Notes:
This was the second project to use Ant to control its build process and I had the benefit of learning from the problems of the first. In the first project there were many problems that I traced to having code destined for different deliverables (several types of client, a communications controller, and numerous EJBs) mixed up in the same directory tree.
Splitting out the code into distinct (but parallel) package trees enabled a massive simplification to the scripts – and a much faster build cycle.
Ant allows multiple targets, so it was possible to script the full build process including compilation, unit and smoke testing, generation of javadoc documentation, packaging the deployable Jar files and deploying them.
Note:
Ant is part of the Apache project (ie it is open source) and is a "make" replacement which seems to be fast becoming the de-facto standard make tool on the Java platform.
http://jakarta.apache.org/ant/