Source: Automatically Retry Failed Jobs in Quartz
If you want to have a job which keeps trying over and over again until it succeeds, all you have to do is throw a JobExecutionException with a flag to tell the scheduler to fire it again when it fails. The following code shows how:
class MyJob implements Job {
public MyJob() {
}
public void execute(JobExecutionContext context) throws JobExecutionException {
try{
//connect to other application etc
}
catch(Exception e){
Thread.sleep(600000); //sleep for 10 mins
JobExecutionException e2 = new JobExecutionException(e);
//fire it again
e2.setRefireImmediately(true);
throw e2;
}
}
}
It gets a bit more complicated if you want to retry a certain number of times. You have to use a StatefulJob and hold a retryCounter in its JobDataMap, which you increment if the job fails. If the counter exceeds the maximum number of retries, then you can disable the job if you wish.
class MyJob implements StatefulJob {
public MyJob() {
}
public void execute(JobExecutionContext context) throws JobExecutionException {
JobDataMap dataMap = context.getJobDetail().getJobDataMap();
int count = dataMap.getIntValue("count");
// allow 5 retries
if(count >= 5){
JobExecutionException e = new JobExecutionException("Retries exceeded");
//make sure it doesn't run again
e.setUnscheduleAllTriggers(true);
throw e;
}
try{
//connect to other application etc
//reset counter back to 0
dataMap.putAsString("count", 0);
}
catch(Exception e){
count++;
dataMap.putAsString("count", count);
JobExecutionException e2 = new JobExecutionException(e);
Thread.sleep(600000); //sleep for 10 mins
//fire it again
e2.setRefireImmediately(true);
throw e2;
}
}
}
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