Add a timer to a java web Program

This Is My Timer class, used to regularly execute a certain task;

Package com. my. time;

Import java. text. ParseException;

Import java. text. SimpleDateFormat;

Import java. util. Date;

Import java. util. Timer;

Public class BugXmlTimer {

Public Timer timer;

Public void timerStart (){

Timer = new Timer ();

Date datetime = new Date ();

Date midnightDate = new Date ();

SimpleDateFormat sdf1 = new SimpleDateFormat ("yyyy-MM-dd ");

SimpleDateFormat sdf2 = new SimpleDateFormat ("yyyy-MM-dd HH: mm: ss ");

Try {

MidnightDate = sdf2.parse (sdf1.format (datetime) + "23:00:00 ");

} Catch (ParseException e ){

// TODO Auto-generated catch block

E. printStackTrace ();

}

Long in = midnightDate. getTime ()-datetime. getTime ();

System. out. println ("before task ");

// Execute immediately, and then execute every 30 s

Timer. schedule (new BugXmlTimerTask (), 0,30000 );

}

Public void timerStop (){

If (timer! = Null)

Timer. cancel ();

}

Public static void main (String [] args ){

BugXmlTimer myTimer = new BugXmlTimer ();

// TODO Auto-generated method stub

MyTimer. timerStart ();

}

}

// This is the class for executing tasks, that is, the tasks to be done at intervals are shown here

Package com. my. time;

Import java. util. TimerTask;

Public class BugXmlTimerTask extends TimerTask {

@ Override

Public void run (){

System. out. print ("run task ");

}

}

// The following is a scheduled operation class, which implements ServletContextListener

Public class MyTimerListener implements ServletContextListener {

Private BugXmlTimer mytimer = new BugXmlTimer ();

Public void contextInitialized (ServletContextEvent event ){

Mytimer. timerStart ();

}

Public void contextDestroyed (ServletContextEvent event ){

Mytimer. timerStop ();

}

}

Then deploy it in web. xml to run the timer after the program starts!

<Listener>

<Listener-class> com. my. time. MyTimerListener </listener-class>

</Listener>