title: Spring security authentication: get username without SPRING_SECURITY_LAST_USERNAME
body: <p>I'm new at spring framework. I'm creating a login page for my webapp and I want the user to login before any action on the app. If the user enters good credentials everything it's ok and working, but if enters bad ones I want to display a message and keep the username on the input element. Displaying a message is not a problem, but I'm not able to keep the username in my jps file without using the deprecated variable SPRING_SECURITY_LAST_USERNAME.</p>
  
  <p>Hope someone can help me, I'm using Spring 3.</p>
  
  <p>UPDATE: the requirements says I don't want to display the username on the url.</p>