新手，刚接触 rails。 路由器真很让我郁闷。。。

在 routes.rb

get "check" => "registrations#check"

添加路由。

然后

class RegistrationsController < Devise::RegistrationsController

类中有方法

def check
  ret = User.find_by_username(params[:user["email"]]);
  render  :text =>ret.to_json;
end

然后访问 http://localhost:3000/check

就一直提示：

AbstractController::ActionNotFound at /check
Could not find devise mapping for path "/check".
This may happen for two reasons:

1) You forgot to wrap your route inside the scope block. For example:

  devise_scope :user do
    get "/some/route" => "some_devise_controller"
  end

2) You are testing a Devise controller bypassing the router.
   If so, you can explicitly tell Devise which mapping to use:

   @request.env["devise.mapping"] = Devise.mappings[:user]

无法找到 action /check
———————————————— 谢谢。