We have a new system we're developing on a JDK 1.4 app server, and we want to expose its stateless-session-bean service layer to a legacy system running JDK 1.3. Hence we can't use plain old RMI because of all kinds of horrible serialization versioning problems.

"Use SOAP," you say! Hah, if only. Axis is still a big ball of hair and we want to stay open source in our whole stack if we can and until we must do otherwise. (We're using JOnAS for our app server, which integrates Axis.)

So I've written a small reflection-based layer around XML-RPC, and we're using that. Seems to work pretty well. Except....

When using RMI, and when we serialize a Hibernate collection, the collection intelligently serializes itself to send over only the contents that have been loaded thus far. In other words, serializing the Hibernate collection won't force lazy loading.

However, my little reflection wrapper doesn't have the benefit of that, and when it goes to traverse the collection (to flatten the contents into a form XML-RPC can handle), it goes and gets a LazyInitializationException since I don't have a session at the point where the traversal is happening. And I don't even WANT to traverse the collection; I only want to flatten the contents that have been loaded thus far (if any). In other words, I already have code that loads only the parts of the dependent graph that I care about; I just want to be able to know *which parts those are* without forcing any further lazy loading.

Is this possible? Any under-the-hood hooks in the Hibernate collections for detecting / enumerating only what's actually been loaded? Anyone else run into similar problems? (I can only assume that anyone working with SOAP or any other non-RMI serialization would have run into this as well....)

Cheers!
Rob

Hibernate.isInitialized()

Thanks!

This seems to work as well:

Not as elegant, though :-)

Also, is it possible that a collection could be initialized but only *partially* lazy-loaded, and that in that case isInitialized() would return true but iterating would still force further lazy loading (which, as I said, is not what I want)? I *know* that calling "entries()" will never force any lazy loading.

Cheers!
Rob

No, a proxied collection will never be partially loaded.