Spring and Quartz Integration Using Custom Annotation

We know Spring has support for integrating with Quartz framework.
But as of now Spring supports only static xml declarative approach only.
If you want to see how to integrate Spring+Quartz you can refer Spring + Quartz Integration .

As part of my pet project requirement I got to schedule the Jobs dynamically and I though of following 2 options:
1. Using Annotations for providing Job Metada
2. Loading the Job Metadata from Database

For now I thought of going ahead with Annotation based approach and I want to integrate it with Spring as well.
Here is how I did it.

1. Create a Custom Annotation QuartzJob

package com.sivalabs.springsamples.jobscheduler;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.stereotype.Component;

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
@Scope("prototype")
public @interface QuartzJob 
{
 
 String name();
 String group() default "DEFAULT_GROUP";
 String cronExp();
}

2. Create an ApplicationListener to scan for all the Job implementation classes and schedule them using Quartz scheduler.

package com.sivalabs.springsamples.jobscheduler;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.quartz.Job;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.scheduling.quartz.CronTriggerBean;
import org.springframework.scheduling.quartz.JobDetailBean;

public class QuartJobSchedulingListener 
    implements ApplicationListener<ContextRefreshedEvent>
{ 
 @Autowired
 private Scheduler scheduler;
 
 @Override
 public void onApplicationEvent(ContextRefreshedEvent event)
 {
  try 
  {
    ApplicationContext applicationContext = event.getApplicationContext();
    List<CronTriggerBean> cronTriggerBeans = this.loadCronTriggerBeans(applicationContext);
    this.scheduleJobs(cronTriggerBeans);
  } 
  catch (Exception e) 
  {
    e.printStackTrace();
  }
 }
 
 private List<CronTriggerBean> loadCronTriggerBeans(ApplicationContext applicationContext)
 {
   Map<String, Object> quartzJobBeans = 
    applicationContext.getBeansWithAnnotation(QuartzJob.class);
  
   Set<String> beanNames = quartzJobBeans.keySet();
  
   List<CronTriggerBean> cronTriggerBeans = new ArrayList<CronTriggerBean>();
  
   for (String beanName : beanNames) 
   {
     CronTriggerBean cronTriggerBean = null;
     Object object = quartzJobBeans.get(beanName);
     System.out.println(object);
     try 
     {
      cronTriggerBean = this.buildCronTriggerBean(object);
     } 
     catch (Exception e) 
     {
      e.printStackTrace();
     }
   
     if(cronTriggerBean != null)
     {
      cronTriggerBeans.add(cronTriggerBean);
     }
   }
   return cronTriggerBeans;
 }
 
 public CronTriggerBean buildCronTriggerBean(Object job) throws Exception
 {
   CronTriggerBean cronTriggerBean = null;
   QuartzJob quartzJobAnnotation = 
     AnnotationUtils.findAnnotation(job.getClass(), QuartzJob.class);
     
   if(Job.class.isAssignableFrom(job.getClass()))
   {
     System.out.println("It is a Quartz Job");
     cronTriggerBean = new CronTriggerBean();
     cronTriggerBean.setCronExpression(quartzJobAnnotation.cronExp());    
     cronTriggerBean.setName(quartzJobAnnotation.name()+"_trigger");
     //cronTriggerBean.setGroup(quartzJobAnnotation.group());
     JobDetailBean jobDetail = new JobDetailBean();
     jobDetail.setName(quartzJobAnnotation.name());
     //jobDetail.setGroup(quartzJobAnnotation.group());
     jobDetail.setJobClass(job.getClass());
     cronTriggerBean.setJobDetail(jobDetail);   
   }
   else
   {
    throw new RuntimeException(job.getClass()+" doesn't implemented "+Job.class);
   }
   return cronTriggerBean;
 }
 
 protected void scheduleJobs(List<CronTriggerBean> cronTriggerBeans)
 {
  for (CronTriggerBean cronTriggerBean : cronTriggerBeans) 
  {
    JobDetail jobDetail = cronTriggerBean.getJobDetail();
    try 
    {
     scheduler.scheduleJob(jobDetail, cronTriggerBean);
    } 
    catch (SchedulerException e) 
    {
     e.printStackTrace();
    }   
  }
 }
}

3. Create a customized JobFactory to use Spring beans as Job implementation objects.

package com.sivalabs.springsamples.jobscheduler;

import org.quartz.Job;
import org.quartz.spi.TriggerFiredBundle;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.scheduling.quartz.SpringBeanJobFactory;

public class SpringQuartzJobFactory extends SpringBeanJobFactory
{
 @Autowired
 private ApplicationContext ctx;

 @Override
 protected Object createJobInstance(TriggerFiredBundle bundle) throws Exception 
 {
     @SuppressWarnings("unchecked")
  Job job = ctx.getBean(bundle.getJobDetail().getJobClass());
     BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(job);
     MutablePropertyValues pvs = new MutablePropertyValues();
     pvs.addPropertyValues(bundle.getJobDetail().getJobDataMap());
     pvs.addPropertyValues(bundle.getTrigger().getJobDataMap());
     bw.setPropertyValues(pvs, true);
     return job;
 } 
}

4. Create the Job implementation classes and Annotate them using @QuartzJob

package com.sivalabs.springsamples.jobscheduler;

import java.util.Date;

import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.quartz.QuartzJobBean;

@QuartzJob(name="HelloJob", cronExp="0/5 * * * * ?")
public class HelloJob extends QuartzJobBean
{  
 @Override
 protected void executeInternal(JobExecutionContext context)
   throws JobExecutionException
 {
  System.out.println("Hello Job is running @ "+new Date());
  System.out.println(this.hashCode());  
 }
}

5. Configure the SchedulerFactoryBean and QuartJobSchedulingListener in applicationContext.xml

6. Test Client

package com.sivalabs.springsamples;

import org.quartz.Job;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.sivalabs.springsamples.jobscheduler.HowAreYouJob;
import com.sivalabs.springsamples.jobscheduler.InvalidJob;

public class TestClient
{
 public static void main(String[] args)
 {
  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
  System.out.println(context);  
 }

}