build.xml

<project name="MyProject" default="compile" basedir=".">
    <description>
        simple example build file
    </description>
  <!-- set global properties for this build -->
  <property name="src" location="src"/>
  <property name="bin" location="bin"/>

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

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

  <target name="init">
    <!-- Create the time stamp -->
    <tstamp/>
    <mkdir dir="${bin}" />
  </target>

  <target name="compile" depends="clean,init"
        description="compile the source " >
    <!-- Compile the java code from ${src} into ${build} -->
    <javac srcdir="${src}/client" destdir="${bin}" classpathref="classpath" />
    <javac srcdir="${src}/server" destdir="${bin}" classpathref="classpath" />
  </target>

  <target name="clean"
        description="clean up" >
    <!-- Delete the ${build} and ${dist} directory trees -->
    <delete dir="${bin}"/>
  </target>
</project>