I am trying to figure out which Apache Ant version is running on the Jenkins server. Starting from Apache Ant 1.7.0, you can make use of the <Antversion> task to determine the running Ant version. The following is a simple build.xml which could serve this purpose.

<project name="ant-antversion-example" default="run" basedir=".">
  <target name="run">
    <echo message="Checking ANT version ..."/>
    <antversion property="antversion"/>
    <echo message="  version: ${antversion}"/>
  </target>
</project>

Try it out. Continue reading Apache Ant – Get the current running Ant version in Ant script →

The following example which check if a string property contains a another string.

<project name="ant-string-contains-example" default="run" basedir=".">
  <target name="run">
    <property name="greeting" value="Hello World!"/>
    <condition property="hasWorld">
      <matches pattern="World" string="${greeting}"/>
    </condition>
    <fail message="No world in the greeting!" unless="hasWorld"/>
    <!-- Move on if no failture -->
    <echo message="Passed!"/>
  </target>
</project>

Done =)

Reference: StackOverflow – Ant: how to fail if property contains a certain string