Assume we have a certain bean (for example a DAO) that will be used concurrently with many threads but will not have any class fields, only fields injected using @In (such as EntityManager)

An example

class SomeDAO {
    @In
    EntityManager entityManager;

    public Item getItem(int id) {
       return em.find(Item.class, id);
    }
} 

How would you implement this? What's the pros/cons of using an Application Scoped POJO vs a Stateless Session Bean?

I know Seam uses an invocation time IoC for Stateless Session Beans, is that true for POJOs too,or POJOs use good ol' instantiation time IoC?

Thanks,

Drew