Is there a way to use java 1.5 reflection to invoke an assocation method of an hibernate object? Let's say I have a hbm.xml -

< class="genClass" table="genTable">
...
<set name="classObjects"
...
</set>
</class>

and in my calling routine -

obj = session.load( "genClass", ID);
...
method = myClass.getDeclaredMethod("getClassObjects", null )
method.invoke( obj, null );

This gives me an error -

failed to lazily initialize a collection of role
no session or session was closed
Exception Class: org.hibernate.LazyInitializationException

It doesn't seem a reflection problem but a mapping one. You should set lazy="false" for your collection in your mapping file.

Yes, you are right. It is a mapping problem. What if I don't want to set fetching to "non-lazy" in my mapping? How can I do it programmatically? I've tried reattaching the object to the session, but it didn't work.

session.refresh(obj)

First thing I would do is setting it to non lazy to check if it behaives as you expect, so you can be sure the problem isn't anywere else. Once it's working, you can "lazy it back", and try to find a programmatic workaround.

Maybe you could fill your collection (Set) via hql just after the session.load() call and the set it to your object with myClass.setClassObects(...). This is something that I've done several times when I didn't want to set a non lazy relation.

Hope it helps

The whole point of having a <set> inside the mapping is so that one can easily retrieve the set of associated objects with a

Object obj = session.load( genClass, ID);
Set set = obj.getClassObjects()

Why do I have to write hsq for the objects and setting it to obj when I should just be able to use "getClassObjects()"?

I am rather hesitant in setting the mapping to "non-lazy" because of performance issues. What if I just want to load genClass, but don't really need the objects?

That's exactly what you have with your lazy initialization, and tha's why you are getting that exception, because you're trying to access an object that was never created. Neither you or hibernate did it at any moment.

Maybe nonsense, but, what if you try something like:

myclass.classObjects = session.load(Set.class, [Set id here]);

Maybe the set mapping makes that work, but I don't know how are you going to get the Set id.

Just giving ideas.

However, I'm really interested in how this topic is solved, because, as you pointed before, the way I understand the lazy inicialization makes you loose the ORM capability.