During development a SPRING based scheduler in a tomcat container, I always get this logoutput at undeploy webapp or shutdown server:
Apr 28, 2010 4:21:33 PM
The only way to ensure that threads are terminated, is to interrupt and join them.
This can by done by implementing org.quartz.InterruptableJob, as described in the answer to the question How to prevent a memory leak in quartz [?].