Hibernate, save the previous state of an object

Question

Is there any generally accepted, proven-to-work way using hibernate, that keeps a history of an entitys changes in the database?

We need to keep track of quite some

Answer 1

I've done this with an Interceptor (creating my own based on EmptyInterceptor). I was able to get all changes (merge, save, saveOrUpdate and delete) in onFlushDirty().

The methods of EmptyInterceptor I used:

@Override
public boolean onFlushDirty(Object object, Serializable id,
    Object[] newValues, Object[] oldValues, String[] properties,
    Type[] types) throws CallbackException {

@Override
public boolean onSave(Object object, Serializable id, Object[] newValues,
    String[] properties, Type[] types) throws CallbackException {

@Override
public void onDelete(Object object, Serializable id, Object[] newValues,
    String[] properties, Type[] types) throws CallbackException {

In onFlushDirty() I had to query the previous state of the entity:

Connection c = sessionFactory.getCurrentSession().connection();
Session session = sessionFactory.openSession(c);

BaseEntity newBaseEntity = (BaseEntity) object;
BaseEntity oldBaseEntity = (BaseEntity) session.get(newBaseEntity.getClass(), newBaseEntity.getId());