Sams Teach Yourself BEA WebLogic Server 7.0 in 21 Days

Today you studied the first of the three types of Enterprise JavaBeans supported by WebLogic Server. This day started with a brief introduction to understanding the concepts of EJBs and WebLogic Server's support for the EJB 2.0 specification.

After this you started with the main topic of this day, the stateful session bean. The life cycle of a stateful session bean was covered, and you looked at the various callback methods that are invoked by the EJB container at different stages in the life cycle of the stateful session bean. You then looked at the flowchart to understand the steps involved in building a stateful session bean.

Next you looked at some of the differentiators in the two types of session beans: stateful session beans and stateless session beans. You then studied the components that make up a stateful session EJB viz the remote (or local) interface, the home interface, and the bean implementation class.

After this you learned about the internal classes and interfaces in EJBs. An important topic covered was to understand the different strategies applied to implement the EJBObject object by vendors. This helped you understand the inner workings of EJBs.

To complete your understanding of stateful session beans, you built the restaurant application, where you implemented the services provided by a waiter as a stateful session bean to a customer acting as an EJB client for the stateful session bean. You will extend this sample application tomorrow to implement the chef as a stateless session bean.

You are now all set to study stateless session beans tomorrow.