how to skip cron trigger firetime

问题

I am transferring files from a directory on a remote host and a trigger fires jobs when interval arrives for this job.But i want be sure that if a job still working on a storage (downloading of files not yet finished) when trigger fire time arrives ,quartz going to skip this interval.I try to use this c r on_trigger.MISFIRE_INSTRUCTION_DO_NOTHING but i seems it only for if there is no available thread for job.

public CronTrigger scheduleJob(RemoteJob job, String cronExpression,Date firstFireTime) throws SchedulerException, ParseException {
    JobDetail jobDetail = new JobDetail(job.getDescription(), job.getName(), job.getClass());
    CronTrigger crTrigger = new CronTrigger(
            "cronTrigger", job.getName(), cronExpression);       
    scheduler.scheduleJob(jobDetail, crTrigger);    
    crTrigger.setStartTime(firstFireTime);
    crTrigger.setMisfireInstruction(CronTrigger.MISFIRE_INSTRUCTION_DO_NOTHING);
    return crTrigger;

}

回答1:

Create a TriggerListener that tracks if one of your download jobs is running, and and then return true for vetoing the execution of the other type of job.

回答2:

I slightly modified the code above, it's worked.

/**
 * not for cluster
 */
@Override
public boolean vetoJobExecution(Trigger trigger, JobExecutionContext context) {
    try {
        List<JobExecutionContext> currentlyExecutingJobs = context.getScheduler().getCurrentlyExecutingJobs();
        for (JobExecutionContext jobContext : currentlyExecutingJobs) {
            if (jobContext.getTrigger().equals(trigger) &&
                    jobContext.getJobDetail().getKey().equals(trigger.getJobKey())) {
                return true;
            }
        }
    } catch (SchedulerException ex) {
        return true;
    }
    return false;
}

回答3:

I did as you say

public boolean vetoJobExecution(Trigger trigger, JobExecutionContext context) { 

    try {

        List<JobExecutionContext> jobs = 
context.getScheduler().getCurrentlyExecutingJobs();

        for (JobExecutionContext job : jobs) {


            if (job.getTrigger().equals(context.getTrigger()) && 
!job.getJobInstance().equals(this)) {

                _logger.info("There's another instance running,So job discarded  " + context.getJobDetail().getGroup()+ ":"+context.getJobDetail().getName());
                return true;
            }
        }
    } catch (SchedulerException ex) {

     return  true;
    }

    return false;
}

来源：https://stackoverflow.com/questions/6155665/how-to-skip-cron-trigger-firetime

标签

quartz-scheduler