Ant的构建文件是用XML编写的与大多数实际应用中的构建文件相比，它要简单一些，但确实能够说明几乎每个Java 工程所需的一些核心概念。
<?xml version="1.0"?>
<!-- build.xml - a simple Ant buildfile -->
<project name="Simple Buildfile" default="compile" basedir=".">
<!-- The directory containing source code -->
<property name="src.dir" value="src"/>
<!-- Temporary build directories -->
<property name="build.dir" value="build"/>
<property name="build.classes" value="${build.dir}/classes"/>
<property name="build.lib" value="${build.dir}/lib"/>
<!-- Target to create the build directories prior to the -->
<!-- compile target. -->
<target name="prepare">
<mkdir dir="${build.dir}"/>
<mkdir dir="${build.classes}"/>
<mkdir dir="${build.lib}"/>
</target>
<target name="clean" description="Removes all generated files.">
<delete dir="${build.dir}"/>
</target>
<target name="compile" depends="prepare"
description="Compiles all source code.">
<javac srcdir="${src.dir}" destdir="${build.classes}"/>
</target>
<target name="jar" depends="compile"
description="Generates test.jar in the 'dist' directory.">
<!-- Exclude unit tests from the final JAR file -->
<jar jarfile="${build.lib}/oreilly.jar"
basedir="${build.classes}"
excludes="**/*Test.class"/>
</target>
<target name="all" depends="clean,jar"
description="Cleans, compiles, then builds the JAR file."/>
</project>