#Netty-socketio Overview

This project is an open-source Java implementation of Socket.IO server. Based on Netty server framework.

Checkout Demo project

Licensed under the Apache License 2.0.

Features

• Supports 0.7+ version of Socket.IO-client up to latest - 0.9.11
• Supports xhr-polling transport
• Supports flashsocket transport
• Supports websocket transport: HyBi 00 (which is the same as Hixie 76), HyBi 8-10 and HyBi 13-17 (17 is the same as IETF 6455).
• Supports namespaces and rooms
• Supports ack (acknowledgment of received data)
• Supports SSL
• Supports client store (Memory, Redis, Hazelcast)
• Supports distributed broadcast across netty-socketio nodes (Redis, Hazelcast)
• Supports OSGi
• Lock-free and thread-safe implementation
• Declarative handler configuration via annotations

Performance

CentOS, 1 CPU, 4GB RAM runned on VM (based on customer report, tested in 2012):

CPU 10%, Memory 15%
6000 xhr-long polling sessions or 15000 websockets sessions
4000 messages per second

Recent Releases

####Please Note: trunk is current development branch.

####19-Dec-2013 - version 1.6.0 released (JDK 1.6+ compatible, Netty 4.0.13) Fixed - XHR-pooling transport regression
Fixed - Websocket transport regression
Fixed - namespace NPE in PacketHandler
Fixed - shutdown executors during server stop added
Feature - client store (Memory, Redis, Hazelcast) support
Feature - distributed broadcast across netty-socketio nodes (Redis, Hazelcast) support
Feature - OSGi support (thanks to rdevera)
Improvement - XHR-pooling optimization
Improvement - SocketIOClient.getAllRooms method added

####07-Dec-2013 - version 1.5.4 released (JDK 1.6+ compatible, Netty 4.0.13) Fixed - flash policy "request leak" after page reload (thanks to ntrp)
Fixed - websocket swf loading (thanks to ntrp)
Fixed - wrong urls causes a potential DDoS
Fixed - Event.class package visibility changed to avoid direct usage
Improvement - Simplified Jackson modules registration

####24-Oct-2013 - version 1.5.2 released (JDK 1.6+ compatible, Netty 4.0.11) Fixed - NPE during shutdown
Improvement - isEmpty method added to Namespace

####13-Oct-2013 - version 1.5.1 released (JDK 1.6+ compatible, Netty 4.0.9) Fixed - wrong ack timeout callback invocation
Fixed - bigdecimal serialization for JSON
Fixed - infinity loop during packet handling exception
Fixed - 'client not found' handling

####27-Aug-2013 - version 1.5.0 released (JDK 1.6+ compatible, Netty 4.0.7) Improvement - encoding buffers allocation optimization.
Improvement - encoding buffers now pooled in memory to reduce GC pressure (netty 4.x feature).

####03-Aug-2013 - version 1.0.1 released (JDK 1.5+ compatible) Fixed - error on unknown property during deserialization.
Fixed - memory leak in long polling transport.
Improvement - logging error info with inbound data.

####07-Jun-2013 - version 1.0.0 released (JDK 1.5+ compatible) First stable release.

Maven

Include the following to your dependency list:

<dependency>
 <groupId>com.corundumstudio.socketio</groupId>
 <artifactId>netty-socketio</artifactId>
 <version>1.5.4</version>
</dependency>

Usage example

##Server

Base configuration. More details about Configuration object is here.

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

    SocketIOServer server = new SocketIOServer(config);

Programmatic handlers binding:

    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);
        }
    });

Declarative handlers binding. Handlers could be bound via annotations on any object:

    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();

##Client

    <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>