Question

I have a spring integration flow triggered by the cron expression like follows:

<int-ftp:inbound-channel-adapter id="my-input-endpoint" ...>
    <int:poller trigger="my-trigger"/>
</int-ftp:inbound-channel-adapter>

<bean id="my-trigger"
   class="org.springframework.scheduling.support.CronTrigger">
  <constructor-arg value="0 * * * * *" />
</bean>

It works fine. But now I have to extend the implementation to make it cluster ready (job execution on only one cluster node at the same point of time).

My wish would be to use the Quartz framework in the cluster mode (persisting the job status in the database) to trigger this integration flow. Quartz provides a beautful solution out of the box. The only problem is how to integrate the Quartz with the existing inbout-channer-adaptor? The “trigger” attribute of the “poller” accepts only the subclasses of the org.springframework.scheduling.Trigger. I could not find any bridge between “poller trigger” and the Quartz framework.

many thanks in advance!

Answer 1

Here’s one way…

Set the auto-startup attribute on the inbound-adapter to false.

Create a custom trigger that only fires once, immediately…

public static class FireOnceTrigger implements Trigger {

    boolean done;

    public Date nextExecutionTime(TriggerContext triggerContext) {
        if (done) {
            return null;
        }
        done = true;
        return new Date();
    }

    public void reset() {
        done = false;
    }
}

In your quartz job, get a reference to the trigger and the SourcePollingChannelAdapter.

When the quartz trigger fires, have the quartz job

1. adapter.stop()
2. trigger.reset()
3. adapter.start()