Altering Quartz Job Schedule

问题

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,

回答1:

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

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);
}

来源：https://stackoverflow.com/questions/13320419/altering-quartz-job-schedule

标签

java

quartz-scheduler