import
      
      
         java.util.Timer;


      
      
        import
      
      
         javax.servlet.ServletContextEvent;

      
      
        import
      
      
         javax.servlet.ServletContextListener;


      
      
        public
      
      
        class
      
       TestListener 
      
        implements
      
      
         ServletContextListener {
  
      
      
        private
      
       Timer timer = 
      
        null
      
      
        ;

  
      
      
        public
      
      
        void
      
      
         contextInitialized(ServletContextEvent event) {
    timer 
      
      = 
      
        new
      
       Timer(
      
        true
      
      
        );
    timer.schedule(
      
      
        new
      
       TestTimer(), 0, 86400000);
      
        //
      
      
        milliseconds
      
      
          }

  
      
      
        public
      
      
        void
      
      
         contextDestroyed(ServletContextEvent event) {
    timer.cancel();
  }
}


      
      ------------------------------------------


      
        import
      
      
         java.util.TimerTask;


      
      
        public
      
      
        class
      
       TestTimer 
      
        extends
      
      
         TimerTask {
  
      
      
        public
      
      
        void
      
      
         run() {
    
      
      
        //
      
      
         do something ...
      
      
          }
}


      
      ------------------------------------------
      
        

web.xml:


      
      <listener>
<listener-
      
        class
      
      >test.TestListener</listener-
      
        class
      
      >
</listener>