C9-Rails似乎正在运行-无法访问该应用

Question

无法访问我的ROR应用。

在c9工作区上，我启动ROR应用并获取此输出

`Array values in the parameter to 
`Gem.paths=` are deprecated.
Please use a String or nil.
An Array ({"GEM_PATH"=>["/usr/local/rvm/gems/ruby-2.3.4", "/usr/local/rvm/gems/ruby-2.3.4@global"]}) was passed in from bin/rails:3:in `load'
=> Booting WEBrick
=> Rails 4.2.3 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2018-07-02 22:39:12] INFO  WEBrick 1.3.1
[2018-07-02 22:39:12] INFO  ruby 2.3.4 (2017-03-30) [x86_64-linux]
[2018-07-02 22:39:12] INFO  WEBrick::HTTPServer#start: pid=1685 port=3000 '

但是，当我尝试使用http://localhost:3000访问该应用程序时 我收到此消息

This site can’t be reached
localhost refused to connect.
Did you mean http://localhost3000.org/?

应用似乎正在运行，但是我无法访问它。为什么？