在servlet的doGet（）仍在运行时检测J2EE容器停止事件

Question

I am trying to detect an application stop event (in Websphere 8.0) to invoke a servlet's static method. I wonder if there's a straightforward way to find out if the application has been ordered to stop.

This is the scenario:

1. I have one servlet, WorkerServlet , running a loop like this while(!forceStop){...} in its doGet(). While the application is up, this loop is continuously running.
2. When the container stops the application (because of any event such as republish, stop, restart the application/server) I would like to invoke the static method WorkerServlet.forceStop(){forceStop = true;} .

This way, WorkerServlet's loop would finish and the servlet could be destroyed by the container right away. The current behaviour is that the container waits for 60 seconds before forcing the destroy which is unacceptable during development time.

I have tried different approaches but none of them works

1. A ServletContextListener.contextDestroyed() . Not called until all servlets are destroyed
2. A Spring ApplicationListener to detect when de application context is going to be destroyed. Not called until all servlets are destroyed.
3. Another servlet with a destroy() method that invokes WorkerServlet.forceStop() . The container doesn't destroy() this servlet since there's another one running a request.

So, is there any other way to detect the container's app shutdown event so that I can invoke that static method?

Answer 1

The only workaround I found was to use a startup bean. Fortunately Webshpere's EJB container is stopped before the servlet container:

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.Singleton;
import javax.ejb.Startup;

@Singleton
@Startup
public class WorkerServletStopper {

    @PreDestroy
    public void preDestroy(){
        WorkerServlet.forceStop();
    }
}