SpringBoot整合微信小程序支付V3(支付、退款)
作者:mmseoamin日期:2023-12-13

文章目录

    • 一、微信支付-准备工作
    • 二、微信支付-基本配置
    • 三、微信支付-调起微信支付
    • 四、微信支付-成功回调
    • 五、微信支付-申请退款
    • 六、微信支付-退款成功回调

      一、微信支付-准备工作

      微信支付开发前,需要先获取商家信息,包括商户号、AppId、证书和密钥。

      1. 获取商户号

        微信商户平台 申请成为商户 => 提交资料 => 签署协议 => 获取商户号

      2. 获取AppID

        微信公众平台 注册服务号 => 服务号认证 => 获取APPID => 绑定商户号

      3. 申请商户证书

        登录商户平台 => 选择 账户中心 => 安全中心 => API安全 => 申请API证书 包括商户证书和商户私钥

      4. 获取微信的证书
      5. 获取APIv3秘钥(在微信支付回调通知和商户获取平台证书使用APIv3密钥)

        登录商户平台 => 选择 账户中心 => 安全中心 => API安全 => 设置APIv3密钥

      二、微信支付-基本配置

      1.引入pom.xml

      
      
          com.github.wechatpay-apiv3
          wechatpay-apache-httpclient
          0.4.2
      
      

      2.配置商户信息、证书、密钥等。将客户端对象构建到Bean中,方便后续使用。

      可以采用两种方式

      ①.配置application.yml

      weixin:
        appid: wx*************acx # appid
        mch-serial-no: 3FB18E2*******0127B3*****0053E2 # 证书序列号
        private-key-path: D:\wx\pem\apiclient_key.pem # 证书路径
        mch-id: 16*****801 # 商户号
        key: F8CDeHBc***********2t5nvVeh1 # api秘钥
        domain: https://api.mch.weixin.qq.com # 微信服务器地址
        notify-domain: https://xw666.mynatapp.cc # 回调,自己的回调地址
      

      然后创建对应的实体

      @Configuration
      @PropertySource("classpath:application.yml") //读取配置文件
      @ConfigurationProperties(prefix = "weixin") //读取wxpay节点
      @Data //使用set方法将wxpay节点中的值填充到当前类的属性中
      @ApiModel("微信支付静态常量类")
      public class WxPayConfig {
          @ApiModelProperty("商户号")
          private String mchId;
          @ApiModelProperty("商户API证书序列号")
          private String mchSerialNo;
          @ApiModelProperty("商户私钥文件")
          private String privateKeyPath;
          @ApiModelProperty("APIv3密钥")
          private String key;
          @ApiModelProperty("APPID")
          private String appid;
          @ApiModelProperty("微信服务器地址")
          private String domain;
          @ApiModelProperty("接收结果通知地址")
          private String notifyDomain;
      }
      

      ②使用数据库存储,在项目启动时加载到redis中,然后从redis中获取

      @Configuration
      @Data
      @ApiModel("微信支付静态常量类")
      public class WxPayConstants {
          @Resource
          private RedisCache redisCache;
          @ApiModelProperty("APPID")
          public String appid;
          @ApiModelProperty("商户API证书序列号")
          public String mchSerialNo;
          @ApiModelProperty("商户私钥文件")
          public String privateKeyPath;
          @ApiModelProperty("商户号")
          public String mchId;
          @ApiModelProperty("APIv3密钥")
          public String key;
          @ApiModelProperty("微信服务器地址")
          public String domain;
          @ApiModelProperty("接收结果通知地址")
          public String notifyDomain;
          @Resource
          public void getParam(RedisCache redisCache){
              appid = redisCache.getCacheObject("WX_PAY_SAVE_WX_APPID");
              mchSerialNo = redisCache.getCacheObject("WX_PAY_SAVE_MCH_SERIAL_NO");
              privateKeyPath = redisCache.getCacheObject("WX_PAY_SAVE_PRIVATE_KEY_PATH");
              mchId = redisCache.getCacheObject("WX_PAY_SAVE_MCH_ID");
              key = redisCache.getCacheObject("WX_PAY_SAVE_KEY");
              domain = redisCache.getCacheObject("WX_PAY_SAVE_DOMAIN");
              notifyDomain = redisCache.getCacheObject("WX_PAY_SAVE_NOTIFY_DOMAIN");
          }
      }
      

      这两个实体有几个共同的方法,无论使用哪一个,放到下面即可

          /**
           * 获取商户的私钥文件
           *
           * @param filename 证书地址
           * @return 私钥文件
           */
          public PrivateKey getPrivateKey(String filename) {
              try {
                  return PemUtil.loadPrivateKey(new FileInputStream(filename));
              } catch (FileNotFoundException e) {
                  throw new ServiceException("私钥文件不存在");
              }
          }
          /**
           * 获取签名验证器
           */
          @Bean
          public Verifier getVerifier() {
              // 获取商户私钥
              final PrivateKey privateKey = getPrivateKey(privateKeyPath);
              // 私钥签名对象
              PrivateKeySigner privateKeySigner = new PrivateKeySigner(mchSerialNo, privateKey);
              // 身份认证对象
              WechatPay2Credentials wechatPay2Credentials = new WechatPay2Credentials(mchId, privateKeySigner);
              // 获取证书管理器实例
              CertificatesManager certificatesManager = CertificatesManager.getInstance();
              try {
                  // 向证书管理器增加需要自动更新平台证书的商户信息
                  certificatesManager.putMerchant(mchId, wechatPay2Credentials, key.getBytes(StandardCharsets.UTF_8));
              } catch (IOException | GeneralSecurityException | HttpCodeException e) {
                  e.printStackTrace();
              }
              try {
                  return certificatesManager.getVerifier(mchId);
              } catch (NotFoundException e) {
                  e.printStackTrace();
                  throw new ServiceException("获取签名验证器失败");
              }
          }
          /**
           * 获取微信支付的远程请求对象
           * @return Http请求对象
           */
          @Bean
          public CloseableHttpClient getWxPayClient() {
              // 获取签名验证器
              Verifier verifier = getVerifier();
              // 获取商户私钥
              final PrivateKey privateKey = getPrivateKey(privateKeyPath);
              WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create().withMerchant(mchId, mchSerialNo, privateKey)
                      .withValidator(new WechatPay2Validator(verifier));
              return builder.build();
          }
      

      3.请求地址枚举类(WxApiConstants)

      为了防止微信支付的请求地址前缀发生变化,因此请求前缀存储在application.yml中,请求时进行拼接即可。

      import io.swagger.annotations.ApiModel;
      import io.swagger.annotations.ApiModelProperty;
      import lombok.AllArgsConstructor;
      import lombok.Getter;
      //为了防止微信支付的请求地址前缀发生变化,因此请求前缀存储在mysql,redis中,请求时进行拼接即可。
      @AllArgsConstructor
      @Getter
      @ApiModel("请求地址")
      public enum WxApiConstants {
          
          @ApiModelProperty("Native下单")
          NATIVE_PAY("/v3/pay/transactions/native"),
          @ApiModelProperty("jsapi下单")
          JSAPI_PAY("/v3/pay/transactions/jsapi"),
          @ApiModelProperty("jsapi下单")
          H5_PAY("/v3/pay/transactions/h5"),
          @ApiModelProperty("APP下单")
          APP_PAY("/v3/pay/transactions/app"),
          @ApiModelProperty("查询订单")
          ORDER_QUERY_BY_NO("/v3/pay/transactions/out-trade-no/%s"),
          @ApiModelProperty("关闭订单")
          CLOSE_ORDER_BY_NO("/v3/pay/transactions/out-trade-no/%s/close"),
          @ApiModelProperty("申请退款")
          DOMESTIC_REFUNDS("/v3/refund/domestic/refunds"),
          @ApiModelProperty("查询单笔退款")
          DOMESTIC_REFUNDS_QUERY("/v3/refund/domestic/refunds/%s"),
          @ApiModelProperty("申请交易账单")
          TRADE_BILLS("/v3/bill/tradebill"),
          @ApiModelProperty("申请资金账单")
          FUND_FLOW_BILLS("/v3/bill/fundflowbill");
          @ApiModelProperty("类型")
          private final String type;
      }
      

      4.回调地址枚举类(WxChatBasePayDto)

      发生请求后微信官方会回调我们传递的地址,这里通过枚举统一管理我们的回调地址,回调地址由application.yml中的

      weixin.notify-domain拼接组成。

      import io.swagger.annotations.ApiModel;
      import io.swagger.annotations.ApiModelProperty;
      import lombok.AllArgsConstructor;
      import lombok.Getter;
      @Getter
      @AllArgsConstructor
      @ApiModel("微信回调地址,根据自己的项目来,不要直接照搬")
      public enum WxNotifyConstants {
          
          @ApiModelProperty("订单支付通知")
          RUN_ERRANDS_NOTIFY("/wx/order/wxOrderCallBack"),
          @ApiModelProperty("卡支付成功通知")
          CAMPUS_CARD_NOTIFY("/wx/campusCardOrder/wxCampusCardOrderCallBack"),
          @ApiModelProperty("卡退款成功通知")
          CAMPUS_CARD_REFUND_NOTIFY("/wx/campusCardOrder/refundWechatCallback");
          @ApiModelProperty("类型")
          private final String type;
      }
      

      5.微信支付基础请求数据对象(WxChatBasePayDto)

      import com.xxx.project.wx.constants.WxNotifyConstants;
      import io.swagger.annotations.ApiModel;
      import io.swagger.annotations.ApiModelProperty;
      import lombok.Data;
      import java.math.BigDecimal;
      @Data
      @ApiModel("微信支付基础请求数据对象")
      public class WxChatBasePayDto {
          @ApiModelProperty("商品描述")
          private String title;
          @ApiModelProperty("商家订单号,对应 out_trade_no")
          private String orderId;
          @ApiModelProperty("订单金额")
          private BigDecimal price;
          @ApiModelProperty("回调地址")
          private WxNotifyConstants notify;
          @ApiModelProperty("支付用户的openid")
          private String openId;
      }
      

      6.将请求参数封装成Map集合(WxPayCommon)

      封装完枚举类后,首先就是请求参数的封装,支付类请求参数都非常相近,我们将都需要的参数提取出来以map的方式进行返回。这里的参数,指每个支付类请求都用到的参数,个别支付需要额外添加数据

      import com.google.gson.Gson;
      import com.xxx.common.exception.ServiceException;
      import com.xxx.project.wx.constants.WxPayConstants;
      import com.xxx.project.wx.constants.WxApiConstants;
      import com.xxx.project.wx.dto.WxChatBasePayDto;
      import lombok.extern.slf4j.Slf4j;
      import org.apache.commons.lang3.StringUtils;
      import org.apache.http.client.methods.CloseableHttpResponse;
      import org.apache.http.client.methods.HttpPost;
      import org.apache.http.entity.StringEntity;
      import org.apache.http.impl.client.CloseableHttpClient;
      import org.apache.http.util.EntityUtils;
      import java.io.IOException;
      import java.math.BigDecimal;
      import java.util.HashMap;
      import java.util.Map;
      @Slf4j
      public class WxPayCommon {
          /**
           * 封装基础通用请求数据
           * @param wxPayConfig 微信的配置文件
           * @param basePayData 微信支付基础请求数据
           * @return 封装后的map对象
           */
          public static Map getBasePayParams(WxPayConstants wxPayConfig, WxChatBasePayDto basePayData) {
              Map paramsMap = new HashMap<>();
              paramsMap.put("appid", wxPayConfig.getAppid());
              paramsMap.put("mchid", wxPayConfig.getMchId());
              // 如果商品名称过长则截取
              String title = basePayData.getTitle().length() > 62 ? basePayData.getTitle().substring(0, 62) : basePayData.getTitle();
              paramsMap.put("description",title);
              paramsMap.put("out_trade_no", basePayData.getOrderId());
              paramsMap.put("notify_url", wxPayConfig.getNotifyDomain().concat(basePayData.getNotify().getType()));
              Map amountMap = new HashMap<>();
              amountMap.put("total", basePayData.getPrice().multiply(new BigDecimal("100")).intValue());
              paramsMap.put("amount", amountMap);
              return paramsMap;
          }
      	/**
           * 获取请求对象(Post请求)
           * @param wxPayConfig 微信配置类
           * @param apiType 接口请求地址
           * @param paramsMap 请求参数
           * @return Post请求对象
           */
          public static HttpPost getHttpPost(WxPayConstants wxPayConfig, WxApiConstants apiType, Map paramsMap) {
              // 1.设置请求地址
              HttpPost httpPost = new HttpPost(wxPayConfig.getDomain().concat(apiType.getType()));
              // 2.设置请求数据
              Gson gson = new Gson();
              String jsonParams = gson.toJson(paramsMap);
              // 3.设置请求信息
              StringEntity entity = new StringEntity(jsonParams, "utf-8");
              entity.setContentType("application/json");
              httpPost.setEntity(entity);
              httpPost.setHeader("Accept", "application/json");
              return httpPost;
          }
       	/**
           * 解析响应数据
           * @param response 发送请求成功后,返回的数据
           * @return 微信返回的参数
           */
          public static HashMap resolverResponse(CloseableHttpResponse response) {
              try {
                  // 1.获取请求码
                  int statusCode = response.getStatusLine().getStatusCode();
                  // 2.获取返回值 String 格式
                  final String bodyAsString = EntityUtils.toString(response.getEntity());
                  Gson gson = new Gson();
                  if (statusCode == 200) {
                      // 3.如果请求成功则解析成Map对象返回
                      HashMap resultMap = gson.fromJson(bodyAsString, HashMap.class);
                      return resultMap;
                  } else {
                      if (StringUtils.isNoneBlank(bodyAsString)) {
                          log.error("微信支付请求失败,提示信息:{}", bodyAsString);
                          // 4.请求码显示失败,则尝试获取提示信息
                          HashMap resultMap = gson.fromJson(bodyAsString, HashMap.class);
                          throw new ServiceException(resultMap.get("message"));
                      }
                      log.error("微信支付请求失败,未查询到原因,提示信息:{}", response);
                      // 其他异常,微信也没有返回数据,这就需要具体排查了
                      throw new IOException("request failed");
                  }
              } catch (Exception e) {
                  e.printStackTrace();
                  throw new ServiceException(e.getMessage());
              } finally {
                  try {
                      response.close();
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
          }
      }
      

      7.创建微信支付订单的三种方式(Native,Jsapi,App)

      商户Native支付下单接口,微信后台系统返回链接参数code_url,商户后台系统将code_url值生成二维码图片,用户使用微信客户端扫码后发起支付,也就是说后端只需要返回code_url即可。

      官方JSAPI支付开发指引

      继续在上方WxPayCommon中加入

       /**
       * 创建微信支付订单-Native方式
       *
       * @param wxPayConfig 微信配置信息
       * @param basePayData 基础请求信息,商品标题、商家订单id、订单价格
       * @param wxPayClient 微信请求客户端()
       * @return 微信支付二维码地址
       */
      public static String wxNativePay(WxPayConstants wxPayConfig, WxChatBasePayDto basePayData, CloseableHttpClient wxPayClient) {
          // 1.获取请求参数的Map格式
          Map paramsMap = getBasePayParams(wxPayConfig, basePayData);
          // 2.获取请求对象
          HttpPost httpPost = getHttpPost(wxPayConfig, WxApiConstants.NATIVE_PAY, paramsMap);
          // 3.完成签名并执行请求
          CloseableHttpResponse response = null;
          try {
              response = wxPayClient.execute(httpPost);
          } catch (IOException e) {
              e.printStackTrace();
              throw new ServiceException("微信支付请求失败");
          }
          // 4.解析response对象
          HashMap resultMap = resolverResponse(response);
          if (resultMap != null) {
              // native请求返回的是二维码链接,前端将链接转换成二维码即可
              return resultMap.get("code_url");
          }
          return null;
      }
      /**
       * 创建微信支付订单-jsapi方式
       * @param wxPayConfig 微信配置信息
       * @param basePayData 基础请求信息,商品标题、商家订单id、订单价格
       * @param openId 通过微信小程序或者公众号获取到用户的openId
       * @param wxPayClient 微信请求客户端()
       * @return 微信支付二维码地址
       */
      public static String wxJsApiPay(WxPayConstants wxPayConfig, WxChatBasePayDto basePayData, String openId, CloseableHttpClient wxPayClient) {
          // 1.获取请求参数的Map格式
          Map paramsMap = getBasePayParams(wxPayConfig, basePayData);
          // 1.1 添加支付者信息
          Map payerMap = new HashMap();
          payerMap.put("openid",openId);
          paramsMap.put("payer",payerMap);
          // 2.获取请求对象
          HttpPost httpPost = getHttpPost(wxPayConfig, WxApiConstants.JSAPI_PAY, paramsMap);
          // 3.完成签名并执行请求
          CloseableHttpResponse response = null;
          try {
              response = wxPayClient.execute(httpPost);
          } catch (IOException e) {
              e.printStackTrace();
              throw new ServiceException("微信支付请求失败");
          }
          // 4.解析response对象
          HashMap resultMap = resolverResponse(response);
          if (resultMap != null) {
              // native请求返回的是二维码链接,前端将链接转换成二维码即可
              return resultMap.get("prepay_id");
          }
          return null;
      }
      /**
       * 创建微信支付订单-APP方式
       *
       * @param wxPayConfig 微信配置信息
       * @param basePayData 基础请求信息,商品标题、商家订单id、订单价格
       * @param wxPayClient 微信请求客户端()
       * @return 微信支付二维码地址
       */
      public static String wxAppPay(WxPayConstants wxPayConfig, WxChatBasePayDto basePayData, CloseableHttpClient wxPayClient) {
          // 1.获取请求参数的Map格式
          Map paramsMap = getBasePayParams(wxPayConfig, basePayData);
          // 2.获取请求对象
          HttpPost httpPost = getHttpPost(wxPayConfig, WxApiConstants.APP_PAY, paramsMap);
          // 3.完成签名并执行请求
          CloseableHttpResponse response = null;
          try {
              response = wxPayClient.execute(httpPost);
          } catch (IOException e) {
              e.printStackTrace();
              throw new ServiceException("微信支付请求失败");
          }
          // 4.解析response对象
          HashMap resultMap = resolverResponse(response);
          if (resultMap != null) {
              // native请求返回的是二维码链接,前端将链接转换成二维码即可
              return resultMap.get("prepay_id");
          }
          return null;
      }
      

      8.创建实体存储前端微信支付所需参数(WxChatPayDto)

      因为前端拉起微信支付需要多个参数,直接用一个实体返回更便捷

      @Data
      @ApiModel("前端微信支付所需参数")
      public class WxChatPayDto {
          @ApiModelProperty("需要支付的小程序id")
          private String appid;
          @ApiModelProperty("时间戳(当前的时间)")
          private String timeStamp;
          @ApiModelProperty("随机字符串,不长于32位。")
          private String nonceStr;
          @ApiModelProperty("小程序下单接口返回的prepay_id参数值,提交格式如:prepay_id=***")
          private String prepayId;
          @ApiModelProperty("签名类型,默认为RSA,仅支持RSA。")
          private String signType;
          @ApiModelProperty("签名,使用字段appId、timeStamp、nonceStr、package计算得出的签名值")
          private String paySign;
      

      三、微信支付-调起微信支付

      设置一个公共方法pay,每次支付可以直接调用

      	@Resource
          private WxPayConstants wxPayConfig;
          @Resource
          private CloseableHttpClient wxPayClient;
          
      	/**
           * 微信用户调用微信支付
           */
          @Override
          public WxChatPayDto pay(WxChatBasePayDto payData) {
              String prepayId = WxPayCommon.wxJsApiPay(wxPayConfig, payData, payData.getOpenId(), wxPayClient);
              WxChatPayDto wxChatPayDto = new WxChatPayDto();
              wxChatPayDto.setAppid(redisCache.getCacheObject("WX_PAY_SAVE_WX_APPID"));
              wxChatPayDto.setTimeStamp(String.valueOf(System.currentTimeMillis() / 1000));
              wxChatPayDto.setNonceStr(UUID.randomUUID().toString().replaceAll("-", ""));
              wxChatPayDto.setPrepayId("prepay_id=" + prepayId);
              wxChatPayDto.setSignType("RSA");
              wxChatPayDto.setPaySign(getSign(wxChatPayDto.getNonceStr(),wxChatPayDto.getAppid(),wxChatPayDto.getPrepayId(),Long.parseLong(wxChatPayDto.getTimeStamp())));
              return wxChatPayDto;
          }
          /**
           * 获取签名
           * @param nonceStr  随机数
           * @param appId     微信公众号或者小程序等的appid
           * @param prepay_id 预支付交易会话ID
           * @param timestamp 时间戳 10位
           * @return String 新签名
           */
          String getSign(String nonceStr, String appId, String prepay_id, long timestamp) {
              //从下往上依次生成
              String message = buildMessage(appId, timestamp, nonceStr, prepay_id);
              //签名
              try {
                  return sign(message.getBytes("utf-8"));
              } catch (IOException e) {
                  throw new RuntimeException("签名异常,请检查参数或商户私钥");
              }
          }
          String sign(byte[] message) {
              try {
                  //签名方式
                  Signature sign = Signature.getInstance("SHA256withRSA");
                  //私钥,通过MyPrivateKey来获取,这是个静态类可以接调用方法 ,需要的是_key.pem文件的绝对路径配上文件名
                  sign.initSign(PemUtil.loadPrivateKey(new FileInputStream(redisCache.getCacheObject("WX_PAY_SAVE_PRIVATE_KEY_PATH").toString())));
                  sign.update(message);
                  return Base64.getEncoder().encodeToString(sign.sign());
              } catch (Exception e) {
                  throw new RuntimeException("签名异常,请检查参数或商户私钥");
              }
          }
          /**
           * 按照前端签名文档规范进行排序,\n是换行
           *
           * @param nonceStr  随机数
           * @param appId     微信公众号或者小程序等的appid
           * @param prepay_id 预支付交易会话ID
           * @param timestamp 时间戳 10位
           * @return String 新签名
           */
          String buildMessage(String appId, long timestamp, String nonceStr, String prepay_id) {
              return appId + "\n"
                      + timestamp + "\n"
                      + nonceStr + "\n"
                      + prepay_id + "\n";
          }
      

      调用pay,获取前端拉起支付所需要的参数

      //支付
      WxChatBasePayDto payData = new WxChatBasePayDto();
      payData.setTitle("订单支付");
      payData.setOrderId(runOrder.getOrderNumber());
      payData.setPrice(new BigDecimal(0.01));
      payData.setNotify(WxNotifyConstants.RUN_ERRANDS_NOTIFY);
      payData.setOpenId(runOrder.getOpenId());
      WxChatPayDto pay = pay(payData);
      

      给前端直接返回pay这个参数,前端通过里面的参数拉起支付

      JSAPI调起支付API

      四、微信支付-成功回调

      同样的通知可能会多次发送给商户系统。商户系统必须能够正确处理重复的通知。 推荐的做法是,当商户系统收到通知进行处理时,先检查对应业务数据的状态,并判断该通知是否已经处理。如果未处理,则再进行处理;如果已处理,则直接返回结果成功。在对业务数据进行状态检查和处理之前,要采用数据锁进行并发控制,以避免函数重入造成的数据混乱。

      如果在所有通知频率后没有收到微信侧回调,商户应调用查询订单接口确认订单状态。

      特别提醒:商户系统对于开启结果通知的内容一定要做签名验证,并校验通知的信息是否与商户侧的信息一致,防止数据泄露导致出现“假通知”,造成资金损失。

      该链接是通过基础下单接口中的请求参数“notify_url”来设置的,要求必须为https地址。请确保回调URL是外部可正常访问的,且不能携带后缀参数,否则可能导致商户无法接收到微信的回调通知信息。

      import com.alibaba.fastjson.JSONObject;
      import com.xxx.framework.redis.RedisCache;
      import com.wechat.pay.contrib.apache.httpclient.auth.Verifier;
      import com.wechat.pay.contrib.apache.httpclient.util.AesUtil;
      import org.springframework.stereotype.Component;
      import javax.annotation.Resource;
      import javax.servlet.ServletInputStream;
      import javax.servlet.http.HttpServletRequest;
      import javax.servlet.http.HttpServletResponse;
      import java.io.BufferedReader;
      import java.io.IOException;
      import java.io.InputStreamReader;
      import java.io.UnsupportedEncodingException;
      import java.security.GeneralSecurityException;
      import java.util.HashMap;
      import java.util.Map;
      import java.util.stream.Collectors;
      import java.util.stream.Stream;
      /**
       * 微信支付回调工具类
       */
      @Component
      public class WxPayCallbackUtil {
          @Resource
          private RedisCache redisCache;
          @Resource
          private Verifier verifier;
          /**
           * 获取回调数据
           * @param request
           * @param response
           * @return
           */
          public Map wxChatPayCallback(HttpServletRequest request, HttpServletResponse response) {
              //获取报文
              String body = getRequestBody(request);
              //随机串
              String nonceStr = request.getHeader("Wechatpay-Nonce");
              //微信传递过来的签名
              String signature = request.getHeader("Wechatpay-Signature");
              //证书序列号(微信平台)
              String serialNo = request.getHeader("Wechatpay-Serial");
              //时间戳
              String timestamp = request.getHeader("Wechatpay-Timestamp");
              //构造签名串  应答时间戳\n,应答随机串\n,应答报文主体\n
              String signStr = Stream.of(timestamp, nonceStr, body).collect(Collectors.joining("\n", "", "\n"));
              Map map = new HashMap<>(2);
              try {
                  //验证签名是否通过
                  boolean result = verifiedSign(serialNo, signStr, signature);
                  if(result){
                      //解密数据
                      String plainBody = decryptBody(body);
                      return convertWechatPayMsgToMap(plainBody);
                  }
              } catch (Exception e) {
                  e.printStackTrace();
              }
              return map;
          }
          /**
           * 转换body为map
           * @param plainBody
           * @return
           */
          public Map convertWechatPayMsgToMap(String plainBody){
              Map paramsMap = new HashMap<>(2);
              JSONObject jsonObject = JSONObject.parseObject(plainBody);
              //商户订单号
              paramsMap.put("out_trade_no",jsonObject.getString("out_trade_no"));
              //交易状态
              paramsMap.put("trade_state",jsonObject.getString("trade_state"));
              //附加数据
              paramsMap.put("attach",jsonObject.getString("attach"));
              if (jsonObject.getJSONObject("attach") != null && !jsonObject.getJSONObject("attach").equals("")){
                  paramsMap.put("account_no",jsonObject.getJSONObject("attach").getString("accountNo"));
              }
              return paramsMap;
          }
          /**
           * 解密body的密文
           *
           * "resource": {
           *         "original_type": "transaction",
           *         "algorithm": "AEAD_AES_256_GCM",
           *         "ciphertext": "",
           *         "associated_data": "",
           *         "nonce": ""
           *     }
           *
           * @param body
           * @return
           */
          public String decryptBody(String body) throws UnsupportedEncodingException, GeneralSecurityException {
              AesUtil aesUtil = new AesUtil(redisCache.getCacheObject("WX_PAY_SAVE_KEY").toString().getBytes("utf-8"));
              JSONObject object = JSONObject.parseObject(body);
              JSONObject resource = object.getJSONObject("resource");
              String ciphertext = resource.getString("ciphertext");
              String associatedData = resource.getString("associated_data");
              String nonce = resource.getString("nonce");
              return aesUtil.decryptToString(associatedData.getBytes("utf-8"),nonce.getBytes("utf-8"),ciphertext);
          }
          /**
           * 验证签名
           *
           * @param serialNo  微信平台-证书序列号
           * @param signStr   自己组装的签名串
           * @param signature 微信返回的签名
           * @return
           * @throws UnsupportedEncodingException
           */
          public boolean verifiedSign(String serialNo, String signStr, String signature) throws UnsupportedEncodingException {
              return verifier.verify(serialNo, signStr.getBytes("utf-8"), signature);
          }
          /**
           * 读取请求数据流
           *
           * @param request
           * @return
           */
          public String getRequestBody(HttpServletRequest request) {
              StringBuffer sb = new StringBuffer();
              try (ServletInputStream inputStream = request.getInputStream();
                   BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
              ) {
                  String line;
                  while ((line = reader.readLine()) != null) {
                      sb.append(line);
                  }
              } catch (IOException e) {
                  e.printStackTrace();
              }
              return sb.toString();
          }
      }
      

      支付成功后的回调方法

      	 /**
           * 订单支付后回调
           */
          @Override
          public Map wxOrderCallBack(HttpServletRequest request, HttpServletResponse response) {
              Map map = new HashMap<>(2);
              try {
                  Map stringMap = wxPayCallbackUtil.wxChatPayCallback(request, response);
                  //支付成功
                  if (stringMap.get("trade_state").equals("SUCCESS")){
                      //编写支付成功后逻辑
                  }
                  //响应微信
                  map.put("code", "SUCCESS");
                  map.put("message", "成功");
              } catch (Exception e) {
                  e.printStackTrace();
              }
              return map;
          }
      

      五、微信支付-申请退款

      1. 申请退款请求对象

      微信支付订单号,微信支付订单号和商家订单号二选一,这个是必不可少的,原订单金额也是必填的,微信会做二次验证。

      @Data
      @ApiModel("微信退款对象")
      public class WxChatRefundDto {
          @ApiModelProperty("微信支付订单号,微信支付订单号和商家订单号二选一")
          private String transactionId;
          @ApiModelProperty("商家订单号,对应 out_trade_no")
          private String orderId;
          @ApiModelProperty("商户退款单号,对应out_refund_no")
          private String refundOrderId;
          @ApiModelProperty("退款原因,选填")
          private String reason;
          @ApiModelProperty("回调地址")
          private WxNotifyConstants notify;
          @ApiModelProperty("退款金额")
          private BigDecimal refundMoney;
          @ApiModelProperty("原订单金额,必填")
          private BigDecimal totalMoney;
      
      1. 将请求参数封装成Map集合
      import com.xxx.common.exception.ServiceException;
      import com.xxx.project.wx.constants.WxApiConstants;
      import com.xxx.project.wx.constants.WxPayConstants;
      import com.xxx.project.wx.dto.WxChatRefundDto;
      import lombok.extern.slf4j.Slf4j;
      import org.apache.commons.lang3.StringUtils;
      import org.apache.http.client.methods.CloseableHttpResponse;
      import org.apache.http.client.methods.HttpPost;
      import org.apache.http.impl.client.CloseableHttpClient;
      import java.io.IOException;
      import java.util.HashMap;
      import java.util.Map;
      @Slf4j
      public class WxPayRefundUtil {
          /**
           * 封装微信支付申请退款请求参数
           * @param dto 微信支付申请退款请求参数
           * @return 封装后的map微信支付申请退款请求参数对象
           */
          private static Map getRefundParams(WxPayConstants wxPayConstants, WxChatRefundDto dto) {
              Map paramsMap = new HashMap<>();
              if (StringUtils.isNoneBlank(dto.getTransactionId())) {
                  paramsMap.put("transaction_id", dto.getTransactionId());
              } else if (StringUtils.isNoneBlank(dto.getOrderId())) {
                  paramsMap.put("out_trade_no", dto.getOrderId());
              } else {
                  throw new ServiceException("微信支付订单号和商户订单号必须填写一个");
              }
              paramsMap.put("out_refund_no", dto.getRefundOrderId());
              if (StringUtils.isNoneBlank(dto.getReason())) {
                  paramsMap.put("reason", dto.getReason());
              }
              paramsMap.put("notify_url", wxPayConstants.getNotifyDomain().concat(dto.getNotify().getType()));
              Map amountMap = new HashMap<>();
              amountMap.put("refund", dto.getRefundMoney());
              amountMap.put("total", dto.getTotalMoney());
              amountMap.put("currency", "CNY");
              paramsMap.put("amount", amountMap);
              return paramsMap;
          }
          /**
           * 发起微信退款申请
           *
           * @param wxPayConfig 微信配置信息
           * @param param       微信支付申请退款请求参数
           * @param wxPayClient 微信请求客户端()
           * @return 微信支付二维码地址
           */
          public static String refundPay(WxPayConstants wxPayConfig, WxChatRefundDto param, CloseableHttpClient wxPayClient) {
              // 1.获取请求参数的Map格式
              Map paramsMap = getRefundParams(wxPayConfig, param);
              // 2.获取请求对象
              HttpPost httpPost = WxPayCommon.getHttpPost(wxPayConfig, WxApiConstants.DOMESTIC_REFUNDS, paramsMap);
              // 3.完成签名并执行请求
              CloseableHttpResponse response = null;
              try {
                  response = wxPayClient.execute(httpPost);
              } catch (IOException e) {
                  e.printStackTrace();
                  throw new ServiceException("微信支付请求失败");
              }
              // 4.解析response对象
              HashMap resultMap = WxPayCommon.resolverResponse(response);
              log.info("发起退款参数:{}",resultMap);
              if (resultMap != null) {
                  // 返回微信支付退款单号
                  return resultMap.get("refund_id");
              }
              return null;
          }
      }
      
      1. 申请退款使用
      @Resource
      private WxPayConstants wxPayConstants;
      @Resource
      private CloseableHttpClient closeableHttpClient;
      WxChatRefundDto dto = new WxChatRefundDto();
      dto.setOrderId(); //订单号
      String refundOrderId = IdWorker.getIdStr();
      dto.setRefundOrderId(refundOrderId);
      dto.setNotify(WxNotifyConstants.CAMPUS_CARD_REFUND_NOTIFY); //回调地址
      dto.setRefundMoney(new BigDecimal(1));//单位为分
      dto.setTotalMoney(new BigDecimal(1));//单位为分
      String s = WxPayRefundUtil.refundPay(wxPayConstants, dto, closeableHttpClient);
      

      注意:

      1、交易时间超过一年的订单无法提交退款

      2、微信支付退款支持单笔交易分多次退款(不超50次),多次退款需要提交原支付订单的商户订单号和设置不同的退款单号。申请退款总>金额不能超过订单金额。一笔退款失败后重新提交,请不要更换退款单号,请使用原商户退款单号

      3、错误或无效请求频率限制:6qps,即每秒钟异常或错误的退款申请请求不超过6次

      4、每个支付订单的部分退款次数不能超过50次

      5、如果同一个用户有多笔退款,建议分不同批次进行退款,避免并发退款导致退款失败

      6、申请退款接口的返回仅代表业务的受理情况,具体退款是否成功,需要通过退款查询接口获取结果

      7、一个月之前的订单申请退款频率限制为:5000/min

      8、同一笔订单多次退款的请求需相隔1分钟

      六、微信支付-退款成功回调

      1. 退款返回数据对象
      import cn.hutool.core.date.DateUtil;
      import io.swagger.annotations.ApiModel;
      import io.swagger.annotations.ApiModelProperty;
      import lombok.Data;
      import java.math.BigDecimal;
      import java.util.Date;
      @Data
      @ApiModel("微信退款回调参数")
      public class WxChatCallbackRefundDto {
          @ApiModelProperty("商户订单号")
          private String orderId;
          @ApiModelProperty("商户退款单号,out_refund_no")
          private String refundId;
          @ApiModelProperty("微信支付系统生成的订单号")
          private String transactionId;
          @ApiModelProperty("微信支付系统生成的退款订单号")
          private String transactionRefundId;
          @ApiModelProperty("退款渠道 1.ORIGINAL:原路退款 2.BALANCE:退回到余额 " +
                  "3.OTHER_BALANCE:原账户异常退到其他余额账户 4.OTHER_BANKCARD:原银行卡异常退到其他银行卡")
          private String 	channel;
          @ApiModelProperty("退款成功时间 当前退款成功时才有此返回值")
          private Date successTime;
          @ApiModelProperty("退款状态  退款到银行发现用户的卡作废或者冻结了,导致原路退款银行卡失败,可前往商户平台-交易中心,手动处理此笔退款。" +
                  "1.SUCCESS:退款成功 2.CLOSED:退款关闭 3.PROCESSING:退款处理中 4.ABNORMAL:退款异常")
          private String 	status;
          @ApiModelProperty("退款金额")
          private BigDecimal refundMoney;
          public Date getSuccessTime() {
              return successTime;
          }
          public void setSuccessTime(String successTime) {
              // Hutool工具包的方法,自动识别一些常用格式的日期字符串
              this.successTime = DateUtil.parse(successTime);
          }
      }
      
      1. 退款业务处理接口
      import com.xxx.project.wx.dto.WxChatCallbackRefundDto;
      /**
       * 退款处理接口,为了防止项目开发人员,不手动判断退款失败的情况
       * 退款失败:退款到银行发现用户的卡作废或者冻结了,导致原路退款银行卡失败,可前往商户平台-交易中心,手动处理此笔退款
       */
      public interface WechatRefundCallback {
          /**
           * 退款成功处理情况
           */
          void success(WxChatCallbackRefundDto refundData);
          /**
           * 退款失败处理情况
           */
          void fail(WxChatCallbackRefundDto refundData);
      }
      
      1. 微信退款回调方法
      public class HttpUtils{
      	/**
           * 将通知参数转化为字符串
           * @param request
           * @return
           */
          public static String readData(HttpServletRequest request) {
              BufferedReader br = null;
              try {
                  StringBuilder result = new StringBuilder();
                  br = request.getReader();
                  for (String line; (line = br.readLine()) != null; ) {
                      if (result.length() > 0) {
                          result.append("\n");
                      }
                      result.append(line);
                  }
                  return result.toString();
              } catch (IOException e) {
                  throw new RuntimeException(e);
              } finally {
                  if (br != null) {
                      try {
                          br.close();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  }
              }
          }
      }
      
      package com.runerrands.project.wx.util;
      import com.wechat.pay.contrib.apache.httpclient.auth.Verifier;
      import org.slf4j.Logger;
      import org.slf4j.LoggerFactory;
      import javax.servlet.http.HttpServletRequest;
      import java.io.IOException;
      import java.nio.charset.StandardCharsets;
      import java.time.DateTimeException;
      import java.time.Duration;
      import java.time.Instant;
      import static com.wechat.pay.contrib.apache.httpclient.constant.WechatPayHttpHeaders.*;
      public class WechatPayValidatorForRequest {
          protected static final Logger log = LoggerFactory.getLogger(WechatPayValidatorForRequest.class);
          /**
           * 应答超时时间,单位为分钟
           */
          protected static final long RESPONSE_EXPIRED_MINUTES = 5;
          protected final Verifier verifier;
          protected final String body;
          protected final String requestId;
          public WechatPayValidatorForRequest(Verifier verifier, String body, String requestId) {
              this.verifier = verifier;
              this.body = body;
              this.requestId = requestId;
          }
          protected static IllegalArgumentException parameterError(String message, Object... args) {
              message = String.format(message, args);
              return new IllegalArgumentException("parameter error: " + message);
          }
          protected static IllegalArgumentException verifyFail(String message, Object... args) {
              message = String.format(message, args);
              return new IllegalArgumentException("signature verify fail: " + message);
          }
          public final boolean validate(HttpServletRequest request) throws IOException {
              try {
                  validateParameters(request);
                  String message = buildMessage(request);
                  String serial = request.getHeader(WECHAT_PAY_SERIAL);
                  String signature = request.getHeader(WECHAT_PAY_SIGNATURE);
                  if (!verifier.verify(serial, message.getBytes(StandardCharsets.UTF_8), signature)) {
                      throw verifyFail("serial=[%s] message=[%s] sign=[%s], request-id=[%s]",
                              serial, message, signature, request.getHeader(REQUEST_ID));
                  }
              } catch (IllegalArgumentException e) {
                  log.warn(e.getMessage());
                  return false;
              }
              return true;
          }
          protected final void validateParameters(HttpServletRequest request) {
              // NOTE: ensure HEADER_WECHAT_PAY_TIMESTAMP at last
              String[] headers = {WECHAT_PAY_SERIAL, WECHAT_PAY_SIGNATURE, WECHAT_PAY_NONCE, WECHAT_PAY_TIMESTAMP};
              String header = null;
              for (String headerName : headers) {
                  header = request.getHeader(headerName);
                  if (header == null) {
                      throw parameterError("empty [%s], request-id=[%s]", headerName, requestId);
                  }
              }
              String timestampStr = header;
              try {
                  Instant responseTime = Instant.ofEpochSecond(Long.parseLong(timestampStr));
                  // 拒绝过期应答
                  if (Duration.between(responseTime, Instant.now()).abs().toMinutes() >= RESPONSE_EXPIRED_MINUTES) {
                      throw parameterError("timestamp=[%s] expires, request-id=[%s]", timestampStr, requestId);
                  }
              } catch (DateTimeException | NumberFormatException e) {
                  throw parameterError("invalid timestamp=[%s], request-id=[%s]", timestampStr, requestId);
              }
          }
          protected final String buildMessage(HttpServletRequest request) throws IOException {
              String timestamp = request.getHeader(WECHAT_PAY_TIMESTAMP);
              String nonce = request.getHeader(WECHAT_PAY_NONCE);
              return timestamp + "\n"
                      + nonce + "\n"
                      + body + "\n";
          }
      }
      
      import com.google.gson.Gson;
      import com.xxx.common.exception.ServiceException;
      import com.xxx.common.utils.http.HttpUtils;
      import com.xxx.project.wx.constants.WxPayConstants;
      import com.xxx.project.wx.dto.WxChatCallbackRefundDto;
      import com.xxx.project.wx.service.WechatRefundCallback;
      import com.wechat.pay.contrib.apache.httpclient.auth.Verifier;
      import com.wechat.pay.contrib.apache.httpclient.util.AesUtil;
      import lombok.extern.slf4j.Slf4j;
      import org.apache.commons.lang3.StringUtils;
      import javax.servlet.http.HttpServletRequest;
      import javax.servlet.http.HttpServletResponse;
      import java.math.BigDecimal;
      import java.nio.charset.StandardCharsets;
      import java.security.GeneralSecurityException;
      import java.util.HashMap;
      import java.util.Map;
      @Slf4j
      public class WxPayRefundCallbackUtil {
          /**
           * 微信支付申请退款回调方法
           *
           * @param verifier       证书
           * @param wxPayConfig    微信配置
           * @param refundCallback 回调方法,用于处理业务逻辑,包含退款成功处理于退款失败处理
           * @return json格式的string数据,直接返回给微信
           */
          public static String wxPayRefundCallback(HttpServletRequest request, HttpServletResponse response, Verifier verifier, WxPayConstants wxPayConfig, WechatRefundCallback refundCallback) {
              Gson gson = new Gson();
              // 1.处理通知参数
              final String body = HttpUtils.readData(request);
              HashMap bodyMap = gson.fromJson(body, HashMap.class);
              // 2.签名验证
              WechatPayValidatorForRequest wechatForRequest = new WechatPayValidatorForRequest(verifier, body, (String) bodyMap.get("id"));
              try {
                  if (!wechatForRequest.validate(request)) {
                      // 通知验签失败
                      response.setStatus(500);
                      final HashMap map = new HashMap<>();
                      map.put("code", "ERROR");
                      map.put("message", "通知验签失败");
                      return gson.toJson(map);
                  }
              } catch (Exception e) {
                  e.printStackTrace();
              }
              // 3.获取明文数据
              String plainText = decryptFromResource(bodyMap, wxPayConfig);
              HashMap plainTextMap = gson.fromJson(plainText, HashMap.class);
      //        log.info("退款plainTextMap:{}", plainTextMap);
              // 4.封装微信返回的数据
              WxChatCallbackRefundDto refundData = getRefundCallbackData(plainTextMap);
              if ("SUCCESS".equals(refundData.getStatus())) {
                  // 执行业务逻辑
                  refundCallback.success(refundData);
              } else {
                  // 特殊情况退款失败业务处理,退款到银行发现用户的卡作废或者冻结了,导致原路退款银行卡失败,可前往商户平台-交易中心,手动处理此笔退款
                  refundCallback.fail(refundData);
              }
              // 5.成功应答
              response.setStatus(200);
              final HashMap resultMap = new HashMap<>();
              resultMap.put("code", "SUCCESS");
              resultMap.put("message", "成功");
              return gson.toJson(resultMap);
          }
          private static WxChatCallbackRefundDto getRefundCallbackData(HashMap plainTextMap) {
              Gson gson = new Gson();
              WxChatCallbackRefundDto refundData = new WxChatCallbackRefundDto();
              String successTime = String.valueOf(plainTextMap.get("success_time"));
              if (StringUtils.isNoneBlank(successTime)) {
                  refundData.setSuccessTime(successTime);
              }
              refundData.setOrderId(String.valueOf(plainTextMap.get("out_trade_no")));
              refundData.setRefundId(String.valueOf(plainTextMap.get("out_refund_no")));
              refundData.setTransactionId(String.valueOf(plainTextMap.get("transaction_id")));
              refundData.setTransactionRefundId(String.valueOf(plainTextMap.get("refund_id")));
              refundData.setChannel(String.valueOf(plainTextMap.get("channel")));
              final String status = String.valueOf(plainTextMap.get("refund_status"));
              refundData.setStatus(status);
              String amount = String.valueOf(plainTextMap.get("amount"));
              HashMap amountMap = gson.fromJson(amount, HashMap.class);
              String refundMoney = String.valueOf(amountMap.get("refund"));
              refundData.setRefundMoney(new BigDecimal(refundMoney).movePointLeft(2));
      //        log.info("refundData:{}", refundData);
              return refundData;
          }
          /**
           * 对称解密
           */
          private static String decryptFromResource(HashMap bodyMap, WxPayConstants wxPayConfig) {
              // 通知数据
              Map resourceMap = (Map) bodyMap.get("resource");
              // 数据密文
              String ciphertext = resourceMap.get("ciphertext");
              // 随机串
              String nonce = resourceMap.get("nonce");
              // 附加数据
              String associateData = resourceMap.get("associated_data");
              AesUtil aesUtil = new AesUtil(wxPayConfig.getKey().getBytes(StandardCharsets.UTF_8));
              try {
                  return aesUtil.decryptToString(associateData.getBytes(StandardCharsets.UTF_8), nonce.getBytes(StandardCharsets.UTF_8), ciphertext);
              } catch (GeneralSecurityException e) {
                  e.printStackTrace();
                  throw new ServiceException("解密失败");
              }
          }
      }
      
      1. 回调方法
      @Resource
      private WxPayConstants wxPayConfig;
      @Resource
      private Verifier verifier;
      @ApiOperation("微信退款回调接口")
          @PostMapping("/refundWechatCallback")
          public String refundWechatCallback(HttpServletRequest request, HttpServletResponse response) {
              return WxPayRefundCallbackUtil.wxPayRefundCallback(request, response, verifier, wxPayConfig, new WechatRefundCallback() {
                  @Override
                  public void success(WxChatCallbackRefundDto refundData) {
                      // TODO 退款成功的业务逻辑,例如更改订单状态为退款成功等
                     System.out.println("退款成功");
                  }
                  @Override
                  public void fail(WxChatCallbackRefundDto refundData) {
                      // TODO 特殊情况下退款失败业务处理,例如银行卡冻结需要人工退款,此时可以邮件或短信提醒管理员,并携带退款单号等关键信息
                      System.out.println("退款失败");
                  }
              });
          }