Java SE 6+/Android 4.1+ WebSocket client and server package, MIT (c) 2020-2025 @miktim

Release notes:

- RFC 6455 compliant package ( https://datatracker.ietf.org/doc/html/rfc6455/ );
- Java SE 6+/Android 4.1+ compatible (see WebSocket-Android-Test repo:
https://github.com/miktim/WebSocket-Android-Test ).
- no external dependencies;
- supported WebSocket version: 13;
- WebSocket extensions ( Per-Message Deflate, ... ) are not supported;
- supports cleartext/TLS connections (without tunneling);
- client supports Internationalized Domain Names (IDNs);
- stream-based messaging.

The ./dist/websocket-... jar file was built with debug info using JDK 1.8 for the target JRE 1.6.

Overview of the package in the file ./README.txt .

Example: creating and running a Java server for TLS connections:

  //... some code
  // create server side connection handler
  WsConnection.Handler handler = new WsConnection.Handler() {
    @Override
    onOpen(WsConnection conn, String subProtocol) {
      conn.send("Hello, Client!");
      // ... do something
    }
    @Override
    onMessage(WsConnection conn, InputStream is, boolean isText) {
      if (isText) { // is UTF-8 text stream?
        // ... UTF-8 text do something
      } else {
        // ... binary data do something
      };
    }
    @Override
    onError(WsConnection conn, Throwable e) {
      // ... do something
    }
    @Override
    onClose(WsConnection conn, WsStatus status) {
      // ... do something
    }
  };
  try {
    // create WebSocket factory
    WebSocket webSocket = new WebSocket();
    // set Java style key store file
    webSocket.setKeyFile(new File("myKeyFile.jks"), "password");
    // create and start server with default server handler and  connection parameters
    WsServer server = webSocket.SecureServer(8443, handler, new WsParameters()).launch();	
  } (Exception e) {
    e.printStackTrace();
  }
  //... some code

Example: creating a TLS connection for an Android client:

  //... some code
  // create client connection handler
  WsConnection.Handler handler = new WsConnection.Handler() {
    @Override
    onOpen(WsConnection conn, String subProtocol) {
      conn.send("Hello, Server!");
      // ... do something
    }
    @Override
    onMessage(WsConnection conn, InputStream is, boolean isText) {
      if (isText) { // is UTF-8 text stream?
        // ... is UTF-8 text. Do something.
      } else {
        // ... is binary data. Do something.
      };
    }
    @Override
    onError(WsConnection conn, Throwable e) {
      // ... do something
    }
    @Override
    onClose(WsConnection conn, WsStatus status) {
      // ... do something
    }
  };
  try {
    // create WebSocket factory
    WebSocket webSocket = new WebSocket();
    // if needed, set the Android styled trusted key store file
    webSocket.setKeyFile(new File("myKeyFile.bks"), "password");
    // create client TLS connection with default parameters
    WsConnection conn = webSocket.connect("wss://hostname:8443", handler, new WsParameters());	
  } (Exception e) {
    e.printStackTrace();
  }
  //... some code

Good luck!