Spring事件发射器停止向新连接上的以前客户端发送事件。

Question

我是Server-Sent-Events的新手。我有一个事件发射器，它每2秒发送一次更新(使用SseEmitter，托管在Tomcat上)，我看到当我在一个新窗口中打开URL时，消息并没有被发送到前面的窗口。请看下面的图片。

这是服务器发送事件的预期行为吗？我需要向所有连接到我的流URL的客户端发送更新。我是否需要在我的应用程序或tomcat服务器上进行任何额外的配置或设置？请帮帮忙

这是控制器

@Controller
public class MySSEController {
    private final SseEmitter sseEmitter = new SseEmitter(100000l);
    private int counter = 0;

    @RequestMapping("/ssestream")
    public SseEmitter getRealTimeMessageAction() throws IOException {

        sseEmitter.send("MessageCounter : " + counter);
        return sseEmitter;
    }

    @Scheduled(fixedDelay = 2*1000)
    public void scheduledMsgEmitter() throws IOException
    {
        if(null != sseEmitter) {
            sseEmitter.send("MessageCounter : " + ++counter);
        }
    }
}

Answer 1

尝试如下：

@Controller
public class MySSEController {
    private List<SseEmitter> sseEmitters = new ArrayList<>();

    private int counter = 0;

    @RequestMapping("/ssestream")
    public SseEmitter getRealTimeMessageAction() throws IOException {
        SseEmitter sseEmitter = new SseEmitter(100000l);
        sseEmitter.send("MessageCounter : " + counter);
        sseEmitters.add(sseEmitter);
        return sseEmitter;
    }

    @Scheduled(fixedDelay = 2 * 1000)
    public void scheduledMsgEmitter() {
        counter++;
        List<SseEmitter> toRemove = new ArrayList<>();

        for (SseEmitter sseEmitter : sseEmitters) {
            try {
                sseEmitter.send("MessageCounter : " + counter);
            } catch (IOException ignore) {
                toRemove.add(sseEmitter);
            }
        }

        for (SseEmitter remove : toRemove) {
            sseEmitters.remove(remove);
        }
    }
}