Entity EJBs, @Service & Thread

[galo.navarro]

Hi, I'm trying to get a service running on my JBoss server that would awake every now and then, get a list of entity beans and throw a message to a JMS queue for each of those items, and sleep for a while.

If I strip the bit loading Entity beans off, everything works, I send a test message to the queue, etc.

But if I do the same loading the beans, I get the exception below. I guess I'm doing something wrong but cannot figure out what.

17:02:32,650 ERROR [STDERR] Exception in thread "Thread-16"
17:02:32,650 ERROR [STDERR] java.lang.NullPointerException
17:02:32,650 ERROR [STDERR] at org.jboss.ejb3.entity.ManagedEntityManagerFactory.getNonTxEntityManager(ManagedEntityManagerFactory.java:58)
17:02:32,650 ERROR [STDERR] at org.jboss.ejb3.entity.ManagedEntityManagerFactory.getTransactionScopedEntityManager(ManagedEntityManagerFactory.java:163)
17:02:32,650 ERROR [STDERR] at org.jboss.ejb3.entity.TransactionScopedEntityManager.createNamedQuery(TransactionScopedEntityManager.java:132)
17:02:32,650 ERROR [STDERR] at tal.noc.beans.NOCManagerService.loadNOCs(NOCManagerService.java:79)
17:02:32,650 ERROR [STDERR] at tal.noc.beans.NOCManagerService.run(NOCManagerService.java:86)
17:02:32,650 ERROR [STDERR] at java.lang.Thread.run(Unknown Source)

This is my service:

@Service(objectName="jboss:custom=NOCManagerService")
public class NOCManagerService implements Runnable, NOCManagementService {

....

public void run() {
 this.running=true;
 while(this.running) {
 System.out.println("Awaken");
 Iterator nocs=this.loadNOCs().iterator();
 while(nocs.hasNext()) {
 NOC noc = (NOC)nocs.next();
 try {
 MessageSender ms=new MessageSender();
 ms.sendMessage("NOC: " + noc.toString(), "queue/msgQueue");
 } catch (Exception e) {
 e.printStackTrace(System.out);
 }
 }
 try {
 MessageSender ms=new MessageSender();
 ms.sendMessage("NOC", "queue/msgQueue");
 } catch (Exception e) {
 e.printStackTrace(System.out);
 }
 try {
 synchronized (this) {
 wait(60*1000);
 }
 } catch (Exception e) {
 e.printStackTrace(System.out);
 }
 }
 }

The service implements the following interface, just in case it makes any difference

@Management
public interface NOCManagementService {

Thanks a lot.

[galo.navarro]

Any ideas please?

[wolfc]

How did you start the thread?

I suspect that you're running a custom thread which has no transaction context. You could try using the EJB Timer Service, it starts business methods within the correct context.

[galo.navarro]

"wolfc" wrote:
How did you start the thread?

I suspect that you're running a custom thread which has no transaction context. You could try using the EJB Timer Service, it starts business methods within the correct context.

In the start() method of my service:

 public void start() throws Exception {
 System.out.println("start");
 Thread thread = new Thread(this);
 thread.start();
 }

I had considered using a Timer for it but would that not be much more unnefficient using a Service for something that doesn't quite need it?

Thanks.