title: Missing header 'Authorization' of type [java.lang.String]
body: <p>I have a client app that communicates to the spring server with REST type calls using basic authentication.
  The controller method signature is below:</p>
  
  <pre><code>    @RequestMapping(value = "/REST/clients", method = RequestMethod.POST)
  protected ModelAndView postClients(@ModelAttribute("ClientsCommand") ClientsCommand cmd,
          @RequestHeader("Authorization") String credentials) throws IOException {
  ...
  }
  </code></pre>
  
  <p>The problem I have is that if no Authorization is present in the header I get an error:</p>
  
  <pre><code>Missing header 'Authorization' of type [java.lang.String]]
  </code></pre>
  
  <p>Whereas, I was kind of hoping the credentials string would just be empty. How do I stop the error from occurring and just receive a blank string if no authorization header entry was sent?</p>