attempt to create saveOrUpdate event with null entity

Question

I have a GWT app that makes an RPC call to a server to save/create a new entity. However, the Spring-Hibernate back-end throws an exception with the following error message:

attempt to create saveOrUpdate event with null entity

I'm not sure what that means. What's null? If it's a new entity I am saving, I am expecting to have the id field be null or possibly 0, and then have hibernate fill it. Is this expectation correct?

Answer 1

null entity could mean that saveOrUpdate() is actually receiving null as an argument, ie:

session.saveOrUpdate(null);

If you're using serialization to pass to object to a remote location (you mentioned RPC), perhaps you should check if serialization is working correctly. Something tells me that failing to serialize might end up with a null reference being passed.