Amazonの商品データをrpaproxy経由で取ってくるサンプル

get_info_from_amazon.rb

require 'net/http'
require 'uri'
require 'timeout'

AMAZON_ECS_URL='http://rpaproxy.tdiary.org/rpaproxy/jp/'
SUBSCRIPTION_ID='xxxxxxxxxxxxxxxxxxxxxxxxxx'
API_VERSION='2007-01-17'

def amazon_fetch(url, limit = 10)
  raise ArgumentError, 'HTTP redirect too deep' if limit == 0

  res = Net::HTTP.get_response(URI::parse(url))
  case res
  when Net::HTTPSuccess
    res.body
  when Net::HTTPRedirection
    amazon_fetch(res['location'].untaint, limit - 1)
  else
    raise ArgumentError, res.error!
  end
end

def amazon_call(asin, id_type)
  aid = 'xxxxxxxxx'

  url = "#{AMAZON_ECS_URL}?Service=AWSECommerceService"
  url << "&SubscriptionId=#{SUBSCRIPTION_ID}"
  url << "&AssociateTag=#{aid}"
  url << "&Operation=ItemLookup"
  url << "&ItemId=#{asin}"
  url << "&IdType=#{id_type}"
  url << "&SearchIndex=Books" if id_type == 'ISBN'
  # url << "&ResponseGroup=Medium"
  # url << "&Version=#{API_VERSION}"
  begin
    Timeout.timeout(10) do
      amazon_fetch(url)
    end
  rescue ArgumentError
  end
end

xml = amazon_call('9784274050657', 'ISBN')
File.open('9784274050657.xml', 'wb') { |f| f.write(xml) }