Scheduling a trigger that contains data in its data map will consistently result in a StackOverflowError. Here is a snippet of the stacktrace:

Exception in thread "DefaultQuartzScheduler_QuartzSchedulerThread" java.lang.StackOverflowError
at java.util.HashMap$KeyIterator.<init>(HashMap.java:821)
at java.util.HashMap$KeyIterator.<init>(HashMap.java:821)
at java.util.HashMap.newKeyIterator(HashMap.java:835)
at java.util.HashMap$KeySet.iterator(HashMap.java:867)
at java.util.Collections$UnmodifiableCollection$1.<init>(Collections.java:1007)
at java.util.Collections$UnmodifiableCollection.iterator(Collections.java:1006)
at java.util.Collections$UnmodifiableCollection$1.<init>(Collections.java:1007)
at java.util.Collections$UnmodifiableCollection.iterator(Collections.java:1006)
at java.util.Collections$UnmodifiableCollection$1.<init>(Collections.java:1007)
at java.util.Collections$UnmodifiableCollection.iterator(Collections.java:1006)

and on and on and on..

I am seeing this problem consistently after 4914 trigger fires.

This problem can be reproduced consistently using the following code:

SchedulerFactory schedFact = new StdSchedulerFactory();
        Scheduler quartzScheduler = schedFact.getScheduler();
        quartzScheduler.start();

// register the callback job.
        JobDetail detail = new JobDetail("b", "b", NoopJob.class);

Trigger trigger = new SimpleTrigger("name", "group", "b", "b", new Date(), null, SimpleTrigger.REPEAT_INDEFINITELY, 50);
        trigger.getJobDataMap().put("a", "a");
        quartzScheduler.scheduleJob(detail, trigger);

where NoopJob.class is a base implementation that does nothing.

The problem is that during each firing of the trigger, the JobExecutionContext calls setMutable(false) on the triggers JobDataMap. This wraps what turns out to be the same map in an UnmodifiableCollection over and over again. It appears that the setMutable method on the JobDataMap should be a little smarter, and only 'wrap' if it is mutable.

Cheers,
-Daniel