[SPARK-12510][STREAMING] Refactor ActorReceiver to support Java

This PR includes the following changes:

1. Rename `ActorReceiver` to `ActorReceiverSupervisor`
2. Remove `ActorHelper`
3. Add a new `ActorReceiver` for Scala and `JavaActorReceiver` for Java
4. Add `JavaActorWordCount` example

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #10457 from zsxwing/java-actor-stream.

1 files changed, 2 insertions, 3 deletions

diff --git a/external/zeromq/src/main/scala/org/apache/spark/streaming/zeromq/ZeroMQReceiver.scala b/external/zeromq/src/main/scala/org/apache/spark/streaming/zeromq/ZeroMQReceiver.scala
index 588e6bac7b..506ba8782d 100644
--- a/external/zeromq/src/main/scala/org/apache/spark/streaming/zeromq/ZeroMQReceiver.scala
+++ b/external/zeromq/src/main/scala/org/apache/spark/streaming/zeromq/ZeroMQReceiver.scala
@@ -19,12 +19,11 @@ package org.apache.spark.streaming.zeromq
 
 import scala.reflect.ClassTag
 
-import akka.actor.Actor
 import akka.util.ByteString
 import akka.zeromq._
 
 import org.apache.spark.Logging
-import org.apache.spark.streaming.receiver.ActorHelper
+import org.apache.spark.streaming.receiver.ActorReceiver
 
 /**
  * A receiver to subscribe to ZeroMQ stream.
@@ -33,7 +32,7 @@ private[streaming] class ZeroMQReceiver[T: ClassTag](
     publisherUrl: String,
     subscribe: Subscribe,
     bytesToObjects: Seq[ByteString] => Iterator[T])
-  extends Actor with ActorHelper with Logging {
+  extends ActorReceiver with Logging {
 
   override def preStart(): Unit = {
     ZeroMQExtension(context.system)