code: public void unscheduleJob(String jobName)
        throws JobException {
      if (this.scheduledJobs.containsKey(jobName)) {
        try {
          this.scheduler.getScheduler().deleteJob(this.scheduledJobs.remove(jobName));
        } catch (SchedulerException se) {
          LOG.error("Failed to unschedule and delete job " + jobName, se);
          throw new JobException("Failed to unschedule and delete job " + jobName, se);
        }
      }
    }
docs: Unschedule and delete a job.
  
  @param jobName Job name
  @throws JobException when there is anything wrong unschedule the job