Gemfile

source 'https://rubygems.org'
gem 'httpclient'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    httpclient (2.3.4.1)

PLATFORMS
  ruby

DEPENDENCIES
  httpclient

sample.rb

# coding: utf-8

require 'httpclient'
require 'json'

begin
  httpClient = HTTPClient.new
  data = httpClient.get_content('https://app.rakuten.co.jp/services/api/IchibaItem/Search/20130805', {
    'applicationId' => '1025899060325418115',
    'affiliateId'   => '0dd78f8a.26c4c8c0.0dd78f8b.0ee811d2',
    'keyword'       => 'うどん'
  })
  jsonData = JSON.parse data


  jsonData['Items'].each do | itemData |
    item = itemData['Item']

    p "#{item['itemName']} #{item['itemPrice']}円"
  end
rescue HTTPClient::BadResponseError => e
  p e.res.code # Error Code
  p e.res.body # Body
rescue HTTPClient::TimeoutError => e
  p "Timeout Error"
end