Web Development with MyEclipse and JBoss – part 2
Tutorial Prerequisites
The reader should be familiar with the basics concepts of J2EE, such as EJB, application server
technologies and how to develop and deploy server side applications.
J2EE Technology Basics
In this section, we briefly introduce the J2EE technologies used throughout this tutorial.
J2EE offers a wide choice of services and containers to develop Web Services, enterprise applications and
web applications. An Enterprise Java Bean (EJB) container is part of J2EE application server specification
and provides features to the developer including distributed communication, threading, scaling, and
transaction management. There are three basic types of EJBs:
• Entity Beans
• Session Beans
• Message Driven Beans.
Entity Bean
The entity bean provides the functionality to map persistent data entities to class objects. An example
entity bean use would be to map a record of a table « dog » to a class object of type « dog ».
Session Bean
The session bean provides functionality to implement business logic. Session beans come in two flavors,
either stateless or stateful. For example, a stateless session bean may be a class which returns only data
when invoked by the client and does not maintain any session state between calls. The stateful session
bean could be used as a shopping cart for an ecommerce site. The cart is stateful, because it saves the
products and other session data between calls in the same session.
Message Driven Beans
Message driven beans allow asynchronous messaging between applications. An internet shop application
can send an order message to a warehouse application.
In our example we will use a session bean to implement the business logic and entity beans to access
entries from the database. The structure of our J2EE application is displayed below in Figure 1.
Enterprise Java Bean Development with MyEclipse
