gistfile1.txt

require 'net/http'
require 'rubygems'
require 'json'

params = {
  :context => {
    :country  => 'ALL',
    :language => 'ja'
  },
  :gadgets => [{
    :url      => 'http://matake.jp/smartfm/index.xml',
    :moduleId => 1
  }]
}

Net::HTTP.version_1_2
req = Net::HTTP::Post.new('/gadgets/metadata')
req.body = params.to_json

puts req.body

Net::HTTP.start('localhost', 8080) {|http|
  res = http.request(req)
  puts "--RESULT--"
  puts res.inspect, res.body
}