Vaadin23 PUSH UIDetachedException

Question

在MainLayout中有以下广播处理程序

@Override
protected void onAttach(AttachEvent attachEvent) {
    super.onAttach(attachEvent);

    SecurityService securityService = serviceFacade.getSecurityService();
    UI ui = attachEvent.getUI();
    if (securityService.isAuthorized()) {
        broadcasterRegistration = serviceFacade.getBroadcasterService().register(securityService.getCurrentUserUuid(), broadcasterMessage -> {
            ui.access(() -> {
                processBroadcasterMessage(broadcasterMessage);
            });
        });
    }
}

我不时地在日志中看到以下异常：

Exception in thread "pool-3-thread-5" com.vaadin.flow.component.UIDetachedException
    at com.vaadin.flow.component.UI.handleAccessDetach(UI.java:415)
    at com.vaadin.flow.component.UI.access(UI.java:515)
    at com.vaadin.flow.component.UI.access(UI.java:502)
    at com.example.ui.layout.MainLayout.lambda$onAttach$2(MainLayout.java:331)
    at com.example.ui.service.broadcaster.BroadcasterServiceImpl.lambda$broadcast$0(BroadcasterServiceImpl.java:46)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
    at java.base/java.lang.Thread.run(Thread.java:833)

尽管存在此异常，但一切都正常工作，所以我的问题是--我是否应该对这个UIDetachedException异常做出某种反应？

Answer 1

UIDetachedException是有目的的。当您试图访问关闭的UI时，会引发它。用户已关闭浏览器。您应该捕获异常，例如停止后台任务，取消广播侦听器的注册。