At the moment when JPA facet is installed, the user enters the selected JPA provider (Hibernate JPA, Eclipselink, Open JPA, Java EE). But afterwards in later stages in the project, they are not able to obtain the information about that setting.

The JPA facet should have a method with the following signature:

PersistenceProvider getPersistenceProvider();

Its implementation should not count on any data stored by Forge on previous step and should work both on projects where JPA was setup by Forge and where the dependencies and persistence.xml were configured by the user with other means.