Leaking is always difficult to find. If you have everything correct this will not happen. But it will be more or less impossible
In your code you should check that every resource/class/reference will be cleared if not longer used.
In case of having such a leak you can check with heap dumps and profiler to find the reason.
Library classes which are used by many applications can be store in common/lib or deploy/.../lib. In that case the applications classloader will find it.
Many a thanks for the response man.. I'll see to it.. In fact apologies for the delay in reply.. wasn't able to login for a while..