check the jrockit memleak:
and/or the standard hprof:
antoher (pure cmdline) way of digging in java heap is "jrcmd <pid> print_object_summary"
We have HPROF functionality in our latest roadmap, so you will see that feature in our next major release called JRockit R28.
I recommend, above from the MemLeak documentation suggested by Makiey, the following information on how to use JRockit tools.
Performance Tuning & Profiling:
Using JRockit tools:
Diagnostics & Troubleshooting