Hi,

Currently I'm investigating wether Hibernate would fit in our architecture, which is event driven.
One of the requirements is that we want to be able to use lazy loading.

Let's say one process fetches object Parent which has a (lazy-loaded) relationship with Child. The process publishes an event with the Parent object on the event router and by doing so the Parent object gets serialized.

Now first of all we don't want that the serialization will initialise the Child collection.

Secondly another process which is "listening" to Parent objects gets the object from the event-router. This process wants to assess the Child collection so this other process which has a connection to the same database as well, wants to be able to initialise the collection.

Does Hibernate fit in this kind of architecture?

Cheers,

Jan-Erik

You'd have to be very clever about it, as the lazy loading requires that the session that loaded parent must still be available when child is referenced. That, of course, means that the parent object can only be referenced on a single machine, and your mention of an "event router" suggests that there's more than one machine involved.

The serialization thing isn't a problem, so long as proxied associations are referenced only where the session is available. You can declare the fields as transient (to prevent serialization) and hibernate will cope fine.

Well that's the thing. The other process which will try to navigate from Parent to Child is on another machine most of the times, so the session which is associated with Parent is not availlable there.
Isn't it possible to tell Hibernate to just use a new session?

Pure lazy loading requires use of the same session. You can work around it in your code though, by detaching the object as it leaves one session (session.evict) and reattaching it when it arrives at the new session (session.lock then session.refresh). It won't be able to take advantage of the original session's cache, but in all other ways, it's the same.