Adding some initial tests to streaming API.

streaming/src/main/scala/spark/streaming/api/java/JavaStreamingContext.scala

@@ -1,6 +1,7 @@
 package spark.streaming.api.java
 
 import scala.collection.JavaConversions._
+import java.util.{List => JList}
 
 import spark.streaming._
 import dstream.SparkFlumeEvent

streaming/src/test/scala/JavaTestUtils.scala

@@ -0,0 +1,42 @@
+package spark.streaming
+
+import collection.mutable.{SynchronizedBuffer, ArrayBuffer}
+import java.util.{List => JList}
+import spark.streaming.api.java.{JavaDStream, JavaStreamingContext}
+import spark.streaming._
+import java.util.ArrayList
+import collection.JavaConversions._
+
+/** Exposes core test functionality in a Java-friendly way. */
+object JavaTestUtils extends TestSuiteBase {
+  def attachTestInputStream[T](ssc: JavaStreamingContext,
+    data: JList[JList[T]], numPartitions: Int) = {
+    val seqData = data.map(Seq(_:_*))
+
+    implicit val cm: ClassManifest[T] =
+      implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[T]]
+    val dstream = new TestInputStream[T](ssc.ssc, seqData, numPartitions)
+    ssc.ssc.registerInputStream(dstream)
+    new JavaDStream[T](dstream)
+  }
+
+  def attachTestOutputStream[T](dstream: JavaDStream[T]) = {
+    implicit val cm: ClassManifest[T] =
+      implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[T]]
+    val ostream = new TestOutputStream(dstream.dstream,
+      new ArrayBuffer[Seq[T]] with SynchronizedBuffer[Seq[T]])
+    dstream.dstream.ssc.registerOutputStream(ostream)
+  }
+
+  def runStreams[V](
+    ssc: JavaStreamingContext, numBatches: Int, numExpectedOutput: Int): JList[JList[V]] = {
+    implicit val cm: ClassManifest[V] =
+      implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[V]]
+    val res = runStreams[V](ssc.ssc, numBatches, numExpectedOutput)
+    val out = new ArrayList[JList[V]]()
+    res.map(entry => out.append(new ArrayList[V](entry)))
+    out
+  }
+
+}
+

streaming/src/test/scala/spark/streaming/JavaAPISuite.java

@@ -1,14 +1,20 @@
 package spark.streaming;
 
+import org.junit.Assert;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import spark.api.java.JavaRDD;
 import spark.api.java.function.Function;
 import spark.api.java.function.Function2;
+import spark.streaming.JavaTestUtils;
+import spark.streaming.api.java.JavaDStream;
 import spark.streaming.api.java.JavaStreamingContext;
 
 import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 // The test suite itself is Serializable so that anonymous Function implementations can be
 // serialized, as an alternative to converting these anonymous classes to static inner classes;
@@ -30,9 +36,36 @@ public class JavaAPISuite implements Serializable {
   }
 
   @Test
-  public void simpleTest() {
-    sc.textFileStream("/var/log/syslog").print();
-    sc.start();
+  public void testCount() {
+    List<List<Integer>> inputData = Arrays.asList(
+            Arrays.asList(1,2,3,4), Arrays.asList(3,4,5), Arrays.asList(3));
+
+    JavaDStream stream = JavaTestUtils.attachTestInputStream(sc, inputData, 1);
+    JavaDStream count = stream.count();
+    JavaTestUtils.attachTestOutputStream(count);
+    List<List<Integer>> result = JavaTestUtils.runStreams(sc, 3, 3);
+
+    Assert.assertTrue(result.equals(
+            Arrays.asList(Arrays.asList(4), Arrays.asList(3), Arrays.asList(1))));
+  }
+
+  @Test
+  public void testMap() {
+    List<List<String>> inputData = Arrays.asList(
+            Arrays.asList("hello", "world"), Arrays.asList("goodnight", "moon"));
+
+    JavaDStream stream = JavaTestUtils.attachTestInputStream(sc, inputData, 1);
+    JavaDStream letterCount = stream.map(new Function<String, Integer>() {
+        @Override
+        public Integer call(String s) throws Exception {
+          return s.length();
+        }
+    });
+    JavaTestUtils.attachTestOutputStream(letterCount);
+    List<List<Integer>> result = JavaTestUtils.runStreams(sc, 2, 2);
+
+    Assert.assertTrue(result.equals(
+        Arrays.asList(Arrays.asList(5, 5), Arrays.asList(9, 4))));
   }
 
   public static void main(String[] args) {