Okt 13 2009

Classloading problems with injected @EJB-Beans

Frank

Yesterday I wrote how to define Quartz-Jobs in JBoss AS. Generally such jobs try to use business logic, which is injected via @EJB. Currently in Version 5.1.0.GA this is not possible if you use the classloader-isolation. You will get the following (or similar) exception:

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Caused by: java.lang.RuntimeException: Can not find interface declared by Proxy in our CL + BaseClassLoader@92c904{vfsfile:...}
at org.jboss.ejb3.proxy.impl.objectfactory.ProxyObjectFactory.redefineProxyInTcl(ProxyObjectFactory.java:343)
at org.jboss.ejb3.proxy.impl.objectfactory.session.SessionProxyObjectFactory.createProxy(SessionProxyObjectFactory.java:134)
at org.jboss.ejb3.proxy.impl.objectfactory.session.stateless.StatelessSessionProxyObjectFactory.getProxy(StatelessSessionProxyObjectFactory.java:79)
at org.jboss.ejb3.proxy.impl.objectfactory.ProxyObjectFactory.getObjectInstance(ProxyObjectFactory.java:158)
at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304)
at org.jnp.interfaces.NamingContext.getObjectInstance(NamingContext.java:1479)
at org.jnp.interfaces.NamingContext.getObjectInstanceWrapFailure(NamingContext.java:1496)
... 39 more

The reason for this ist that the Quartz-Service has another classloader as your application and the started job contains to the classloader of the Quartz-Service. There is also a bug posted. Maybe this will be possible in the near future.
One solution is to call a MBean from the job and this MBean injects the business logic via @EJB. The advantage of this solution is that you also can control and monitor the cronjob itselfs and can run the logic on demand via JMX-Console.
An example job would look like:

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@MessageDriven(messageListenerInterface = StatefulJob.class, activationConfig = { @ActivationConfigProperty(propertyName = "cronTrigger", propertyValue = "0 0 0 ? * MON-SAT") })
@ResourceAdapter("quartz-ra.rar")
@Depends(ImportDataManagement.ID)
public class DailyUpdateJob implements StatefulJob {
    private static final Logger log = Logger
            .getLogger(DailyUpdateJob.class);
 
    public void execute(JobExecutionContext context)
            throws JobExecutionException {
        try {
            MBeanServer server = MBeanServerLocator.locate();
            ImportDataManagement bp = (ImportDataManagement) MBeanProxyExt
                    .create(ImportDataManagement.class,
                            ImportDataManagement.ID, server);
            bp.importDaily();
        } catch (Exception e) {
            log.error("run", e);
        }
    }
}

Helpful links:

no comments   |  tags: , , , , , | posted in JBoss

Okt 12 2009

Cronjobs using Quartz in JBossAS

Frank

With the introduction of EJB3 a new method for implementing cronjobs was added. These jobs uses quartz as framework and there are two ways to setup:

1. Variant: Defining a MDB-Consumer

The preferred way is the definition of an MDB-Consumer. The only thing you need is to implement the Job-Interface (org.quartz.Job) and add some Annotations to it:

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@MessageDriven(activationConfig = { @ActivationConfigProperty(propertyName = "cronTrigger", propertyValue = "0/2 * * * * ?") })
@ResourceAdapter("quartz-ra.rar")
public class MySampleCronJob implements Job {
 
    public void execute(JobExecutionContext context) throws JobExecutionException {
        System.out.println("job is called");
    }
 
}

If this job should only be called once at a specific time, you can use the interface StatefulJob. When the job is called is defined in the property cronTrigger. A full documentation can be found at the Quartz-API-Documentation.
Pay attention that the Component only implements one interface or you have to define the property “messageListenerInterface” at @MessageDriven. Otherwise the deployer cannot find the using type. Especially if you use AspectJ this is important.

2. Variant: Using a Quartz-Service

This is the old version. You can define a managed-bean via an XML which instantiate a Quartz-Service.

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< ?xml version="1.0" encoding="UTF-8"?>
<server>
  <mbean code="org.quartz.ee.jmx.jboss.QuartzService" name="user:service=QuartzService,name=QuartzService">
    <attribute name="Properties">
      org.quartz.scheduler.instanceName = DefaultQuartzScheduler
      org.quartz.scheduler.rmi.export = false
      org.quartz.scheduler.rmi.proxy = false
      org.quartz.scheduler.xaTransacted = false
      org.quartz.threadPool.class = org.quartz.simpl.SimpleThreadPool
      org.quartz.threadPool.threadCount = 5
      org.quartz.threadPool.threadPriority = 4
    </attribute>
  </mbean>
</server>

Then you can use this managed bean to add a new trigger and to assign a job to this trigger. This code can be used in an own managed bean, which setups the application.

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public class CronManagementBean {
    @Resource(mappedName = "/Quartz")
    private Scheduler scheduler;
 
    public void start() {
        try {
            Trigger trigger = new CronTrigger("myTrigger",
                    "mygroup",
                    "0 0 4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23 ? * *");
 
            JobDetail jobDetail = new JobDetail("myJob",
                    "myjobgroup", StatusJob.class);
            scheduler.scheduleJob(jobDetail, trigger);
 
        } catch (SchedulerException e) {
            throw new RuntimeException(e);
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }
    }
 
    public void stop() {
        try {
            scheduler.deleteJob("myJob", "myjobgroup");
        } catch (SchedulerException e) {
            log.warn("shutdown fails", e);
        }
    }
}

1 comment   |  tags: , , , | posted in JBoss