Spring Boot中Stomp Session Handler连接后afterConnected()未触发问题

核心问题：协议不匹配 #

Finnhub提供的WebSocket是原生WebSocket协议，而你使用的WebSocketStompClient是专门用于连接STOMP协议的WebSocket服务端的。两者协议不兼容，导致STOMP握手流程无法完成，因此afterConnected()永远不会被触发，最终超时出现传输异常。

解决方案：改用原生WebSocket客户端 #

放弃StompSessionHandler相关组件，直接使用StandardWebSocketClient结合WebSocketHandler实现原生WebSocket连接：

修改后的代码示例 #

import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Service;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.client.standard.StandardWebSocketClient;
import org.springframework.web.socket.handler.TextWebSocketHandler;

@Service
public class MyWebSocketClient {

    @EventListener(value = ApplicationReadyEvent.class)
    public void connect() {
        System.out.println("In connection...");
        StandardWebSocketClient client = new StandardWebSocketClient();
        
        WebSocketHandler handler = new TextWebSocketHandler() {
            @Override
            public void afterConnectionEstablished(WebSocketSession session) throws Exception {
                System.out.println("After Connected Called");
                // 连接建立后可发送Finnhub要求的订阅指令，示例为订阅AAPL行情
                session.sendMessage(new TextMessage("{\"type\":\"subscribe\",\"symbol\":\"AAPL\"}"));
            }

            @Override
            protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
                // 处理服务端推送的消息
                System.out.println("Received message: " + message.getPayload());
            }

            @Override
            public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
                System.out.println("failed in transport: " + exception.getMessage());
            }
        };

        try {
            client.doHandshake(handler, "wss://ws.finnhub.io/?token=my_token").get();
            System.out.println("connected");
        } catch (Exception e) {
            System.out.println("Failed: " + e.getMessage());
            e.printStackTrace();
        }
    }
}

额外说明 #

• Finnhub的WebSocket仅支持原生协议，需发送JSON格式的订阅/取消订阅指令，不兼容STOMP的帧格式。
• 原代码中connectAsync().get()会阻塞线程等待STOMP握手完成，但由于服务端不支持STOMP，会一直等待至超时，这就是控制台延迟出现传输异常的原因。

内容的提问来源于stack exchange，提问作者GDA 973