Java Extreme Programming Cookbook

Generating the EJB Deployment Descriptor

Problem

You want to use XDoclet to generate the EJB deployment descriptor, ejb-jar.xml.

Solution

Add the necessary XDoclet tags to your EJB source files and update your Ant buildfile to use XDoclet to generate the deployment descriptor.

Discussion

Anyone who has worked with EJBs knows that maintaining deployment descriptors is tedious and often frustrating, especially when dealing with a large number of beans. If a syntax error creeps into the deployment descriptor, you may not know until you have deployed the application to the server. Even then the error messages you receive may or may not be helpful to pinpoint the problem. Another problem is that the deployment descriptors and source files can get out of sync, causing even more deployment frustrations. The solution is to use XDoclet to generate the deployment descriptors whenever an EJB change is made.

Note

Avoiding duplication is a key to simple, maintainable code. XDoclet allows you to make changes in one place and generate all of the tedious, duplicated code.

It is also worth mentioning that XDoclet is immensely less labor-intensive than using point-and-click GUI tools provided by most commercial IDEs. Once the development environment is configured, the Ant build process magically does the dirty work.

XDoclet provides a simple mechanism for generating EJB deployment descriptors. The first step is to mark up the EJB with the necessary XDoclet tags. Example 9-2 shows how this might be done ...