/**

 * 因为微信总是很多个商户号很多和appid。很多个密钥文件，所以全部改成手动传值的方式，就可以支持多商户调用

 *

 * @param appId    商户的appid

 * @param mchId    商户的商户号

 * @param key      商户的支付用的密钥

 * @param certPath 商户的退款用的退款文件地址，非必传，没有就传null,具体看开发文档是否需退款文件

 * @throws Exception

 */

调用示例测试代码。扫码支付返回的是一个base64格式的二维码。需要拼接前缀的（有逗号） ：  data:image/jpeg;base64,

public static void main(String[] args) throws Exception {

        WXPayEntrance wxPayEntrance = new WXPayEntrance("wxab8acb865bb1637e", "11473623", "2ab9071b06b9f739b950ddb41db2690d", null);

        WXPayVO wxPayVO = new WXPayVO();

        wxPayVO.setBody("1231231666623");

        wxPayVO.setTotalFee("1");

        wxPayVO.setNotifyUrl("https://********/api/wxpayreturn");

        wxPayVO.setTradeType("NATIVE");

        wxPayVO.setOutTradeNo("ty190523151415047046");

        wxPayVO.setUid(123123123);

        wxPayVO.setSpbillCreateIp("192.168.17.214");

        Map<String, String> map = wxPayEntrance.doUnifiedOrder(wxPayVO);

        System.out.println(map);

//        PayRefundVo payRefundVo = new PayRefundVo();

//        payRefundVo.setOutRefundNo("A190523155119103");

//        payRefundVo.setOutTradeNo("ty190523155047046");

//        payRefundVo.setRefundDesc("退款");

//        payRefundVo.setRefundFee("10");

//        payRefundVo.setUid(123123123);

//        payRefundVo.setRefundFeeType("CNY");

//        payRefundVo.setTotalFee("120");

//        Map<String, String> map = wxPayEntrance.doRefund(payRefundVo);

//        System.out.println(map);

    }

异步回调代码如下：

package com.huis.portal.controller;

import com.huis.portal.weixinpay.WXPayUtil;

import io.swagger.annotations.Api;

import io.swagger.annotations.ApiOperation;

import org.apache.commons.lang3.StringUtils;

import org.springframework.transaction.annotation.Transactional;

import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.util.Map;

import java.util.SortedMap;

import java.util.TreeMap;

@RestController

@Api(description = "支付模块模块")

@CrossOrigin(origins = "*", maxAge = 3600)

@Transactional(rollbackFor = Exception.class)

public class PayRestController {

   @ApiOperation(value = "微信回调接口", notes = "微信回调接口")

   @RequestMapping(value = "/api/wxpayreturn", method = RequestMethod.POST)

   public String WeixinParentNotifyPage(HttpServletRequest request, HttpServletResponse response) throws Exception {

      // 返回给微信的处理结果

      String result = null;

      String inputLine;

      String notityXml = "";

      request.setCharacterEncoding("UTF-8");

      response.setCharacterEncoding("UTF-8");

      response.setContentType("text/html;charset=UTF-8");

      response.setHeader("Access-Control-Allow-Origin", "*");

      // 微信给返回的东西

      try {

         while ((inputLine = request.getReader().readLine()) != null) {

            notityXml += inputLine;

         }

         request.getReader().close();

      } catch (Exception e) {

         e.printStackTrace();

         result = setXml("fail", "xml获取失败");

         return result;

      }

      if (StringUtils.isEmpty(notityXml)) {

         result = setXml("fail", "xml为空");

         return result;

      }

      Map<String, String> map = WXPayUtil.xmlToMap(notityXml);

      String out_trade_no = (String) map.get("out_trade_no");// 获取商户订单号

      String result_code = (String) map.get("result_code");// 业务结果

      String total_fee = (String) map.get("total_fee");// 获取订单金额

      String appid = (String) map.get("appid");// 获取订单金额

      if (map.get("result_code").equals("SUCCESS")) {

         //TODO

         result = setXml("SUCCESS", "OK");

         return result;

      }else {

         result = setXml("fail", "xml为空");

         return result;

      }

   }

   // 通过xml 发给微信消息

   public static String setXml(String return_code, String return_msg) {

      SortedMap<String, String> parameters = new TreeMap<String, String>();

      parameters.put("return_code", return_code);

      parameters.put("return_msg", return_msg);

      return "<xml><return_code><![CDATA[" + return_code + "]]>" + "</return_code><return_msg><![CDATA[" + return_msg

            + "]]></return_msg></xml>";

   }

}

<plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-resources-plugin</artifactId>

                <configuration>

                    <nonFilteredFileExtensions>

                        <nonFilteredFileExtension>p12</nonFilteredFileExtension>

                        <nonFilteredFileExtension>pem</nonFilteredFileExtension>

                    </nonFilteredFileExtensions>

                </configuration>

            </plugin>