One issue I have come across is the usage of String concatenation. As far as I've understood, those are never removed from memory.
William Brogden wrote:
Use arrays instead of ArrayList - what a bizarre idea - use either as appropriate, just be sure to discard when finished.
If number of elements is determined, use an Array instead of an ArrayList, because it is much faster.
An Array also provides type checking, so there is no need to cast the result when looking up an object.
Matthias Merz wrote:A profiler is just a tool.