Event-driven whiteboard pattern?

[Tim Moloney]

Is it possible to use the whiteboard pattern for an event-driven 
application?

I have a prototype of what I want to accomplish using the listener 
pattern.  I experienced first-hand the extra admin of getting service 
references, etc.  I've read a couple of the tutorials which describe 
using the whiteboard pattern in OSGi but they aren't event-driven.  The 
timing of these examples is controlled by the event-listener, not the 
event source.  I need the interaction to take place when the event 
occurs, not when the listener gets around to it.

Am I missing something obvious or should I just stick with the listener 
pattern?

Perhaps another way to ask this is, what is the best way for an 
event-driven app to use the OSGi service registry?

Thanks,
 Tim