java使用websocket代码

可以使用Java的WebSocket API来实现WebSocket通信。以下是一个简单的Java WebSocket服务器的示例代码：

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.concurrent.Executors;

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
import com.sun.net.httpserver.Headers;

import javax.websocket.server.ServerEndpoint;
import javax.websocket.OnMessage;
import javax.websocket.Session;
import javax.websocket.server.PathParam;

@ServerEndpoint("/websocket/{username}")
public class WebSocketServer {

    private static final int PORT = 808;

    @OnMessage
    public void onMessage(Session session, String message, @PathParam("username") String username) throws IOException {
        // 处理收到的消息
    }

    public static void main(String[] args) throws Exception {
        HttpServer server = HttpServer.create(new InetSocketAddress(PORT), );
        server.createContext("/websocket", new WebSocketHandler());
        server.setExecutor(Executors.newCachedThreadPool());
        server.start();
    }

    static class WebSocketHandler implements HttpHandler {
        public void handle(HttpExchange exchange) throws IOException {
            if ("GET".equals(exchange.getRequestMethod())) {
                Headers headers = exchange.getResponseHeaders();
                headers.add("Upgrade", "websocket");
                headers.add("Connection", "Upgrade");
                headers.add("Sec-WebSocket-Accept", "...");
                exchange.sendResponseHeaders(101, -1);
                Session session = null;
                // 创建WebSocket会话
                session.getBasicRemote().sendText("连接成功");
            }
        }
    }
}

以上代码仅供参考，具体实现需要根据实际需求进行修改。