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How to stop threads when undeploying a JEE application?

Answer 1

+3 A:

Rather use ScheduledExecutorService#scheduleAtFixedRate() instead of the old fashioned Thread#sleep(). You can use ServletContextListener to run it on webapp's startup and stop it on webapp's shutdown.

public class Config implements ServletContextListener {

    private ScheduledExecutorService scheduler;

    @Override
    public void contextInitialized(ServletContextEvent event) {
        scheduler = Executors.newSingleThreadScheduledExecutor();
        scheduler.scheduleAtFixedRate(new Task(), 0, 1, TimeUnit.MINUTES); // Schedule to run every minute.
    }

    @Override
    public void contextDestroyed(ServletContextEvent event) {
        scheduler.shutdown(); // Important! This stops the thread.
    }

}

Where Task can look like this:

public class Task implements Runnable {

    @Override
    public void run() {
        log(something);
    }

}

To get the Config to run, register it in web.xml as follows:

<listener>
    <listener-class>com.example.Config</listener-class>
</listener>

BalusC 2010-07-22 16:05:33

Thanks for your answer. I did not implement the logger myself, it comes with the Drools rules engine. Therefore I cannot change the implementation. Neither can I get the thread it uses to do the logging. There is no getter for that. I just looked into the source of the drools classes and saw the implementation with the sleep function. So my question remains: is there any way to know when the app is undeployed? finallize comes too late, @PreDestroy is called during normal operation from the container. How can the app know when it is undeployed?

Arne 2010-07-23 07:37:30

To clarify: the Exception say: "Input stream has been finalized or forced closed without being explicitly closed". My question is: how can I close it when I undeploy? closing is done with the close() method, but when?

Arne 2010-07-23 07:49:51

Answer 2

A:

I did not made clear enough what I wanted in this question, sorry for that. I asked a new question here

Arne 2010-07-23 07:58:27

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