Chapter 11: Infrastructure and Application Implementation

Overview

In this chapter, we'll look at implementing business logic in J2EE applications. However, first we'll consider infrastructure that enables us to limit application code to implementing business logic. This is a key goal of the J2EE specifications, but unfortunately the complexity of the J2EE APIs means that it isn't delivered out of the box.

In this chapter, we'll look at how additional infrastructure can be used to solve common problems and simplify the use of J2EE. We'll consider:

• The goals that a strong application infrastructure should deliver, and why it's important that applications should use one.

• The motivation behind and implementation of some generic packages included with the sample application, including:

  • Packages that enable a consistent approach to application configuration via JavaBeans and facilitate interface-based design, as discussed in Chapter 4.

  • Packages that simplify the use of complex J2EE APIs such as EJB and JMS.

Finally, we'll look at implementation of some of the key functionality of the sample application using the generic infrastructure described in this chapter, illustrating how it simplifies application code, benefiting both productivity and maintainability.