socket.io-java-client is an easy to use implementation of socket.io for Java.

It uses Weberknecht as transport backend, but it's easy to write your own transport. See description below. An XHR-Transport is included, too. But it's not functional in its current state.

The API is inspired by java-socket.io.client.

Features:

• transparent reconnecting - The API cares about re-establishing the connection to the server when the transport is interrupted.
• easy to use API - implement an interface, instantiate a class - you're done.
• output buffer - send data while the transport is still connecting. No problem, socket.io-java-client handles that.
• meaningful exceptions - If something goes wrong, SocketIO tries to throw meaningful exceptions with hints for fixing.

Status: Connecting with Websocket is production ready. XHR is in beta.

Using socket.io-java-client is quite simple. But lets see:

Checkout and compile the project:

git clone git://github.com/Gottox/socket.io-java-client.git
cd socket.io-java-client
ant jar
mv jar/socketio.jar /path/to/your/libs/project

cd examples
javac -cp ../jar/socketio.jar basic/BasicExample.java
java -cp ../jar/socketio.jar:. basic.BasicExample

If you're using ant, change your build.xml to include socketio.jar. If you're eclipse, add the jar to your project buildpath.

Afterwards, you'll be able to use this library:

		SocketIO socket = new SocketIO("http://127.0.0.1:3001/");
		socket.connect(new IOCallback() {
			@Override
			public void onMessage(JSONObject json, IOAcknowledge ack) {
				try {
					System.out.println("Server said:" + json.toString(2));
				} catch (JSONException e) {
					e.printStackTrace();
				}
			}

			@Override
			public void onMessage(String data, IOAcknowledge ack) {
				System.out.println("Server said: " + data);
			}

			@Override
			public void onError(SocketIOException socketIOException) {
				System.out.println("an Error occured");
				socketIOException.printStackTrace();
			}

			@Override
			public void onDisconnect() {
				System.out.println("Connection terminated.");
			}

			@Override
			public void onConnect() {
				System.out.println("Connection established");
			}

			@Override
			public void on(String event, IOAcknowledge ack, Object... args) {
				System.out.println("Server triggered event '" + event + "'");
			}
		});
		
		// This line is cached until the connection is establisched.
		socket.send("Hello Server!");

For further informations, read the Javadoc.

• Class SocketIO
• Interface IOCallback

• with git

   git clone git://github.com/Gottox/socket.io-java-client.git
  

• with mercurial

   hg clone https://bitbucket.org/Gottox/socket.io-java-client 
  

Both repositories are synchronized and up to date.

to build a jar-file:

cd $PATH_TO_SOCKETIO_JAVA
ant jar
ls jar/socketio.jar

You'll find the socket.io-jar in jar/socketio.jar

Please report any bugs feature requests to the Github issue tracker

This Library was designed with portability in mind.

• Android is fully supported.
• JRE is fully supported.
• GWT does not work at the moment, but a port would be possible.
• Java ME does not work at the moment, but a port would be possible.
• ... is there anything else out there?

There comes a JUnit test suite with socket.io-java-client. Currently it's tested with Eclipse.

You need node installed in PATH.

• open the project with eclipse
• open tests/io.socket/AllTests.java
• run it as JUnit4 test.

• Socket.io needs more unit-tests.
• XhrTransport needs to pass all tests.
• If websockets are failing (due to proxy servers e.g.), use XHR automaticly instead.

This library is distributed under MIT Licence.

You'll find further documentation at the Socket.io-java-client Github Wiki