Error : RuntimeException: No JPA EntityManagerFactory configured for name [default] in Play Framework 2.0

I got this error : [RuntimeException: No JPA EntityManagerFactory configured for name [default]] when i try to create a controller method with @Transactional.

Solution:
In application.conf file, put the following entry and assign it to the default  entry in Persistance.xml

jpa.default=Default non-jts-data-source entry from Persistance.xml