Java StompSession 发送消息 - Spring Boot

Question

我正在尝试在两个 Spring Boot 应用程序之间建立 websocket 连接；我在这里遵循示例代码:https://github.com/eugenp/tutorials/blob/master/spring-boot-client/src/main/java/org/baeldung/websocket/client/MyStompSessionHandler.java

由此看来，这部分对我来说效果很好:

 @Override
    public void afterConnected(StompSession session, StompHeaders connectedHeaders) {
   logger.info("New session established : " + session.getSessionId());
   session.subscribe("/topic/messages", this);
   logger.info("Subscribed to /topic/messages");
   session.send("/app/chat", getSampleMessage());
   logger.info("Message sent to websocket server");
}

但是，我不知道如何在 afterConnected 函数之外重用 session.send() 。换句话说，我想要一个如下所示的函数:

void sendMessage(String message){
    session.send("/app/chat", message);
}

Answer 1

我也遇到了同样的问题，我想在这篇文章中分享我的解决方案。我已经实现了一个配置类，该类公开带有 bean 的 StompSession，该 bean 可以作为服务注入(inject)到另一个组件中。

@Configuration
@RequiredArgsConstructor
public class WebSocketClientConfig {

    private static final Logger logger = LoggerFactory.getLogger(WebSocketClientConfig.class);

    /**
     * Provide Stomp Session Handler
     *
     * @return
     */
    @Bean
    protected StompSessionHandler provideStompSessionHandler() {
        return new WebSocketStompSessionHandler();
    }

    /**
     * Provide WebSocket Client
     *
     * @return
     */
    @Bean
    protected WebSocketClient provideWebSocketClient() {
        return new StandardWebSocketClient();
    }

    /**
     * Provide StompSession session
     *
     * @param sessionHandler
     * @param webSocketClient
     * @return
     * @throws java.lang.InterruptedException
     * @throws java.util.concurrent.ExecutionException
     */
    @Bean
    protected StompSession provideStompSession(
            final StompSessionHandler sessionHandler,
            final WebSocketClient webSocketClient
    ) throws InterruptedException, ExecutionException {
        final WebSocketStompClient stompClient = new WebSocketStompClient(webSocketClient);
        stompClient.setMessageConverter(new MappingJackson2MessageConverter());
        return stompClient.connect("ws://localhost:8080/messages", sessionHandler).get();
    }
}

现在我可以在 afterConnection 之外使用 StomSession:

@Service
@RequiredArgsConstructor
public class PublishMessageServiceImpl implements IPublishMessageService {

    /**
     * Stomp Session
     */
    private final StompSession stompSession;

    /**
     *
     * @param message
     */
    @Override
    public void publish(final PublishMessageDTO message) {
        Assert.notNull(message, "Message can not be null");
        stompSession.send("/topic/message", message);
    }

}

希望它对某人有用，问候