As you've probably guessed, the target can't be determined unambiguously
- any annotation declared on an interface will appear in the
implementation as well. I see a couple of ways around that:
1. You can use a manual mapping (good old XML) with the GWTHandler -
maybe disqualified because of your use of annotations
2. You could create a business interface GreetingsService devoid of any
GWT semantics, have GreetingsServiceImpl implement that interface,
create a new interface GWTGreetingsService which extends
GreetingsService and adds the RPC semantics and have the proxy implement it
3. File a proposal of how you would like to have this solved with the SL
I hope that helps,
G.