Question

I’m using Spring Security 3 and Spring MVC 3.05.

I would like to print username of currently logged in user,how can I fetch UserDetails in my Controller?

@RequestMapping(value="/index.html", method=RequestMethod.GET)
    public ModelAndView indexView(){
         UserDetails user = ?
                mv.addObject("username", user.getUsername());
        ModelAndView mv = new ModelAndView("index");
        return mv;
    }   

Answer 1

If you already know for sure that the user is logged in (in your example if /index.html is protected):

UserDetails userDetails =
 (UserDetails)SecurityContextHolder.getContext().getAuthentication().getPrincipal();

To first check if the user is logged in, check that the current Authentication is not a AnonymousAuthenticationToken.

Authentication auth = SecurityContextHolder.getContext().getAuthentication();
if (!(auth instanceof AnonymousAuthenticationToken)) {
        // userDetails = auth.getPrincipal()
}