基于nodejs实现微信支付功能

<xml> 
  <return_code><![CDATA[<%-return_code%>]]></return_code> 
  <return_msg><![CDATA[<%=return_msg%>]]></return_msg> 
</xml> 

var config = require('../config'); ／／配置文件 appid 等信息 
var Q = require("q"); 
var request = require("request"); 
var crypto = require('crypto'); 
var ejs = require('ejs'); 
var fs = require('fs'); 
var key = "此处为申请微信支付的API密码"; 
var messageTpl = fs.readFileSync(__dirname + '/message.ejs', 'utf-8'); 
 
var WxPay = { 
  getXMLNodeValue: function(node_name, xml) { 
    var tmp = xml.split("<" + node_name + ">"); 
    var _tmp = tmp[1].split("</" + node_name + ">"); 
    return _tmp[0]; 
  }, 
 
  raw: function(args) { 
    var keys = Object.keys(args); 
    keys = keys.sort() 
    var newArgs = {}; 
    keys.forEach(function(key) { 
      newArgs[key] = args[key]; 
    }); 
    var string = ''; 
    for (var k in newArgs) { 
      string += '&' + k + '=' + newArgs[k]; 
    } 
    string = string.substr(1); 
    return string; 
  }, 
 
  paysignjs: function(appid, nonceStr, package, signType, timeStamp) { 
    var ret = { 
      appId: appid, 
      nonceStr: nonceStr, 
      package: package, 
      signType: signType, 
      timeStamp: timeStamp 
    }; 
    var string = this.raw(ret); 
    string = string + '&key=' + key; 
    var sign = crypto.createHash('md5').update(string, 'utf8').digest('hex'); 
    return sign.toUpperCase(); 
  }, 
 
  paysignjsapi: function(appid, attach, body, mch_id, nonce_str, notify_url, openid, out_trade_no, spbill_create_ip, total_fee, trade_type) { 
    var ret = { 
      appid: appid, 
      attach: attach, 
      body: body, 
      mch_id: mch_id, 
      nonce_str: nonce_str, 
      notify_url: notify_url, 
      openid: openid, 
      out_trade_no: out_trade_no, 
      spbill_create_ip: spbill_create_ip, 
      total_fee: total_fee, 
      trade_type: trade_type 
    }; 
    var string = this.raw(ret); 
    string = string + '&key=' + key; //key为在微信商户平台(pay.weixin.qq.com)-->账户设置-->API安全-->密钥设置 
    var crypto = require('crypto'); 
    var sign = crypto.createHash('md5').update(string, 'utf8').digest('hex'); 
    return sign.toUpperCase(); 
  }, 
 
  // 随机字符串产生函数 
  createNonceStr: function() { 
    return Math.random().toString(36).substr(2, 15); 
  }, 
 
  // 时间戳产生函数 
  createTimeStamp: function() { 
    return parseInt(new Date().getTime() / 1000) + ''; 
  },