微信小程序支付以及微信退款开发

最近公司项目急着测试，需要开发微信小程序+微信支付+微信退款，本着这几天的一些研究，决定记录一下开发的过程。

本着知识分享的原则，希望对大家有所帮助。

本篇针对的是微信小程序的支付开发，如果有对微信公众号的支付开发需要的，可以去我的github上看看，有个sell的项目很好的完成了公众号方面的支付与退款，代码很全，用的是最优秀的sdk，肯定对你们学习和工作有帮助，下面贴一下github链接： https://github.com/wenbingshen/springboot

也可以关注我的微信公众号：《小沈干货》不迷路。

废话不多说，开始我们的小程序支付开发之旅：

首先呢，开发之前，需要交代的是，有关微信支付的开发需要有自己的商户号和密钥，这在微信支付开发文档上面讲的很清楚，有过支付开发经验的对这一点很清楚。

了解了上面的情况后咱们就开始着手开发吧！

先编写一个常量类Constant，将有关的配置常量配在里面：

public class Constant {

    public static final String DOMAIN = "http://sellbin.natapp1.cc";//配置自己的域名

    public static final String APP_ID = "填写自己的";

    public static final String APP_SECRET = "填写自己的";

    public static final String APP_KEY = "填写自己的";

    public static final String MCH_ID = "填写自己的";  //商户号

    public static final String URL_UNIFIED_ORDER = "https://api.mch.weixin.qq.com/pay/unifiedorder";

    public static final String URL_NOTIFY = Constant.DOMAIN + "/wxpay/views/payInfo.jsp";

    public static final String TIME_FORMAT = "yyyyMMddHHmmss";

    public static final int TIME_EXPIRE = 2;  //单位是day

}

支付的时候，我们需要利用发起支付的用户code去微信接口获取用户的openid，只有得到了openid才能去申请预付单获得prepayId，然后去唤起微信支付。

微信支付文档上面也写的很清楚：

接下来我们编写PayController类去调用微信支付的接口:

package luluteam.wxpay.controller;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import luluteam.wxpay.constant.Constant;
import luluteam.wxpay.entity.PayInfo;
import luluteam.wxpay.util.*;
import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import org.codehaus.jackson.map.ObjectMapper;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import java.util.*;

@Controller
public class PayController {

    private static Logger log = Logger.getLogger(PayController.class);

    @ResponseBody
    @RequestMapping(value = "/prepay", produces = "text/html;charset=UTF-8")
    public String prePay(String code, ModelMap model, HttpServletRequest request) {

        System.out.println("code:"+code);
        String content = null;
        Map map = new HashMap();
        ObjectMapper mapper = new ObjectMapper();

        boolean result = true;
        String info = "";

        log.error("\n======================================================");
        log.error("code: " + code);

        String openId = getOpenId(code);
        System.out.println("获取openid啊"+openId);
        if(StringUtils.isBlank(openId)) {
            result = false;
            info = "获取到openId为空";
        } else {
            openId = openId.replace("\"", "").trim();

            String clientIP = CommonUtil.getClientIp(request);

            log.error("openId: " + openId + ", clientIP: " + clientIP);

            String randomNonceStr = RandomUtils.generateMixString(32);
            String prepayId = unifiedOrder(openId, clientIP, randomNonceStr);

            log.error("prepayId: " + prepayId);

            if(StringUtils.isBlank(prepayId)) {
                result = false;
                info = "出错了，未获取到prepayId";
            } else {
                map.put("prepayId", prepayId);
                map.put("nonceStr", randomNonceStr);
            }
        }

        try {
            map.put("result", result);
            map.put("info", info);
            content = mapper.writeValueAsString(map);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return content;
    }

    private String getOpenId(String code) {
        String url = "https://api.weixin.qq.com/sns/jscode2session?appid=" + Constant.APP_ID +
                "&secret=" + Constant.APP_SECRET + "&js_code=" + code + "&grant_type=authorization_code";

        HttpUtil httpUtil = new HttpUtil();
        try {

            HttpResult httpResult = httpUtil.doGet(url, null, null);

            if(httpResult.getStatusCode() == 200) {

                JsonParser jsonParser = new JsonParser();
                JsonObject obj = (JsonObject) jsonParser.parse(httpResult.getBody());

                log.error("getOpenId: " + obj.toString());

                if(obj.get("errcode") != null) {
                    log.error("getOpenId returns errcode: " + obj.get("errcode"));
                    return "";
                } else {
                    return obj.get("openid").toString();
                }
                //return httpResult.getBody();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    /**
     * 调用统一下单接口
     * @param openId
     */
    private String unifiedOrder(String openId, String clientIP, String randomNonceStr) {

        try {

            String url = Constant.URL_UNIFIED_ORDER;

            PayInfo payInfo = createPayInfo(openId, clientIP, randomNonceStr);
            String md5 = getSign(payInfo);
            payInfo.setSign(md5);

            log.error("md5 value: " + md5);

            String xml = CommonUtil.payInfoToXML(payInfo);
            xml = xml.replace("__", "_").replace("<![CDATA[1]]>", "1");
            //xml = xml.replace("__", "_").replace("<![CDATA[", "").replace("]]>", "");
            log.error(xml);

            StringBuffer buffer = HttpUtil.httpsRequest(url, "POST", xml);
            log.error("unifiedOrder request return body: \n" + buffer.toString());
            Map<String, String> result = CommonUtil.parseXml(buffer.toString());

            String return_code = result.get("return_code");
            if(StringUtils.isNotBlank(return_code) && return_code.equals("SUCCESS")) {

                String return_msg = result.get("return_msg");
                if(StringUtils.isNotBlank(return_msg) && !return_msg.equals("OK")) {
                    //log.error("统一下单错误！");
                    return "";
                }

                String prepay_Id = result.get("prepay_id");
                return prepay_Id;

            } else {
                return "";
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return "";
    }

    private PayInfo createPayInfo(String openId, String clientIP, String randomNonceStr) {

        Date date = new Date();
        String timeStart = TimeUtils.getFormatTime(date, Constant.TIME_FORMAT);
        String timeExpire = TimeUtils.getFormatTime(TimeUtils.addDay(date, Constant.TIME_EXPIRE), Constant.TIME_FORMAT);

        String randomOrderId = CommonUtil.getRandomOrderId();

        PayInfo payInfo = new PayInfo();
        payInfo.setAppid(Constant.APP_ID);
        payInfo.setMch_id(Constant.MCH_ID);
        payInfo.setDevice_info("WEB");
        payInfo.setNonce_str(randomNonceStr);
        payInfo.setSign_type("MD5");  //默认即为MD5
        payInfo.setBody("JSAPI支付测试");
        payInfo.setAttach("支付测试4luluteam");
        payInfo.setOut_trade_no(randomOrderId);
        payInfo.setTotal_fee(1);
        payInfo.setSpbill_create_ip(clientIP);
        payInfo.setTime_start(timeStart);
        payInfo.setTime_expire(timeExpire);
        payInfo.setNotify_url(Constant.URL_NOTIFY);
        payInfo.setTrade_type("JSAPI");
        payInfo.setLimit_pay("no_credit");
        payInfo.setOpenid(openId);

        return payInfo;
    }

    private String getSign(PayInfo payInfo) throws Exception {
        StringBuffer sb = new StringBuffer();
        sb.append("appid=" + payInfo.getAppid())
                .append("&attach=" + payInfo.getAttach())
                .append("&body=" + payInfo.getBody())
                .append("&device_info=" + payInfo.getDevice_info())
                .append("&limit_pay=" + payInfo.getLimit_pay())
                .append("&mch_id=" + payInfo.getMch_id())
                .append("&nonce_str=" + payInfo.getNonce_str())
                .append("&notify_url=" + payInfo.getNotify_url())
                .append("&openid=" + payInfo.getOpenid())
                .append("&out_trade_no=" + payInfo.getOut_trade_no())
                .append("&sign_type=" + payInfo.getSign_type())
                .append("&spbill_create_ip=" + payInfo.getSpbill_create_ip())
                .append("&time_expire=" + payInfo.getTime_expire())
                .append("&time_start=" + payInfo.getTime_start())
                .append("&total_fee=" + payInfo.getTotal_fee())
                .append("&trade_type=" + payInfo.getTrade_type())
                .append("&key=" + Constant.APP_KEY);

        log.error("排序后的拼接参数：" + sb.toString());

        return CommonUtil.getMD5(sb.toString().trim()).toUpperCase();
    }

}

小程序端通过wx.request发起网络请求，通过服务器发起预支付，获取prepayId以及其他支付需要签名的参数后，利用wx.requestPayment发起支付。

// 1. 完成页面结构、布局、样式
// 2. 设计数据结构
// 3. 完成数据绑定
// 4. 设计交互操作事件
// 5. 数据存储
var app = getApp()   //实例化小程序，从而获取全局数据或者使用全局函数
// console.log(app.globalData)
var MD5Util = require('../../utils/md5.js');

Page({
  // ===== 页面数据对象 =====
  data: {
    input: '',
    todos: [],
    leftCount: 0,
    allCompleted: false,
    logs: [],
    price: 0.01,
    number: 18820000000,
    deviceNo: 10080925
  },

  // ===== 页面生命周期方法 =====
  onLoad: function () {

  },
  // ===== 事件处理函数 =====
  wxPay: function (e) {
    var code = ''     //传给服务器以获得openId
    var timestamp = String(Date.parse(new Date()))   //时间戳
    var nonceStr = ''   //随机字符串，后台返回
    var prepayId = ''    //预支付id，后台返回
    var paySign = ''     //加密字符串

    //获取用户登录状态
    wx.login({
      success: function (res) {
        if (res.code) {
          code = res.code
          //发起网络请求,发起的是HTTPS请求，向服务端请求预支付
          wx.request({
            url: 'http://sellbin.natapp1.cc/prepay',
            data: {
              code: res.code
            },
            success: function (res) {
              console.log(res.data);
              if (res.data.result == true) {
                nonceStr = res.data.nonceStr
                prepayId = res.data.prepayId
                // 按照字段首字母排序组成新字符串
                var payDataA = "appId=" + app.globalData.appId + "&nonceStr=" + res.data.nonceStr + "&package=prepay_id=" + res.data.prepayId + "&signType=MD5&timeStamp=" + timestamp;
                var payDataB = payDataA + "&key=" + app.globalData.key;
                // 使用MD5加密算法计算加密字符串
                paySign = MD5Util.MD5(payDataB).toUpperCase();
                // 发起微信支付
                wx.requestPayment({
                  'timeStamp': timestamp,
                  'nonceStr': nonceStr,
                  'package': 'prepay_id=' + prepayId,
                  'signType': 'MD5',
                  'paySign': paySign,
                  'success': function (res) {
                    // 保留当前页面，跳转到应用内某个页面，使用wx.nevigeteBack可以返回原页面
                    wx.navigateTo({
                      url: '../pay/pay'
                    })
                  },
                  'fail': function (res) {
                    console.log(res.errMsg)
                  }
                })
              } else {
                console.log('请求失败' + res.data.info)
              }
            }
          })
        } else {
          console.log('获取用户登录态失败！' + res.errMsg)
        }
      }
    });
  },
   formSubmit: function (e) {
    console.log('form发生了submit事件，携带数据为：', e.detail.value)
  },
  formReset: function () {
    console.log('form发生了reset事件')
  }
})

接下来，我们贴一下微信退款相关的代码RefundController

package luluteam.wxpay.controller;

import luluteam.wxpay.constant.Constant;
import luluteam.wxpay.entity.WxRefundInfoEntity;
import luluteam.wxpay.service.WxRefundInfoService;
import luluteam.wxpay.util.common.PayUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import java.text.DecimalFormat;
import java.util.*;

@Controller
public class RefundController extends HttpServlet {

    private static Logger log = Logger.getLogger(PayController.class);

    @Autowired
    private WxRefundInfoService wxRefundInfoService;

    @RequestMapping(params = "refund", method = RequestMethod.POST)
    @Transactional
    public @ResponseBody
    Map<String, Object> refund(String openid, String orderId, HttpServletRequest request) {
        Map<String, Object> result = new HashMap<String, Object>();
        String currTime = PayUtils.getCurrTime();
        String strTime = currTime.substring(8, currTime.length());
        String strRandom = PayUtils.buildRandom(4) + "";
        String nonceStr = strTime + strRandom;
        String outRefundNo = "wx@re@" + PayUtils.getTimeStamp();
        String outTradeNo = "";
        String transactionId = "";

        String unionId = openid;
        String appid = Constant.APP_ID;
        String mchid = Constant.MCH_ID;
        String key =  Constant.APP_KEY;//mch_key
//        String key = ResourceUtil.getConfigByName("wx.application.mch_key");
        if (StringUtils.isNotEmpty(orderId)) {
            int total_fee = 1;
            //商户侧传给微信的订单号32位
            outTradeNo = "115151sdasdsadsadsadas";
            DecimalFormat df = new DecimalFormat("0.00");
            //String fee = String.valueOf(df.format((float)total_fee/100));
            String fee = String.valueOf(total_fee);
            SortedMap<String, String> packageParams = new TreeMap<String, String>();
            packageParams.put("appid", appid);
            packageParams.put("mch_id", mchid);//微信支付分配的商户号
            packageParams.put("nonce_str", nonceStr);//随机字符串，不长于32位
            packageParams.put("op_user_id", mchid);//操作员帐号, 默认为商户号
            //out_refund_no只能含有数字、字母和字符_-|*@
            packageParams.put("out_refund_no", outRefundNo);//商户系统内部的退款单号，商户系统内部唯一，同一退款单号多次请求只退一笔
            packageParams.put("out_trade_no", outTradeNo);//商户侧传给微信的订单号32位
            packageParams.put("refund_fee", fee);
            packageParams.put("total_fee", fee);
            packageParams.put("transaction_id", transactionId);//微信生成的订单号，在支付通知中有返回
            String sign = PayUtils.createSign(packageParams, key);

            String refundUrl = "https://api.mch.weixin.qq.com/secapi/pay/refund";
            String xmlParam = "<xml>" +
                    "<appid>" + appid + "</appid>" +
                    "<mch_id>" + mchid + "</mch_id>" +
                    "<nonce_str>" + nonceStr + "</nonce_str>" +
                    "<op_user_id>" + mchid + "</op_user_id>" +
                    "<out_refund_no>" + outRefundNo + "</out_refund_no>" +
                    "<out_trade_no>" + outTradeNo + "</out_trade_no>" +
                    "<refund_fee>" + fee + "</refund_fee>" +
                    "<total_fee>" + fee + "</total_fee>" +
                    "<transaction_id>" + transactionId + "</transaction_id>" +
                    "<sign>" + sign + "</sign>" +
                    "</xml>";
            log.info("---------xml返回:" + xmlParam);
            String resultStr = PayUtils.post(refundUrl, xmlParam);
            log.info("---------退款返回:" + resultStr);
            //解析结果
            try {
                Map map = PayUtils.doXMLParse(resultStr);
                String returnCode = map.get("return_code").toString();
                if (returnCode.equals("SUCCESS")) {
                    String resultCode = map.get("result_code").toString();
                    if (resultCode.equals("SUCCESS")) {
                        //保存退款记录,可在数据库建一个退款表记录
                        WxRefundInfoEntity refundInfoEntity = new WxRefundInfoEntity();
                        refundInfoEntity.setCreateDate(new Date());
                        refundInfoEntity.setAppid(appid);
                        refundInfoEntity.setMchId(mchid);
                        refundInfoEntity.setNonceStr(nonceStr);
                        refundInfoEntity.setSign(sign);
                        refundInfoEntity.setOutRefundNo(outRefundNo);
                        refundInfoEntity.setOutTradeNo(outTradeNo);
                        refundInfoEntity.setTotalFee(total_fee);
                        refundInfoEntity.setRefundFee(total_fee);
                        refundInfoEntity.setUnionid(unionId);
                        wxRefundInfoService.save(refundInfoEntity);
                        result.put("status", "success");
                    } else {
                        result.put("status", "fail");
                    }
                } else {
                    result.put("status", "fail");
                }
            } catch (Exception e) {
                e.printStackTrace();
                result.put("status", "fail");
            }
        }
        return result;
    }
}

支付与退款有关的工具类和实体类一并贴在下面，如果有不清楚的，可以去我的github上面下载源码：

https://github.com/wenbingshen/wechatpay

entity包：

package luluteam.wxpay.entity;

import java.io.Serializable;

public class PayInfo implements Serializable {

    private String appid;
    private String mch_id;
    private String device_info; //设备号，小程序传"WEB"
    private String nonce_str;
    private String sign;
    private String sign_type;  //签名类型
    private String body;
    //private String detail;
    private String attach;
    private String out_trade_no;
    private int total_fee;
    private String spbill_create_ip;
    private String time_start;
    private String time_expire;
    private String notify_url;
    private String trade_type; //交易类型,JSAPI
    private String limit_pay;  //指定支付方式，no_credit
    private String openid;

    public String getAppid() {
        return appid;
    }

    public void setAppid(String appid) {
        this.appid = appid;
    }

    public String getMch_id() {
        return mch_id;
    }

    public void setMch_id(String mch_id) {
        this.mch_id = mch_id;
    }

    public String getDevice_info() {
        return device_info;
    }

    public void setDevice_info(String device_info) {
        this.device_info = device_info;
    }

    public String getNonce_str() {
        return nonce_str;
    }

    public void setNonce_str(String nonce_str) {
        this.nonce_str = nonce_str;
    }

    public String getSign() {
        return sign;
    }

    public void setSign(String sign) {
        this.sign = sign;
    }

    public String getSign_type() {
        return sign_type;
    }

    public void setSign_type(String sign_type) {
        this.sign_type = sign_type;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    public String getAttach() {
        return attach;
    }

    public void setAttach(String attach) {
        this.attach = attach;
    }

    public String getOut_trade_no() {
        return out_trade_no;
    }

    public void setOut_trade_no(String out_trade_no) {
        this.out_trade_no = out_trade_no;
    }

    public int getTotal_fee() {
        return total_fee;
    }

    public void setTotal_fee(int total_fee) {
        this.total_fee = total_fee;
    }

    public String getSpbill_create_ip() {
        return spbill_create_ip;
    }

    public void setSpbill_create_ip(String spbill_create_ip) {
        this.spbill_create_ip = spbill_create_ip;
    }

    public String getTime_start() {
        return time_start;
    }

    public void setTime_start(String time_start) {
        this.time_start = time_start;
    }

    public String getTime_expire() {
        return time_expire;
    }

    public void setTime_expire(String time_expire) {
        this.time_expire = time_expire;
    }

    public String getNotify_url() {
        return notify_url;
    }

    public void setNotify_url(String notify_url) {
        this.notify_url = notify_url;
    }

    public String getTrade_type() {
        return trade_type;
    }

    public void setTrade_type(String trade_type) {
        this.trade_type = trade_type;
    }

    public String getLimit_pay() {
        return limit_pay;
    }

    public void setLimit_pay(String limit_pay) {
        this.limit_pay = limit_pay;
    }

    public String getOpenid() {
        return openid;
    }

    public void setOpenid(String openid) {
        this.openid = openid;
    }
}

WxRefundInfoEntity类，用来退款后向数据添加退款的记录，方面查账：

package luluteam.wxpay.entity;

import javax.persistence.Entity;
import java.io.Serializable;
import java.util.Date;

@Entity
public class WxRefundInfoEntity implements Serializable {
    private Date createDate;

    private String appid;

    private String mchId;

    private String nonceStr;

    private String sign;

    private String outRefundNo;

    private String outTradeNo;

    private int totalFee;

    private int refundFee;

    private String unionid;

    public Date getCreateDate() {
        return createDate;
    }

    public void setCreateDate(Date createDate) {
        this.createDate = createDate;
    }

    public String getAppid() {
        return appid;
    }

    public void setAppid(String appid) {
        this.appid = appid;
    }

    public String getMchId() {
        return mchId;
    }

    public void setMchId(String mchId) {
        this.mchId = mchId;
    }

    public String getNonceStr() {
        return nonceStr;
    }

    public void setNonceStr(String nonceStr) {
        this.nonceStr = nonceStr;
    }

    public String getSign() {
        return sign;
    }

    public void setSign(String sign) {
        this.sign = sign;
    }

    public String getOutRefundNo() {
        return outRefundNo;
    }

    public void setOutRefundNo(String outRefundNo) {
        this.outRefundNo = outRefundNo;
    }

    public String getOutTradeNo() {
        return outTradeNo;
    }

    public void setOutTradeNo(String outTradeNo) {
        this.outTradeNo = outTradeNo;
    }

    public int getTotalFee() {
        return totalFee;
    }

    public void setTotalFee(int totalFee) {
        this.totalFee = totalFee;
    }

    public int getRefundFee() {
        return refundFee;
    }

    public void setRefundFee(int refundFee) {
        this.refundFee = refundFee;
    }

    public String getUnionid() {
        return unionid;
    }

    public void setUnionid(String unionid) {
        this.unionid = unionid;
    }
}

util包：

package luluteam.wxpay.util.common;

import java.security.MessageDigest;

public class MD5 {
    private final static String[] hexDigits = {"0", "1", "2", "3", "4", "5", "6", "7",
            "8", "9", "a", "b", "c", "d", "e", "f"};

    /**
     * 转换字节数组为16进制字串
     * @param b 字节数组
     * @return 16进制字串
     */
    public static String byteArrayToHexString(byte[] b) {
        StringBuilder resultSb = new StringBuilder();
        for (byte aB : b) {
            resultSb.append(byteToHexString(aB));
        }
        return resultSb.toString();
    }

    /**
     * 转换byte到16进制
     * @param b 要转换的byte
     * @return 16进制格式
     */
    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n = 256 + n;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    /**
     * MD5编码
     * @param origin 原始字符串
     * @return 经过MD5加密之后的结果
     */
    public static String MD5Encode(String origin) {
        String resultString = null;
        try {
            resultString = origin;
            MessageDigest md = MessageDigest.getInstance("MD5");
            resultString = byteArrayToHexString(md.digest(resultString.getBytes("utf-8")));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return resultString;
    }

}

package luluteam.wxpay.util.common;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.KeyStore;
import java.security.MessageDigest;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;

import javax.net.ssl.SSLContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import luluteam.wxpay.constant.Constant;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContexts;
import org.apache.http.util.EntityUtils;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;

@SuppressWarnings("deprecation")
public class PayUtils {
    private static Object Server;
    @SuppressWarnings("deprecation")
    public static DefaultHttpClient httpclient;
    private static SortedMap parameters;

    static {
        httpclient = new DefaultHttpClient();
        // httpclient = (DefaultHttpClient) HttpClientConnectionManager.getSSLInstance(httpclient);
        parameters = new TreeMap();
    }

    public static final String KEY_PATH = "E:/wxzf/cert/apiclient_cert.p12";

    /**
     * 把对象转换成字符串
     *
     * @param obj
     * @return String 转换成字符串,若对象为null,则返回空字符串.
     */
    public static String toString(Object obj) {
        if (obj == null)
            return "";

        return obj.toString();
    }

    /**
     * 把对象转换为int数值.
     *
     * @param obj
     *            包含数字的对象.
     * @return int 转换后的数值,对不能转换的对象返回0。
     */
    public static int toInt(Object obj) {
        int a = 0;
        try {
            if (obj != null) {
                a = Integer.parseInt(obj.toString());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return a;
    }

    /**
     * 获取从1970年开始到现在的秒数
     *
     * @param
     * @return
     */
    public static String getTimeStamp() {
        long seconds = System.currentTimeMillis() / 1000;
        return String.valueOf(seconds);
    }

    /**
     * 获取当前时间 yyyyMMddHHmmss
     * @return String
     */
    public static String getCurrTime() {
        Date now = new Date();
        SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss");
        String s = outFormat.format(now);
        return s;
    }

    /**
     * 获取当前日期 yyyyMMdd
     * @param date
     * @return String
     */
    public static String formatDate(Date date) {
        SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd");
        String strDate = formatter.format(date);
        return strDate;
    }

    /**
     * 取出一个指定长度大小的随机正整数.
     * @param length  int 设定所取出随机数的长度。length小于11
     * @return int 返回生成的随机数。
     */
    public static int buildRandom(int length) {
        int num = 1;
        double random = Math.random();
        if (random < 0.1) {
            random = random + 0.1;
        }
        for (int i = 0; i < length; i++) {
            num = num * 10;
        }
        return (int) ((random * num));
    }

    /**
     * 获取编码字符集
     * @param request
     * @param response
     * @return String
     */

    public static String getCharacterEncoding(HttpServletRequest request, HttpServletResponse response) {

        if (null == request || null == response) {
            return "utf-8";
        }
        String enc = request.getCharacterEncoding();
        if (null == enc || "".equals(enc)) {
            enc = response.getCharacterEncoding();
        }
        if (null == enc || "".equals(enc)) {
            enc = "utf-8";
        }
        return enc;
    }

    public static String URLencode(String content) {
        String URLencode;
        URLencode = replace(Server.equals(content), "+", "%20");
        return URLencode;
    }

    private static String replace(boolean equals, String string, String string2) {
        return null;
    }

    /**
     * 获取unix时间，从1970-01-01 00:00:00开始的秒数
     * @param date
     * @return long
     */
    public static long getUnixTime(Date date) {
        if (null == date) {
            return 0;
        }
        return date.getTime() / 1000;
    }

    public static String QRfromGoogle(String chl) {
        int widhtHeight = 300;
        String EC_level = "L";
        int margin = 0;
        String QRfromGoogle;
        chl = URLencode(chl);
        QRfromGoogle = "http://chart.apis.google.com/chart?chs=" + widhtHeight + "x" + widhtHeight + "&cht=qr&chld="
                + EC_level + "|" + margin + "&chl=" + chl;
        return QRfromGoogle;
    }

    /**
     * 时间转换成字符串
     * @param date  时间
     * @param formatType  格式化类型
     * @return String
     */
    public static String date2String(Date date, String formatType) {
        SimpleDateFormat sdf = new SimpleDateFormat(formatType);
        return sdf.format(date);
    }

    /**
     * 创建签名SHA1
     * @param signParams
     * @return
     * @throws Exception
     */
    public static String createSHA1Sign(SortedMap<String, String> signParams) throws Exception {
        StringBuffer sb = new StringBuffer();
        Set es = signParams.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            sb.append(k + "=" + v + "&");
            // 要采用URLENCODER的原始值！
        }
        String params = sb.substring(0, sb.lastIndexOf("&"));
        return getSha1(params);
    }

    /**
     * Sha1签名
     * @param str
     * @return
     */
    public static String getSha1(String str) {
        if (str == null || str.length() == 0) {
            return null;
        }
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
        try {
            MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
            mdTemp.update(str.getBytes("UTF-8"));

            byte[] md = mdTemp.digest();
            int j = md.length;
            char buf[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
                buf[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(buf);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 获得预支付订单号
     * @param url
     * @param xmlParam
     * @return
     */
    public static String getPayNo(String url, String xmlParam) {
        String prepay_id = "";
        try {
            String jsonStr = postWithXmlParams(url, xmlParam);
            if (jsonStr.indexOf("FAIL") != -1) {
                return prepay_id;
            }
            Map<String, Object> map = doXMLParse(jsonStr);
            prepay_id = (String) map.get("prepay_id");
            System.out.println("prepay_id:" + prepay_id);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return prepay_id;
    }

    /**
     * 发送请求
     * @param url 请求路径
     * @param xmlParams xml字符串
     * @return
     */
    public static String postWithXmlParams(String url, String xmlParams) {
        HttpPost httpost = new HttpPost(url);
        try {
            httpost.setEntity(new StringEntity(xmlParams, "UTF-8"));
            HttpResponse response = httpclient.execute(httpost);
            return EntityUtils.toString(response.getEntity(), "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
    }

    /**
     * 解析xml,返回第一级元素键值对。如果第一级元素有子节点，则此节点的值是子节点的xml数据。
     * @param strxml
     * @return
     * @throws IOException
     */
    public static Map doXMLParse(String strxml) throws Exception {
        if (null == strxml || "".equals(strxml)) {
            return null;
        }
        Map m = new HashMap();
        InputStream in = String2Inputstream(strxml);
        SAXBuilder builder = new SAXBuilder();
        Document doc = builder.build(in);
        Element root = doc.getRootElement();
        List list = root.getChildren();
        Iterator it = list.iterator();
        while (it.hasNext()) {
            Element e = (Element) it.next();
            String k = e.getName();
            String v = "";
            List children = e.getChildren();
            if (children.isEmpty()) {
                v = e.getTextNormalize();
            } else {
                v = PayUtils.getChildrenText(children);
            }
            m.put(k, v);
        }
        // 关闭流
        in.close();
        return m;
    }

    /**
     * 获取子结点的xml
     * @param children
     * @return String
     */
    public static String getChildrenText(List children) {
        StringBuffer sb = new StringBuffer();
        if(!children.isEmpty()) {
            Iterator it = children.iterator();
            while(it.hasNext()) {
                Element e = (Element) it.next();
                String name = e.getName();
                String value = e.getTextNormalize();
                List list = e.getChildren();
                sb.append("<" + name + ">");
                if(!list.isEmpty()) {
                    sb.append(PayUtils.getChildrenText(list));
                }
                sb.append(value);
                sb.append("</" + name + ">");
            }
        }

        return sb.toString();
    }

    public static InputStream String2Inputstream(String str) {
        return new ByteArrayInputStream(str.getBytes());
    }

    public String getParameter(String parameter) {
        String s = (String) this.parameters.get(parameter);
        return (null == s) ? "" : s;
    }

    /**
     * 特殊字符处理
     * @param src
     * @return
     * @throws UnsupportedEncodingException
     */
    public String UrlEncode(String src) throws UnsupportedEncodingException {
        return URLEncoder.encode(src, "UTF-8").replace("+", "%20");
    }

    /**
     * 获取package的签名包
     * @param packageParams
     * @param key
     * @return
     * @throws UnsupportedEncodingException
     */
    public String genPackage(SortedMap<String, String> packageParams, String key) throws UnsupportedEncodingException {
        String sign = createSign(packageParams, key);

        StringBuffer sb = new StringBuffer();
        Set es = packageParams.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            sb.append(k + "=" + UrlEncode(v) + "&");
        }

        // 去掉最后一个&
        String packageValue = sb.append("sign=" + sign).toString();
        return packageValue;
    }

    /**
     * 创建md5摘要,规则是:按参数名称a-z排序,遇到空值的参数不参加签名。
     */
    public static String createSign(SortedMap<String, String> packageParams, String key) {
        StringBuffer sb = new StringBuffer();
        Set es = packageParams.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) {
                sb.append(k + "=" + v + "&");
            }
        }
        sb.append("key=" + key);
        System.out.println("md5:" + sb.toString());
        String sign =  MD5.MD5Encode(sb.toString()).toUpperCase();
        System.out.println("packge签名:" + sign);
        return sign;

    }

    /**
     * 创建package签名
     */
    public boolean createMd5Sign(String signParams) {
        StringBuffer sb = new StringBuffer();
        Set es = this.parameters.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            if (!"sign".equals(k) && null != v && !"".equals(v)) {
                sb.append(k + "=" + v + "&");
            }
        }

        // 算出摘要
        String sign = MD5.MD5Encode(sb.toString()).toUpperCase();
        String paySign = this.getParameter("sign").toLowerCase();
        return paySign.equals(sign);
    }

    /**
     * 输出XML
     * @return
     */
    public String parseXML() {
        StringBuffer sb = new StringBuffer();
        sb.append("<xml>");
        Set es = this.parameters.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            String v = (String) entry.getValue();
            if (null != v && !"".equals(v) && !"appkey".equals(k)) {

                sb.append("<" + k + ">" + getParameter(k) + "</" + k + ">\n");
            }
        }
        sb.append("</xml>");
        return sb.toString();
    }

    public static String post(String url, String xmlParam) {
        StringBuilder sb = new StringBuilder();
        try {
            KeyStore keyStore = KeyStore.getInstance("PKCS12");
            FileInputStream instream = new FileInputStream(new File(KEY_PATH));
//            String mchid = ResourceUtil.getConfigByName("wx.application.mch_id");
            String mchid = Constant.MCH_ID;
            try {
                keyStore.load(instream, mchid.toCharArray());
            } finally {
                instream.close();
            }

            // 证书
            SSLContext sslcontext = SSLContexts.custom()
                    .loadKeyMaterial(keyStore, mchid.toCharArray())
                    .build();
            // 只允许TLSv1协议
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
                    sslcontext,
                    new String[]{"TLSv1"},
                    null,
                    SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
            //创建基于证书的httpClient,后面要用到
            CloseableHttpClient client = HttpClients.custom()
                    .setSSLSocketFactory(sslsf)
                    .build();

            HttpPost httpPost = new HttpPost(url);//退款接口
            StringEntity reqEntity = new StringEntity(xmlParam);
            // 设置类型
            reqEntity.setContentType("application/x-www-form-urlencoded");
            httpPost.setEntity(reqEntity);
            CloseableHttpResponse response = client.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();
                System.out.println(response.getStatusLine());
                if (entity != null) {
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));
                    String text = "";
                    while ((text = bufferedReader.readLine()) != null) {
                        sb.append(text);
                    }
                }
                EntityUtils.consume(entity);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            /*try {

                HttpGet httpget = new HttpGet("https://api.mch.weixin.qq.com/secapi/pay/refund");

                System.out.println("executing request" + httpget.getRequestLine());

                CloseableHttpResponse response = httpclient.execute(httpget);
                try {
                    HttpEntity entity = response.getEntity();

                    System.out.println("----------------------------------------");
                    System.out.println(response.getStatusLine());
                    if (entity != null) {
                        System.out.println("Response content length: " + entity.getContentLength());
                        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));
                        String text;
                        while ((text = bufferedReader.readLine()) != null) {
                            System.out.println(text);
                            sb.append(text);
                        }

                    }
                    EntityUtils.consume(entity);
                } finally {
                    response.close();
                }
            } finally {
                httpclient.close();
            }*/
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sb.toString();
    }
}

package luluteam.wxpay.util;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.core.util.QuickWriter;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
import com.thoughtworks.xstream.io.xml.XppDriver;
import luluteam.wxpay.entity.PayInfo;
import org.apache.commons.lang3.StringUtils;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.util.*;

/**
 * Created by Hyman on 2017/2/28.
 */
public class CommonUtil {

    public static String getRandomOrderId() {
        // UUID.randomUUID().toString().replace("-","")
        Random random = new Random(System.currentTimeMillis());
        int value = random.nextInt();
        while (value < 0) {
            value = random.nextInt();
        }
        return value + "";
    }

    private static XStream xstream = new XStream(new XppDriver() {
        public HierarchicalStreamWriter createWriter(Writer out) {
            return new PrettyPrintWriter(out) {
                //增加CDATA标记
                boolean cdata = true;
                @SuppressWarnings("rawtypes")
                public void startNode(String name, Class clazz) {
                    super.startNode(name, clazz);
                }
                protected void writeText(QuickWriter writer, String text) {
                    if (cdata) {
                        writer.write("<![CDATA[");
                        writer.write(text);
                        writer.write("]]>");
                    } else {
                        writer.write(text);
                    }
                }
            };
        }
    });

    public static String payInfoToXML(PayInfo pi) {
        xstream.alias("xml", pi.getClass());
        return xstream.toXML(pi);
    }

    @SuppressWarnings("unchecked")
    public static Map<String, String> parseXml(String xml) throws Exception {
        Map<String, String> map = new HashMap<String, String>();
        Document document = DocumentHelper.parseText(xml);
        Element root = document.getRootElement();
        List<Element> elementList = root.elements();
        for (Element e : elementList)
            map.put(e.getName(), e.getText());
        return map;
    }

    public static String getClientIp(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if(StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)){
            //多次反向代理后会有多个ip值，第一个ip才是真实ip
            int index = ip.indexOf(",");
            if(index != -1){
                return ip.substring(0,index);
            }else{
                return ip;
            }
        }
        ip = request.getHeader("X-Real-IP");
        if(StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)){
            return ip;
        }
        return request.getRemoteAddr();
    }

    /**
     * 对字符串md5加密
     *
     * @param str
     * @return
     */
    public static String getMD5(String str) throws Exception {
        try {
            // 生成一个MD5加密计算摘要
            MessageDigest md = MessageDigest.getInstance("MD5");
            // 计算md5函数
            md.update(str.getBytes());
            // digest()最后确定返回md5 hash值，返回值为8为字符串。因为md5 hash值是16位的hex值，实际上就是8位的字符
            // BigInteger函数则将8位的字符串转换成16位hex值，用字符串来表示；得到字符串形式的hash值
            return new BigInteger(1, md.digest()).toString(16);
        } catch (Exception e) {
            throw new Exception("MD5加密出现错误");
        }
    }

}

package luluteam.wxpay.util;

import java.util.HashMap;
import java.util.List;

import org.apache.http.Header;
import org.apache.http.cookie.Cookie;

public class HttpResult {

    private List<Cookie> cookies;

    private HashMap<String, Header> headers;

    private int statusCode;

    private String body;

    public List<Cookie> getCookies() {
        return cookies;
    }

    public void setCookies(List<Cookie> cookies) {
        this.cookies = cookies;
    }

    public HashMap<String, Header> getHeaders() {
        return headers;
    }

    public void setHeaders(Header[] headerAll) {
        headers = new HashMap<String, Header>();
        for (Header header : headerAll) {
            headers.put(header.getName(), header);
        }
    }

    public int getStatusCode() {
        return statusCode;
    }

    public void setStatusCode(int statusCode) {
        this.statusCode = statusCode;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    @Override
    public String toString() {
        StringBuffer sb = new StringBuffer();
        sb.append("======================= HttpResult toString start ========================\n");
        sb.append("----- statusCode: " + statusCode + "\n");
        if(headers != null) {
            sb.append("----- headers:\n");
            for(String key : headers.keySet()) {
                sb.append("\t" + key + " : " + headers.get(key) + "\n");
            }
        }
        if(cookies != null) {
            sb.append("----- cookies:\n");
            for(Cookie cookie : cookies) {
                sb.append("\t" + cookie.getName() + " : " + cookie.getValue() + "\n");
            }
        }
        sb.append("======================= body start ========================\n");
        sb.append(body);
        sb.append("======================= body end ========================\n");
        sb.append("======================= HttpResult toString end   =======================");

        return sb.toString();
    }

    public String getCookieValue(String cookieName) {

        if(cookies.isEmpty()) {
            return null;
        }

        for(Cookie cookie : cookies) {
            if(cookie.getName().equals(cookieName)) {
                return cookie.getValue();
            }
        }

        return null;
    }
}

package luluteam.wxpay.util;

import java.io.*;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.http.Consts;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContextBuilder;
import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import javax.net.ssl.HttpsURLConnection;

public class HttpUtil {

    // User-Agent
    public static final String USERAGENT_FIREFOX = "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0";
    public static final String USERAGENT_IE = "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0) like Gecko";  

    private CloseableHttpClient httpClient;

    private BasicCookieStore cookieStore;
    private HttpGet get;
    private HttpPost post;

    public static StringBuffer httpsRequest(String requestUrl, String requestMethod, String output) throws IOException {
        URL url = new URL(requestUrl);
        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        connection.setDoOutput(true);
        connection.setDoInput(true);
        connection.setUseCaches(false);
        connection.setRequestMethod(requestMethod);
        if (null != output) {
            OutputStream outputStream = connection.getOutputStream();
            outputStream.write(output.getBytes("UTF-8"));
            outputStream.close();
        }
        // 从输入流读取返回内容
        InputStream inputStream = connection.getInputStream();
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "UTF-8");
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        String str = null;
        StringBuffer buffer = new StringBuffer();
        while ((str = bufferedReader.readLine()) != null) {
            buffer.append(str);
        }
        bufferedReader.close();
        inputStreamReader.close();
        inputStream.close();
        inputStream = null;
        connection.disconnect();
        return buffer;
    }

    public HttpResult doGet(String url, Map<String, String> headers, Map<String, String> params) throws NoSuchAlgorithmException, KeyStoreException, KeyManagementException, ClientProtocolException, IOException {

        if (url == null|| url.equals("")) {
            return null;
        }

        SSLContextBuilder builder = new SSLContextBuilder();
        builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(builder.build());
        cookieStore = new BasicCookieStore();
        CloseableHttpClient httpclient = HttpClients.custom().setDefaultCookieStore(cookieStore)
                .setSSLSocketFactory(sslsf).build();

        HttpResult result = null;
        try {

            url = url + "?" + parseParams(params);
            HttpGet httpget = new HttpGet(url);
            httpget.setHeaders(parseHeader(headers));

            CloseableHttpResponse response = httpclient.execute(httpget);
            try {
                HttpEntity entity = response.getEntity();

                if (entity != null) {
                    result = new HttpResult();
                    result.setCookies(cookieStore.getCookies());
                    result.setStatusCode(response.getStatusLine().getStatusCode());
                    result.setHeaders(response.getAllHeaders());
                    result.setBody(EntityUtils.toString(entity));
                }

            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }

        return result;

    }

    public HttpResult doPost(String url, Map<String, String> headers, Map<String, String> postData, String encoding) throws Exception {

        if (url == null|| url.equals("")) {
            return null;
        }
        if (encoding == null|| encoding.equals("")) {
            encoding = "utf-8";
        }

        SSLContextBuilder builder = new SSLContextBuilder();
        builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(builder.build());
        cookieStore = new BasicCookieStore();
        CloseableHttpClient httpClient = HttpClients.custom().setDefaultCookieStore(cookieStore)
                .setSSLSocketFactory(sslsf).build();

        post = new HttpPost(url);
        List<NameValuePair> list = new ArrayList<NameValuePair>();
        for (String tmp : postData.keySet()) {
            list.add(new BasicNameValuePair(tmp, postData.get(tmp)));
        }
        post.setEntity(new UrlEncodedFormEntity(list, encoding));
        post.setHeaders(parseHeader(headers));

        CloseableHttpResponse response = httpClient.execute(post);
        HttpEntity entity = response.getEntity();

        HttpResult result = new HttpResult();
        result.setCookies(cookieStore.getCookies());
        result.setStatusCode(response.getStatusLine().getStatusCode());
        result.setHeaders(response.getAllHeaders());
        result.setBody(EntityUtils.toString(entity, encoding));

        close(entity, response);

        return result;
    }

    private String parseParams(Map<String, String> params) {
        if (params == null || params.isEmpty()) {
            return "";
        }

        StringBuffer sb = new StringBuffer();
        for (String key : params.keySet()) {
            sb.append(key + "=" + params.get(key) + "&");
        }
        return sb.substring(0, sb.length() - 1);

    }

    private Header[] parseHeader(Map<String, String> headers) {
        if (headers == null || headers.isEmpty()) {
            return getDefaultHeaders();
        }

        Header[] retHeader = new BasicHeader[headers.size()];
        int i = 0;
        for (String str : headers.keySet()) {
            retHeader[i++] = new BasicHeader(str, headers.get(str));
        }
        return retHeader;
    }

    private Header[] getDefaultHeaders() {
        Header[] headers = new BasicHeader[3];
        headers[0] = new BasicHeader("User-Agent", USERAGENT_IE);
        headers[1] = new BasicHeader("Accept-Encoding", "gzip, deflate");
        headers[2] = new BasicHeader("Accept-Language", "en-US,en;q=0.8,zh-Hans-CN;q=0.5,zh-Hans;q=0.3");
        return headers;
    }

    private void close(HttpEntity entity, CloseableHttpResponse response) {
        try {
            if (entity != null) {
                InputStream input = entity.getContent();
                input.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                //e.printStackTrace();
            }
        }
    }

    /**
     * 下载文件
     * @param url 下载文件的链接
     * @param destFile 包含路径的目标文件名
     * @param headers 请求头
     * @return
     */
    public HttpResult downloadFile(String url, String destFile, Map<String, String> headers) throws Exception {

        SSLContextBuilder builder = new SSLContextBuilder();
        builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(builder.build());
        BasicCookieStore cookieStore = new BasicCookieStore();
        CloseableHttpClient httpclient = HttpClients.custom().setDefaultCookieStore(cookieStore).setSSLSocketFactory(sslsf).build();

        HttpGet get = new HttpGet(url);
        get.setHeaders(parseHeader(headers));
        InputStream input = null;
        CloseableHttpResponse response = null;
        HttpResult result = null;

        try {
            response = httpclient.execute(get);
            HttpEntity entity = response.getEntity();
            input = entity.getContent();
            File file = new File(destFile);

            FileOutputStream fos = new FileOutputStream(file);
            int len = -1;
            byte[] tmp = new byte[1024];
            while((len=input.read(tmp)) != -1) {
                fos.write(tmp, 0, len);
            }
            fos.flush();
            fos.close();

            result = new HttpResult();
            result.setCookies(cookieStore.getCookies());
            result.setStatusCode(response.getStatusLine().getStatusCode());
            result.setHeaders(response.getAllHeaders());
            result.setBody(EntityUtils.toString(entity, Consts.UTF_8));

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if(input != null) {
                    input.close();
                }
                if(response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

}

package luluteam.wxpay.util;

import java.util.Random;

/**
 * 随机数、随即字符串工具
 */
public class RandomUtils {
    public static final String allChar = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    public static final String letterChar = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    public static final String numberChar = "0123456789";

    /**
     * 返回一个定长的随机字符串(只包含大小写字母、数字)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateString(int length) {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            sb.append(allChar.charAt(random.nextInt(allChar.length())));
        }
        return sb.toString();
    }

    /**
     * 返回一个定长的随机纯字母字符串(只包含大小写字母)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateMixString(int length) {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            sb.append(allChar.charAt(random.nextInt(letterChar.length())));
        }
        return sb.toString();
    }

    /**
     * 返回一个定长的随机纯小写字母字符串(只包含小写字母)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateLowerString(int length) {
        return generateMixString(length).toLowerCase();
    }

    /**
     * 返回一个定长的随机纯大写字母字符串(只包含大写字母)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateUpperString(int length) {
        return generateMixString(length).toUpperCase();
    }

    public static void main(String[] args) {
        System.out.println(generateString(32));
        System.out.println(generateMixString(32));
        System.out.println(generateLowerString(32));
        System.out.println(generateUpperString(32));
    }
}

这篇博客的主要意义是给大家提供一个开发小程序微信支付和微信退款的思路，上面的支付代码和退款代码在我看来写的很难看，大家有想法的可以自己简化，多做一些处理，也可以利用一些较好sdk简化开发，凡是对代码有问题的，可以去我的github下载源码(配有小程序源码)：https://github.com/wenbingshen/wechatpay

学习微信支付在理解了微信支付开发文档以后，利用一些优秀的开源sdk是帮助我们开发的最好利器，我的公众号支付开发就利用优秀的sdk，有想学习建立开发思路的，可以戳下面的链接下载源码：

https://github.com/wenbingshen/springboot

微信支付的开发文档对java语言真的很不利，有时候利用一些前人的成果可以有效简化我们的开发任务。

祝大家学习快乐。