Question

I’ve seen many answers on this topic but still can’t find a clean solution.

public class ProcessScheduler {
    static {
        Timer timer=new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            public void run() {
                LogProcessorServiceImpl.processPageRequestsLogs();
            }
        }, 0, 120);
    }
} 

How do I make this execute and be happy with quality solution? My application is based on Spring (unfortunately) and I know I can reference this class in one of my controllers and it’d probably work. But that’s silly. There just must be a better way. I’m on Tomcat with no EJB support, so timer annotation will not work for me. Also, I don’t want to do CRON. I want to schedule all my maintenance tasks within this scheduler class.

Servlet classes can be loaded via web.xml (1). Can we do something similar on non-servlet classes?

Answer 1

Instead of writing this in a static block, I would prefer to

• write an event listener that extends javax.servlet.ServletContextListener
• move that piece of code into the contextInitialized method
• define the contextDestroyed method to cancel the timer

• configure the class as <listener> in web.xml file for my application.

  <listener>
      <listener-class>
          com.vikdor.webapps.ProcessSchedulerListener
      </listener-class>
  </listener>