Question

here i am again in my self learning hibernate and personal experiment project to gain more understanding.
Here is the description of my environment:
i have a super model entity that all my model inherit from.it has only id property
i use the genericDAO pattern found on hibernate web site.
Now my problem is that i use list instead of set for my one to many mapping (there is no need to avoid duplication here) and when i reference the super entity id in list index or list-index property i have this error :
org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session
here is the super entity interface

public interface Model extends Serializable {
public Long getId();
public void setId(Long id);
}

//here is its implementation.they are not in the same physical file
public abstract class ModelImpl implements Model {
private Long id;
public Long getId() {
    return id;
}
public void setId(Long id) {
    this.id = id;
}

}

here is it’s mapping file

<class abstract="true" name="ModelImpl">
<!--i removed doctype and stuffs-->
<id name="id">
  <generator class="assigned"/>
</id>
</class>

here is on pojo interface this is my parent

public interface Message extends Model {
Date getDateSent();
String getGlobalStatus(); 

}
//its implementation is here but on different physical file
public class MessageImpl extends ModelImpl implements Message{
private String globalStatus;
private List response = new ArrayList();
private Date dateSent;
//setters and getters….
}

its mapping file is like so :

<union-subclass extends="ModelImpl" name="MessageImpl">
<property name="globalStatus"/>
<property name="dateSent" type="timestamp"/>

</set>–>

i commented the set because its was given a casting error which makes me realize my error
so the Response class which is the parent is here :

public interface Response extends Model {
String getGatewayMessageId();
Message getMessageId();
}
//its implementation but in different physical file
public class ResponseImpl extends ModelImpl implements Response{

private static final long serialVersionUID = 1L;

private Message messageId;
private String gatewayMessageId;
//setters and getters..
}

so that is basically that.now during my test when i try to save message with its children it throws this :

org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session

i can do all persitent methods exception the one i just talked about.
i’m a bit lost here coz all of them are inheriting Model id so what am i doing wrong?
thanks for reading.I dont’ really understand the problem here.

Answer 1

solve it.i have a manager(which creates pojos and daos) that inject new Id to every newly create POJO.and during testing i add the id manually.thanks for your help