ruby-on-rails-3 – rails 3机架中间件问题,未定义方法`每个’

我想用机架中间件打印模板的主体.下面是我的设置……

#config/initializers/response_timer.rb
         class ResponseTimer
            def initialize(app)
                 @app = app
            end

            def call(env)
             status, headers, response = @app.call(env)
             [status, headers, response.body]
            end

         end  


       #application.rb file
       config.middleware.use "ResponseTimer"

当我提出请求domainname / students /我收到以下错误.

undefined method `each' for #<String:0xd69a2e0>

请帮助.

我通过将[status,headers,response.body]更改为[status,headers,[response.body]]来解决我自己的问题,将response.body放在数组中.