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JavaOnTracks: Scheduler

The scheduler allows you to schedule jobs to run at interval(every n minutes) or at specific times (cron like) in your application.

Here is how to use it:

Creating a job

To create a job, you need to implement JOTScheduledItem

Example Job:

Scheduled Job Example

public class MyJob implements JOTScheduledItem
{
    public void run()
    {
	// here you will add the "meat" of your job, say deleting some files etc ....
	// new File("/tmp/mytempFile").delete();
    }

    public boolean skipRun()
    {
	// you could return true in certain cases if you want to skip the job for some reason
        return false;
    }

    public boolean forceRun()
    {
	// return true to force a run ASAP even though it's not matching the schedule
        return false;
    }

    public void runCompleted()
    {
	// if you want something to be done after a run is completed, you can add it here
    }

}

Registering the job in the scheduler

Example 1: a job that runs every 10 mn

	// whether to run once right away, or wait for schedule match.
        Boolean runNow = true;
        JOTSchedulingOptions siteMapOptions = new JOTSchedulingOptions();
        siteMapOptions.setRunEvery(10,runNow);
        JOTScheduler.getInstance().registerItem(new MyJob(), siteMapOptions);

Example 2: a job that runs on the hour

	// wether to run once right away, or wait for schedule match.
        Boolean runNow = false;
	// this means every hour (see javadoc of JOTSchedulingOptions for schedule format infos.)
        String schedule = "* * * 1 0";
        JOTSchedulingOptions siteMapOptions = new JOTSchedulingOptions();
        siteMapOptions.setRunNow(runNow.booleanValue());
        siteMapOptions.setRunAt(schedule);
        JOTScheduler.getInstance().registerItem(new MyJob(), siteMapOptions);

You should only register each job once, usually when initializing your (web)application.

Starting the scheduler

            JOTScheduler.getInstance().start();

You should only start the scheduler once ! Usually when initializing your (web)application.

JavaDoc

http://www.colar.net/jotdoc/javaontracks/net/jot/scheduler/package-summary.html

Last modified: Wed Dec 10 19:07:30 EST 2008 by Thibaut Colar

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