Quartz is an open source job scheduling framework. It can be used to manage and schedule jobs in the application.

STEP 1 : CREATE MAVEN PROJECT
A maven project is created as below. (It can be created by using Maven or IDE Plug-in).

STEP 2 : LIBRARIES

Quartz dependencies are added to Maven’ s pom.xml. These dependency libraries will be downloaded by Maven Central Repository.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>OTV_Quartz</groupId>
	<artifactId>OTV_Quartz</artifactId>
	<version>0.0.1-SNAPSHOT</version>

	<dependencies>

		<!-- Quartz library -->
		<dependency>
		    <groupId>org.quartz-scheduler</groupId>
		    <artifactId>quartz</artifactId>
		    <version>2.0.2</version>
		</dependency>		 

		<!-- Log4j library -->
		<dependency>
		    <groupId>log4j</groupId>
		    <artifactId>log4j</artifactId>
		    <version>1.2.16</version>
		</dependency>	

	</dependencies>

</project>

STEP 3 : CREATE NEW JOB

A new Job is created by implementing the Quartz Job interface as below. TestJob Class specifies business logic which will be scheduled.

package com.otv.job;

import org.apache.log4j.Logger;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;

public class TestJob implements Job {

   private Logger log = Logger.getLogger(TestJob.class);

   public void execute(JobExecutionContext jExeCtx) throws JobExecutionException {
      log.debug("TestJob run successfully...");
   }

}

STEP 4 : LINK JOB WITH JOBDETAIL OBJECT

Created TestJob class is linked with a JobDetail object.

JobDetail job = JobBuilder.newJob(TestJob.class)
			    .withIdentity("testJob")
			    .build();

STEP 5 : CREATE NEW TRIGGER

A new trigger is created as below. Trigger Class specifies running period of the job which will be scheduled. There are two kind of Quartz Triggers as :

Trigger : specifies start time, end time, running period of the job.

CronTrigger : specifies start time, end time, running period of the job according to Unix cron expression.

//Trigger the job to run on the next round minute
Trigger trigger = TriggerBuilder.newTrigger()
		      .withSchedule(
	                    SimpleScheduleBuilder.simpleSchedule()
	                    .withIntervalInSeconds(30)
	                    .repeatForever())
                                   .build();

// CronTrigger the job to run on the every 20 seconds
CronTrigger cronTrigger = TriggerBuilder.newTrigger()
                             .withIdentity("crontrigger","crontriggergroup1")
                             .withSchedule(CronScheduleBuilder.cronSchedule("10 * * * * ?"))
                             .build();

STEP 6 : CREATE SchedulerFactory

A new SchedulerFactory is created and a Scheduler object is gotten from SchedulerFactory Class.

SchedulerFactory schFactory = new StdSchedulerFactory();
Scheduler sch = schFactory.getScheduler();

STEP 7 : START Scheduler

Scheduler Object is started.

// Start the schedule
sch.start();

STEP 8 : SCHEDULE JOB

TestJob is scheduled:

// Tell quartz to schedule the job using the trigger
sch.scheduleJob(job, trigger);

STEP 9 : FULL EXAMPLE

TestJob will run two times per minute.

package com.otv;

import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleScheduleBuilder;
import org.quartz.Trigger;
import org.quartz.TriggerBuilder;
import org.quartz.impl.StdSchedulerFactory;

import com.otv.job.TestJob;

/**
* @author onlinetechvision.com
* @since 17 Sept 2011
* @version 1.0.0
*
*/
public class JobScheduler {

   public static void main(String[] args) {

      try {

         // specify the job' s details..
         JobDetail job = JobBuilder.newJob(TestJob.class)
                                   .withIdentity("testJob")
                                   .build();

         // specify the running period of the job
         Trigger trigger = TriggerBuilder.newTrigger()
                                         .withSchedule(SimpleScheduleBuilder.simpleSchedule()
                                                                            .withIntervalInSeconds(30)
                                                                            .repeatForever())
                                          .build();

         //schedule the job
         SchedulerFactory schFactory = new StdSchedulerFactory();
         Scheduler sch = schFactory.getScheduler();
         sch.start();
         sch.scheduleJob(job, trigger);

      } catch (SchedulerException e) {
         e.printStackTrace();
      }
   }

}

STEP 10 : OUTPUT

When JobScheduler Class is run, the output will be seen as below :

17.09.2011 23:39:37 DEBUG (TestJob.java:13) - TestJob run successfully...
17.09.2011 23:40:07 DEBUG (TestJob.java:13) - TestJob run successfully...
17.09.2011 23:40:37 DEBUG (TestJob.java:13) - TestJob run successfully...
17.09.2011 23:41:07 DEBUG (TestJob.java:13) - TestJob run successfully...

STEP 11 : DOWNLOAD
OTV_Quartz_Project