title: Can @PathVariable return null if it's not found?
body: <p>Is it possible to make the <code>@PathVariable</code> to return null if the path variable is not in the url? Otherwise I need to make two handlers. One for <code>/simple</code> and another for <code>/simple/{game}</code>, but both do the same just if there is no game defined i pick first one from a list however if there is a game param defined then i use it.</p>
  
  <pre><code>@RequestMapping(value = {"/simple", "/simple/{game}"}, method = RequestMethod.GET)
  public ModelAndView gameHandler(@PathVariable("example") String example,
              HttpServletRequest request) {
  </code></pre>
  
  <p>And this is what I get when trying to open page <code>/simple</code>:</p>
  
  <blockquote>
    <p>Caused by: java.lang.IllegalStateException: Could not find @PathVariable [example] in @RequestMapping</p>
  </blockquote>