一、resources
生成7个地址对应于7个controller#action，其中controller#update对于put和patch两种http请求。
resources :topics
二、命名空间
namespace :admin do
resources :topics
end
三、嵌套
resources :users do
resources :topics
end
四、添加更多的RESTful操作
resources :topics do
member do
post :upvote
end
end
resources :topics do
collection do
post :upvote
end
end
五、使用单个地址
resources :group, only: [:new, :show]
