From a16396df76cc27099011bfb96b28cbdd7f964ca8 Mon Sep 17 00:00:00 2001
From: Jacker Hu <gt.hu.chang@gmail.com>
Date: Sat, 10 Oct 2015 11:36:18 +0100
Subject: [PATCH] [SPARK-10772] [STREAMING] [SCALA] NullPointerException when
transform function in DStream returns NULL
Currently, the ```TransformedDStream``` will using ```Some(transformFunc(parentRDDs, validTime))``` as compute return value, when the ```transformFunc``` somehow returns null as return value, the followed operator will have NullPointerExeception.
This fix uses the ```Option()``` instead of ```Some()``` to deal with the possible null value. When ```transformFunc``` returns ```null```, the option will transform null to ```None```, the downstream can handle ```None``` correctly.
NOTE (2015-09-25): The latest fix will check the return value of transform function, if it is ```NULL```, a spark exception will be thrown out
Author: Jacker Hu <gt.hu.chang@gmail.com>
Author: jhu-chang <gt.hu.chang@gmail.com>
Closes #8881 from jhu-chang/Fix_Transform.
---
.../streaming/dstream/TransformedDStream.scala | 12 ++++++++++--
.../spark/streaming/BasicOperationsSuite.scala | 13 +++++++++++++
2 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala
index 5d46ca0715..ab01f47d5c 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/TransformedDStream.scala
@@ -17,9 +17,11 @@
package org.apache.spark.streaming.dstream
+import scala.reflect.ClassTag
+
+import org.apache.spark.SparkException
import org.apache.spark.rdd.{PairRDDFunctions, RDD}
import org.apache.spark.streaming.{Duration, Time}
-import scala.reflect.ClassTag
private[streaming]
class TransformedDStream[U: ClassTag] (
@@ -38,6 +40,12 @@ class TransformedDStream[U: ClassTag] (
override def compute(validTime: Time): Option[RDD[U]] = {
val parentRDDs = parents.map(_.getOrCompute(validTime).orNull).toSeq
- Some(transformFunc(parentRDDs, validTime))
+ val transformedRDD = transformFunc(parentRDDs, validTime)
+ if (transformedRDD == null) {
+ throw new SparkException("Transform function must not return null. " +
+ "Return SparkContext.emptyRDD() instead to represent no element " +
+ "as the result of transformation.")
+ }
+ Some(transformedRDD)
}
}
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
index 255376807c..9988f410f0 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
@@ -211,6 +211,19 @@ class BasicOperationsSuite extends TestSuiteBase {
)
}
+ test("transform with NULL") {
+ val input = Seq(1 to 4)
+ intercept[SparkException] {
+ testOperation(
+ input,
+ (r: DStream[Int]) => r.transform(rdd => null.asInstanceOf[RDD[Int]]),
+ Seq(Seq()),
+ 1,
+ false
+ )
+ }
+ }
+
test("transformWith") {
val inputData1 = Seq( Seq("a", "b"), Seq("a", ""), Seq(""), Seq() )
val inputData2 = Seq( Seq("a", "b"), Seq("b", ""), Seq(), Seq("") )
--
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