title: How to process a form login using Spring Security / Spring MVC
body: <p>Simple question, I just need a pointer in the right direction:</p>
  
  <p>I have a simple Spring MVC/Spring Security webapp. Initially I set up Spring Security so that the default login page shows and authenticates properly (I implemented the <code>UserDetailsService</code> with the <code>DaoAuthenticationProvider</code> to do this).</p>
  
  <p>Next step: replace the default spring login page with my login page and post the credentials.</p>
  
  <p><em><strong>But what do I do with the submitted login credentials?</em></strong> I assume I post the form to a controller, verify the credentials, but I'm not clear what the right step is after that. E.g.:</p>
  
  <ul>
  <li>Am I calling a method of AuthenticationManager?</li>
  <li>Do I need to define a bean for this? </li>
  <li>Is there an interface/service I need to implement like an AuthenticationEntryPoint or something?</li>
  </ul>
  
  <p>I've hit the docs 3 times over and don't quite follow them. I know this is dirt simple, so I just need to hear how the process should flow.</p>