def page_execute_url(params)
      params = prepare_params(params)

      uri = URI(@url)
      uri.query = URI.encode_www_form(params)
      uri.to_s
    end
def page_execute_url(params)
      params = prepare_params(params)

      uri = URI(@url)
      uri.query = URI.encode_www_form(params)
      uri.to_s
    end
Generate a url that use to redirect user to Alipay payment page.

 Example:

   alipay_client.page_execute_url(
     method: 'alipay.trade.page.pay',
     biz_content: {
       out_trade_no: '20160401000000',
       product_code: 'FAST_INSTANT_TRADE_PAY',
       total_amount: '0.01',
       subject: 'test'
     }.to_json(ascii_only: true),
     timestamp: '2016-04-01 00:00:00'
   )
   # => 'https://openapi.alipaydev.com/gateway.do?app_id=2016...'