# engine.io-client-java

**Repository Path**: mirrors_addons/engine.io-client-java

## Basic Information

- **Project Name**: engine.io-client-java
- **Description**: Engine.IO Client Library for Java
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-05-03
- **Last Updated**: 2025-09-06

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Engine.IO-client Java

[![Build Status](https://github.com/socketio/engine.io-client-java/workflows/CI/badge.svg)](https://github.com/socketio/engine.io-client-java/actions)

This is the Engine.IO Client Library for Java, which is simply ported from the [JavaScript client](https://github.com/socketio/engine.io-client).

See also: [Socket.IO-client Java](https://github.com/socketio/socket.io-client-java)

## Table of content

- [Compatibility](#compatibility)
- [Installation](#installation)
  - [Maven](#maven)
  - [Gradle](#gradle)
- [Usage](#usage)
- [Features](#features)
- [License](#license)

## Compatibility

| Client version | Engine.IO server | Socket.IO server |
| -------------- | ---------------- | ---------------- |
| 0.9.x  | 1.x | 1.x |
| 1.x    | 3.x | 2.x |
| 2.x    | 4.x | 3.x |

## Installation
The latest artifact is available on Maven Central.

### Maven
Add the following dependency to your `pom.xml`.

```xml
<dependencies>
  <dependency>
    <groupId>io.socket</groupId>
    <artifactId>engine.io-client</artifactId>
    <version>2.1.0</version>
  </dependency>
</dependencies>
```

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

```groovy
compile ('io.socket:engine.io-client:2.1.0') {
  // 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:

```java
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:

```java
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:

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

socket = new Socket(opts);
```

Sending and receiving binary data:

```java
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:

```java
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