Altering Quartz Job Schedule

Question

I'm looking into scheduling my application with Quartz, but in all cases, the job trigger seems to be a one-time activity, and changes to the trigger need the application to be re-deployed to take effect.
Is there any way I can have the job trigger check for changes to the job schedule without having to redeploy the code?
Thanks,

Answer 1

1. Trap some user-driven event, like updating a text value, for example a cron-string to schedule a job
2. Locate and unschedule/delete the old job and trigger.

3. Schedule the job again, using the new trigger.

    public static <T> T scheduleCronJob(Class<T> clazz, String cronString, String uid){ try{ if(cronString == null){ throw new CronStringConfigurationException(); } String jobGroupName = "cronJobsGroup"; String jobName = "cronJob" + uid; String triggerGroupName = "cronTriggers"; String triggerName = "triggerFor" + uid; JobDetail jobDetail = new JobDetail(jobName, jobGroupName, clazz); CronTrigger trigger = new CronTrigger( triggerName, triggerGroupName, jobName, jobGroupName, cronString); JobDataMap jobDataMap = new JobDataMap(); jobDetail.setJobDataMap(jobDataMap); getScheduler().scheduleJob(jobDetail, trigger); } catch(Exception e){ // print error message, throw stack trace } return null; } public static void reloadCronJob(Class clazz, String cronString, String uid) throws SystemException, ParseException, SchedulerException, CronStringConfigurationException, PortalException{ // locate the job String jobGroupName = "cronJobs"; String jobName = "jobFor" + uid; if(cronString == null){ throw new CronStringConfigurationException(); } JobDetail jobDetail = null; Class<?> jobClass = null; // remove the old job/trigger if it exists try{ jobDetail = scheduler.getJobDetail(jobName, jobGroupName); if(jobDetail != null){ jobClass = jobDetail.getJobClass(); } scheduler.deleteJob(jobName, jobGroupName); } catch(Exception e){ e.printStackTrace(); } if(jobClass == null){ jobClass = clazz; } // create a new trigger scheduleCronJob(jobClass, expandoColumnName, uid); System.out.println("(re)scheduled job " + jobName + " using new cron string " + cronString); }