ant task to run all the tests or only one test. You'll need to supply the properties where to find your test source, libs and what not. Mainly here so i don't have to look this up again because it's not often need to do this but ant's as poorly written as this sentence.

ant-build-snippet.xml

    <target name="run-tests" depends="compile">

        <junit failureproperty="test.failure" includeantruntime="false">
            <classpath refid="run.classpath"/>

            <formatter type="plain" usefile="no"/>
            <batchtest todir="${reports.dir}" unless="test">
                <fileset dir="${source.dir}" includes="**/*Test.java"/>
                <formatter type="xml"/>
            </batchtest>

            <!-- if you only want to run *one* test use
               ant run-tests -Dtest=Classname
              -->
            <batchtest todir="${reports.dir}" if="test">
                <fileset dir="${source.dir}" includes="**/${test}.java"/>
            </batchtest>

        </junit>
        <fail message="One or more test cases failed" if="test.failure"/>
    </target>