1) According to a source code of ApplicationListenerMethodAdapter class we can see that return type of a method annotated with @EventListener can be not only a Collection<?> but also array. 2) Method annotated with @EventListener can have any visibility (public, protected, package-private and private) and can be final and static.
Comment From: sbrannen
This has been merged into master in a80c5fcfaf2786ab506d176e4a713ae983f9bfe5 and revised in bcc6171a72b0a7fa3e21919f2c2fc7b3daf36a30.
Thanks