merge problem - version of returned instance not updated

cristith · **Posted:** Tue Feb 27, 2007 9:30 am

Hi, we have a big problem regarding merge()

We use version property for optimisting locking
and we are saving detached objects using merge()

Because consecutive saves on the same detached objects can occur,
we're trying to keep the version updated, by reading it from the returned persistent instance of the same object.

This is supposed to be the current state of the object (as the api states), BUT it is not !!! The version of the returned instance it is the OLD one.
So when trying to save the object again we're getting a StaleObjectStateException

Hibernate version: 3.2.2.ga

Base DAO
We are using org.springframework.orm.hibernate3.support.HibernateDaoSupport

Code:

public abstract class AppBaseDAOHibernate<E extends BaseEntity>
        extends HibernateDaoSupport {}

Save method

Code:

public BaseEntity save(final E entity) {
    BaseEntity savedEntity = (BaseEntity) getSession().merge(entity);
    entity.setXversion(savedEntity.getXversion());
    return savedEntity;
}

Please help!

dharmendra.pandey · **Posted:** Wed Feb 28, 2007 1:29 am

Hi cristith,

always use merge in this way

public BaseEntity save(final E entity) {
BaseEntity savedEntity = (BaseEntity) getSession().merge(entity);
return savedEntity;
}

and it will change your ref .So you need to use returned ref.Merge use to merge your current intity to old entity.and old entity will remain in session and new entity will not attached .So using megre is programming cost.I would prefer avoid to use merge.

cristith · **Posted:** Wed Feb 28, 2007 3:10 am

Hi,

I don't need the new reference of the entity, I just need to know the VERSION property. The entity I'm trying to save has refs to some collections, so I wouldn't want to loose them.

The thing is the returned instance is identical to the one saved. It is not the one updated in the DB (so the version property is the old one).