build.xml

<project name="TrieDataStructure" 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="."/>

    <property name="main-class"     value="trie.main"/>
    <target name="clean">
        <delete dir="${build.dir}"/>
    </target>

    <target name="compile">
        <mkdir dir="${classes.dir}"/>
        <javac debug="true" srcdir="${src.dir}" destdir="${classes.dir}"/>
    </target>

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

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