title: CAS and Spring-Security: regularly check if a ticket has expired
body: <p>I have a CAS-Server and a Client configured via Spring-Security. Single Sign On and Single Logout are working fine so far.</p>
  
  <p>I'm still facing an issue with session timeout. As I understand the ticket expiration policy is not affected by idleness of the secured CAS client side session. So a client must actively revalidate a ticket to see if it has expired and is not being posted the expiration event by the CAS server as it is the case when a single logout is performed. </p>
  
  <p>To force my spring secured client to regularly check for the expiration of the ticket I might set the session timeout to a low value like a minute or so. But that has the drawback of all my session data to be removed. Not very user friendly. </p>
  
  <p>Is there a way to tell spring-security to regularly check if a ticket is still valid without destroying the user session first? </p>