我在注册后使用以下方法进行程序化登录

private void autoLogin(User user,
            HttpServletRequest request)
    {

GrantedAuthority[] grantedAuthorities = new GrantedAuthority[] { new GrantedAuthorityImpl(
                "ROLE_ADMIN") };

        UsernamePasswordAuthenticationToken token = new UsernamePasswordAuthenticationToken(
                user.getUsername(), user.getPassword(),grantedAuthorities);

        // generate session if one doesn't exist
        request.getSession();

        token.setDetails(new WebAuthenticationDetails(request));
        Authentication authenticatedUser = authenticationManager.authenticate(token);

        SecurityContextHolder.getContext().setAuthentication(authenticatedUser);
    }

用户已通过身份验证，但始终具有ROLE_ANONYMOUS我不知道为什么？有任何想法吗 ？