How to resume the same webflow incase of any error

Hi I am new to Spring webflow. I have an urgent requirement in my application.
In web.xml my application is configured to be session timed out in 20 mins.
In a particular webflow (login workflow) i have to resume the same webflow even if session timeout occurs.

Currently application is catching NoSuchConversationException exception but i have no clue that how to continue the same flow and same state.

Obviously you cannot, the flow isn't there anymore, neither is the state. So if you want something like this you would need to change the way state is stored and destroyed and how flows are terminated and destroyed.