We have not yet contributed the EclipseLink vendor adapter and dialect
classes into Spring so that EclipseLink can be used. We need to get this
done before you can replace TopLink Essentials with EclipseLink in you
Spring application.
Once this is done you can use EclipseLink in a similar fashion to how you
use TopLink Essentials. You will also find additional features such as
XMLType mapping support.