How to achieve Java Multi-mapping in PI 7.31?

Hi,

     I have a simple file to file scenario. Want to do 1:n transformation using java mapping.

     Followed this link  Multi-Mapping using Java Mapping - Process Integration - SCN Wiki . But the result was a single message with three root segments. where as the requirement is to get three messages each having one root segment. Please suggest how can we achieve this.

PS: Please suggest a solution specifically using java mapping.

Thanks