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

Table of content

• Compatibility
• Installation
  • Maven
  • Gradle
• Usage
• Features
• License

Compatibility

Installation

The latest artifact is available on Maven Central.

Maven

Add the following dependency to your pom.xml.

<dependencies>
  <dependency>
    <groupId>io.socket</groupId>
    <artifactId>engine.io-client</artifactId>
    <version>2.0.0</version>
  </dependency>
</dependencies>

Gradle

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

compile ('io.socket:engine.io-client:2.0.0') {
  // excluding org.json which is provided by Android
  exclude group: 'org.json', module: 'json'
}

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.

License

MIT