String sign = signByFridemen(params,key);

    //3.添加参数sign
    params.put("sign", sign);

    //4.将参数转换为xml格式的字符串
    String requestXml = PayUtil.parseParams2Xml(params);

    System.out.println("请求的参数：" + requestXml);

    //5.以post方式请求获得结果
    String result = HttpUtils.doPost("https://api2.fridemen.com/pay/unifiedorder",requestXml);

    System