build.xml

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

  <path id="classpath">
    <fileset dir="${lib.dir}" includes="**/*.jar"/>
  </path>
  
  <target name="clean">
    <delete dir="build"/>
  </target>
  
  <target name="compile" depends="clean">
    <mkdir dir="build/classes"/>
    <javac srcdir="src" destdir="build/classes"  classpathref="classpath" source="1.6" target="1.6" debug="on"/>
  </target>
  
  <target name="jar" depends="compile">
    <mkdir dir="build/jar"/>
    <jar destfile="build/jar/countlinesaggregator.jar" basedir="build/classes">
      <manifest>
        <attribute name="Main-Class" value="org.apache.hadoop.examples.CountLinesAggregator"/>
      </manifest>
    </jar>
  </target>
  
  <target name="run">
    <java jar="build/jar/countlinesaggregator.jar" fork="true"/>
  </target>
</project>