+act #3770 Added Java 8 friendly APIs for Actor and FSM

akka-samples/akka-sample-java8/src/main/java/sample/java8/SampleActor.java

@@ -0,0 +1,32 @@
+package sample.java8;
+
+//#sample-actor
+import akka.actor.AbstractActor;
+import akka.japi.pf.ReceiveBuilder;
+import scala.PartialFunction;
+import scala.runtime.BoxedUnit;
+
+public class SampleActor extends AbstractActor {
+
+  private PartialFunction<Object, BoxedUnit> guarded = ReceiveBuilder.
+    match(String.class, s -> s.contains("guard"), s -> {
+      sender().tell("contains(guard): " + s, self());
+      context().unbecome();
+    }).build();
+
+  @Override
+  public PartialFunction<Object, BoxedUnit> receive() {
+    return ReceiveBuilder.
+      match(Double.class, d -> {
+        sender().tell(d.isNaN() ? 0 : d, self());
+      }).
+      match(Integer.class, i -> {
+        sender().tell(i * 10, self());
+      }).
+      match(String.class, s -> s.startsWith("guard"), s -> {
+        sender().tell("startsWith(guard): " + s.toUpperCase(), self());
+        context().become(guarded, false);
+      }).build();
+  }
+}
+//#sample-actor