I had this same problem, azureus not starting with a gjl error. I'm running stock gentoo, not sabayon, but *shrug*.. this is the ONLY thread with this problem google could find. I got the same error from gjl just with different line numbers... it seemed pretty cryptic but I think the dep stuff in the error means a missing dependency is the REAL problem... I used "java-config -l" which lists all your java packages, and where the ".env" file describing it is. For azureus this is /usr/share/azureus/package.env, which had this line:
I ran "emerge --oneshot log4j commons-cli swt bcprov"
While these reinstalled, emerge also installed junit which I did not have installed. I would guess this was the REAL problem.
If any other java apps you had broken are still broken (didn't just need junit..) I suspect running a similar procedure of reinstalling stuff from package.env DEPENDS line would work. I wonder if there is a working revdep-rebuild or python-updater equivalent for java stuff?