How to Write Quartz JobListener?

In my previous posts I have explained about writing simple quartz scheduler and how to list jobs. This tutorial explains how to write a listener for the scheduler. In certain scenarios, we have to execute few lines of code or log messages before and after the batch process. The listeners are very useful for achieving those goals. In quartz, JobListener interface provides jobToBeExecuted and jobWasExecuted as the callback methods for before and after every job is executed. These methods takes the parameter of JobExecutionContext, with this you can access the current Job details and print them. For the complete setup of the quartz scheduler, please refer my previous tutorial. If you have any questions, please write it in the comments section.

1. Create a Job

FirstJob.java

[code lang=”java”]
package javabeat.net.quartz;

import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;

public class FirstJob implements Job{

@Override
public void execute(JobExecutionContext arg0) throws JobExecutionException {
System.out.println("This is my first quartz job!!");
}

}
[/code]

2. Create Quartz Job Listener

FirstJobListener.java

[code lang=”java”]
package javabeat.net.quartz;

import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.JobListener;

public class FirstJobListener implements JobListener{

@Override
public String getName() {
return "FirstJobListener";
}

@Override
public void jobToBeExecuted(JobExecutionContext context) {
System.out.println("jobToBeExecuted : " + context.getJobDetail().getKey().toString());

}
@Override
public void jobWasExecuted(JobExecutionContext context,
JobExecutionException arg1) {
System.out.println("jobWasExecuted : " + context.getJobDetail().getKey().toString());

}
@Override
public void jobExecutionVetoed(JobExecutionContext context) {
System.out.println("jobExecutionVetoed : " + context.getJobDetail().getKey().toString());
}

}
[/code]

3. Add Quartz Job Listener to Scheduler

QuartzExample.java

[code lang=”java”]
package javabeat.net.quartz;

import java.util.Date;

import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleTrigger;
import org.quartz.impl.JobDetailImpl;
import org.quartz.impl.StdSchedulerFactory;
import org.quartz.impl.triggers.SimpleTriggerImpl;

public class QuartzExample {
public static void main(String args[]) throws SchedulerException{
//Creating scheduler factory and scheduler
SchedulerFactory factory = new StdSchedulerFactory();
Scheduler scheduler = factory.getScheduler();

//Creating Job and link to our Job class
JobDetailImpl jobDetail = new JobDetailImpl();
jobDetail.setName("First Job");
jobDetail.setJobClass(FirstJob.class);

//Creating schedule time with trigger
SimpleTriggerImpl simpleTrigger = new SimpleTriggerImpl();
simpleTrigger.setStartTime(new Date(System.currentTimeMillis() + 1000));
simpleTrigger.setRepeatCount(SimpleTrigger.REPEAT_INDEFINITELY);
simpleTrigger.setRepeatInterval(2000);
simpleTrigger.setName("FirstTrigger");

//Start scheduler
scheduler.start();
scheduler.scheduleJob(jobDetail,simpleTrigger);

//Adding the listener
scheduler.getListenerManager().addJobListener(new FirstJobListener());
}
}
[/code]