Event handling: lastModification tracing

JGebhardt · **Joined:** Fri Jun 17, 2005 2:51 am **Posts:** 11

Hi,

I want to record the last modification of a data record by using the event handling system. I wrote my own SaveOrUpdateEvent like this:

Code:

public class MySaveOrUpdateEventListener extends DefaultSaveOrUpdateEventListener {
   
   public Serializable onSaveOrUpdate(SaveOrUpdateEvent event) {
      if (event.getObject() instanceof IAuditedObject) {
         IAuditedObject audObj = (IAuditedObject)event.getObject();
         audObj.setLastModification(new Date());
      }
      return super.onSaveOrUpdate(event);
   }
   
}

and registered this event like this in the hibernate.cfg.xml:

Code:

    <listener type="save" class="MySaveOrUpdateEventListener"/>
    <listener type="update" class="MySaveOrUpdateEventListener"/>
    <listener type="save-update" class="MySaveOrUpdateEventListener"/>

As this woks fine when creating new records, the event handler is not called when updating an existing record like this:

Code:

MyObject myObj = HibernateUtil.getSession().load(MyObject.class, myIdId);
myObj.setAttr("some value");

Most likely the event handler is not called because I don't save the changed object explicitely on the session (session.saveOrUpdate(myObj)).
Which event handler will be called in this case? Do I have to extend more than one event handler or does there exist a event handler that will be called before every DB writing?

Thanks in advance,
Joern

alesj · **Posted:** Mon Jun 20, 2005 11:04 am

See the Inteceptor usage.

alesj · **Posted:** Mon Jun 20, 2005 11:08 am

http://www.hibernate.org/hib_docs/v3/re ... le/#events

JGebhardt · **Joined:** Fri Jun 17, 2005 2:51 am **Posts:** 11

Hi alesj,

I know that I can write the last modification date using interceptors. However, I like the event handling system because you can configure it in the hibernate.cfg.xml file, so I was looking for a solution based on the event system.
Most likely I have to play around with the FlushEntityEventListner to write the last modification date on every entity change.
By the way, instead of writing the last modification date I want to create a change entry in another table and reference this change from all changed entites within the transaction. And from what I know by reading this forum is creating new entities from within the interceptor somewhat tricky. But I keep on playing around....

Best regards,
Joern

scesbron · **Joined:** Thu Sep 04, 2003 8:23 am **Posts:** 368

In your case, the PostUpdateEventListener is called, so you can put your code in such an event listener.

Seb

hackingbear · **Joined:** Mon Mar 21, 2005 12:27 am **Posts:** 17

I have the same confusions over these listeners.

The SaveOrUpdateEventListener is not invoked during update of an entity.

The PreUpdateEventListener is invoked for entity update after the updated fields are collected by Hibernate, so that any changes made to the updating entity are never written to database.

jt_1000 · **Posted:** Sun Mar 26, 2006 12:31 am

what is the complete mapping (hbm.xml) for the class "MyObject"?