Running a Job only once Using Quartz

In quartz > 2.0, you can get the scheduler to unschedule any job after work is done:

@Override
protected void execute(JobExecutionContext context)
            throws JobExecutionException {
    ...
    // process execution
    ...
    context.getScheduler().unscheduleJob(triggerKey);
    ...
}

where triggerKey is the ID of the job to run only once. After this, the job wouldn't be called anymore.

You should use SimpleTrigger that fires at specific time and without repeating. TriggerUtils has many handy methods for creating these kind of things.

Yes, it's possible!

JobKey jobKey = new JobKey("testJob");
JobDetail job = newJob(TestJob.class)
            .withIdentity(jobKey)
            .storeDurably()
            .build();
scheduler.addJob(job, true);
scheduler.triggerJob(jobKey); //trigger a job inmediately