Question

I’m trying to schedule a task depending on it’s response. The task is something like:

public Date scheduledTask() {
    Date nextRun;
    // ...
    nextRun = something();
    // ...
    return nextRun;
}

How can I make sure that the same task is called again when reaching the nextRun?

Thank you.

Answer 1

This is very simple with standard Quartz scheduler API. Inside your Job compute nextRun time and create a trigger with startAt() defined:

public class ScheduledJob implements Job {

    @Override
    public void execute(JobExecutionContext context) throws JobExecutionException {
        final Date nextRun = something();

        Trigger trigger = newTrigger().
                startAt(nextRun).
                forJob(context.getJobDetail()).
                build();

        context.getScheduler().scheduleJob(trigger);
    }

}

Tested, works like a charm.