How to keep the servlet continously running?

27 down vote accepted

Your problem is that you misunderstand the purpose of the servlet. It's intented to act on HTTP requests, nothing more. You want just a background task which runs once on daily basis. For that Quartz or even ScheduledExecutorService is perfect. This needs to be initiated by a ServletContextListener. Here's a kickoff example: public class Config implements ServletContextListener { private ScheduledExecutorService scheduler; @Override public void contextInitialized(ServletContextEvent event) { scheduler = Executors.newSingleThreadScheduledExecutor(); scheduler.scheduleAtFixedRate(new UpdateCounts(), 0, 1, TimeUnit.DAYS); } @Override public void contextDestroyed(ServletContextEvent event) { scheduler.shutdownNow(); } } Where the class UpdateCounts look like this: public class UpdateCounts implements Runnable { @Override public void run() { // Do your job here. } } To get the ServletContextListener to run, just register it in web.xml as follows: <listener> <listener-class>com.example.Config</listener-class> </listener> Or, when you're already on Servlet 3.0, just annotate it with @WebListener @WebListener public class Config implements ServletContextListener {}

http://www.blogger.com/blogger.g?blogID=2583984764735864664#editor