Question

我需要在Spring Boot中服务器发送事件时从SQL数据库向用户发送通知。我已经使用SseEmitter来实现这一点。

1) @GetMapping(value = "/v2/user/notifications/event",produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public ResponseEntity<SseEmitter> sendNotification(@RequestHeader(value = "Authorization") final String token) {

        HttpHeaders headers = new HttpHeaders();
        headers.add("Connection","keep-alive");
        headers.add("Cache-Control", "no-cache");
        List<HttpStatus> httpStatuses = new ArrayList<>();
        httpStatuses.add(0, HttpStatus.OK);


        SseEmitter sseEmitter = new SseEmitter(Long.MAX_VALUE);
        Integer nextEventFireTime = appConfig.getConfiguration().getInteger("sse.nextEventFireTime");

        ScheduledExecutorService scheduledExecutorService =
                Executors.newScheduledThreadPool(Constants.MAX_THREAD_POOL_SSE);

        scheduledExecutorService.scheduleAtFixedRate(() -> {
            try {
                service.sendNotification(sseEmitter, token);
            } catch (BaseException e) {
                httpStatuses.add(0, HttpStatus.INTERNAL_SERVER_ERROR);
                sseEmitter.completeWithError(e);
                scheduledExecutorService.shutdown();
            }
        } , 0, nextEventFireTime, TimeUnit.SECONDS);

        return new ResponseEntity<>(sseEmitter, headers, httpStatuses.get(0));
    }

* nextEventFireTime配置为15

2)@Override
    public synchronized void sendNotification(SseEmitter emitter, String token) throws BaseException {

        NotificationMetadata notificationMetadata =
                getUnreadNotificationCount(token);

        List<Notification2> notificationList;
        notificationList =
                getSseNotifications(token);

        SseEmitter.SseEventBuilder event = SseEmitter.event();

        NotificationResponse2 notificationResponse2 = new NotificationResponse2();
        notificationResponse2.setData(notificationList);
        notificationResponse2.setMetadata(notificationMetadata);

        event.name(Constants.SSE_EVENT_NAME).data(notificationResponse2)
                .build();
        try {
            emitter.send(event.reconnectTime(15000L));
        } catch (Exception e) {
            throw new BaseException("Failed to send notification event.. "+e.getMessage(), Constants.ERROR_CODE_INTERNAL_ERROR,
                    "sendNotification", HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

客户端正在等待响应，当db中没有用于通知的数据但计数查询正在获取数据时，客户端花了将近17分钟，而在有数据的情况下，还需要4-5分钟才能给出响应。

我是第一次使用SseEmitter，并且在调试服务器时执行了代码，但响应仍未决。

有人可以帮助我解决这个问题吗？

服务器使用侦听器发送事件，需要更多时间来进行响应

0 个答案: