@PostMapping
    public String userSave(@RequestParam("userId") User user,
                           @RequestParam Map<String, String> form,
                           @RequestParam String username){
        System.out.println(user);
        user.setUsername(user.getUsername());
        Set<String> roles = Arrays.stream(Role.values()).map(Role::name).collect(Collectors.toSet());

        user.getRoles().clear();

        for (String key : form.keySet()){
            if(roles.contains(key)){
                user.getRoles().add(Role.valueOf(key));
            }
        }

        userRepo.save(user);
        return "redirect:/user";
    }
}