Pre-existing session required for handler method "methodHandlerName"

Question

I realise my handler "methodHandlerName" has an argument HttpSession session which is why my spring mvc application throws the error: Pre-existing session required for handler method "methodHandlerName"

But where in my application would I have to set a session. I presume there's no session in my application is it's set to false by default; and would to set it somewhere in my application context.

thanks