How do a I specify class level lazy attribute w/annotations?

bblount · **Joined:** Mon Jun 06, 2005 3:49 pm **Posts:** 3

I am just moving up to Hibernate 3.0.5 and Hibernate Annotations 3.0 beta 2 from Hibernate 2.1. I use "table per class hierarchy" inheritance for some of my classes, and need to load them by id with the base class:

Code:

session.load(BaseClass.class, databaseId);

However, this does not work with lazy/proxying enabled for the class. I searched this forum and the annotations docs, and cannot find anyway to specify lazy="false" using annotations at the class level. Is it possible to do, and if not, will it be available in a future release?

gavin · **Posted:** Tue Jun 07, 2005 12:11 am

What do you mean it does not work?? Of course it works.

Remember, proxy type != underlying instance type.

(Also, you can use get() instead.)

bblount · **Joined:** Mon Jun 06, 2005 3:49 pm **Posts:** 3

I'm sorry, my question was not clear.

My DAO exposes the method:

Code:

BaseClass getBaseClassById(Serializable databaseId)
{
    return (BaseClass)session.load(BaseClass.class, databaseId); 
}

However, consumers of this API need to cast the returned value to specifc instances:

Code:

SpecificClass specificClass = (SpecificClass)dao.getBaseClassById(id);

When lazy loading is enabled for the class, and there is a table per class hierarchy, then the proxy type will not be a subclass of my specific class, and I will get a ClassCastException, correct?

It seems that I have three alternatives
1. Expose an API for every concrete class in my DAO
2. Turn off proxying / lazy loading in the class (which I don't know how to do with annotations).
3. Change my load method to use HQL to force the initial load.

Thanks for your help.

Marcos Silva Pereira · **Posted:** Wed Jun 08, 2005 5:03 pm

bblount wrote:

It seems that I have three alternatives
1. Expose an API for every concrete class in my DAO

This seems more correct to me. Anyway, you can use generics too, something like:

Code:

public class MyDao<T extends BaseClass> {
   public T get(Serializable id) {
      ...
   }

   public T save(T obj) {
      ...
   }
}

bblount wrote:

2. Turn off proxying / lazy loading in the class (which I don't know how to do with annotations).

Are you talking about it:
http://www.hibernate.org/hib_docs/annot ... Proxy.html

?

valeuz...