Example build.xml for projects.

build.xml

<project name="FooBar" basedir="." default="main">
	<property name="src.dir"     value="src"/>

	<property name="build.dir"   value="build"/>
	<property name="classes.dir" value="${build.dir}/classes"/>
	<property name="jar.dir"     value="${build.dir}/jar"/>

	<property name="lib.dir"     value="lib"/>

	<path id="classpath">
		<fileset dir="${lib.dir}" includes="**/*.jar"/>
	</path>

	<property name="main-class"  value="com.example.Foo.Bar"/>

	<target name="clean">
		<delete dir="${build.dir}"/>
	</target>

	<target name="build">
		<mkdir dir="${classes.dir}"/>
		<javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath"/>
	</target>

	<target name="jar" depends="build">
		<mkdir dir="${jar.dir}"/>
		<jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}">
			<manifest>
				<attribute name="Main-Class" value="${main-class}"/>
			</manifest>
		</jar>
	</target>

	<target name="run" depends="jar">
		<java fork="true" classname="${main-class}">
			<classpath>
            	<path refid="classpath"/>
				<path location="${jar.dir}/${ant.project.name}.jar"/>
			</classpath>
		</java>
	</target>

	<target name="clean-build" depends="clean,jar"/>

	<target name="main" depends="clean,run"/>
</project>