How to persist an object in Asynchronous method in a cron job

[lsqfjbn]

I tried to persist an object in an Asynchronous method, but it failed.

public void schedule(@Observes @Every(nth=10, value=Interval.SECOND) Trigger t){
          
    for (TestRunner runner: pendingRunners){
     
     Executor e = new Executor();
     e.run(runner);
     }
    }
}

@Transactional @Dependent
public class Executor implements Serializable {
     
     /**
      * 
      */
     private static final long serialVersionUID = 5413892488805663161L;
     
     @PersistenceContext
     EntityManager em;
     
     
     
     @Asynchronous
     public void run(TestRunner runner){
     
          try {
               
               TestAgent agent = runner.getTestAgent();
               
               if (agent!=null){
                    
                                runner.setStartTime(new Date());
                    em.merge(runner);
                          em.flush();
                    
                    Thread.sleep(30000);
                    //TO-DO
                    //Call STAF lib to run test script
                    
                                runner.setStopTime(new Date());
                    em.merge(runner);
                          em.merge(agent);
                          em.flush();
                    
               
               }
          } catch (Exception e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
          }
}

After running the cron job, I got following error:

17:28:06,279 ERROR [STDERR] java.lang.NullPointerException

It seems entitymanager is null.
Can anyone help on this?

[pgmjsd]

I think you probably meant to use the Seam-Managed EntityManager with @Inject.   I'm not sure if @PersistenceContext works outside of an EJB.

[pgmjsd]

Ah, I was mistaken: @PersistenceContext can be used outside of an EJB.  But, I'm sure that the transaction management won't be handled.  I still think using the persistence module is the way to go.

[ssachtleben.ssachtleben.gmail.com]

@PersistenceContext works fine without EJB.

But I think you Problem is here:

Executor e = new Executor();

The entity manager will not inject if you create your class due constructor.

Try to use this which should inject the bean properly:

public void schedule(@Observes @Every(nth=10, value=Interval.SECOND) Trigger t, Executor e){     
    for (TestRunner runner: pendingRunners){
     e.run(runner);
    }
}

or

@Inject Executor e;

[lsqfjbn]

If I use

@Inject Executor e;

there will be only one Executor instance, right?

But what I want is in the 'for' statement, each runner can have one Executor instance and execute in parallel.

[lightguard]

Try @Inject Instance<Executor> and use the Instance API.

[lsqfjbn]

Jason Porter wrote on Jun 22, 2011 15:17:


Try @Inject Instance<Executor> and use the Instance API.

That works perfectly!

Thank you!