Sprockets文件未找到例外

我正在为Rails尝试一些示例应用程序.我创建了一些控制器和页面.但是当我尝试访问其中一个时,我在网页上得到一个例外:

Sprockets::FileNotFound in Pages#home
Showing c:/railscode/test_app/app/views/layouts/application.html.erb
where line #6 raised:

couldn't find file 'jquery'
  (in c:/railscode/test_app/app/assets/javascripts/application.js:7)
Extracted source (around line #6):

    3:  
    4:    
    5:   <%= stylesheet_link_tag    "application" %> 
    6:   <%= javascript_include_tag "application" %> 
    7:   <%= csrf_meta_tags %> 8:  9: 

Rails.root:`c:/railscode/test_app`

我使用命令创建了一些控制器:

$ rails generate controller Pages home contact

  create  app/controllers/pages_controller.rb
   route  get "pages/contact"
   route  get "pages/home"
  invoke  erb
  create    app/views/pages
  create    app/views/pages/home.html.erb
  create    app/views/pages/contact.html.erb
  invoke  rspec
  create    spec/controllers/pages_controller_spec.rb
  create    spec/views/pages
  create    spec/views/pages/home.html.erb_spec.rb
  create    spec/views/pages/contact.html.erb_spec.rb
  invoke  helper
  create    app/helpers/pages_helper.rb
  invoke  rspec
  create     spec/helpers/pages_helper_spec.rb
  invoke  assets
  invoke    js
  create      app/assets/javascripts/pages.js
  invoke    css
  create      app/assets/stylesheets/pages.css

只是想知道问题出在哪里以及在哪里看？我通过URL访问该页面:http:// localhost:3000/pages/home

取消评论该行

//= require jquery

在application.js文件中,重新启动应用程序对我有用.

也有类似的问题,FileNotFound对twitter/bootstrap安装后http://metaskills.net/2011/09/26/less-is-more-using-twitter-bootstrap-in-the-rails-3-1-asset-pipeline/

我做了rake assets:clean assets:precompile,但那没有帮助.正如afaf12所建议的那样有助于重新启动rails应用程序.