protected
  def authenticate_user!
    if user_signed_in?
      super
    else
      redirect_to login_path,:notice => 'if you want to add a notice'
      ## if you want render 404 page
      ## render :file => File.join(Rails.root,'public/404'),:formats => [:html],:status => 404,:layout => false
    end
  end

并且你可以在before_filter上调用这个方法,你想要的另一个控制器.

例如：

class HomesController < ApplicationController
  before_filter :authenticate_user!
  ## if you want spesific action for require authentication
  ## before_filter :authenticate_user!,:only => [:action1,:action2]
end

别忘了将login_path添加到routes.rb中

devise_scope :user do
  match '/sign-in' => "devise/sessions#new",:as => :login
end

注意：当我使用设备进行应用程序身份验证时,我总是使用这种方式(rails 3.2和rails 4.0.1)