Entities and Maps

amidrunk · **Joined:** Sun Sep 02, 2007 5:45 am **Posts:** 4

Hi,

I'm having trouble getting an entity up and running. I have a "TextEntity" that has an id and a Language->String map, like this:

Code:

@Entity
public class TextEntity implements Serializable {
   @Id
   public Long getId() { ... }
   public Map<String, String> getTranslations() { ... }
}

When deploying, I'm getting the following error message:
javax.persistence.PersistenceException: org.hibernate.MappingException: Could not determine type for: java.util.Map, for columns: [org.hibernate.mapping.Column(translations)]

How can I accomplish this? I would like to keep it all in a single table, looking like this:

Code:

-----------------------------
| ID  |    LANGUAGE | VALUE |
|---------------------------|
|  1  |       en    |  Hi   |
|  1  |       sv    |  Hej  |
-----------------------------

So, in essence I have a composite primary key (ID, LANGUAGE), where the seccond element should be the key in the table.

andydale · **Posted:** Tue Sep 04, 2007 6:08 am

Hi,

I think you are missing @MapKey annotation on the Map.

Cheers,

Andy

amidrunk · **Joined:** Sun Sep 02, 2007 5:45 am **Posts:** 4

Hi,

I've tried setting the MapKey, but it doesn't make a difference w.r.t. the mapping failure. I need to be able to tell hibernate the key and value types.

Any ideas? Btw, this works with the traditional hibernate approach (XML mapping definitions) without any problems.

Regards,
Nille

andydale · **Posted:** Mon Sep 10, 2007 7:55 am

just as an extra note, you have to be careful to put all your annotations at the same level i.e. all at veriable declaration, or all at getter level.

I have had the MappingException before with relationship mapping because of mixing where the annotations are.

Cheers,

Andy

kimptoc · **Joined:** Tue Jun 27, 2006 6:14 am **Posts:** 24

Hi

Did you get this to work?

Thanks,
Chris