使用Spring Security时获取当前登录的用户名

Question

Its a coupon system app using Spring security, spring MVC, now. when the app starts, I need to somehow initialize the current logged in user into the controller.

Issue is:

1. If I try to get the current user via SecurityContextHolder it is impossible because it seems like spring is initializing the controllers before the security so I cannot get it in the controller.

Is there anything I'm missing? a different approach of getting the current logged in user after he logs in?

Answer 1

What you need is called @AuthenticationPrincipal . You can inject it in controller method like this:

@GetMapping("/")
public void get(@AuthinticationPrincipal User user){ ... }

Here is documentation

Alternatively, you can create your own annotation and custom argument resolver, and inject whatever you want.

Answer 2

Solution 1: Principal principal

    @RequestMapping(value = {"/", ""})
    public String start(Principal principal, Model model) {
           String currentUser = principal.getName();       
           return currentUser;
    }

---

Solution 2: Authentication authentication

@RequestMapping(value = {"/", ""})
public String currentUserName(Authentication authentication) {
        return authentication.getName();
}

---

Solution 3: SecurityContextHolder

Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
if (principal instanceof UserDetails) {
  String username = ((UserDetails)principal).getUsername();
} else {
  String username = principal.toString();
}

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