diff --git a/core/src/main/scala/spark/api/java/JavaRDDLike.scala b/core/src/main/scala/spark/api/java/JavaRDDLike.scala index 81d3a944668d007af6e84da90147ed95b499e153..d15f6dd02f5acfe30827355a2d23e52bcc8adab8 100644 --- a/core/src/main/scala/spark/api/java/JavaRDDLike.scala +++ b/core/src/main/scala/spark/api/java/JavaRDDLike.scala @@ -298,4 +298,12 @@ trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable { * Save this RDD as a SequenceFile of serialized objects. */ def saveAsObjectFile(path: String) = rdd.saveAsObjectFile(path) + + /** + * Creates tuples of the elements in this RDD by applying `f`. + */ + def keyBy[K](f: JFunction[T, K]): JavaPairRDD[K, T] = { + implicit val kcm: ClassManifest[K] = implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[K]] + JavaPairRDD.fromRDD(rdd.keyBy(f)) + } } diff --git a/core/src/test/scala/spark/JavaAPISuite.java b/core/src/test/scala/spark/JavaAPISuite.java index 0817d1146c4b05772701450ada951eef92e089e2..c61913fc82797e1ede6bd46f47a83ba50af73e7c 100644 --- a/core/src/test/scala/spark/JavaAPISuite.java +++ b/core/src/test/scala/spark/JavaAPISuite.java @@ -629,4 +629,16 @@ public class JavaAPISuite implements Serializable { floatAccum.setValue(5.0f); Assert.assertEquals((Float) 5.0f, floatAccum.value()); } + + @Test + public void keyBy() { + JavaRDD<Integer> rdd = sc.parallelize(Arrays.asList(1, 2)); + List<Tuple2<String, Integer>> s = rdd.keyBy(new Function<Integer, String>() { + public String call(Integer t) throws Exception { + return t.toString(); + } + }).collect(); + Assert.assertEquals(new Tuple2<String, Integer>("1", 1), s.get(0)); + Assert.assertEquals(new Tuple2<String, Integer>("2", 2), s.get(1)); + } }