At work I had run into a memory leak when scrolling through large result sets returned from Hibernate. I thought I had fixed it by performing a evict()/clear()/flush() in the HibernateTemplate that I was using but suddenly the leak was back. I was using VisualVm to monitor the heap so I started poking around to see if there was anything to help diagnose where the leak was.
» Read more: Debugging memory leaks with VisualVM