Java Enterprise in a Nutshell, Third Edition

Chapter 21. Annotations with XDoclet and J2SE Metadata

Code annotations can simplify enterprise development tasks. They allow you to place metadata about your code directly into your code and then use this metadata in various ways, such as automatically generating artifacts related to the code (documentation, deployment descriptors, and configuration files), running reports of various kinds over the code, and even generating supplementary code.

There are currently a number of annotation-related tools and libraries available through open source projects as well as tools available for specific Java IDEs and application server environments. In addition, a standard code metadata facility was added to the language as of J2SE 5.0.

What’s Covered Here?

In this chapter, we will be discussing two complementary annotation systems: XDoclet and J2SE annotations. XDoclet is arguably the most popular open source annotation tool in the Java community. We’ll examine various ways that you can use the annotations available in XDoclet to make enterprise development tasks easier. The examples shown in this chapter were written using XDoclet 1.2.3.

We also provide an overview of the J2SE 5.0 annotation facility, which is now part of the Java language and is the basis for various proposed annotation extensions to key Java enterprise APIs like EJB and JAX-RPC. The annotation facility built into J2SE is based on the JSR-175 specification. The J2SE annotation examples shown in this chapter were developed using ...