/src/main/scala/org/apache/spark/tools/StoragePerfTester.scala
index 6b666a0384..f2d135397c 100644
--- a/tools/src/main/scala/org/apache/spark/tools/StoragePerfTester.scala
+++ b/tools/src/main/scala/org/apache/spark/tools/StoragePerfTester.scala
@@ -32,7 +32,7 @@ import org.apache.spark.util.Utils
  * Writes simulated shuffle output from several threads and records the observed throughput.
  */
 object StoragePerfTester {
-  def main(args: Array[String]) = {
+  def main(args: Array[String]): Unit = {
     /** Total amount of data to generate. Distributed evenly amongst maps and reduce splits. */
     val dataSizeMb = Utils.memoryStringToMb(sys.env.getOrElse("OUTPUT_DATA", "1g"))
 
@@ -58,7 +58,7 @@ object StoragePerfTester {
     val sc = new SparkContext("local[4]", "Write Tester", conf)
     val hashShuffleManager = sc.env.shuffleManager.asInstanceOf[HashShuffleManager]
 
-    def writeOutputBytes(mapId: Int, total: AtomicLong) = {
+    def writeOutputBytes(mapId: Int, total: AtomicLong): Unit = {
       val shuffle = hashShuffleManager.shuffleBlockResolver.forMapTask(1, mapId, numOutputSplits,
         new KryoSerializer(sc.conf), new ShuffleWriteMetrics())
       val writers = shuffle.writers
@@ -78,7 +78,7 @@ object StoragePerfTester {
     val totalBytes = new AtomicLong()
     for (task <- 1 to numMaps) {
       executor.submit(new Runnable() {
-        override def run() = {
+        override def run(): Unit = {
           try {
             writeOutputBytes(task, totalBytes)
             latch.countDown()