What are the steps to change a simple login application into a Spring Security applicaiton

I have a login page and users can login(passwords and user names are at a file) with that page. After login process a new web page opens. If anybody else doesn't login and tries to see that page they can't see that page. I have that simple architecture and want to change this into a Spring Security 3.x.

开发者_StackOverflow

What are the every step for that?