SpringBoot对接小程序微信支付的实现

        <!-- 微信支付 SDK -->
        <dependency>
            <groupId>com.github.wxpay</groupId>
            <artifactId>wxpay-sdk</artifactId>
            <version>0.0.3</version>
        </dependency>

# 微信支付配置 notifyUrl：微信支付异步回调地址
pay:
  appId: #应用id
  apiKey: #商户私钥key
  mchId: #商户id
  appSecret: #小程序密钥
  notifyUrl: #支付回调地址

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
/**
 * 微信支付配置
 * @author lf
 * @date 2023/8/30
 */
@Data
@Component
@Configuration
@ConfigurationProperties(prefix = "pay")
public class WxPayConfig {
    /**
     * 微信公众号appid
     */
    private String appId;
    /**
     * 公众号设置的API v2密钥
     */
    private String apiKey;
    /**
     * 微信商户平台 商户id
     */
    private String mchId;
    /**
     *小程序密钥
     */
    private String appSecret;
    /**
     * 小程序支付异步回调地址
     */
    private String notifyUrl;
}

import lombok.Data;
import lombok.experimental.Accessors;
import java.math.BigDecimal;
/**
 * 微信支付预下单实体类
 */
@Data
@Accessors(chain = true)
public class WeChatPay {
    /**
     * 返回状态码  此字段是通信标识，非交易标识，交易是否成功需要查看result_code来判断
     */
    public String return_code;
    /**
     * 返回信息 当return_code为FAIL时返回信息为错误原因 ，例如 签名失败 参数格式校验错误
     */
    private String return_msg;
    /**
     * 公众账号ID 调用接口提交的公众账号ID
     */
    private String appid;
    /**
     * 商户号 调用接口提交的商户号
     */
    private String mch_id;
    /**
     * api密钥 详见：https://pay.weixin.qq.com/index.php/extend/employee
     */
    private String api_key;
    /**
     * 设备号  自定义参数，可以为请求支付的终端设备号等
     */
    private String device_info;
    /**
     * 随机字符串    5K8264ILTKCH16CQ2502SI8ZNMTM67VS   微信返回的随机字符串
     */
    private String nonce_str;
    /**
     * 签名 微信返回的签名值，详见签名算法:https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=4_3
     */
    private String sign;
    /**
     * 签名类型
     */
    private String sign_type;
    /**
     * 业务结果 SUCCESS SUCCESS/FAIL
     */
    private String result_code;
    /**
     * 错误代码 当result_code为FAIL时返回错误代码，详细参见下文错误列表
     */
    private String err_code;
    /**
     * 错误代码描述 当result_code为FAIL时返回错误描述，详细参见下文错误列表
     */
    private String err_code_des;
    /**
     * 交易类型 JSAPI JSAPI -JSAPI支付 NATIVE -Native支付 APP -APP支付 说明详见；https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=4_2
     */
    private String trade_type;
    /**
     * 预支付交易会话标识 微信生成的预支付会话标识，用于后续接口调用中使用，该值有效期为2小时
     */
    private String prepay_id;
    /**
     * 二维码链接     weixin://wxpay/bizpayurl/up?pr=NwY5Mz9&groupid=00 trade_type=NATIVE时有返回，此url用于生成支付二维码，然后提供给用户进行扫码支付。注意：code_url的值并非固定，使用时按照URL格式转成二维码即可
     */
    private String code_url;
    /**
     * 商品描述  商品简单描述，该字段请按照规范传递，具体请见 https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=4_2
     */
    private String body;
    /**
     * 商家订单号 商户系统内部订单号，要求32个字符内，只能是数字、大小写字母_-|* 且在同一个商户号下唯一。详见商户订单号 https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=4_2
     */
    private String out_trade_no;
    /**
     * 标价金额 订单总金额，单位为分，详见支付金额 https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=4_2
     */
    private String total_fee;
    /**
     * 终端IP 支持IPV4和IPV6两种格式的IP地址。用户的客户端IP
     */
    private String spbill_create_ip;
    /**
     * 通知地址 异步接收微信支付结果通知的回调地址，通知url必须为外网可访问的url，不能携带参数。公网域名必须为https，如果是走专线接入，使用专线NAT IP或者私有回调域名可使用http
     */
    private String notify_url;
    /**
     * 子商户号 sub_mch_id 非必填（商户不需要传入，服务商模式才需要传入） 微信支付分配的子商户号
     */
    private String sub_mch_id;
    /**
     * 附加数据，在查询API和支付通知中原样返回，该字段主要用于商户携带订单的自定义数据
     */
    private String attach;
    /**
     * 商户系统内部的退款单号，商户系统内部唯一，只能是数字、大小写字母_-|*@ ，同一退款单号多次请求只退一笔。
     */
    private String out_refund_no;
    /**
     * 退款总金额，单位为分，只能为整数，可部分退款。详见支付金额 https://pay.weixin.qq.com/wiki/doc/api/native_sl.php?chapter=4_2
     */
    private String refund_fee;
    /**
     * 退款原因 若商户传入，会在下发给用户的退款消息中体现退款原因 注意：若订单退款金额≤1元，且属于部分退款，则不会在退款消息中体现退款原因
     */
    private String refund_desc;
    /**
     * 交易结束时间 订单失效时间，格式为yyyyMMddHHmmss，如2009年12月27日9点10分10秒表示为20091227091010。其他详见时间规则 注意：最短失效时间间隔必须大于5分钟
     */
    private String time_expire;
    /**
     * 用户标识 trade_type=JSAPI，此参数必传，用户在主商户appid下的唯一标识。openid和sub_openid可以选传其中之一，如果选择传sub_openid,则必须传sub_appid。下单前需要调用【网页授权获取用户信息: https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/Wechat_webpage_authorization.html 】接口获取到用户的Openid。
     */
    private String openid;
    /**
     * 时间戳
     */
    private String time_stamp;
    /**
     * 会员类型
     */
    private String memberShipType;
}

/**
 * 微信支付API地址
 * @author lf
 * @date 2023/8/30
 */
public class WeChatPayUrlConstants {
    /**
     * 统一下单预下单接口url
     */
    public static final String Uifiedorder = "https://api.mch.weixin.qq.com/pay/unifiedorder";
    /**
     * 订单状态查询接口URL
     */
    public static final String Orderquery = "https://api.mch.weixin.qq.com/pay/orderquery";
    /**
     * 订单申请退款
     */
    public static final String Refund = "https://api.mch.weixin.qq.com/secapi/pay/refund";
    /**
     * 付款码 支付
     */
    public static final String MicroPay = "https://api.mch.weixin.qq.com/pay/micropay";
    /**
     * 微信网页授权 获取“code”请求地址
     */
    public static final String GainCodeUrl = "https://open.weixin.qq.com/connect/oauth2/authorize";
    /**
     * 微信网页授权 获取“code” 回调地址
     */
    public static final String GainCodeRedirect_uri = "http://i5jmxe.natappfree.cc/boss/WeChatPayMobile/SkipPage.html";
}

import lombok.Data;
@Data
public class OrderReturnInfo {
    private String return_code;
    private String return_msg;
    private String result_code;
    private String appid;
    private String mch_id;
    private String nonce_str;
    private String sign;
    private String prepay_id;
    private String trade_type;
}

import lombok.Data;
/**
 * 查询订单返回实体类
 * @author lf
 * @date 2023/9/1
 */
@Data
public class QueryReturnInfo {
    private String return_code;
    private String return_msg;
    private String result_code;
    private String err_code;
    private String err_code_des;
    private String appid;
    private String mch_id;
    private String nonce_str;
    private String sign;
    private String prepay_id;
    private String trade_type;
    private String device_info;
    private String openid;
    private String is_subscribe;
    private String trade_state;
    private String bank_type;
    private int total_fee;
    private int settlement_total_fee;
    private String fee_type;
    private int cash_fee;
    private String cash_fee_type;
    private int coupon_fee;
    private int coupon_count;
    private String coupon_type_$n;
    private String coupon_id_$n;
    private String transaction_id;
    private String out_trade_no;
    private String time_end;
    private String trade_state_desc;
}

/**
 * 签名实体类
 * @author lf
 * @date 2023/9/1
 */
@Data
public class SignInfo {
    private String appId;//小程序ID
    private String timeStamp;//时间戳
    private String nonceStr;//随机串
    @XStreamAlias("package")
    private String repay_id;
    private String signType;//签名方式
    public String getAppId() {
        return appId;
    }
    public void setAppId(String appId) {
        this.appId = appId;
    }
    public String getTimeStamp() {
        return timeStamp;
    }
    public void setTimeStamp(String timeStamp) {
        this.timeStamp = timeStamp;
    }
    public String getNonceStr() {
        return nonceStr;
    }
    public void setNonceStr(String nonceStr) {
        this.nonceStr = nonceStr;
    }
    public String getRepay_id() {
        return repay_id;
    }
    public void setRepay_id(String repay_id) {
        this.repay_id = repay_id;
    }
    public String getSignType() {
        return signType;
    }
    public void setSignType(String signType) {
        this.signType = signType;
    }
}

/**
 * Http工具类
 * @author lf
 * @date 2023/9/1
 */
public class HttpRequest {
    //连接超时时间，默认10秒
    private static final int socketTimeout = 10000;
    //传输超时时间，默认30秒
    private static final int connectTimeout = 30000;
    /**
     * post请求
     *
     * @throws IOException
     * @throws ClientProtocolException
     * @throws NoSuchAlgorithmException
     * @throws KeyStoreException
     * @throws KeyManagementException
     * @throws UnrecoverableKeyException
     */
    public static String sendPost(String url, Object xmlObj) throws ClientProtocolException, IOException, UnrecoverableKeyException, KeyManagementException, KeyStoreException, NoSuchAlgorithmException {
        HttpPost httpPost = new HttpPost(url);
        //解决XStream对出现双下划线的bug
        XStream xStreamForRequestPostData = new XStream(new DomDriver("UTF-8", new XmlFriendlyNameCoder("-_", "_")));
        xStreamForRequestPostData.alias("xml", xmlObj.getClass());
        //将要提交给API的数据对象转换成XML格式数据Post给API
        String postDataXML = xStreamForRequestPostData.toXML(xmlObj);
        //得指明使用UTF-8编码，否则到API服务器XML的中文不能被成功识别
        StringEntity postEntity = new StringEntity(postDataXML, "UTF-8");
        httpPost.addHeader("Content-Type", "text/xml");
        httpPost.setEntity(postEntity);
        //设置请求器的配置
        RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(socketTimeout).setConnectTimeout(connectTimeout).build();
        httpPost.setConfig(requestConfig);
        HttpClient httpClient = HttpClients.createDefault();
        HttpResponse response = httpClient.execute(httpPost);
        HttpEntity entity = response.getEntity();
        String result = EntityUtils.toString(entity, "UTF-8");
        return result;
    }
    /**
     * 自定义证书管理器，信任所有证书
     *
     * @author pc
     */
    public static class MyX509TrustManager implements X509TrustManager {
        @Override
        public void checkClientTrusted(
                java.security.cert.X509Certificate[] arg0, String arg1)
                throws CertificateException {
        }
        @Override
        public void checkServerTrusted(
                java.security.cert.X509Certificate[] arg0, String arg1)
                throws CertificateException {
        }
        @Override
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            return null;
        }
    }
}

/**
 * 微信签名
 * @author lf
 * @date 2023/9/1
 */
public class SignUtils {
    /**
     * 签名算法
     *
     * @param o 要参与签名的数据对象
     * @return 签名
     * @throws IllegalAccessException
     */
    public static String getSign(Object o) throws IllegalAccessException {
        ArrayList<String> list = new ArrayList<String>();
        Class cls = o.getClass();
        Field[] fields = cls.getDeclaredFields();
        for (Field f : fields) {
            f.setAccessible(true);
            if (f.get(o) != null && f.get(o) != "") {
                String name = f.getName();
                XStreamAlias anno = f.getAnnotation(XStreamAlias.class);
                if (anno != null) {
                    name = anno.value();
                }
                list.add(name + "=" + f.get(o) + "&");
            }
        }
        int size = list.size();
        String[] arrayToSort = list.toArray(new String[size]);
        Arrays.sort(arrayToSort, String.CASE_INSENSITIVE_ORDER);
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < size; i++) {
            sb.append(arrayToSort[i]);
        }
        String result = sb.toString();
        result += "key=" + Configure.getKey();
        System.out.println("签名数据：" + result);
        result = MD5.MD5Encode(result).toUpperCase();
        return result;
    }
    public static String getSign(Map<String, Object> map) {
        ArrayList<String> list = new ArrayList<String>();
        for (Map.Entry<String, Object> entry : map.entrySet()) {
            if (entry.getValue() != "") {
                list.add(entry.getKey() + "=" + entry.getValue() + "&");
            }
        }
        int size = list.size();
        String[] arrayToSort = list.toArray(new String[size]);
        Arrays.sort(arrayToSort, String.CASE_INSENSITIVE_ORDER);
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < size; i++) {
            sb.append(arrayToSort[i]);
        }
        String result = sb.toString();
        result += "key=" + Configure.getKey();
        //Util.log("Sign Before MD5:" + result);
        result = MD5.MD5Encode(result).toUpperCase();
        //Util.log("Sign Result:" + result);
        return result;
    }
}

import java.security.MessageDigest;
/**
 * MD5加密工具类
 * @author lf
 * @date 2023/9/1
 */
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()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return resultString;
    }
}

/**
 * 微信支付配置类
 * @author lf
 * @date 2023/9/1
 */
public class Configure {
    /**
     * 商户支付秘钥
     */
    private static String key = "";
    public static String getKey() {
        return key;
    }
    public static void setKey(String key) {
        Configure.key = key;
    }
}

    /**
     * 小程序支付下单接口
     * @return 返回结果
     */
    @ApiOperation("小程序支付功能")
    @PostMapping("/pay")
    public AjaxResult wxPay(@RequestBody PayParameterVO payParameterVO){
        Map payHistory = wxPayInfoService.insertPayRecord(payParameterVO);
        return success("success",payHistory);
    }
    /**
     * 查询订单
     */
    @ApiOperation("订单查询")
    @PostMapping("/wx/query")
    public AjaxResult orderQuery(@RequestParam("out_trade_no") String out_trade_no) {
       Map query = wxPayInfoService.orderQuery(out_trade_no);
       return success("success", query);
    }

import com.ruoyi.ai.doamin.PayParameterVO;
import java.util.Map;
/**
 * 微信小程序支付-业务接口层
 * @author lf
 * @date 2023/8/31
 */
public interface WxPayInfoService {
    /**
     * 插入订单记录
     */
    Map insertPayRecord(PayParameterVO payParameterVO);
    /**
     * 查询订单
     * @param out_trade_no 订单号
     * @return 返回结果
     */
    Map orderQuery(String out_trade_no);
}

import cn.hutool.core.util.ObjectUtil;
import com.github.wxpay.sdk.WXPayConstants;
import com.github.wxpay.sdk.WXPayUtil;
import com.ruoyi.ai.doamin.PayParameterVO;
import com.ruoyi.ai.service.WxPayInfoService;
import com.ruoyi.common.config.WxPayConfig;
import com.ruoyi.common.constant.WeChatPayUrlConstants;
import com.ruoyi.common.core.domain.pay.WeChatPay;
import com.ruoyi.common.utils.pay.HttpRequest;
import com.ruoyi.common.utils.pay.SignUtils;
import com.ruoyi.common.utils.pay.entity.OrderReturnInfo;
import com.ruoyi.common.utils.pay.entity.QueryReturnInfo;
import com.ruoyi.common.utils.pay.entity.SignInfo;
import com.thoughtworks.xstream.XStream;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import javax.annotation.Resource;
import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.util.*;
/**
 * 微信小程序支付-业务接口实现层
 * @author lf
 * @date 2023/8/31
 */
@Service
@Slf4j
public class WxPayInfoServiceImpl implements WxPayInfoService {
    @Resource
    private WxPayConfig payProperties;
    private static final DecimalFormat df = new DecimalFormat("#");
    /**
     * 插入订单记录
     * @param payParameterVO 用户ID 会员套餐ID
     * @return 返回结果
     */
    @Override
    @Transactional
    public Map insertPayRecord(PayParameterVO payParameterVO) {
            //接收返回的参数
            Map<String, Object> map = new HashMap<>();
            String title = "koko测试点数";
            //金额 * 100 以分为单位
            BigDecimal fee = BigDecimal.valueOf(1);
            BigDecimal RMB = new BigDecimal(100);
            BigDecimal totalFee = fee.multiply(RMB);
            try {
                WeChatPay weChatPay = new WeChatPay();
                weChatPay.setAppid(payProperties.getAppId());
                weChatPay.setMch_id(payProperties.getMchId());
                weChatPay.setNonce_str(getRandomStringByLength(32));
                weChatPay.setBody(title);
                weChatPay.setOut_trade_no(getRandomStringByLength(32));
                weChatPay.setTotal_fee( df.format(Double.parseDouble(String.valueOf(totalFee))));
                weChatPay.setSpbill_create_ip("127.0.0.1");
                weChatPay.setNotify_url(payProperties.getNotifyUrl());
                weChatPay.setTrade_type("JSAPI");
                //这里直接使用当前用户的openid
                weChatPay.setOpenid("oOKq*******xj8o");
                weChatPay.setSign_type("MD5");
                //生成签名
                String sign = SignUtils.getSign(weChatPay);
                weChatPay.setSign(sign);
                String result = HttpRequest.sendPost(WeChatPayUrlConstants.Uifiedorder, weChatPay);
                System.out.println(result);
                //将返回结果从xml格式转换为map格式
                Map<String, String> wxResultMap = WXPayUtil.xmlToMap(result);
                if (ObjectUtil.isNotEmpty(wxResultMap.get("return_code")) && wxResultMap.get("return_code").equals("SUCCESS")){
                    if (wxResultMap.get("result_code").equals("FAIL")){
                        map.put("msg", "统一下单失败");
                        map.put("status",500);
                        map.put("data", wxResultMap.get("err_code_des"));
                        return map;
                    }
                }
                XStream xStream = new XStream();
                xStream.alias("xml", OrderReturnInfo.class);
                OrderReturnInfo returnInfo = (OrderReturnInfo) xStream.fromXML(result);
                // 二次签名
                if ("SUCCESS".equals(returnInfo.getReturn_code()) && returnInfo.getReturn_code().equals(returnInfo.getResult_code())) {
                    SignInfo signInfo = new SignInfo();
                    signInfo.setAppId(payProperties.getAppId());
                    long time = System.currentTimeMillis() / 1000;
                    signInfo.setTimeStamp(String.valueOf(time));
                    signInfo.setNonceStr(WXPayUtil.generateNonceStr());
                    signInfo.setRepay_id("prepay_id=" + returnInfo.getPrepay_id());
                    signInfo.setSignType("MD5");
                    //生成签名
                    String sign1 = SignUtils.getSign(signInfo);
                    Map<String, String> payInfo = new HashMap<>();
                    payInfo.put("timeStamp", signInfo.getTimeStamp());
                    payInfo.put("nonceStr", signInfo.getNonceStr());
                    payInfo.put("package", signInfo.getRepay_id());
                    payInfo.put("signType", signInfo.getSignType());
                    payInfo.put("paySign", sign1);
                    map.put("status", 200);
                    map.put("msg", "统一下单成功!");
                    map.put("data", payInfo);
                    //预下单成功，处理业务逻辑
                    //****************************//
                    // 业务逻辑结束 回传给小程序端唤起支付
                    return map;
                }
                map.put("status", 500);
                map.put("msg", "统一下单失败!");
                map.put("data", null);
                return map;
            } catch (Exception e) {
                e.printStackTrace();
            }
        return null;
    }
    /**
     * 查询订单
     * @param out_trade_no 订单号
     * @return 返回结果
     */
    @Override
    public Map orderQuery(String out_trade_no){
        Map<String, Object> map = new HashMap<>();
        try {
            WeChatPay weChatPay = new WeChatPay();
            weChatPay.setAppid(payProperties.getAppId());
            weChatPay.setMch_id(payProperties.getMchId());
            weChatPay.setNonce_str(WXPayUtil.generateNonceStr());
            weChatPay.setOut_trade_no(out_trade_no);
            //order.setSign_type("MD5");
            //生成签名
            String sign = SignUtils.getSign(weChatPay);
            weChatPay.setSign(sign);
            String result = HttpRequest.sendPost(WXPayConstants.ORDERQUERY_URL, weChatPay);
            System.out.println(result);
            XStream xStream = new XStream();
            xStream.alias("xml", QueryReturnInfo.class);
            QueryReturnInfo returnInfo = (QueryReturnInfo) xStream.fromXML(result);
            map.put("status", 500);
            map.put("msg", "统一下单失败!");
            map.put("data", returnInfo);
            return map;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    /**
     * 获取一定长度的随机字符串
     *
     * @param length 指定字符串长度
     * @return 一定长度的字符串
     */
    public static String getRandomStringByLength(int length) {
        String base = "abcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < length; i++) {
            int number = random.nextInt(base.length());
            sb.append(base.charAt(number));
        }
        return sb.toString();
    }
}

    /**
     * 微信小程序支付成功回调
     * @param request 请求
     * @param response 响应
     * @return 返回结果
     * @throws Exception 异常处理
     */
    @RequestMapping("/weixin/callback")
    public String callBack(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("接口已被调用");
        ServletInputStream inputStream = request.getInputStream();
        String notifyXml = StreamUtils.inputStream2String(inputStream, "utf-8");
        System.out.println(notifyXml);
        // 解析返回结果
        Map<String, String> notifyMap = WXPayUtil.xmlToMap(notifyXml);
        // 判断支付是否成功
        if ("SUCCESS".equals(notifyMap.get("result_code"))) {
            //支付成功时候，处理业务逻辑
            System.out.println("支付成功");
            System.out.println("<xml>" + "<return_code><![CDATA[SUCCESS]]></return_code>"
                    + "<return_msg><![CDATA[OK]]></return_msg>" + "</xml> ");
            /**
             * 注意
             * 因为微信回调会有八次之多,所以当第一次回调成功了,那么我们就不再执行逻辑了
             * return返回的结果一定是这种格式，当result_code返回的结果是SUCCESS时，则不进行调用了
             * 如果不返回下面的格式，业务逻辑会出现回调多次的情况，我就遇到过这种情况。
             */
            return "<xml>" + "<return_code><![CDATA[SUCCESS]]></return_code>"
                        + "<return_msg><![CDATA[OK]]></return_msg>" + "</xml> ";
        }
        // 创建响应对象：微信接收到校验失败的结果后，会反复的调用当前回调函数
        Map<String, String> returnMap = new HashMap<>();
        returnMap.put("return_code", "FAIL");
        returnMap.put("return_msg", "");
        String returnXml = WXPayUtil.mapToXml(returnMap);
        response.setContentType("text/xml");
        System.out.println("校验失败");
        return returnXml;
    }

package: "prepay_id=wx*********0000";