Spring Boot websocket通知片状

Question

我在 Angular 中使用 Spring Boot WebSocket 通知和 Stomp 客户端库来连接和订阅 WebSocket。但是，有时我会在 UI 屏幕上收到通知，有时我没有收到通知。行为有缺陷。

谁能给我建议解决方案？

public getNotification(){
var isConnected = this.notification.initConnnection();
const _this=this;

_this.stompClient.connect({}, function (frame){

const url='topic/topicName';
_this.StompClient.subscribe(url,(message)=>{

console.log(message)
});
},_this.stompCallBack);

)
}

public stopCallBack;any function(error){
console.log(error)
setTimeOut(this.notification,10000)

}

服务器端：

@Autowire
SimMessagingTemplate simMessagingTemplate;


simMessagingTemplate.convertAndSend('topic/topicName', message)

Answer 1

这是一个配置示例：

@Slf4j
@Configuration
@EnableWebSocketMessageBroker
@RequiredArgsConstructor
public class NotificationsWebSocketConfig implements WebSocketMessageBrokerConfigurer {

....

 @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.interceptors(new ChannelInterceptor() {
            @Override
            public Message<?> preSend(Message<?> message, MessageChannel channel) {
                StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
                if (isNull(accessor) || isNull(accessor.getCommand())) {
                    log.warn("Unable to subscribe/unsubscribe: accessor or command is empty.");
                    return message;
                }
                switch (accessor.getCommand()) {
                    case SUBSCRIBE: {
                        wsSessionService.subscribe(accessor);
                        break;
                    }
                    case UNSUBSCRIBE:
                    case DISCONNECT:
                    case ABORT:
                        wsSessionService.unsubscribe(accessor);
                        break;
                }
                return message;
            }
        });
    }

wsSessionService 包含一些业务逻辑。此服务/组件存储所有活动会话并使用以下方式将所有通知发送到目的地：

@Slf4j
@Service
@RequiredArgsConstructor
public class MessageSender {

    private final ObjectMapper mapper;
    private final SimpMessagingTemplate simpMessagingTemplate;

    @SneakyThrows
    public <T> void sendMessage(String destination, T payload) {
        if (isNull(destination) || isNull(payload)) {
            log.warn("Destination or payload is empty. Cannot send message.");
            return;
        }
        Map<String, Object> headers = new HashMap<>();
        headers.put("content-type", MediaType.APPLICATION_JSON_UTF8);
        MessageHeaders messageHeaders = new MessageHeaders(headers);

        byte[] bytes = mapper.writeValueAsBytes(payload);
        Message<Object> message = MessageBuilder.createMessage(bytes, messageHeaders);

        log.debug("Incoming  message for to destination -> {}", destination);
        simpMessagingTemplate.send(destination, message);
    }
}