Socket.IO-client Java

This is the Socket.IO v1.x Client Library for Java, which is simply ported from the JavaScript client.

Installation

The latest artifact is available on Maven Central. You'll also need dependencies to install.

WARNING: The package name was changed to "io.socket" on v0.6.1 or later. Please make sure to update your dependency settings.

Maven

Add the following dependency to your pom.xml.

<dependencies>
  <dependency>
    <groupId>io.socket</groupId>
    <artifactId>socket.io-client</artifactId>
    <version>0.8.3</version>
  </dependency>
</dependencies>

Gradle

Add it as a gradle dependency for Android Studio, in build.gradle:

compile ('io.socket:socket.io-client:0.8.3') {
  // excluding org.json which is provided by Android
  exclude group: 'org.json', module: 'json'
}

Usage

Socket.IO-client Java has almost the same api and features with the original JS client. You use IO#socket to initialize Socket:

socket = IO.socket("http://localhost");
socket.on(Socket.EVENT_CONNECT, new Emitter.Listener() {

  @Override
  public void call(Object... args) {
    socket.emit("foo", "hi");
    socket.disconnect();
  }

}).on("event", new Emitter.Listener() {

  @Override
  public void call(Object... args) {}

}).on(Socket.EVENT_DISCONNECT, new Emitter.Listener() {

  @Override
  public void call(Object... args) {}

});
socket.connect();

This Library uses org.json to parse and compose JSON strings:

// Sending an object
JSONObject obj = new JSONObject();
obj.put("hello", "server");
obj.put("binary", new byte[42]);
socket.emit("foo", obj);

// Receiving an object
socket.on("foo", new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    JSONObject obj = (JSONObject)args[0];
  }
});

Options are supplied as follows:

IO.Options opts = new IO.Options();
opts.forceNew = true;
opts.reconnection = false;

socket = IO.socket("http://localhost", opts);

You can supply query parameters with the query option. NB: if you don't want to reuse a cached socket instance when the query parameter changes, you should use the forceNew option, the use case might be if your app allows for a user to logout, and a new user to login again:

IO.Options opts = new IO.Options();
opts.forceNew = true;
opts.query = "auth_token=" + authToken;
Socket socket = IO.socket("http://localhost", opts);

You can get a callback with Ack when the server received a message:

socket.emit("foo", "woot", new Ack() {
  @Override
  public void call(Object... args) {}
});

And vice versa:

// ack from client to server
socket.on("foo", new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    Ack ack = (Ack) args[args.length - 1];
    ack.call();
  }
});

SSL (HTTPS, WSS) settings:

// default settings for all sockets
IO.setDefaultSSLContext(mySSLContext);
IO.setDefaultHostnameVerifier(myHostnameVerifier);

// set as an option
opts = new IO.Options();
opts.sslContext = mySSLContext;
opts.hostnameVerifier = myHostnameVerifier;
socket = IO.socket("https://localhost", opts);

See the Javadoc for more details.

http://socketio.github.io/socket.io-client-java/apidocs/

Transports and HTTP Headers

You can access transports and their HTTP headers as follows.

// Called upon transport creation.
socket.io().on(Manager.EVENT_TRANSPORT, new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    Transport transport = (Transport)args[0];

    transport.on(Transport.EVENT_REQUEST_HEADERS, new Emitter.Listener() {
      @Override
      public void call(Object... args) {
        @SuppressWarnings("unchecked")
        Map<String, List<String>> headers = (Map<String, List<String>>)args[0];
        // modify request headers
        headers.put("Cookie", Arrays.asList("foo=1;"));
      }
    });

    transport.on(Transport.EVENT_RESPONSE_HEADERS, new Emitter.Listener() {
      @Override
      public void call(Object... args) {
        @SuppressWarnings("unchecked")
        Map<String, List<String>> headers = (Map<String, List<String>>)args[0];
        // access response headers
        String cookie = headers.get("Set-Cookie").get(0);
      }
    });
  }
});

Features

This library supports all of the features the JS client does, including events, options and upgrading transport. Android is fully supported.

License

MIT

Who Uses

Keikai - a sophisticated spreadsheet for big data

keikai/socket.io-client-java