A memory profiler can tell you which objects are staying in memory, and what is referencing them so that they can't be garbage collected. Finding out which ones are wrong and therefore indicate "memory leakage" can only be done by a developer who knows the system.
I had good luck using JProfiler in the past.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus