Building an EJB 3.0 Persistence Model with Oracle JDeveloper - EJB 3.0 Database Persistence with Oracle Fusion Middleware 11g - page 70

We did not need to specify the unitName attribute in the @PersistenceContext
because the variable name is the same as the persistence unit. Similarly, an
EntityManagerFactory variable may be injected with the persistence context as
follows, emf being also the persistence unit name:
@PersistenceUnit
private EntityManagerFactory emf;
Another value-added feature in WebLogic server 10.x is support for vendor-specific
subinterfaces of the EntityManager interface. For example, the BEA Kodo persistence
provider provides the KodoEntityManager subinterface, which may be injected with
the persistence context as follows:
@PersistenceContext
private KodoEntityManager em;
Setting the environment
Before getting started, we need to install Oracle JDeveloper 11 g , which may be
downloaded from http://www.oracle.com/technology/products/jdev/index.
html . Download the Studio Edition, which is the complete version of JDevloper
with all the features. Oracle JDeveloper 11 g is distributed as a GUI self-extractor
application. Click on the jdevstudio11110install application. The Oracle Installer
gets started. Click on Next in the Oracle Installer. Choose a middleware home
directory and click on Next .