Hello,
If you use "Jboss + Eclipse + Jboss-Seam + Jboss-Tools" and start your Jboss from Eclipse Server View, you need to add the argument into "Window/Preferences/Java/Installed JREs" and edit the entry you use, then, add argument -Doracle.jdbc.V8Compatible=true into "DefaultVM Arguments" field.
I use obdbc14.jar library with same configuration and working.
With that, all Date fields will use date/time format. If you want use only date format, you must add "@Temporal(TemporalType.DATE)" annotation to desired field.
Regards.
Francisco.