I am currently working on porting a Seam 2/JBoss 4.x application to Seam 3/JBoss AS 7.x. The old codebase contains some “jobs” that use ServiceMBeanSupport, that are triggered at regular intervals using JBoss varia module. Since the module isn’t there anymore, I wanted port the “jobs” to Quartz. Adding quartz was easy enough, but the jobs needed other (injected) beans to do their work. I created a custom JobFactory that used BeanManager to give out the instances of Job classes.
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package com.vijaykiran.jobs; import org.jboss.solder.beanManager.BeanManagerAware; import org.quartz.Job; import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.spi.JobFactory; import org.quartz.spi.TriggerFiredBundle; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.enterprise.context.spi.CreationalContext; import javax.enterprise.inject.spi.Bean; import javax.enterprise.inject.spi.BeanManager; import javax.inject.Named; @Named public class CdiJobFactory extends BeanManagerAware implements JobFactory { private final Logger log = LoggerFactory.getLogger(getClass()); protected Logger getLog() { return log; } public Job newJob(TriggerFiredBundle bundle, Scheduler Scheduler) throws SchedulerException { final JobDetail jobDetail = bundle.getJobDetail(); final Class<? extends Job> jobClass = jobDetail.getJobClass(); try { if (log.isDebugEnabled()) { log.debug( "Producing instance of Job '" + jobDetail.getKey() + "', class=" + jobClass.getName()); } return getBean(jobClass); } catch (Exception e) { throw new SchedulerException( "Problem instantiating class '" + jobDetail.getJobClass().getName() + "'", e); } } private Job getBean(Class jobClazz) { final BeanManager bm = getBeanManager(); final Bean<?> bean = bm.getBeans(jobClazz).iterator().next(); final CreationalContext<?> ctx = bm.createCreationalContext(bean); return (Job) bm.getReference(bean, jobClazz, ctx); } } |
And here’s a sample Job:
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package com.vijaykiran.jobs; import org.quartz.Job; import org.quartz.JobExecutionContext; import org.quartz.JobExecutionException; import javax.inject.Inject; import javax.inject.Named; import java.util.List; @Named public class TestJob implements Job { @Inject private SomeBean sombean; @Override public void execute(JobExecutionContext context) throws JobExecutionException { someBean.doSomethingFancy(); } } |
There are couple of ways to start the scheduler itself, one was to use a @Startup bean with @PostConstruct method which starts the scheduler and in @PreDestroy, the scheduler is stopped, as shown below:
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package com.vijaykiran.jobs; import org.quartz.JobBuilder; import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.SimpleScheduleBuilder; import org.quartz.SimpleTrigger; import org.quartz.TriggerBuilder; import org.quartz.impl.StdSchedulerFactory; import javax.annotation.PostConstruct; import javax.annotation.PreDestroy; import javax.ejb.Singleton; import javax.ejb.Startup; import javax.inject.Inject; import java.util.Date; @Singleton @Startup public class CustomJobScheduler { private Scheduler scheduler; @Inject private CustomJobFactory customCdiJobFactory; @Inject private Logger logger; @PostConstruct public void scheduleJobs() { try { scheduler = new StdSchedulerFactory().getScheduler(); scheduler.setJobFactory(cdiJobFactory); final JobDetail testJobDetail = JobBuilder.newJob(TestJob.class).withIdentity("test", "test-jobs").build(); final SimpleTrigger trigger = TriggerBuilder.newTrigger() .startAt(new Date()) .withSchedule(SimpleScheduleBuilder.repeatSecondlyForTotalCount(5)) .build(); scheduler.scheduleJob(testJobDetail, trigger); scheduler.start(); } catch (SchedulerException e) { logger.error("Unable to start scheduler", e); } } @PreDestroy public void stopJobs() { if(scheduler != null) { try { scheduler.shutdown(true); } catch (SchedulerException e) { logger.error("Unable to stop scheduler", e); } } } } |
The other approach is to start the scheduler when the Webapplication has started using the CDI Event listener mechanism.
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package com.vijaykiran.jobs; import org.jboss.solder.logging.Logger; import org.jboss.solder.servlet.WebApplication; import org.jboss.solder.servlet.event.Destroyed; import org.jboss.solder.servlet.event.Started; import org.quartz.JobBuilder; import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.SimpleScheduleBuilder; import org.quartz.SimpleTrigger; import org.quartz.TriggerBuilder; import org.quartz.impl.StdSchedulerFactory; import javax.enterprise.context.ApplicationScoped; import javax.enterprise.event.Observes; import javax.inject.Inject; import javax.inject.Named; import java.util.Date; @Named @ApplicationScoped public class CustomJobScheduler { private Scheduler scheduler; @Inject private CdiJobFactory cdiJobFactory; @Inject private Logger logger; public void onStartup(@Observes @Started WebApplication webapp) { try { scheduler = new StdSchedulerFactory().getScheduler(); scheduler.setJobFactory(cdiJobFactory); final JobDetail testJobDetail = JobBuilder.newJob(TestJob.class).withIdentity("test", "test-jobs").build(); final SimpleTrigger trigger = TriggerBuilder.newTrigger() .startAt(new Date()) .withSchedule(SimpleScheduleBuilder.repeatSecondlyForTotalCount(5)) .build(); scheduler.scheduleJob(testJobDetail, trigger); //Start the scheduler a minute after the webapplication is started. scheduler.startDelayed(60); } catch (SchedulerException e) { logger.error("Unable to start Scheduler ", e); } } public void onShutdown(@Observes @Destroyed WebApplication webapp) { if (scheduler != null) { try { scheduler.shutdown(true); } catch (SchedulerException e) { logger.error("Error while shutting down scheduler", e); } } } } |
Posted in:
Programming
Hi vijay,
Great article! I’m having a BeanManagerUnavailableException though. I’m not sure what to do in this case. Admittedly, I’m still doing some more googling as I type this
Hi,
Not sure what environment/server you are using:
But you can lookup the Beanmanager using JNDI
public static BeanManager getBeanManager() {
try {
InitialContext initialContext = new InitialContext();
return (BeanManager) initialContext.lookup("java:comp/BeanManager");
} catch (NamingException e) {
e.printStackTrace();//BAD!
return null;
}
}
Thats quite simple but sometimes does not work, especially when the lookup is carried out from an “unmanaged thread” on IBM WebSphere. The problem is indeed to get hands on the BeanManager; the remaining is quite straight forward.
Hey, it is a neat guide. I also encountered trouble finding the BeanManager.
The simple solution is simply to
@Inject
BeanManager beanManager;
It works!
Hey, I need to use CDI to inject an EJB inside a Job to get my data updated. But I couldn’t seem to find a way out. And I can’t understand these Seam 3 things. I want the most simple basic CDI enabled in the Job, for that as I understand I’ll have to implement my own JobFactory, right? Can you please help a bit?
Stuart
Yes you need to create a JobFactory – the code in this post should work for injecting EJBs – otherwise you can take a look at https://github.com/symbiont/cdiqi for more in-depth integration (With BoundRequestContext/Listener etc.)
But this BeanManagerAware is it a Weld component? I’m not using Seam. And I checked that integration, I probably don’t need that much, yours only looks good to me. But These same interfaces would work or I need to use some different Components to inject beans via Weld?
BeanManagerAware is part of Solder – which can be used with “any CDI runtime” (from the Docs).
If you don’t want all the she-bang, then the approach outlined here in the post should work.