tootallnate/java-websocket

★ 10,809JavaAudience · developerComplexity · 2/5LicenseSetup · easy

Mindmap

mindmap
  root((Java-WebSocket))
    What it does
      WebSocket server
      WebSocket client
      Event handling
    How it works
      Extend base class
      Override event methods
      Non-blocking NIO
    Features
      Secure wss support
      RFC 6455 compliant
      Maven and Gradle
    Audience
      Java developers

mindmap root((Java-WebSocket)) What it does WebSocket server WebSocket client Event handling How it works Extend base class Override event methods Non-blocking NIO Features Secure wss support RFC 6455 compliant Maven and Gradle Audience Java developers

Click or tap to explore — scroll the page freely

Things people build with this

USE CASE 1

Build a real-time chat server in Java where clients send and receive messages instantly without polling.

USE CASE 2

Add a WebSocket client to a Java app that connects to a ws:// or wss:// server and reacts to incoming messages.

USE CASE 3

Handle many simultaneous WebSocket connections in a Java backend without blocking threads, using the library's NIO-based design.

Tech stack

JavaMavenGradleSLF4J

Getting it running

Difficulty · easy Time to first run · 30min

SSL connections need a valid certificate or extra configuration steps for self-signed certs in development.

Use freely for any purpose, including commercial use, as long as you keep the MIT copyright notice.

In plain English

Java-WebSocket is a library that lets Java applications send and receive messages over WebSocket connections. WebSocket is a communication protocol that keeps a two-way connection open between a client (like a browser or app) and a server, so either side can send data at any time without the overhead of making a new request each time. The library is written entirely in Java and uses the java.nio package, which means it handles connections without blocking other work while waiting for data to arrive. This makes it suitable for applications that need to handle many simultaneous connections. To build a server, you extend the library's WebSocketServer class and implement the event methods you care about. To build a client, you extend WebSocketClient and connect to a ws:// or wss:// address. In both cases the library fires events like onOpen, onClose, onMessage, and onError, and you write the code that responds to each one. The library supports the two main versions of the WebSocket protocol (RFC 6455 and RFC 7692) and also works with secure WebSocket connections (wss://). Secure connections require a valid certificate, the README includes notes on handling self-signed certificates during development. Adding the library to a Java project is straightforward via Maven or Gradle. A standalone jar is available for projects that do not use a dependency manager. The library uses SLF4J for logging, which means you choose and supply your own logging framework rather than having one forced on you. Java 8 or higher is required. The project is MIT-licensed.

Copy-paste prompts

Prompt 1

Using Java-WebSocket, write a minimal WebSocket server that listens on port 8887 and echoes back every message it receives.

Prompt 2

How do I create a secure WebSocket server using wss:// with Java-WebSocket and a self-signed certificate for local development?

Prompt 3

Show me how to add Java-WebSocket to a Gradle project and connect to an external WebSocket API, printing every incoming message to the console.

Prompt 4

Using Java-WebSocket, how do I broadcast a message to all connected clients when one specific client sends a particular command?

Open on GitHub → Explain another repo

← tootallnate on gitmyhub — every repo by this author, as a profile.

Verify against the repo before relying on details.