java发送websocket请求

你可以使用Java的WebSocket API来发送WebSocket请求。下面是一个简单的示例代码：

import java.net.URI;
import java.net.URISyntaxException;
import java.nio.ByteBuffer;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import javax.websocket.ClientEndpoint;
import javax.websocket.CloseReason;
import javax.websocket.ContainerProvider;
import javax.websocket.DeploymentException;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.WebSocketContainer;

@ClientEndpoint
public class WebSocketClient {

    private final CountDownLatch latch;
    private Session session;

    public WebSocketClient() {
        this.latch = new CountDownLatch(1);
    }

    public void connect(String uri) throws DeploymentException, URISyntaxException, InterruptedException {
        WebSocketContainer container = ContainerProvider.getWebSocketContainer();
        container.connectToServer(this, new URI(uri));
        this.latch.await(10, TimeUnit.SECONDS);
    }

    public void sendMessage(String message) {
        this.session.getAsyncRemote().sendText(message);
    }

    public void sendBinary(ByteBuffer buffer) {
        this.session.getAsyncRemote().sendBinary(buffer);
    }

    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        this.latch.countDown();
    }

    @OnClose
    public void onClose(CloseReason reason) {
        System.out.println("Connection closed: " + reason);
    }

    @OnError
    public void onError(Throwable cause) {
        System.out.println("Error: " + cause.getMessage());
    }

    @OnMessage
    public void onMessage(String message) {
        System.out.println("Received message: " + message);
    }

    @OnMessage
    public void onMessage(ByteBuffer buffer) {
        System.out.println("Received binary message: " + buffer);
    }
}

你可以使用`WebSocketClient`类来连接WebSocket服务器并发送消息。以下是使用示例：

public static void main(String[] args) {
    try {
        WebSocketClient client = new WebSocketClient();
        client.connect("wss://example.com/ws");
        client.sendMessage("Hello, world!");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

在上面的示例中，我们创建了一个`WebSocketClient`实例，并使用`connect()`方法连接到WebSocket服务器。一旦连接成功，我们可以使用`sendMessage()`方法发送文本消息，或使用`sendBinary()`方法发送二进制消息。在接收到消息时，`onMessage()`方法将被调用。