Ant is helpful in any java project involving large number of resources. Ant based on xml and java itself can help to compile java classes, put the classes in a jar or war, create file folders before building projects and interfacing with servers like tomcat to perform application installation. This is useful in java enterprise web applications and enterprise applications. Ant ships with popular IDEs like eclipse and Rational Application Developer.
Ant manual webpage provides a sample build.xml file that can be customized by developers instead of writing it from scratch. This is a modification of that, file with modifications pertaining to ; building webapps for tomcat 7.0.26. For example a change is the compilations of classes and creating a war using war rather than jar (purpose!). Some changes were needed for tomcat 7.0.26 for example the manager url.
The sample folder structure used for eclipse dynamic web application is shown here.
The project tag is here. Base dir is .. since the ant build.xml is in 'Ant' folder. Multiple ant files can be grouped in this folder in a huge project.
The properties declaration that I use
The compile element with changes
The dist element which creates the distribution war file in the dist folder.
New elements to stop, remove, compile, install and start the web application.