class ApplicationController < ActionController::Base
 protect_from_forgery
end

命名空间的应用程序控制器如下所示：

class Admin::ApplicationController < ApplicationController

def authenticate_admin!
 if current_admin.nil?
  redirect_to new_admin_session_url
 end
end

private

 def current_admin
  @current_admin ||= Admin.find(session[:admin_id]) if session[:admin_id]
 end

helper_method :current_admin
end

当我们使用before_filter“authenticate_admin！”时像这样：

class Admin::AssetsController < Admin::ApplicationController
  before_filter :authenticate_admin!
end

抛出“Admin :: AssetsController #new中的NoMethodError”.仅当我们在命名空间路由之前命中全局路由时才会发生这种情况.如果服务器重新启动并且加载了命名空间路由,则一切正常.