Signle sign out filter customization

Hi,

Sorry I m quite a newbie here. I looking for a way to apply custom logout code uppon the CAS single sign out. I managed to get the single sign out working with Spring Security and everything seems to work fine (sessions are invalidated). However we do have a certain amount of custom code for each application when the user logs out (for instance logging the action etc.) but I do not find a way to add extra logout handlers.

So the question is is there a way to extend the filter somehow (the SingleSignOutFilter class is final, I cannot overwrite it) or add custom logout handlers ?

Thanks !
Nonak