Conditional subscriptions with Guava EventBus

Question

I am looking at using the Guava EventBus in my application to distribute data (Doubles for example) from one or more data creators through to data consumer.

I know in my consumer class, I need to annotate my data handler with @Subscribe. Is there a way in which to make this subscription conditional? So for example

@Subscribe {newValue > 0.0} public void valueUpdated(Double newValue)

I could add the check within my valueUpdated method, but is there a way to stop the EventBus from dispatching values that my Subscriber is not interested in?

Is there a product similar to EventBus that may provide this sort of function?

Answer 1

Spring Expression Language (SpEL) may help.

Plus: after checking the EventBus, I think it's type-based dispatch, no way to apply condition-based dispatch. If you insist on using Expression Language, you could put it in subscriber as Louis comment. But Expression Language is designed for flexibility rather than speed.