Question

Is it possible to use type variance in CDI events? here is the case:

• Suppose i have a root event type MyEvent and subclass DummyEvent
• My goal is to process a list of events received from a remote source List<? extends MyEvent>, containing DummyEvent instances

How can i do this?

If i loop through the collection calling fire() on each event, it will invoke @Observes MyEvent evt but not @Observes DummyEvent evt methods.

** update **

Created a sample code to clarify the issue:

https://github.com/jfaerman/jfaerman/blob/master/test-cdi/src/main/java/jfaerman/App.java

I would like the event to be fired twice, one time individually and one time from the list.

Answer 1

It works injecting the BeanManager instad of Event, as tested by this servlet:

https://github.com/jfaerman/cdi-tests/blob/master/src/main/java/jfaerman/TestEventsServlet.java

Answered by Jozef Hartinger in this thread in the Weld forum:

https://community.jboss.org/message/716185