Question

I’d like to log the error or the success of an EJB method that is participating in a transaction. Where shall I put the logging? As far as I know the transaction will be committed after my doSomething has finished. So in that method I cannot be sure that the commit would be successful or not. That raised this question.

public class MyEjb {

  @Inject
  AnotherEjb anotherEjb;

  @Inject
  LoggerEjb logger;

  public void doSomeThing() {
     MyBean b = getSomething();
     anotherEjb.persistSg(b);

     /* logger.log is transaction if of attrubute NOT_SUPPORTED to
        ensure separation from caller transaction */
     logger.log("Did something successfully.");
  }

}

public class AnotherEjb {

  @Inject
  EntitiyManager em;

  public void persistSg(MyBean entity) {
    em.persist(entity);
  }
}

Answer 1

Have you tried CDI’s transactional observers?

http://docs.jboss.org/weld/reference/latest/en-US/html/events.html#d0e4075

This code fires an event:

@Inject Event<CategoryUpdate> categoryUpdateEvent;

public void someTransactionalMethod() {
    CategoryUpdate categoryUpdate = new CategoryUpdate();
    categoryUpdateEvent.fire(categoryUpdate);
}

And this piece of code observes the same event, but will be called only if the transaction succeeds:

public void refreshCategoryTree(@Observes(during = AFTER_SUCCESS) CategoryUpdate event) {
    ......
}