build.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="HelloWorld" default="run" basedir=".">
<property name="src" value="src"/>
<property name="dest" value="classes"/>
<property name="hello_jar" value="hello1_jar"/>
<target name="init">
   <mkdir dir="${dest}" />
</target>
<target name="compile" depends="init" >
  <javac srcdir="${src}" destdir="${dest}"/>
</target>
<target name="build" depends="compile" >
   <jar jarfile="${hello_jar}" basedir="${dest}"/>
</target>
<target name="run" depends="build">
  <java classname="test.ant.HelloWorld" classpath="${hello_jar}"/>
</target>

<!--target name="clean" >
  <delete dir="${dest}"/>
    <delete file="${hello_jar}"/>
</target>
<target name="return" depends="clean,run">
  <ant target="${dest}"/>
  <ant target="${run}"/>
</target>-->
</project>