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Section 1. About this tutorial

Purpose of this tutorial

This tutorial shows J2EE developers how to use XDoclet to speed development.

XDoclet simplifies continuous integration between components using attribute oriented

programming. It allows you to radically reduce development time by generating

deployment descriptors and support code, allowing you to focus on application logic

code.

If you are a J2EE development veteran, then you realize keeping code in sync with

deployment descriptors can be a drag. Often you may need to reuse components with

other applications or in other environments like other application servers or with other

database systems. You need to keep separate deployment descriptor for each

application/environment combination, even if only one or two lines of the large

deployment descriptor changes, you need to have a deployment descriptor for every

possible configuration. This can really slow down development. At times you may feel

you spend more time syncing deployment descriptors than writing code.

XDoclet facilitates automated deployment descriptor generation. As a code generation

utility, it allows you to tack on metadata to language features like classes, method, and

fields using what looks like JavaDoc tags. Then it uses that extra metadata to generate

related files like deployment descriptor and source code. This concept has been coined

attribute oriented programming (not to be confused with aspect oriented programming,

the other "AOP").

XDoclet generates these related files by parsing your source files similar to the way the

JavaDoc engine parses your source to create JavaDoc documentation. In fact earlier

versions of XDoclet relied on JavaDoc. XDoclet, like JavaDoc, not only has access to

these extra metadata that you tacked on in the form of JavaDoc tags to your code, but

also access to the structure of your source, that is, packages, classes, methods, and

fields. It then applies this hierarchy tree of data to templates. It uses all of this and

templates that you can define to generate what would otherwise be monotonous

manual creation of support files. This tutorial focuses on using existing templates that

ship with XDoclet.

XDoclet ships an

Ant

task that enables you to create

web.xml

files,

ejb jar.xml

files,

and much more. In this tutorial, you will use XDoclet to generate a Web application

deployment descriptor with the

webdoclet

Ant task. In addition you will generate

Enterprise JavaBeans (EJB) support files. Note that XDoclet Ant tasks do not ship with

the standard distribution of Ant. You will need to download the XDoclet Ant tasks from

XDoclet site on Sourceforge.net

.

This tutorial is a hands on approach to learning how to use XDoclet to do J2EE

component development. By the end of this tutorial, you will build several J2EE

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Enhance J2EE component reuse with XDoclets