Using timers with EJB3.0 entity beans

I am attempting to use TimerService with an entity bean in an EJB3.0 application.  I have spent a couple of days looking for a way to get the EntityContext so that I can call EntityContext.getTimerService().  The problem is that EJB3.0 entity beans annotated with @Entity don't support @Resource injection.  I have tried implementing the setEntityContext() method but, given that I am not implementing javax.ejb.EntityBean, that unsuprisingly didn't work.  How do I get the EntityContext from an entity bean annotated with @Entity?  Is there a different way to get the TimerService?  My code follows:


@Entity
@Table(name = "periodic_script")
public class PeriodicScript {

    private static final long serialVersionUID = 1;

    // Entity bean properties
        .
        .
        .

    private EntityContext ctx;
      
    public void setEntityContext(EntityContext ec) {
          this.ctx = ec;
    }
   
        .
        .
        .

    @PostPersist
    public void scheduleScriptExecution() {
      ctx.getTimerService().createTimer(Calendar.getInstance().getTime(), getPeriod() * 1000, getId());
    }

    @Timeout
    public void executeScript(Timer timer) {
        // logic to execute when timeout occurs
            .
            .
            .
    }
      
    @PreRemove
    public void removeTimer() {
      for (Object timerObject : ctx.getTimerService().getTimers()) {
          Timer timer = (Timer) timerObject;
          if (timer.getInfo().equals(getId())) {
            timer.cancel();
          }
      }
    }
      
        .
        .
        .

}