unclear about transaction in this case...

[tsar_bomba]

I've got a simple storefront app that has a few stateless EJBs that act as DAO objects, basically. The app also has a single stateful bean which acts as a session for the shopping cart, it's called ShoppingCartBean.

I've got it all working just fine but I'm not happy w/ the final checkout action where all order (entities) data is persisted and the SFSB is terminated w/ @Remove.

I want to make it transactional but I'm unclear how I should do this, really. I'm using CMT entirely, no BMT in any of this.

Each of the stateless beans declares an EntityManager and the methods there in use it to query/persist data...really straight-forward stuff.

Now, if I take my SFSB and declare an EntityManager in it...could I make the methods I call from the injected stateless beans transactional?

Here's an example of what I'm imagining:

@Stateful
//@Local(ShoppingCart.class)
public class ShoppingCartBean
 implements Serializable, ShoppingCartLocal, ShoppingCartRemote
{
 @PersistenceContext
 private EntityManager em;
 private Order order;
 private Customer customer;
 @EJB Authenticate authBean;
 @EJB Orders orderBean;

 public void completeOrder()
 {
 //begin transaction
 this.em.getTransaction().begin();

 //get Order in session
 Order order = this.getOrder();

 //Customer/User in session
 Customer customer = order.getCustomer();
 User user = customer.getUser();

 //Address entities
 Address billing = this.getBillingAddress();
 Address shipping = this.getShippingAddress();

 //persist User
 this.authBean.saveUser(user);

 //persist Customer
 this.orderBean.saveCustomer(customer);

 //commit transaction
 this.em.getTransaction().commit();
 }
}

Is this the proper way to go about this? What are the ramifications for injecting the other EJBs and the EntityManager in a stateful bean?

All advice is greatly appreciated, thank you!