Spring MVC - Checking if User is already logged in via Spring Security?

Question

I have a Spring MVC application.It uses its own custom Login page. Upon successful login, a \'LOGGED_IN_USER\' object is placed in the HTTPSession.

Answer 1

Many of the authentication providers will create a UserDetails object as the principal.

Another way I found - using spring-security - is to check whether the return value of Authentication.getPrincipal() is an instance of UserDetails; the method returns "anonymousUser"(String) by default.

boolean isUserLoggedIn(){
   return SecurityContextHolder.getContext().getAuthentication().getPrincipal() instanceof UserDetails
}