Redeploy a singleton with timer task

Question

I have a web server application runing with JVM, where i manage the class loader. My application have an singleton with a cycle timertask. During the redeployment i clean all the references to Class(es). I look like that my singleton with the timerTask doen't die. I add a finalize method with print. the finalize method was never call. Any solution?

Answer 1

Take a look at the Servlet lifecycle. Your servlet can implement destroy(), which will get called on unloading. Use that to switch off timers etc.

Note that you can never rely on finalize() being called.

Answer 2

These things are much easier with Spring and Quartz. In Spring you can define a bean to be a singleton (not exactly the same with the singleton design pattern, but it will serve your needs). Also Quartz is much more powerful/flexible/easy to work with than TimerTask.

Spring will take care redeployment issues for you. You just need to define a destroy method.