You can download the jar file also. If you go to a download page for the project, such as this:
http://sourceforge.net/projects/jodconverter/files/JODConverter/2.2.2/
You'll be given the opportunity to download a tomcat zip, a webapp zip, or the .. other zip, that is just the name of the library: jodconverter-2.2.2.zip
. Download that one, and include it as a Play library. Fun project! Enjoy!