When we login the website(base in seam),
do not click logout button,
and redirect to the login page,
we will see the identiy exists,
and we can't change account, because the method 'authenticator.authenticate' will not
How to force logout when login and redirent the login page?
You could have a page action for the login page and logout if the user is logged in. You should probably find some earlier discussion on this (or on the old forums). Think there was a feature request JIRA around this too(?)