/*** 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")) {//TODOresult = 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>";}}