Back door means of redirecting someone to a protected page
(i.e., the JSP listed in the url pattern here) to force them
to login, even if your app is mostly public. The OPTIONAL
J2EE Role based authorization handler may also force a user
to this protected page if you inadvertently forgot to protect
a model with a security constraint, but still specified optional
model security property based list of roles via the Designer.
View the source of this JSP page to see how it works and what
it does after the user has been logged in and gets to this
page, which should do nothing other than redirect you to where
you were trying to go before.
<description>Roles allowed through forced login redirect page (typically all roles)</description>