How to do notifications after a JTA commit

I had trouble finding the solution to this by googling my requirements, for some reason. I actually had to RTFM to figure it out :-(

The problem:

You have a @Stateless EJB that uses container-managed transactions to do stuff. When a transaction has committed you want to notify other parties to inform them that updates have been made. I used to make use of JMS for this, but that is truly overkill and JMS and I are no longer friends anyway. JMS is like the Post Office, you don't want to rely on them for important things like notifications.

Here is how it's done:

    import javax.transaction.*;

    ...

    @Resource
    TransactionManager tm;

    public void doMyUpdate() {
	reallyDoMyUpdate();
	try {
	    tm.getTransaction().registerSynchronization(new Synchronization() {
		    public void beforeCompletion() {}
		    public void afterCompletion(int status) {
			if (status == Status.STATUS_COMMITTED) {
			    notifyAllMyFriends();
			}
		    }
		});
	} catch (RollbackException ignore) {
	    logger.fine("Not done due to setRollbackOnly");
	} catch (Exception e) {
	    throw new RuntimeException(e);
	}
    }
   

According to the specs this feature is meant to be used by the application server, but since it's so useful I can't see why anyone would ever be so heartless as to deprive poor ordinary proletarian applications of this. Anyway it works in Apache TomEE and I hope it will keep on working...

Note: when I implement "notifyAllMyFriends" as an @Asynchronous call, the above provides all the features that I previously used JMS for, with all the unnecessary extra fat removed!