title: Spring MVC - Checking if User is already logged in via Spring Security?
body: <p>I have a Spring MVC application.<strong>It uses its own custom Login page</strong>. Upon successful login, a 'LOGGED_IN_USER' object is placed in the HTTPSession.</p>
  
  <p>I want to allow only authenticated users to access URLs. I know i can achieve this by using a web filter. But, This part i want to do using Spring Security (my check will remain the same - look for 'LOGGED_IN_USER' object in HTTPSession, if present you are logged in).</p>
  
  <p><em>My constraint is i cannot change Login behavior at present - that will not use Spring Security yet.</em></p>
  
  <p><strong>What aspect of Spring Security can i use to achieve this part alone - check if the request is authenticated (from logged in user)?</strong> </p>