Yes, this Workaround works. But it is only a temporary solution, as the driver works as intended and the patch adds "wrong" behaviour. Every Oracle-Update breaks this solution.

While you could say, that the problem lies with Java itself, because java.sql.date has a time-part, which it should not have by design, we know that this won't change. @Temporal's functionality is currently broken due to Oracle's change (in this setup anyway), so the functionality should be restored. As I see it, Hibernate is an abstraction that provides the same behaviour, no matter which database is used underneath. That's why I think Oracle12cDialect is the correct class to fix this problem.