<project name="lib" default="download-libs" 
         xmlns:artifact="urn:maven-artifact-ant">

  <property name="maven.ant.tasks.jar" value="maven-ant-tasks-2.1.0.jar" />

  <target name="download-libs" depends="-init-maven-task">
    <artifact:dependencies pathId="dependencies.classpath">
      <dependency groupId="org.codehaus.groovy" 
                      artifactId="groovy" version="1.7.2" /> 
      <dependency groupId="org.ccil.cowan.tagsoup" 
                      artifactId="tagsoup" version="1.2" />

      <remoteRepository id="maven-central" 
                      url="http://repo1.maven.org/maven2/" />
    </artifact:dependencies>

    <move todir=".">
      <path refid="dependencies.classpath"/>
    </move>
  </target>

  <target name="-init-maven-task" depends="-obtain-maven-task-jar">
    <available property="maven.ant.tasks.jar.exists" 
               file="${maven.ant.tasks.jar}" />
    <typedef resource="org/apache/maven/artifact/ant/antlib.xml" 
             uri="urn:maven-artifact-ant" classpath="${maven.ant.tasks.jar}" /> 
  </target>

  <target name="-obtain-maven-task-jar">
    <available property="maven.ant.tasks.jar.exists" 
               file="${maven.ant.tasks.jar}" />
    <antcall target="download-maven-jar"/>
  </target>

  <target name="download-maven-jar" unless="maven.ant.tasks.jar.exists">
    <property name="maven.ant.tasks.url" 
              value="http://www.apache.org/dist/maven/binaries/${maven.ant.tasks.jar}" />
    <get src="${maven.ant.tasks.url}" dest="${maven.ant.tasks.jar}" />
  </target>

</project>