How do I parse JSON with Ruby on Rails? [duplicate]

I’m looking for a simple way to parse JSON, extract a value and write it into a database in Rails.

Specifically what I’m looking for, is a way to extract shortUrl from the JSON returned from the bit.ly API:

{
  "errorCode": 0,
  "errorMessage": "",
  "results":
  {
    "http://www.foo.com":
    {
       "hash": "e5TEd",
       "shortKeywordUrl": "",
       "shortUrl": "http://bit.ly/1a0p8G",
       "userHash": "1a0p8G"
    }
  },
  "statusCode": "OK"
}

And then take that shortUrl and write it into an ActiveRecord object associated with the long URL.

This is one of those things that I can think through entirely in concept and when I sit down to execute I realize I’ve got a lot to learn.