We are putting our current application under Hibernate. In my old code I was having some complicated stuff allowing to keep what I called the original state of business objects, In fact it's a copy of my object right after it's loaded from the database. The object is then modified and in my business code I'm sometime comparing the initial and current values to see what has changed.

An example is: you send a client report only is your object went from a status to another.

Another is that you need to audit everything that changed and then put a String in DB with all that.

Now, I'm thinking about how I'm going to implement that in hibernate. I've notice that hibernate keeps a loaded state. Is there an API to access it? Does it fulfill my needs?

If not, does anybody have some ideas of how to do that?

One solution is to keep my copy system and adding an interceptor. BTW, how does hibernate creates the loaded state? I want the exact same thing (do not copy associations).

thanks,
Henri

Look at Interceptor

Yeah, as I said it's what I will do unless there is a way where I don't have to code the initial state creation all by myself.

You may want to take a *closer* look at Interceptor. During onFlushDirty() you are passed the initial and current state of the entity

That's sound good. I'll take a *closer* look indeed. :-) Sorry to have missed the point the first time.

I am currently in the process of implementing audit log functionality for our application. What I want to do is to create a new row in the audit table whenever an object's state is modified (more specifically, whenever data in certain columns is modified). However, I also need the logged in user who is modifying the data. How do I propagate this to the Interceptor? It does not take the javax.security.Principal as a method parameter.

Thanks for the great work on Hibernate...it is a wonderful persistence framework.

Well, Interceptor is just an interface which *you* implement, right? That implementation can get a user in any way it needs to.

Maybe you pass it into the constructor for a session-level Interceptor. Personally, I pass a SessionFactory-level Interceptor an instance of an object which it can use to retreive the current user.

May be I am doing something wrong, but my interceptor is never getting called. Here is how I am using the Interceptor.

and in MyInterceptor, I am overrriding the onflushDirty() method, here are the first few lines, that just test if this method is ever getting called when an object is modified:

Here is my test code, where I modify a Hibernate generated object:

As expected, Hibernate modifies the object and I can see the changes in database, but it looks like it never calls my interceptor's onFlushDirty() method (because it never prints the log/print statements I have at the beginning of that method).

Any help is highly appreciated.

Somehow in your system, the "sessionFactory.openSession(new MyInterceptor());" call you think is happening is not happening...

As always, a simplified main() will help you track this down. Create a main() which opens a session in the fashion you describe then does the object modifications.

Thanks steve. I found the problem. I used IDEA to generate the default implementation for the Interceptor interface methods and then just changed the onFlushDirty() method implementation. It turned out IDEA did not do a good job in implementing the defult behavior for the findDirty() method (it did not return null), and that's why the onFlushDirty() method never got called.