How to fix " Problem: failed to create task or type if" when building ant on Middleware/Oracle_SOA1/soa/modules/oracle.soa.ext_11.1.1

Download the code from http://sourceforge.net/projects/ant-contrib/files/

Finally add the following lines to the task files

<taskdef resource="net/sf/antcontrib/antcontrib.properties">
  <classpath>
    <pathelement location="[downloaded path]/ant-contrib-1.0b3.jar"/>
  </classpath>
</taskdef>

Execute ant and issue will be fixed