Enterprise JavaBeans, Second Edition

Chapter 11. Java 2, Enterprise Edition

The specification for the Java 2, Enterprise Edition ( J2EE) defines a platform for developing web-enabled applications that includes Enterprise JavaBeans, Servlets, and Java Server Pages ( JSP). J2EE products are application servers that provide a complete implementation of the EJB, Servlet, and JSP technologies. In addition, the J2EE outlines how these technologies work together to provide a complete solution. To understand what J2EE is, it’s important that we introduce Servlets and JSP and explain the synergy between these technologies and Enterprise JavaBeans.

At risk of spoiling the story, J2EE provides two kinds of “glue” to make it easier for components to interact. We’ve already seen both types of glue. The JNDI Enterprise Naming Context (ENC) is used to standardize the way components look up resources that they need. We’ve seen the ENC in the context of enterprise beans; in this chapter, we’ll look briefly at how servlets, JSPs, and even some clients can use the ENC to find resources. Second, the idea of deployment descriptors—in particular, the use of XML to define a language for deployment descriptors—has been extended to servlets and JSP. Java servlets and server pages can be packaged with deployment descriptors that define their relationship to their environment. Deployment descriptors are also used to define entire assemblies of many components into applications.

Servlets

The Servlet 2.2 specification defines a server-side component ...