问题是 json.这解决了我的问题.无论如何，我的问题不清楚，所以赏金去了Juri

The problem it was a json. This solve my problem. Anyway, my question was not clear, so the bounty goes to Juri

require 'uri'
require 'net/http'
require 'net/https'
require 'json'

@toSend = {
    "date" => "2012-07-02",
    "aaaa" => "bbbbb",
    "cccc" => "dddd"
}.to_json

uri = URI.parse("https:/...")
https = Net::HTTP.new(uri.host,uri.port)
https.use_ssl = true
req = Net::HTTP::Post.new(uri.path, initheader = {'Content-Type' =>'application/json'})
req['foo'] = 'bar'
req.body = "[ #{@toSend} ]"
res = https.request(req)
puts "Response #{res.code} #{res.message}: #{res.body}"