A quick-and-dirty solution would be to have a ThreadLocal that holds the entity. If the threadlocal is empty - update the signature, set the threadlocal, and save the entity. On the next invocation the threadlocal will be filled and you can return from the listener.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.