java代码发送websocket请求

以下是Java代码发送WebSocket请求的示例：

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Scanner;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.java_websocket.client.WebSocketClient;
import org.java_websocket.handshake.ServerHandshake;

public class WebSocketExample {

    public static void main(String[] args) throws URISyntaxException, InterruptedException {
        
        // Replace this with the actual WebSocket URL
        String webSocketUrl = "ws://example.com/websocket";
        
        // Create a WebSocket client instance
        WebSocketClient client = new WebSocketClient(new URI(webSocketUrl)) {

            // The onOpen method is called when the WebSocket connection is established
            @Override
            public void onOpen(ServerHandshake handshakedata) {
                System.out.println("WebSocket connection established");
            }

            // The onMessage method is called when a message is received from the WebSocket server
            @Override
            public void onMessage(String message) {
                System.out.println("Received message: " + message);
            }

            // The onClose method is called when the WebSocket connection is closed
            @Override
            public void onClose(int code, String reason, boolean remote) {
                System.out.println("WebSocket connection closed");
            }

            // The onError method is called when an error occurs on the WebSocket connection
            @Override
            public void onError(Exception ex) {
                System.out.println("WebSocket error: " + ex.getMessage());
            }
        };
        
        // Connect to the WebSocket server
        client.connect();
        
        // Wait for the WebSocket connection to be established
        CountDownLatch latch = new CountDownLatch(1);
        latch.await(5, TimeUnit.SECONDS);
        
        // Send a message to the WebSocket server
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter message to send: ");
        String message = scanner.nextLine();
        client.send(message);
        
        // Wait for the WebSocket connection to be closed
        latch.await();
        
        // Close the WebSocket connection
        client.close();
    }
}

在这个示例中，我们使用了 `org.java_websocket.client.WebSocketClient` 类来创建一个 WebSocket 客户端实例。我们覆盖了 `onOpen`、`onMessage`、`onClose` 和 `onError` 方法来处理 WebSocket 连接的各种事件。我们调用 `connect` 方法来连接到 WebSocket 服务器，然后使用 `CountDownLatch` 等待连接成功。我们使用 `Scanner` 类从控制台读取用户输入的消息，并使用 `send` 方法将消息发送到 WebSocket 服务器。最后，我们等待 `CountDownLatch` 以等待 WebSocket 连接关闭，并调用 `close` 方法来关闭 WebSocket 连接。