I am trying to detect changes made to the entity before commiting the transaction. I'm successufully using the following algorithm:

1. Clone managed entity to a new one by copying all the arrtibutes
2. Refresh the managed entity to lose all the changes
3. Compare these objects to see where changes occured
4. Merge the cloned entity so that the changes were saved eventually

This artificial detaching single entity is working great for me, but not when entityManager uses FlushModeType.MANUAL. In that mode merging throws Can anyone help me bypass that?

FYI: MANUAL mode works fine with merge(). I had a fatal typo - setter of field used for JPA optimistic locking was private, so cloned entity just had to be considered obsolete. Thanks anyway :)