java发送websocket请求

在Java中发送WebSocket请求可以使用Java API中的Java WebSocket API。下面是一个简单的例子：

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.WebSocket;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

public class WebSocketExample {
    public static void main(String[] args) throws InterruptedException, ExecutionException {
        HttpClient client = HttpClient.newHttpClient();
        WebSocket webSocket = client.newWebSocketBuilder()
                .buildAsync(URI.create("wss://example.com"), new WebSocketListener())
                .get(10, TimeUnit.SECONDS);
        CompletableFuture<Void> completionFuture = new CompletableFuture<>();
        webSocket.sendText("Hello, world!", true).thenRun(() -> completionFuture.complete(null));
        completionFuture.get();
    }

    static class WebSocketListener implements WebSocket.Listener {
        @Override
        public void onOpen(WebSocket webSocket) {
            System.out.println("WebSocket opened");
        }

        @Override
        public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
            System.out.println("Received text: " + data);
            return null;
        }

        @Override
        public void onError(WebSocket webSocket, Throwable error) {
            System.out.println("WebSocket error: " + error.getMessage());
        }

        @Override
        public void onClose(WebSocket webSocket, int statusCode, String reason) {
            System.out.println("WebSocket closed with code " + statusCode + ", reason: " + reason);
        }
    }
}

以上代码使用Java标准库中的HttpClient和WebSocket API来发送WebSocket请求。在WebSocket构建器中指定WebSocket的URI和一个WebSocket监听器，然后调用sendText方法来发送消息。在监听器中实现onText方法来处理接收到的消息。