How to deserialize JSON objects

Question

I'm trying to use the get request by:

  req = Net::HTTP::Get.new("/api/v1/users/external/1/features/DOWNLOAD7ab8d82b40/alloc?paymentPlanId=PRO_SUBSCRD725FCCCC6");
  req.add_field('ISV_API_KEY', '548f3d4b34ffdb2f294a870a9728af6940a75b66ba944d8ab6eef5a7543ca3db'); 
  req.add_field('ISV_API_SECRET', '69dafa8923f2b0da8153e6bcca3841de0fa88f1a031a5eb1946e54eb982cef48');                           

  res = Net::HTTP.start("localhost", 3000) {|http|
      res = http.request(req)
  }

'postman` is an application that shows me the result of this request

According to the postman, this request returns me:

{
"total":"1200.0",
"used":"35.0",
"available":1165.0
}

How can I deserialize this Json object? Assuming I want the "used" parameter.

I tried:

json_string = req2.to_json
puts json_string

but I got:

{"accept":["*/*"],"user-agent":["Ruby"],"isv_api_key":["548f3d4b34ffdb2f294a870a9728af6940a75b66ba944d8ab6eef5a7543ca3db"],"isv_api_secret":["69dafa8923f2b0da8153e6bcca3841de0fa88f1a031a5eb1946e54eb982cef48"]}

I also tried:

puts JSON.parse(res)

but I got:

can't convert Net::HTTPOK into String

Answer 1

Use Ruby's JSON library.

res = '{"total":"1200.0","used":"35.0","available":1165.0}'
JSON.parse(res) # => {"total"=>"1200.0", "used"=>"35.0", "available"=>1165.0}

Note: If you're on Ruby 1.8.X you may have to require the json class. Rails requires it for you if you are working within a rails app.