# (JSF + JPA) - EJB = Bloat

Without an EJB you will need for every EntityManager interaction at least 4 lines of code:tx.beginEntityManager interactiontx.commitconsistent error handling +  tx.rollbackThe creation and management of an EntityManager is not even included. The code will look like this:public class ManufacturerJpaController {    private EntityManagerFactory emf = null;    public ManufacturerJpaController() {        emf = Persistence.createEntityManagerFactory("WithOrWithoutEJBPU");    }    public EntityManager getEntityManager() {        return emf.createEntityManager();    }    public void create(Manufacturer manufacturer) throws PreexistingEntityException, Exception {        EntityManager em = null;        try {            em = getEntityManager();            em.getTransaction().begin();            em.persist(manufacturer); // the only interesting method            em.getTransaction().commit();        } catch (Exception ex) {            if (findManufacturer(manufacturer.getManufacturerId()) != null) {                throw new PreexistingEntityException("Manufacturer " + manufacturer + " already exists.", ex);            }            throw ex;        } finally {            if (em != null) {                em.close();            }        }    }With a single EJB 3 you can eliminate all the bloat - the EntityManager will be properly managed and injected by the container. The same code will look like:@Statelesspublic class ManufacturerFacade {    @PersistenceContext    private EntityManager em;    public void create(Manufacturer manufacturer) {        em.persist(manufacturer);    } You could even build a generic and reusable CRUD Service. The @Stateless session bean can be directly injected into the backing bean then:@ManagedBean (name="manufacturerController")@SessionScopedpublic class ManufacturerController {    @EJB private ManufacturerFacade ejbFacade;} There is no additional XML, libraries or additional frameworks needed. You can just jar everything in a WAR and you are done. Btw. the whole EJB 3 container in Glassfish v3 is < 1MB. The project WithOrWithoutEJB was pushed into: http://kenai.com/projects/javaee-patterns/. An average, incremental deployment takes < 1 second.[See Chapter 1 (the basics), page 27, 37, 46 in "Real World Java EE Patterns Rethinking Best Practices" for state / transactions, dependency injection and JPA+EJB synergies]