不用HttpClient,改成restTemplet

当使用`RestTemplate`发送WebSocket请求时，您需要使用`WebSocketClient`类，并将其注入到`RestTemplate`中。以下是一个示例代码：

import java.net.URI;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.client.ClientHttpRequest;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;
import org.springframework.web.client.RequestCallback;
import org.springframework.web.client.ResponseExtractor;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.socket.WebSocketHttpHeaders;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.client.standard.StandardWebSocketClient;
import org.springframework.web.socket.handler.AbstractWebSocketHandler;

public class WebSocketClient {
    public static void main(String[] args) throws Exception {
        String url = "wss://example.com/websocket";
        HttpHeaders headers = new HttpHeaders();
        WebSocketHttpHeaders webSocketHeaders = new WebSocketHttpHeaders(headers);

        RestTemplate restTemplate = new RestTemplate();
        restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
        restTemplate.setRequestFactory(new HttpComponentsClientHttpRequestFactory());

        StandardWebSocketClient webSocketClient = new StandardWebSocketClient();
        ListenableFuture<WebSocketSession> future = webSocketClient.doHandshake(new AbstractWebSocketHandler() {
            @Override
            public void afterConnectionEstablished(WebSocketSession session) throws Exception {
                session.sendMessage(new TextMessage("Hello, server!"));
            }

            @Override
            protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
                System.out.println(message.getPayload());
            }
        }, webSocketHeaders, URI.create(url));

        future.addCallback(new ListenableFutureCallback<WebSocketSession>() {
            @Override
            public void onSuccess(WebSocketSession result) {
                System.out.println("WebSocket connection established");
            }

            @Override
            public void onFailure(Throwable ex) {
                System.err.println("WebSocket connection error: " + ex.getMessage());
            }
        });

        // Wait for the WebSocket connection to be established
        WebSocketSession session = future.get(10, TimeUnit.SECONDS);

        // Send a message over the WebSocket connection
        session.sendMessage(new TextMessage("Hello, server!"));
    }
}

在上面的代码中，我们使用`RestTemplate`创建了一个`WebSocketClient`实例，并使用`doHandshake`方法连接到WebSocket服务器。在`WebSocketClient`的回调方法中，您可以处理服务器返回的消息。在`session.sendMessage`方法中，我们发送了一个文本消息给服务器。