Get EJB Concepts in the form of PPTS

EJB 2 Message Driven Beans
Enterprise Java Beans-1
Enterprise Java Beans-QL
EntityBeans
J2EE Design Pattern
Java Messaging Services
Transactions

Leveraging Spring with EJB 3.0
EJB 3.0 caters to the growing preference among enterprise Java developers for a POJO-based development model and IoC support in the container. However, this does not mean that tools like Spring don't have a place, or that EJB 3.0 and Spring have to be an either/or proposition. They certainly can be complementary. In fact, you can continue using the same development pattern you do with Spring and seamlessly integrate it with EJB 3.0 components—all while filling in some holes in the EJB 3.0 specification.

The composite model proposed in this article enables you to combine EJB 3.0 features such as message-driven beans, web services implementation, declarative component security, clustering, component pooling, and stateful components with Spring features such as strong AOP (using tools like AspectJ), POJO injection, productive helper classes, Java Persistence API (JPA) integration, and resource integration.

You can use either of the following two methods to leverage Spring effectively in J2EE applications using EJB 3.0 components:

  1. Use Spring as a general IoC-AOP container, and then integrate EJB components as regular beans to implement business functionality.
  2. Use Spring as a provider of EntityManager for the underlying JPA implementation. In this case, Spring goes beyond basic container support to manage the state of the EntityManager and ensure compatibility with third-party JPA providers, automatic participation in transactions, exception handling, and so on.