JAVA websocket 请求

下面是一个简单的Java WebSocket请求示例：

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.WebSocket;
import java.util.concurrent.CompletionStage;

public class WebSocketClient {

    public static void main(String[] args) {

        HttpClient client = HttpClient.newHttpClient();

        WebSocket webSocket = client.newWebSocketBuilder()
                .buildAsync(URI.create("wss://echo.websocket.org"), new WebSocket.Listener() {

                    @Override
                    public void onOpen(WebSocket webSocket) {
                        System.out.println("WebSocket opened");
                        webSocket.sendText("Hello, Server!");
                    }

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

                    @Override
                    public CompletionStage<?> onClose(WebSocket webSocket, int statusCode, String reason) {
                        System.out.println("WebSocket closed: " + statusCode + " " + reason);
                        return null;
                    }

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

                }).join();

    }

}

在此示例中，我们使用Java 11中的HttpClient API和WebSocket API。我们创建了一个WebSocket客户端，该客户端连接到一个WebSocket服务器，并在连接打开时发送“Hello，Server！”消息。当客户端收到消息时，它将在控制台上打印该消息。当连接关闭时，它将在控制台上打印状态代码和原因。如果发生错误，则在控制台上打印错误消息。