Adds throttle example

akka-docs/src/test/java/jdocs/stream/operators/sourceorflow/Throttle.java

@@ -0,0 +1,49 @@
+package jdocs.stream.operators.sourceorflow;
+
+import akka.NotUsed;
+import akka.actor.ActorSystem;
+import akka.stream.Materializer;
+import akka.stream.ThrottleMode;
+import akka.stream.javadsl.Sink;
+import akka.stream.javadsl.Source;
+
+import java.time.Duration;
+import java.util.stream.Stream;
+import docs.stream.operators.sourceorflow.ThrottleCommon.Frame;
+
+/**
+ *
+ */
+public class Throttle {
+
+    public static void main(String[] args) {
+        ActorSystem actorSystem = ActorSystem.create("25fps-throttled-stream");
+        Materializer mat = Materializer.matFromSystem(actorSystem);
+
+        Source<Frame, NotUsed> frameSource =
+                Source
+                        .fromIterator(() -> Stream.iterate(0 , i -> i+1).iterator())
+                        .map(i -> new Frame(i.intValue())) ;
+
+        // #throttle
+        int framesPerSecond = 24;
+
+        Source<Frame, NotUsed> videoThrottling = frameSource
+                .throttle(
+                        framesPerSecond,
+                        Duration.ofSeconds(1),
+                        framesPerSecond * 30,
+                        ThrottleMode.shaping()
+                );
+        // serialize `Frame` and send over the network.
+        // #throttle
+
+        videoThrottling
+                .map(f -> f.i())
+                .to(Sink.foreach(System.out::println))
+                .run(mat);
+
+    }
+
+
+}