build.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="ContestBot" default="jar" basedir=".">
    <property name="src" location="src"/>
    <property name="bin" location="bin"/>
    <property name="lib" location="lib"/>
    <property name="jarfile" location="${ant.project.name}.jar"/>

    <fileset id="lib.jars" dir="${lib}">
        <include name="**/*.jar"/>
    </fileset>

    <path id="lib.path">
        <fileset refid="lib.jars"/>
    </path>

    <target name="compile">
        <mkdir dir="${bin}"/>
        <javac srcdir="src"
               destdir="bin"
               includeAntRuntime="no"
               classpathref="lib.path">
            <compilerarg value="-nowarn"/>
        </javac>
    </target>

    <target name="jar" depends="compile" description="Build jar">
        <jar jarfile="${jarfile}" basedir="${bin}" manifest="Manifest">
            <!-- Merge library jars into final jar file -->
            <zipgroupfileset refid="lib.jars"/>
        </jar>
    </target>

    <target name="clean" description="Remove build and dist directories">
        <delete dir="${bin}"/>
        <delete file="${jarfile}"/>
    </target>
</project>