Java™ Application Development on Linux - Dator

220Chapter 9Ant: An IntroductionIt begins to differ at this point. The ant source package comes with a shellscript, build.sh, that actually builds a minimal version of ant and then runsant to complete the install.Make sure that the JAVA_HOME and ANT_HOME are set as you want them,then execute build.sh install. Unless you have installed the optional tasks, 5you will see several warnings about missing classes. You may safely ignore these.As with the installation of other packages built from source, you will needto have appropriate permissions for the target directories. This might meanrunning the install as root, with all appropriate attention and dread.9.4A SAMPLE ANT BUILDFILELet’s go over the basics of creating an Ant buildfile. We’ll start with an introductionto XML, and then move on to the specific tags Ant supports and howyou might use them to automate a build.9.4.1 XML for the UninitiatedThe buildfiles of ant, usually named build.xml, are written in ExtensibleMarkup Language, or XML. Some of the reasons for this are:• XML is hierarchical.• XML is standardized.• XML is widely used and familiar to many programmers.• Java has many classes for reading, parsing, and using XML.• XML-based representations of hierarchical data structures are easy to readand parse for both humans and programs.XML is a successor to SGML, Standard Generalized Markup Language,which is a language for defining markup languages. A markup document maybe validated. A validated document is one that conforms to a structural specificationof the markup tags in the document. Such a specification may be madeusing a Document Type Definition (DTD), which is a holdover from the waySGML markup languages were specified, or using one of the newer specification5. There is a horde of optional tasks. As the name suggests, they are optional. Include these ifyou need them. This is the only mention they will receive.