Fuse ESB uses karaf server with OSGi.
for the code if anybody has steps to get the debugger for the application it will help.
I am currently using Eclipse In
You just need to put the following line in the Fuse ESB startup script (e.g. fuseesb.bat or karaf.bat):
set KARAF_DEBUG=true
After that Fuse ESB will start in debug mode using 5005 port.