Playframework付属のサンプル'websocket-chat'を見てみる(3/4) ref: http://qiita.com/yyyske/items/87c49e925237a208373e

Application.java

public static WebSocket<JsonNode> chat(final String username) {

    return new WebSocket<JsonNode>() {
        // Called when the Websocket Handshake is done.
        public void onReady(WebSocket.In<JsonNode> in, WebSocket.Out<JsonNode> out){

            // Join the chat room.
            try { 
                ChatRoom.join(username, in, out);
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    };
}

ChatRoom.java

if("OK".equals(result)) {

    // For each event received on the socket,
    in.onMessage(new Callback<JsonNode>() {
       public void invoke(JsonNode event) {

           // Send a Talk message to the room.
           defaultRoom.tell(new Talk(username, event.get("text").asText()), null);

       } 
    });

    // When the socket is closed.
    in.onClose(new Callback0() {
       public void invoke() {

           // Send a Quit message to the room.
           defaultRoom.tell(new Quit(username), null);

       }
    });

} else {

    // Cannot connect, create a Json error.
    ObjectNode error = Json.newObject();
    error.put("error", result);

    // Send the error to the socket.
    out.write(error);

}

file3.txt

def result[T](awaitable: Awaitable[T], atMost: Duration): T
Await and return the result (of type T) of an Awaitable.

file4.txt

 def ask (actor: ActorRef, message: Any, timeoutMillis: Long): Future[AnyRef]

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target actor needs to send the result to the sender reference provided. The Future will be completed with an akka.actor.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)).

file7.txt

public static akka.actor.ActorSystem system()

    Retrieve the application Akka Actor system. 

file8.txt

 def actorOf (props: Props): ActorRef

Create new actor as child of this context and give it an automatically generated name (currently similar to base64-encoded integer count, reversed and with “$” prepended, may change in the future).

file9.txt

 static Props   create(java.lang.Class<?> clazz, java.lang.Object... args)
          Java API: create a Props given a class and its constructor arguments.