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 5d46ca0715ffd0146d0d523719f20097ae28dca8..ab01f47d5cf99ca355aee0b23fc1692a483e60ba 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 255376807c957d0619ee01fe0afa187379717b49..9988f410f0bc1542f6ae014c4b873bdb09ab1094 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("") )