Engine.IO-client Java

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

See also: Socket.IO-client Java

Installation

The latest artifact is available on Maven Central. To install manually, please refer dependencies.

Maven

Add the following dependency to your pom.xml.

<dependencies>
  <dependency>
    <groupId>io.socket</groupId>
    <artifactId>engine.io-client</artifactId>
    <version>1.0.0</version>
  </dependency>
</dependencies>

Gradle

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

compile ('io.socket:engine.io-client:1.0.0') {
  // excluding org.json which is provided by Android
  exclude group: 'org.json', module: 'json'
}

Engine.IO Server 1.x suppport

The current version of engine.io-client-java doesn't support engine.io server 1.x. Please use engine.io-client-java 0.9.x for that instead.

Usage

Engine.IO-client Java has the similar api with the JS client. You can use Socket to connect:

socket = new Socket("ws://localhost");
socket.on(Socket.EVENT_OPEN, new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    socket.send("hi");
    socket.close();
  }
});
socket.open();

You can listen events as follows:

socket.on(Socket.EVENT_MESSAGE, new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    String data = (String)args[0];
  }
}).on(Socket.EVENT_ERROR, new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    Exception err = (Exception)args[0];
  }
});

How to set options:

opts = new Socket.Options();
opts.transports = new String[] {WebSocket.NAME};

socket = new Socket(opts);

Sending and receiving binary data:

socket = new Socket();
socket.on(Socket.EVENT_OPEN, new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    // send binary data
    byte[] data = new byte[42];
    socket.send(data);
  }
}).on(Socket.EVENT_MESSAGE, new Emitter.Listener() {
  @Override
  public void call(Object... args) {
    // receive binary data
    byte[] data = (byte[])args[0];
  }
});

Use custom SSL settings:

OkHttpClient okHttpClient = new OkHttpClient.Builder()
    .hostnameVerifier(myHostnameVerifier)
    .sslSocketFactory(mySSLContext.getSocketFactory(), myX509TrustManager)
    .build();

// default SSLContext for all sockets
Socket.setDefaultOkHttpWebSocketFactory(okHttpClient);
Socket.setDefaultOkHttpCallFactory(okHttpClient);

// set as an option
opts = new Socket.Options();
opts.callFactory = okHttpClient;
opts.webSocketFactory = okHttpClient;
socket = new Socket(opts);

Features

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

Extra features only for Java client

Accessing HTTP Headers

You can access HTTP headers like the following.

socket.on(Socket.EVENT_TRANSPORT, new Emitter.listener() {
  @Override
  public void call(Object... args) {
    // Called on a new transport created.
    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];
        // send cookie value to server.
        headers.put("Cookie", Arrays.asList("foo=1;"));
      }
    }).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];
        // receive cookie value from server.
        String cookie = headers.get("Set-Cookie").get(0);
      }
    });
  }
});

See the Javadoc for more details.

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

License

MIT