[SPARK-4535][Streaming] Fix the error in comments

change `NetworkInputDStream` to `ReceiverInputDStream`
change `ReceiverInputTracker` to `ReceiverTracker`

Author: q00251598 <qiyadong@huawei.com>

Closes #3400 from watermen/fix-comments and squashes the following commits:

75d795c [q00251598] change 'NetworkInputDStream' to 'ReceiverInputDStream' && change 'ReceiverInputTracker' to 'ReceiverTracker'

(cherry picked from commit a51118a34a4617c07373480c4b021e53124c3c00)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>

Conflicts:
	examples/src/main/scala/org/apache/spark/examples/streaming/StatefulNetworkWordCount.scala

4 files changed, 7 insertions, 7 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala b/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala
index 54b219711e..ec59221459 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/StreamingContext.scala
@@ -187,7 +187,7 @@ class StreamingContext private[streaming] (
   /**
    * Set each DStreams in this context to remember RDDs it generated in the last given duration.
    * DStreams remember RDDs only for a limited duration of time and releases them for garbage
-   * collection. This method allows the developer to specify how to long to remember the RDDs (
+   * collection. This method allows the developer to specify how long to remember the RDDs (
    * if the developer wishes to query old data outside the DStream computation).
    * @param duration Minimum duration that each DStream should remember its RDDs
    */
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala
index 7db66c69a6..d8695b8e05 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala
@@ -479,7 +479,7 @@ class JavaStreamingContext(val ssc: StreamingContext) extends Closeable {
   /**
    * Sets each DStreams in this context to remember RDDs it generated in the last given duration.
    * DStreams remember RDDs only for a limited duration of duration and releases them for garbage
-   * collection. This method allows the developer to specify how to long to remember the RDDs (
+   * collection. This method allows the developer to specify how long to remember the RDDs (
    * if the developer wishes to query old data outside the DStream computation).
    * @param duration Minimum duration that each DStream should remember its RDDs
    */
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReceiverInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReceiverInputDStream.scala
index 3e67161363..c834744631 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReceiverInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/ReceiverInputDStream.scala
@@ -29,7 +29,7 @@ import org.apache.spark.streaming.scheduler.ReceivedBlockInfo
 /**
  * Abstract class for defining any [[org.apache.spark.streaming.dstream.InputDStream]]
  * that has to start a receiver on worker nodes to receive external data.
- * Specific implementations of NetworkInputDStream must
+ * Specific implementations of ReceiverInputDStream must
  * define `the getReceiver()` function that gets the receiver object of type
  * [[org.apache.spark.streaming.receiver.Receiver]] that will be sent
  * to the workers to receive data.
@@ -39,17 +39,17 @@ import org.apache.spark.streaming.scheduler.ReceivedBlockInfo
 abstract class ReceiverInputDStream[T: ClassTag](@transient ssc_ : StreamingContext)
   extends InputDStream[T](ssc_) {
 
-  /** This is an unique identifier for the network input stream. */
+  /** This is an unique identifier for the receiver input stream. */
   val id = ssc.getNewReceiverStreamId()
 
   /**
    * Gets the receiver object that will be sent to the worker nodes
    * to receive data. This method needs to defined by any specific implementation
-   * of a NetworkInputDStream.
+   * of a ReceiverInputDStream.
    */
   def getReceiver(): Receiver[T]
 
-  // Nothing to start or stop as both taken care of by the ReceiverInputTracker.
+  // Nothing to start or stop as both taken care of by the ReceiverTracker.
   def start() {}
 
   def stop() {}
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/scheduler/ReceiverTracker.scala b/streaming/src/main/scala/org/apache/spark/streaming/scheduler/ReceiverTracker.scala
index 1c3984d968..32e481dabc 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/scheduler/ReceiverTracker.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/scheduler/ReceiverTracker.scala
@@ -46,7 +46,7 @@ private[streaming] case class DeregisterReceiver(streamId: Int, msg: String, err
   extends ReceiverTrackerMessage
 
 /**
- * This class manages the execution of the receivers of NetworkInputDStreams. Instance of
+ * This class manages the execution of the receivers of ReceiverInputDStreams. Instance of
  * this class must be created after all input streams have been added and StreamingContext.start()
  * has been called because it needs the final set of input streams at the time of instantiation.
  *