Migrating EJB 2.1 Entity and Session Beans to EJB 3.0

The nuts and bolts

Summary

So, to summarise this tutorial:

  • EJB development in EJB 3.0 specification is simplified by replacing abstract bean classes with POJOs.
  • Component and Home interfaces are not required in EJB 3.0.
  • Deployment descriptors are replaced with metadata annotations in the bean class. Familiarity with JDK 5.0 annotations is required to migrate EJB 2.0/2.1 to EJB 3.0.
  • The EntityManager API is used to create and find entity bean instances in EJB 3.0 instead of the create, and finder methods in EJB 2.1.
  • JNDI, which is required to obtain references to resources in EJB 2.1 is replaced with the @Resource, @Inject and @EJB annotations in EJB 3.0 specification.

Deepak Vohra is a Sun Certified Java Programmer and Sun Certified Web Component Developer. Deepak is a Web developer; and has published in XML Journal, WebLogic Developer's Journal and ONJava.com.

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