<dependency>
 <groupId>com.corundumstudio.socketio</groupId>
 <artifactId>netty-socketio</artifactId>
 <version>1.5.0</version>
</dependency>

    Configuration config = new Configuration();
    config.setHostname("localhost");
    config.setPort(81);

    SocketIOServer server = new SocketIOServer(config);

    server.addMessageListener(new DataListener<String>() {
        @Override
        public void onData(SocketIOClient client, String message, AckRequest ackRequest) {
            ...
        }
    });

    server.addEventListener("someevent", SomeClass.class, new DataListener<SomeClass>() {
        @Override
        public void onData(SocketIOClient client, Object data, AckRequest ackRequest) {
            ...
        }
    });

    server.addConnectListener(new ConnectListener() {
        @Override
        public void onConnect(SocketIOClient client) {
            ...
        }
    });

    server.addDisconnectListener(new DisconnectListener() {
        @Override
        public void onDisconnect(SocketIOClient client) {
            ...
        }
    });


    // Don't forget to include type field on javascript side,
    // it named '@class' by default and should equals to full class name.
    //
    // TIP: you can customize type field name via Configuration.jsonTypeFieldName property.

    server.addJsonObjectListener(SomeClass.class, new DataListener<SomeClass>() {
        @Override
        public void onData(SocketIOClient client, SomeClass data, AckRequest ackRequest) {

            ...

            // send object to socket.io client
            SampleObject obj = new SampleObject();
            client.sendJsonObject(obj);
        }
    });

    pubic class SomeBusinessService {
    
         ...
         // some stuff code
         ...

         // SocketIOClient, AckRequest and Data could be ommited
         @OnEvent('someevent')
         public void onSomeEventHandler(SocketIOClient client, SomeClass data, AckRequest ackRequest) {
             ...
         }
         
         @OnConnect
         public void onConnectHandler(SocketIOClient client) {
             ...
         }

         @OnDisconnect
         public void onDisconnectHandler(SocketIOClient client) {
             ...
         }

         // only data object is required in arguments, 
         // SocketIOClient and AckRequest could be ommited
         @OnJsonObject
         public void onSomeEventHandler(SocketIOClient client, SomeClass data, AckRequest ackRequest) {
             ...
         }

         // only data object is required in arguments, 
         // SocketIOClient and AckRequest could be ommited
         @OnMessage
         public void onSomeEventHandler(SocketIOClient client, String data, AckRequest ackRequest) {
             ...
         }

    }
    
    SomeBusinessService someService = new SomeBusinessService();
    server.addListeners(someService);


    server.start();
    
    ...
    
    server.stop();

    <script type="text/javascript" src="socket.io.js" charset="utf-8"></script>

    <script type="text/javascript">

           var socket = io.connect('http://localhost:81', {
             'reconnection delay' : 2000,
             'force new connection' : true
           });

           socket.on('message', function(data) {
                // here is your handler on messages from server
           });

       socket.on('connect', function() {
                // connection established, now we can send an objects


                // send json-object to server
                // '@class' property should be defined and should 
                // equals to full class name.
                var obj = { '@class' : 'com.sample.SomeClass',
                             ...
                          };
                socket.json.send(obj);



                // send event-object to server
                // '@class' property is NOT necessary in this case
                var event = { 
                             ...
                          };
                socket.emit('someevent', event);

       });

    </script>