stopping threads gracefully

Question

I am using ScheduledExecutorService for scheduling a thread. I wonder what happens when JBoss is shut down? Does it kill all the threads that are started within the server, including the the one I scheduled? Do I have to do it manually using ScheduledFuture, and cancel the thread when ServletContext is destroyed?

Answer 1

There are two methods:

• java.util.concurrent.ExecutorService.shutdown()
• java.util.concurrent.ExecutorService.shutdownNow()

JBoss won't call any of these unless you do it in method which will be called upon shutdown. For web applications you have the chance to do it in javax.servlet.ServletContextListener.contextDestroyed(ServletContextEvent) .

Of course this is the JavaEE/Servlets way. You can hide it by using eg Spring Framework. By creating org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler you'll get shutting down for free (this class implements org.springframework.beans.factory.DisposableBean ). See the details here .