There are lots of compiler warnings in the Admin GUI code. Also some old-style code that does not use JDK5 for-loop iteration or JDK7 diamond syntax. This should be fixed.
I have some fixes locally that didn't make it into 6.11. I'll try to finish this task up if it does not take too much time.
WIll only fix "easy" warnings under this issue, not ones that require code restructuring etc.