!act #15626 expose DatagramChannel creation in DatagramChannelCreator

* move channel creation logic to a separate trait
* new Java API: AbstractSocketOption

akka-samples/akka-docs-udp-multicast/src/test/java/docs/io/JavaUdpMulticastTest.java

@@ -0,0 +1,63 @@
+/**
+ * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
+ */
+
+package docs.io;
+
+import akka.actor.ActorRef;
+import akka.actor.ActorSystem;
+import akka.actor.Props;
+import akka.testkit.JavaTestKit;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.util.Enumeration;
+
+public class JavaUdpMulticastTest {
+
+    static ActorSystem system;
+
+    @BeforeClass
+    public static void setup() {
+        system = ActorSystem.create("JavaUdpMulticastTest");
+    }
+
+    @Test
+    public void testUdpMulticast() throws Exception {
+        new JavaTestKit(system) {{
+            NetworkInterface ipv6Iface = null;
+            for (Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces(); interfaces.hasMoreElements() && ipv6Iface == null;) {
+                NetworkInterface interf = interfaces.nextElement();
+                for (Enumeration<InetAddress> addresses = interf.getInetAddresses(); addresses.hasMoreElements() && ipv6Iface == null;) {
+                    InetAddress address = addresses.nextElement();
+                    if (address instanceof Inet6Address) {
+                        ipv6Iface = interf;
+                    }
+                }
+            }
+
+            final String group = "FF33::1200";
+            final Integer port = TestUtils.temporaryUdpIpv6Port(ipv6Iface);
+            final String msg = "ohi";
+            final ActorRef sink = getRef();
+
+            final ActorRef listener = system.actorOf(Props.create(Listener.class, ipv6Iface.getName(), group, port, sink));
+            final ActorRef sender = system.actorOf(Props.create(Sender.class, group, port, msg));
+
+            expectMsgEquals(msg);
+
+            // unbind
+            system.stop(listener);
+        }};
+    }
+
+    @AfterClass
+    public static void tearDown() {
+        JavaTestKit.shutdownActorSystem(system);
+        system = null;
+    }
+}