Using a JDBC Pool with different credentials

In both Tomcat and WebLogic, I can configure connection pools that require the DataSource.getConnection(String user, String pass). How do I do this in GlassFish 4?

Basically, I need to have JDBC connection pools that allow different credentials. The only other option would be to create so many single-user connection pools that it would be unmaintainable under GlassFish.

Thanks for any help or suggestions!