I have a hibernate entity which is kept in the http session. Upon retrieval from the session I try to lock the entity if the id is set (it is persistent). Unfortunately this provokes problems when collection properties are brand new - not of type PersistentCollection. I don't understand this. I use lock in order to reattach an entity which may have lazy properties to the current session. Basically editing a persistent entity in a conversation.

Do I always have to use an existent persistent collection - which is always provided with persistent instances ? Usually we set a new collection and have had no issues yet.

It seems that even editing the persistent collection does not help. When reattaching the entity with the new session an exception is thrown because the collection is dirty.

I want to flush at the end of the conversation only.