CDI - 当观察者观察到事件时是否通知调用者？
我正在使用 CDI，想知道如何通知调用者观察者是否观察到事件。如果没有观察者对该事件采取行动，那么我想做点什么。除了通知调用者的提示之外，我没有看到文档中的任何地方记录了这一点。
谢谢，
沃尔特
I am using CDI and want to know how the caller is notified that the observer has observed an event or didn't. If no observes act on that event, then I want to do something. I don't see this being documented anywhere in the documentation other than there was a hint that the caller is notified.
Thanks,
Walter
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我认为调用者不会收到通知（这不是观察者模式实际上的目的）。但您可以尝试通过以下方式解决此问题：
您可以在事件对象上设置一个字段 -
private boolean Consumer并在使用时将其设置为true。然后，（事件同步处理）在事件生成器中检查该变量。从事件生产者观察到的观察者激发一个新事件
如果您想放弃松散耦合的好处，并且您确切地知道事件生产者是谁，您可以将其
@Inject到所有侦听器中，并让它们调用其上的方法I don't think the caller is notified (it's not what the observer pattern is about actually). But you can try to work this around by:
you can have a field one the event object -
private boolean consumedand set it totrueif it is consumed. Then, (the events are handled synchronously) in the event-producer check that variable.firing a new event from the observers that is observed by the event producer
If you want to drop the benefit of the loose coupling, and you know exactly which the event producer is is, you can
@Injectit into all listeners, and let them invoke a method on it