Java+微信支付（下预购单+回调+退款+查询账单）

前言：

现在的APP的离不开微信支付， 现在项目里接入微信支付 ， 微信支付的官方文档是：https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9_1 。 也很明了，这里是我的示例。

作为客户端， 需要接入的功能大概四个：

1  下预购单， 这里生成签名去请求微信， 返回预购单交易号。 再拼接客户端需要的对象，让客户端发起支付。

2  回调接口， 当APP完成支付， 微信会调用商户的回调接口， 告诉回调结果。

3  退款, 发起的支付 需要退款， 这里需要下载证书。

4   查询订单结果， 回调可能失败， 这时候需要商户服务端主动去查询 订单处理结果。

代码：

1.1 微信工具类 生成签名， 验签等

package com.yupaopao.trade.api.gateway.utils;

import com.yupaopao.trade.api.gateway.code.SignType;
import com.yupaopao.trade.api.gateway.code.WXPayConstants;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.input.SAXBuilder;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.*;
import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.URL;
import java.security.MessageDigest;
import java.util.*;

public class WxUtil {

    /**
     * XML格式字符串转换为Map
     *
     * @param strXML XML字符串
     * @return XML数据转换后的Map
     * @throws Exception
     */
    public static Map<String, String> xmlToMap(String strXML) throws Exception {
        Map<String, String> data = new HashMap<String, String>();
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder= documentBuilderFactory.newDocumentBuilder();
        InputStream stream = new ByteArrayInputStream(strXML.getBytes("UTF-8"));
        org.w3c.dom.Document doc = documentBuilder.parse(stream);
        doc.getDocumentElement().normalize();
        NodeList nodeList = doc.getDocumentElement().getChildNodes();
        for (int idx=0; idx<nodeList.getLength(); ++idx) {
            Node node = nodeList.item(idx);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                org.w3c.dom.Element element = (org.w3c.dom.Element) node;
                data.put(element.getNodeName(), element.getTextContent());
            }
        }
        try {
            stream.close();
        }
        catch (Exception ex) {

        }
        return data;
    }

    /**
     * 将Map转换为XML格式的字符串
     *
     * @param data Map类型数据
     * @return XML格式的字符串
     * @throws Exception
     */
    public static String mapToXml(Map<String, String> data) throws Exception {
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder= documentBuilderFactory.newDocumentBuilder();
        org.w3c.dom.Document document = documentBuilder.newDocument();
        org.w3c.dom.Element root = document.createElement("xml");
        document.appendChild(root);
        for (String key: data.keySet()) {
            String value = data.get(key);
            if (value == null) {
                value = "";
            }
            value = value.trim();
            org.w3c.dom.Element filed = document.createElement(key);
            filed.appendChild(document.createTextNode(value));
            root.appendChild(filed);
        }
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer = tf.newTransformer();
        DOMSource source = new DOMSource(document);
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        StringWriter writer = new StringWriter();
        StreamResult result = new StreamResult(writer);
        transformer.transform(source, result);
        String output = writer.getBuffer().toString(); //.replaceAll("\n|\r", "");
        try {
            writer.close();
        }
        catch (Exception ex) {
        }
        return output;
    }

    /**
     * 生成带有 sign 的 XML 格式字符串
     *
     * @param data Map类型数据
     * @param key API密钥
     * @return 含有sign字段的XML
     */
    public static String generateSignedXml(final Map<String, String> data, String key) throws Exception {
        return generateSignedXml(data, key, SignType.MD5);
    }

    /**
     * 生成带有 sign 的 XML 格式字符串
     *
     * @param data Map类型数据
     * @param key API密钥
     * @param signType 签名类型
     * @return 含有sign字段的XML
     */
    public static String generateSignedXml(final Map<String, String> data, String key, SignType signType) throws Exception {
        String sign = generateSignature(data, key, signType);
        data.put(WXPayConstants.FIELD_SIGN, sign);
        return mapToXml(data);
    }

    /**
     * 判断签名是否正确
     *
     * @param xmlStr XML格式数据
     * @param key API密钥
     * @return 签名是否正确
     * @throws Exception
     */
    public static boolean isSignatureValid(String xmlStr, String key) throws Exception {
        Map<String, String> data = xmlToMap(xmlStr);
        if (!data.containsKey(WXPayConstants.FIELD_SIGN) ) {
            return false;
        }
        String sign = data.get(WXPayConstants.FIELD_SIGN);
        return generateSignature(data, key).equals(sign);
    }

    /**
     * 判断签名是否正确，必须包含sign字段，否则返回false。使用MD5签名。
     *
     * @param data Map类型数据
     * @param key API密钥
     * @return 签名是否正确
     * @throws Exception
     */
    public static boolean isSignatureValid(Map<String, String> data, String key) throws Exception {
        return isSignatureValid(data, key, SignType.MD5);
    }

    /**
     * 判断签名是否正确，必须包含sign字段，否则返回false。
     *
     * @param data Map类型数据
     * @param key API密钥
     * @param signType 签名方式
     * @return 签名是否正确
     * @throws Exception
     */
    public static boolean isSignatureValid(Map<String, String> data, String key, SignType signType) throws Exception {
        if (!data.containsKey(WXPayConstants.FIELD_SIGN) ) {
            return false;
        }
        String sign = data.get(WXPayConstants.FIELD_SIGN);
        return generateSignature(data, key, signType).equals(sign);
    }

    /**
     * 生成签名
     *
     * @param data 待签名数据
     * @param key API密钥
     * @return 签名
     */
    public static String generateSignature(final Map<String, String> data, String key) throws Exception {
        return generateSignature(data, key, SignType.MD5);
    }

    /**
     * 生成签名. 注意，若含有sign_type字段，必须和signType参数保持一致。
     *
     * @param data 待签名数据
     * @param key API密钥
     * @param signType 签名方式
     * @return 签名
     */
    public static String generateSignature(final Map<String, String> data, String key, SignType signType) throws Exception {
        Set<String> keySet = data.keySet();
        String[] keyArray = keySet.toArray(new String[keySet.size()]);
        Arrays.sort(keyArray);
        StringBuilder sb = new StringBuilder();
        for (String k : keyArray) {
            if (k.equals(WXPayConstants.FIELD_SIGN)) {
                continue;
            }
            if (data.get(k).trim().length() > 0) // 参数值为空，则不参与签名
                sb.append(k).append("=").append(data.get(k).trim()).append("&");
        }
        sb.append("key=").append(key);
        if (SignType.MD5.equals(signType)) {
            return MD5(sb.toString()).toUpperCase();
        }
        else if (SignType.HMACSHA256.equals(signType)) {
            return HMACSHA256(sb.toString(), key);
        }
        else {
            throw new Exception(String.format("Invalid sign_type: %s", signType));
        }
    }

    /**
     * 获取随机字符串 Nonce Str
     *
     * @return String 随机字符串
     */
    public static String generateNonceStr() {
        return UUID.randomUUID().toString().replaceAll("-", "").substring(0, 32);
    }

    /**
     * 生成 MD5
     *
     * @param data 待处理数据
     * @return MD5结果
     */
    public static String MD5(String data) throws Exception {
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] array = md.digest(data.getBytes("UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (byte item : array) {
            sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
        }
        return sb.toString().toUpperCase();
    }

    /**
     * 生成 HMACSHA256
     * @param data 待处理数据
     * @param key 密钥
     * @return 加密结果
     * @throws Exception
     */
    public static String HMACSHA256(String data, String key) throws Exception {
        Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
        SecretKeySpec secret_key = new SecretKeySpec(key.getBytes("UTF-8"), "HmacSHA256");
        sha256_HMAC.init(secret_key);
        byte[] array = sha256_HMAC.doFinal(data.getBytes("UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (byte item : array) {
            sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
        }
        return sb.toString().toUpperCase();
    }

    /**
     * xml解析
     * @param strxml
     * @return
     * @throws Exception
     */
    public static Map<String, String> doXMLParse(String strxml) throws Exception {
        Map<String,String> m = new HashMap<String,String>();
        try {
             strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");
                if(null == strxml || "".equals(strxml)) {
                    return null;
                }
                InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8"));
                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 = getChildrenText(children);
                    }

                    m.put(k, v);
                }

                //关闭流
                in.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return m;

    }

    /**
     * 获取子节点数据
     * @param children
     * @return
     */
    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(getChildrenText(list));
                }
                sb.append(value);
                sb.append("</" + name + ">");
            }
        }
        return sb.toString();
    }

    //发起微信支付请求
    public static String httpsRequest(String requestUrl, String requestMethod, String outputStr) {
        try {
            URL url = new URL(requestUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setUseCaches(false);
            // 设置请求方式（GET/POST）
            conn.setRequestMethod(requestMethod);
            conn.setRequestProperty("content-type", "application/x-www-form-urlencoded");
            // 当outputStr不为null时向输出流写数据
            if (null != outputStr) {
                OutputStream outputStream = conn.getOutputStream();
                // 注意编码格式
                outputStream.write(outputStr.getBytes("UTF-8"));
                outputStream.close();
            }
            // 从输入流读取返回内容
            InputStream inputStream = conn.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);
            }
            // 释放资源
            bufferedReader.close();
            inputStreamReader.close();
            inputStream.close();
            inputStream = null;
            conn.disconnect();
            return buffer.toString();
        } catch (ConnectException ce) {
            ce.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 返回给微信服务端的xml
     * @param return_code
     * @return
     */
    public static String returnXML(String return_code) {

        return "<xml><return_code><![CDATA["

                + return_code

                + "]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>";
    }

    //Map转xml数据
    public static String GetMapToXML(Map<String,String> param){
        StringBuffer sb = new StringBuffer();
        sb.append("<xml>");
        for (Map.Entry<String,String> entry : param.entrySet()) {
            sb.append("<"+ entry.getKey() +">");
            sb.append(entry.getValue());
            sb.append("</"+ entry.getKey() +">");
        }
        sb.append("</xml>");
        return sb.toString();
    }

    /**
     * 获取Ip
     * @return
     */
    public static String GetIp() {
        InetAddress ia=null;
        try {
            ia= InetAddress.getLocalHost();
            String localip=ia.getHostAddress();
            return localip;
        } catch (Exception e) {
            return null;
        }
    }

    public static String getRequestXml(SortedMap<String,String> parameters){
        StringBuffer sb = new StringBuffer();
        sb.append("<xml>");
        Set es = 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 ("attach".equalsIgnoreCase(k)||"body".equalsIgnoreCase(k)||"sign".equalsIgnoreCase(k)) {
                sb.append("<"+k+">"+"<![CDATA["+v+"]]></"+k+">");
            }else {
                sb.append("<"+k+">"+v+"</"+k+">");
            }
        }
        sb.append("</xml>");
        return sb.toString();
    }

}

2 service实现类

package com.yupaopao.trade.gateway.service.impl;

import com.yupaopao.trade.api.account.response.WXGzhResponse;
import com.yupaopao.trade.api.account.response.WXPayResponse;
import com.yupaopao.trade.api.gateway.code.*;
import com.yupaopao.trade.api.gateway.request.PayRequest;
import com.yupaopao.trade.api.gateway.request.RefundRequest;
import com.yupaopao.trade.api.gateway.request.WeixinOrderFindRequest;
import com.yupaopao.trade.api.gateway.sdk.qqpay.config.ClientCustomSSL;
import com.yupaopao.trade.api.gateway.utils.WxUtil;
import com.yupaopao.trade.api.payment.code.PaymentConstant;
import com.yupaopao.trade.api.payment.dto.YppException;
import com.yupaopao.trade.api.utils.IdWorker;
import com.yupaopao.trade.common.config.ThirdUrlConfig;
import com.yupaopao.trade.common.exception.TradeException;
import com.yupaopao.trade.domain.mapper.PayMapper;
import com.yupaopao.trade.domain.mapper.PaymentDetailMapper;
import com.yupaopao.trade.domain.mapper.RefundDetailMapper;
import com.yupaopao.trade.domain.model.PaymentDetail;
import com.yupaopao.trade.domain.model.RefundDetail;
import com.yupaopao.trade.gateway.service.WxPayService;
import com.yupaopao.trade.payment.service.TradeService;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
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.HttpClients;
import org.apache.http.ssl.SSLContexts;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.util.ResourceUtils;

import javax.net.ssl.SSLContext;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.security.KeyStore;
import java.util.HashMap;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

/**
 * Created by zhuliangxing on 2017/4/21.
 */
@Service
public class WxpayServiceImpl implements WxPayService {

    private static final Logger LOGGER = LoggerFactory.getLogger(WxpayServiceImpl.class);

    @Autowired
    private PayMapper payMapper;

    @Autowired
    private TradeService tradeService;

    @Value("${third.callback.net_url}")
    private String notifyUrl;

    @Autowired
    private PaymentDetailMapper paymentDetailsMapper;

    @Autowired
    private RefundDetailMapper refundDetailMapper;

    /**
     * 统一下单
     *
     * @param request
     * @return
     */
    public WXPayResponse wxPay(PayRequest request) {
        WXPayResponse response = new WXPayResponse();

        PaymentDetail detail = null;
        Map<String, String> data = null;
        try {
            // 组装XML
            String xml = WXParamGenerate(request.getSubject(), request.getOutTradeNo(), request.getTotalFee());
            // 发送http请求到微信服务端，获取返回的参数
            String res = WxUtil.httpsRequest(WXPayConstants.WX_PAYURL, "POST", xml);
            data = WxUtil.doXMLParse(res);
            detail = new PaymentDetail();
            detail.setCallbackStatus(CallbackType.unCall.getStatusValue());
            detail.setUserId(request.getUserId());
            detail.setType(PayType.wxPay.getStatusValue());
            detail.setPaymentId(request.getPaymentId());
            detail.setOrderType(request.getOrderType());
            detail.setTotalFee(request.getTotalFee());
            detail.setStatus(PayStatus.unPay.getStatusValue());
            detail.setOutTradeNo(request.getOutTradeNo());
            detail.setSubject(request.getSubject());

            Map<String, String> param = new HashMap<String, String>();
            param.put("appid", WXPayConstants.APP_ID);

            param.put("partnerid", WXPayConstants.MCH_ID);
            param.put("prepayid", data.get("prepay_id"));
            param.put("noncestr", data.get("nonce_str"));

            String timeStamp = System.currentTimeMillis() / 1000 + "";
            param.put("timestamp", timeStamp);
            param.put("package", "Sign=WXPay");
            String sign = WxUtil.generateSignature(param, WXPayConstants.WX_PARTNERKEY, SignType.MD5);
            response.setAppId(WXPayConstants.APP_ID);
            response.setPartnerId(WXPayConstants.MCH_ID);
            response.setTimestamp(timeStamp);
            response.setNoncestr(data.get("nonce_str"));
            response.setSign(sign);
            response.setPrepayId(data.get("prepay_id"));
            paymentDetailsMapper.insertPayment(detail);
            return response;
        } catch (Exception e) {
            throw new YppException(PayException.xmlParseError);
        }
    }

    /**
     * 微信统一下单参数设置
     *
     * @param description
     * @param orderOutId
     * @param totalFee
     * @return
     * @throws Exception
     */
    public String WXParamGenerate(String description, String orderOutId, Long totalFee) throws Exception {
        Map<String, String> param = new HashMap<String, String>();
        param.put("appid", WXPayConstants.APP_ID);
        param.put("mch_id", WXPayConstants.MCH_ID);
        param.put("nonce_str", WxUtil.generateNonceStr());
        param.put("body", description);
        param.put("out_trade_no", orderOutId);
        param.put("total_fee", totalFee + "");
        param.put("spbill_create_ip", WxUtil.GetIp());
        param.put("notify_url", notifyUrl + WXPayConstants.NOTIFU_URL);
        param.put("trade_type", "APP");
        String sign = WxUtil.generateSignature(param, WXPayConstants.WX_PARTNERKEY, SignType.MD5);
        param.put("sign", sign);
        return WxUtil.GetMapToXML(param);
    }

    /**
     * 拼接微信退款XML
     *
     * @param request
     * @return
     * @throws Exception
     */
    public static SortedMap<String, String> WXRefundParamGenerate(RefundRequest request) {

        SortedMap<String, String> param = new TreeMap<String, String>();
        try {
            param.put("appid", WXPayConstants.APP_ID);
            param.put("mch_id", WXPayConstants.MCH_ID);
            param.put("nonce_str", WxUtil.generateNonceStr());
            param.put("out_trade_no", request.getOutTradeNo());
            // 支付网关生成订单流水
            param.put("out_refund_no", String.valueOf(IdWorker.nextId()));
            param.put("total_fee", String.valueOf(request.getTotalFee()));// 单位为分
            param.put("refund_fee", String.valueOf(request.getRefundFee()));// 单位为分
            param.put("op_user_id", WXPayConstants.MCH_ID);// 操作人员,默认为商户账号
            String sign = WxUtil.generateSignature(param, WXPayConstants.WX_PARTNERKEY, SignType.MD5);
            param.put("sign", sign);
        } catch (Exception e) {
            throw new YppException(PayException.signError);
        }
        return param;
    }

    /**
     * 解析微信返回的xml 参数
     *
     * @param request
     */
    public Map<String, String> xmlParserCallback(HttpServletRequest request) {
        Map<String, String> map = null;
        BufferedReader reader = null;
        String line = "";
        String xmlString = null;
        try {
            reader = request.getReader();
            StringBuffer inputString = new StringBuffer();

            while ((line = reader.readLine()) != null) {
                inputString.append(line);
            }
            xmlString = inputString.toString();
            request.getReader().close();
            LOGGER.info("----接收到的数据如下：---" + xmlString);
            map = WxUtil.doXMLParse(xmlString);
        } catch (Exception e) {
            throw new YppException(PayException.xmlParseError);
        }
        return map;
    }

    /**
     * IO解析获取微信的数据
     *
     * @param request
     * @return
     */
    public String getXmlString(HttpServletRequest request) {
        BufferedReader reader = null;
        String line = "";
        String xmlString = null;
        try {
            reader = request.getReader();
            StringBuffer inputString = new StringBuffer();

            while ((line = reader.readLine()) != null) {
                inputString.append(line);
            }
            xmlString = inputString.toString();
        } catch (Exception e) {
            throw new YppException(PayException.xmlParseError);
        }

        return xmlString;
    }

    /**
     * 微信回调
     *
     * @param request
     * @return
     */
    public String wxNotify(HttpServletRequest request) {
        LOGGER.info("微信正在回调》》》》》》》》》");
        PaymentDetail detail = null;
        String xmlString = "";
        String lastXml = "";

        try {
            xmlString = getXmlString(request);
            LOGGER.info("微信返回的回调结果是：：：：：：：" + xmlString);
            // 先解析返回的数据
            Map<String, String> dataMap = WxUtil.xmlToMap(xmlString);
            String returnCode = dataMap.get("return_code");
            // 通信成功
            if (ReturnStatus.success.getStatusValue().equals(returnCode)) {
                LOGGER.info("通信成功++++++++++++");

                // 验证通过才能记到流水表中，否则不计入
                if (WxUtil.isSignatureValid(xmlString, WXPayConstants.WX_PARTNERKEY)) {

                    try {
                        detail = new PaymentDetail();
                        detail.setTradeNo(dataMap.get("transaction_id"));
                        detail.setOutTradeNo(dataMap.get("out_trade_no"));
                        if (dataMap.get("result_code").equals(ReturnStatus.success)) {
                            detail.setStatus(PayStatus.paySuccess.getStatusValue());
                        } else {
                            detail.setStatus(PayStatus.payFail.getStatusValue());
                        }
                        detail.setType(PayType.wxPay.getStatusValue());
                        // 设置为已经回调
                        detail.setCallbackStatus(CallbackType.callable.getStatusValue());
                        paymentDetailsMapper.updatePayment(detail);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                }
                tradeService.dealWithPayCallBack(dataMap.get("out_trade_no").toString(),
                        dataMap.get("transaction_id").toString(), PaymentConstant.PayCallBackStatus.SUCCESS,
                        PaymentConstant.TradeAction.WEIXIN_ACCOUNT);
                lastXml = WxUtil.returnXML(ReturnStatus.success.getStatusValue());
            } else {

                lastXml = WxUtil.returnXML(ReturnStatus.fail.getStatusValue());
            }
        } catch (Exception e) {

            throw new TradeException(GatewayCode.PayBackError);
        }
        LOGGER.info("最终给微信的结果是：" + lastXml);
        return lastXml;

    }

    /**
     * 微信退款
     *
     * @param request
     * @return
     */
    public String wxRefund(RefundRequest request) {

        RefundDetail detail = null;
        // 拼装Map
        SortedMap<String, String> map = WXRefundParamGenerate(request);
        // 拼装XML
        String requestXml = WxUtil.getRequestXml(map);
        // 获取返回数据
        String refundResult = "";
        try {
            refundResult = ClientCustomSSL.doRefund(WXPayConstants.WX_REFUND, requestXml);
        } catch (Exception e) {
            throw new TradeException(GatewayCode.RefundBackXmlError);
        }
        System.out.println("退款产生的json字符串：" + refundResult);
        // 转换为Map
        Map<String, String> responseMap = new HashMap<>();
        try {
            responseMap = WxUtil.doXMLParse(refundResult);
        } catch (Exception e) {
            throw new TradeException(GatewayCode.RefundBackXmlError);
        }
        String returnCode = responseMap.get("return_code");
        // 通信正常
        if (returnCode.equals(ReturnStatus.success.getStatusValue())) {
            String resultCode = responseMap.get("result_code");
            detail = new RefundDetail();
            // 微信生成的退款ID
            String tradeNo = responseMap.get("out_refund_no");

            detail.setTradeNo(tradeNo);
            detail.setRefundId(IdWorker.unique());
            detail.setType(PayType.wxPay.getStatusValue());
            detail.setUserId(request.getUserId());
            detail.setSubject(responseMap.get("err_code_des"));
            detail.setorderOutId(request.getOutTradeNo());
            detail.setRefundFee(request.getRefundFee());
            detail.setTotalFee(request.getTotalFee());
            detail.setOriginTradeNo(tradeNo);
            // 退款成功
            if (resultCode.equals(ReturnStatus.success)) {
                detail.setStatus(PayStatus.paySuccess.getStatusValue());
                payMapper.saveRefund(detail);
                return ReturnStatus.success.getStatusValue();

            } else {
                detail.setStatus(PayStatus.payFail.getStatusValue());
                refundDetailMapper.insertRefund(detail);
                return ReturnStatus.fail.getStatusValue();

            }

        } else {
            throw new TradeException(GatewayCode.RefundHasGone);
        }

    }

    /**
     * 微信公众号支付下单
     */
    @Override
    public WXGzhResponse wxGZHPay(PayRequest request) {
        WXGzhResponse response = new WXGzhResponse();
        PaymentDetail detail = null;
        Map<String, String> data = null;
        try {
            // 组装XML
            String xml = WXGZHParamGenerate(request.getSubject(), request.getOutTradeNo(), request.getTotalFee(),
                    request.getPayExt().get("openId").toString());
            // 发送http请求到微信服务端，获取返回的参数
            String res = WxUtil.httpsRequest(WXPayConstants.WX_PAYURL, "POST", xml);
            data = WxUtil.doXMLParse(res);
            detail = new PaymentDetail();
            detail.setCallbackStatus(CallbackType.unCall.getStatusValue());
            detail.setUserId(request.getUserId());
            detail.setType(PayType.wxPay.getStatusValue());
            detail.setPaymentId(request.getPaymentId());
            detail.setOrderType(request.getOrderType());
            detail.setTotalFee(request.getTotalFee());
            detail.setStatus(PayStatus.unPay.getStatusValue());
            detail.setOutTradeNo(request.getOutTradeNo());
            detail.setSubject(request.getSubject());

            String timeStamp = System.currentTimeMillis() / 1000 + "";
            Map<String, String> param = new HashMap<String, String>();
            param.put("appId", WXPayConstants.WEIXIN_GZH_APPID);

            param.put("signType", "MD5");
            param.put("nonceStr", data.get("nonce_str"));

            param.put("timeStamp", timeStamp);
            param.put("package", "prepay_id=" + data.get("prepay_id"));

            String sign = WxUtil.generateSignature(param, WXPayConstants.WEIXIN_GZH_KEY, SignType.MD5);

            response.setAppId(WXPayConstants.WEIXIN_GZH_APPID);
            response.setNonceStr(data.get("nonce_str"));
            response.setPaySign(sign);
            response.setTimeStamp(timeStamp);
            response.setWxpackage("prepay_id=" + data.get("prepay_id"));
            response.setSignType("MD5");
            payMapper.saveDetail(detail);
            return response;
        } catch (Exception e) {
            e.printStackTrace();
            throw new YppException(PayException.xmlParseError);
        }
    }

    /**
     * 微信公众号统一下单
     *
     * @param description
     * @param orderOutId
     * @param totalFee
     * @return
     * @throws Exception
     */
    public String WXGZHParamGenerate(String description, String orderOutId, Long totalFee, String openId)
            throws Exception {
        Map<String, String> param = new HashMap<String, String>();
        param.put("appid", WXPayConstants.WEIXIN_GZH_APPID);
        param.put("mch_id", WXPayConstants.WEIXIN_GZH_MACHID);
        param.put("nonce_str", WxUtil.generateNonceStr());
        param.put("body", description);
        param.put("out_trade_no", orderOutId);
        param.put("openid", openId);
        param.put("total_fee", totalFee + "");
        param.put("spbill_create_ip", WxUtil.GetIp());
        param.put("notify_url", notifyUrl + WXPayConstants.NOTIFU_URL);
        param.put("trade_type", "JSAPI");
        String sign = WxUtil.generateSignature(param, WXPayConstants.WEIXIN_GZH_KEY, SignType.MD5);
        param.put("sign", sign);
        return WxUtil.GetMapToXML(param);
    }

    /**
     * 微信公众号账单查询
     */
    @Override
    public void wxGZHOrderFind(WeixinOrderFindRequest request) {
        Map<String, String> data = null;
        try {
            String xml = WXGZHOrderGenerate(request.getOutTradeNo());
            String res = WxUtil.httpsRequest(WXPayConstants.WEIXIN_ORDER_FIND_URL, "POST", xml);
            data = WxUtil.doXMLParse(res);
            // 通信异常
            if (!data.get("return_code").equals("SUCCESS")) {
                throw new TradeException(GatewayCode.CommunicationError);
            }
            if (!data.get("result_code").equals("SUCCESS")) {
                throw new TradeException(GatewayCode.OrderFindErrror);
            }
            if (!data.get("trade_state").equals("SUCCESS")) {
                throw new TradeException(GatewayCode.OrderPayError);
            }

        } catch (Exception e) {
            throw new TradeException(GatewayCode.PayXmlError);
        }

    }

    /**
     * 微信公众号生成订单。
     *
     * @param orderOutId
     * @return
     * @throws Exception
     */
    public String WXGZHOrderGenerate(String orderOutId) throws Exception {
        Map<String, String> param = new HashMap<String, String>();
        param.put("appid", WXPayConstants.WEIXIN_GZH_APPID);
        param.put("mch_id", WXPayConstants.WEIXIN_GZH_MACHID);
        param.put("nonce_str", WxUtil.generateNonceStr());
        param.put("out_trade_no", orderOutId);
        String sign = WxUtil.generateSignature(param, WXPayConstants.WEIXIN_GZH_KEY, SignType.MD5);
        param.put("sign", sign);
        return WxUtil.GetMapToXML(param);
    }
}

3下单返回的参数model 给 APP

package com.yupaopao.trade.api.account.response;

import com.alibaba.fastjson.JSONObject;

public class WXPayResponse {

    private String appId;

    private String partnerId;

    private String wxpackage="Sign=WXPay";

    private String noncestr;

    private String timestamp;

    private String sign;

    private String prepayId;

    public String getAppId() {
        return appId;
    }

    public void setAppId(String appId) {
        this.appId = appId;
    }

    public String getPartnerId() {
        return partnerId;
    }

    public void setPartnerId(String partnerId) {
        this.partnerId = partnerId;
    }

    public String getWxpackage() {
        return wxpackage;
    }

    public void setWxpackage(String wxpackage) {
        this.wxpackage = wxpackage;
    }

    public String getNoncestr() {
        return noncestr;
    }

    public void setNoncestr(String noncestr) {
        this.noncestr = noncestr;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }

    public String getSign() {
        return sign;
    }

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

    public String getPrepayId() {
        return prepayId;
    }

    public void setPrepayId(String prepayId) {
        this.prepayId = prepayId;
    }

    @Override
    public String toString() {

        JSONObject json  = new JSONObject();
        json.put("appId", appId);
        json.put("partnerId", partnerId);
        json.put("wxpackage", wxpackage);
        json.put("noncestr", noncestr);
        json.put("timestamp", timestamp);
        json.put("sign", sign);
        json.put("prepayId", prepayId);

        return json.toString();
    }

}

    /**
     * 微信支付回调
     *
     * @param request
     * @param response
     * @return
     * @throws Exception
     */
    @RequestMapping(method = RequestMethod.POST, value = "/wx/wxCallback")
    public YppResponse wxCallback(HttpServletRequest request, HttpServletResponse response) throws Exception {
        return YppResponse.success(wxPayService.wxNotify(request));
    }