How to get the number of threads in a Java process

Useful tool for debugging java programs, it gives the number of threads and other relevant info on them:

jconsole <process-id>

java.lang.Thread.activeCount()

It will return the number of active threads in the current thread's thread group.

docs: http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#activeCount()

ManagementFactory.getThreadMXBean().getThreadCount() doesn't limit itself to thread groups as Thread.activeCount() does.