java - Mapping enum to a table with hibernate annotation

Question

I have a table DEAL and a table DEAL_TYPE. I would like to map this code:

public class Deal {
   DealType type;
}

public enum DealType {
   BASE("Base"), EXTRA("Extra");
}

The problem is that the data already exist in the database. And I'm having a hard time mapping the classes to the database.

The database looks something like that:

   TABLE DEAL {
      Long id;
      Long typeId;
   }

   TABLE DEAL_TYPE {
       Long id;
       String text;
   }

I know I could use a simple @OneToMany relationship from deal to deal type, but I would prefer to use an enum. Is this possible?

I almost got it working by using a EnumType.ORDINAL type. But unfortunately, my IDs in my deal type table are not sequential, and do not start at 1.

Any suggestions?

Answer 1

Hibernate is kind of terrible at Enums. It's a strange failing of an otherwise pretty good ORM. The "easiest" way to get around it is to declare your Enum a custom hibernate type. Fortunately, Hibernate wrote an example implementation which you can crib verbatim into your app:

http://www.hibernate.org/265.html

They even include instructions on how to use it. This is the pattern I use whenever I end up with the need to persist enums.