Day 4. Introduction to Enterprise JavaBeans

J2EE provides different types of components for different purposes. Today, you will start to look at one of the principal types of component in J2EE—Enterprise JavaBeans (EJBs).

The study of EJBs is continued on Day 5, “Session EJBs,” Day 6, “Entity EJBs,” Day 7, “Container-Managed Persistence and EJB Query Language,” Day 8, “Transactions and Persistence,” and Day 10, “Message-Driven Beans.” As you can see, there is a lot to learn about EJBs, so today serves as a first step on the road to all of this EJB knowledge.

Today, you will

• Examine the different types of EJB available

• See how EJBs are applied

• Explore the structure of one of the EJBs that forms part of the case study to see how the different parts fit together

• Deploy and use some of the EJBs from the case study

• Write a simple client for an EJB

First, you need to understand what EJBs are and why you would use them.