add new Streams Quick Start

also move IOResult to akka.stream package

akka-docs/rst/java/code/docs/stream/QuickStartDocTest.java

@@ -0,0 +1,88 @@
+/**
+ * Copyright (C) 2016 Typesafe Inc. <http://www.typesafe.com>
+ */
+package docs.stream;
+
+import java.io.File;
+import java.math.BigInteger;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.*;
+
+import akka.Done;
+import akka.NotUsed;
+import akka.actor.ActorSystem;
+//#imports
+import akka.stream.*;
+import akka.stream.javadsl.*;
+//#imports
+import akka.util.ByteString;
+import scala.concurrent.duration.Duration;
+
+/**
+ * This class is not meant to be run as a test in the test suite, but it
+ * is set up such that it can be run interactively from within an IDE.
+ */
+public class QuickStartDocTest {
+  
+  static
+  //#create-materializer
+  final ActorSystem system = ActorSystem.create("QuickStart");
+  final Materializer materializer = ActorMaterializer.create(system);
+  //#create-materializer
+
+  @AfterClass
+  public static void teardown() {
+    system.terminate();
+  }
+  
+  @Test
+  public void demonstrateSource() throws InterruptedException, ExecutionException {
+    //#create-source
+    final Source<Integer, NotUsed> source = Source.range(1, 100);
+    //#create-source
+    
+    //#run-source
+    source.runForeach(i -> System.out.println(i), materializer);
+    //#run-source
+    
+    //#transform-source
+    final Source<BigInteger, NotUsed> factorials =
+      source
+        .scan(BigInteger.ONE, (acc, next) -> acc.multiply(BigInteger.valueOf(next)));
+    
+    final CompletionStage<IOResult> result =
+      factorials
+        .map(num -> ByteString.fromString(num.toString() + "\n"))
+        .runWith(FileIO.toFile(new File("factorials.txt")), materializer);
+    //#transform-source
+
+    //#use-transformed-sink
+    factorials.map(BigInteger::toString).runWith(lineSink("factorial2.txt"), materializer);
+    //#use-transformed-sink
+    
+    //#add-streams
+    final CompletionStage<Done> done =
+      factorials
+        .zipWith(Source.range(0, 99), (num, idx) -> String.format("%d! = %s", idx, num))
+        .throttle(1, Duration.create(1, TimeUnit.SECONDS), 1, ThrottleMode.shaping())
+        //#add-streams
+        .take(2)
+        //#add-streams
+        .runForeach(s -> System.out.println(s), materializer);
+    //#add-streams
+    
+    done.toCompletableFuture().get();
+  }
+  
+  //#transform-sink
+  public Sink<String, CompletionStage<IOResult>> lineSink(String filename) {
+    return Flow.of(String.class)
+      .map(s -> ByteString.fromString(s.toString() + "\n"))
+      .toMat(FileIO.toFile(new File(filename)), Keep.right());
+  }
+  //#transform-sink
+  
+}