Using Hibernate 3

Hi,

Before I start, I have an error in my logic whilst using Hibernate rather than a Hibernate error in the stack trace itself. I need a Hibernate education i guess.

In English I am trying to

0 - Using AJAX I call a server method that completes and returns my model
1 - Load a model object A from the DB using Hibernate
2 - Update some variables in A
3 - return updated A to my JSP
4 - do not update the new version of A in the database

The problem

5 - I do not call save or persist on anything but Hibernate takes it upon itself to update the database

I guess that basically Hibernate is persisting my changes to object A because i have a reference to the object. I.e. when i am updating, i actually want a new copy of the object A rather than the one Hibernate has given me a reference to.

Solutions

1 - I am aware that i could write a deep clone of the object that Hibernate gives me but that is going to be very long winded in my situation. To the point that i gave up twice.

2 - ?

Is there any way i can ask Hibernate to give me a copy of an object rather that a reference?

Any help very welcome and please feel free to correct me above

Thanks

Matt

If you commit transaction / close session before you update the object, then you would get exactly what you are looking for.

Thanks for the response.

I am using Hibernate via my application context in my DAO.

At present I call

List<Page> list = (List<Page>) getHibernateTemplate().find(sql,
c.getId());

there is no method on getHibernateTemplate() to commit transaction.

How do i commit a transaction in this context?

Thanks again

if that is Spring's HibernateUtil class, it creates, and manages transactions for you. And hibernate is acting exactly as expected, it persists chagnes it detects to the database.


is serializing and using a byte stream for cloning out of the question? Easiest way IMO

Hi,

Thanks for getting back to me

I don't have permission to serialize the classes involved so couldnt use that method to create a deep clone.

I am pretty well stumped on this

If you don't want changes to your loaded object to be reflected in the database, you'll have to explicitly detach the loaded object form hibernate's persistence context.
Just call evict(A) on your HibernateTemplate after loading and hibernate won't care about your changes any longer.