Duplicate class mapping

El_Homer · **Joined:** Mon Nov 07, 2005 8:51 am **Posts:** 4

Hi,

I'm a newbie what concerns Hibernate and i'm experiencing some problems with inheritance and annotations...

I've read in the docs that the easiest way was the TABLE_PER_CLASS strategy, and that is what i would like to start with..

I have following Superclass:

Code:

@Entity
public class happening{...}

I have following SubClasses:

Code:

@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class Activity extends happening{...}

Code:

@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class ActivityWithCard extends happening{...}

Code:

@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class Exam extends Activity{...}

I read in the docs that you have to declare '@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)' on every leaf, so in this case Activity, ActivityWithCard and Exam. Though i always get a mappingexception: "Duplicate class mapping: duplicate found for class "Happening".

I've probably made some stupid mistake, I would be very gratefull if someone could help me out...

Much Thanks in Advance

El_Homer

nathanmoon · **Posted:** Mon Nov 07, 2005 3:29 pm

My first guess would be that something (likely in the annotations part) is expecting your happening class to follow standard Java naming conventions - all classes start with a capital letter.

Try renaming your base class to Happening (capital H) and see if the problem goes away...

d · **Joined:** Mon Jul 04, 2005 5:19 pm **Posts:** 720

Make sure Happening is not mapped more than once in hibernate.cfg.xml, make sure hibernate.cfg.xml is not being loaded more than once.

El_Homer · **Joined:** Mon Nov 07, 2005 8:51 am **Posts:** 4

nathanmoon wrote:

Try renaming your base class to Happening (capital H) and see if the problem goes away...

I've renamed the class with a capital, but still i get the error...

My hibernate.cfg.xml his mapping classes are:

Code:

<mapping class="com.hodori.model.Happening"/>
<mapping class="com.hodori.model.Activity"/>
<mapping class="com.hodori.model.ActivityWithCard"/>
<mapping class="com.hodori.model.Exam"/>

Could this been seen as duplicates ? How can you check the time of loading hibernate.cfg.xml ? In my Junit TestCase i only make one configuration (= annotationconfiguration) and one sessionfactory (configuration.configure.buildSessionFactory).

Many thanks allready

El_Homer

El_Homer · **Joined:** Mon Nov 07, 2005 8:51 am **Posts:** 4

Is it needed/mandatory to repeat the classes that extend of the superclass ? Or can you leave the superclass behind in the hibernate.cfg.xml ?

El_Homer · **Joined:** Mon Nov 07, 2005 8:51 am **Posts:** 4

Hey everybody,

I've been able to fix my problem with the JOINED method.

Tnx anyway for your reply's.

Greetzzz,

El_Homer