WebSockets production ready server in Java?

Question

EDIT: removed reference to C# as the only accepted answer is about Java. If someone needs information about websocket server implementation in C#, ask a new

Answer 1

The Vert.x option is also worth considering.

Creating a ws server can be as simple as

vertx.websocketHandler(new Handler() {
    public void handle(ServerWebSocket ws) {
        // A WebSocket has connected!
    }
}).listen(8080);

or

vertx.createHttpServer().websocketHandler(new Handler() {
        @Override
        public void handle(final ServerWebSocket ws) {
            logger.info("ws connection established with " + ws.remoteAddress());
            ws.dataHandler(new Handler() {
                @Override
                public void handle(Buffer data) {
                    JsonObject item = new JsonObject(data.toString());
                    logger.info("data in -> " + item.encodePrettily());
                       // if you want to write something back in response to the client
                    //ws.writeTextFrame(...);
            }
            });
        }
    }).listen(port, new Handler>() {
        @Override
        public void handle(AsyncResult event) {
            logger.info("ws server is up and listening on port " + port);
        }
    });

For more details look here http://vertx.io/docs/vertx-core/java/#_websockets

So one can write his own WebSocket server with Vert.x, package it as FatJar, and run it on its own.

Or you can embed Vert.x env. in your app, and deploy your verticle (that implements the ws server) programmatically.

---

Another alternative is JBoss's web server Undertow. Which is easily embeddable in applications.

Add these dependencies:

  io.undertow
  undertow-servlet
  ${version.io.undertow}



  io.undertow
  undertow-websockets-jsr
  ${version.io.undertow}

And here's a sample ws server:

Undertow server = Undertow.builder()
            .addHttpListener(8080, "localhost")
            .setHandler(path()
                    .addPrefixPath("/myapp", websocket(new WebSocketConnectionCallback() {

                        @Override
                        public void onConnect(WebSocketHttpExchange exchange, WebSocketChannel channel) {
                            channel.getReceiveSetter().set(new AbstractReceiveListener() {

                                @Override
                                protected void onFullTextMessage(WebSocketChannel channel, BufferedTextMessage message) {
                                    final String messageData = message.getData();
                                    for (WebSocketChannel session : channel.getPeerConnections()) {
                                        WebSockets.sendText(messageData, session, null);
                                    }
                                }
                            });
                            channel.resumeReceives();
                        }
                    }))
            .build();

    server.start();