Create transaction token object and place to HttpSession as Globals.TRANSACTION_TOKEN_KEY attribute

Create transaction token and save it before loading the JSP page.
Then check the return value of the isTokenValid() method when user submits the form

Create transaction token, bind it with action and save in HttpSession object

Save transaction token on first submit and check if the transaction token was saved at next submits

Check isTokenValid() method return value when user submits the form