前面已經講過微信APP支付的統一下單、支付結果通知、申請退款的介面開發，現在我們講述一下退款結果通知的流程開發。

1、應用場景

當商戶申請的退款有結果後，微信會把相關結果傳送給商戶，商戶需要接收處理，並返回應答。 
對後臺通知互動時，如果微信收到商戶的應答不是成功或超時，微信認為通知失敗，微信會通過一定的策略定期重新發起通知，儘可能提高通知的成功率，但微信不保證通知最終能成功。 （通知頻率為15/15/30/180/1800/1800/1800/1800/3600，單位：秒） 
注意：同樣的通知可能會多次傳送給商戶系統。商戶系統必須能夠正確處理重複的通知。 
推薦的做法是，當收到通知進行處理時，首先檢查對應業務資料的狀態，判斷該通知是否已經處理過，如果沒有處理過再進行處理，如果處理過直接返回結果成功。在對業務資料進行狀態檢查和處理之前，要採用資料鎖進行併發控制，以避免函式重入造成的資料混亂。 
特別說明：退款結果對重要的資料進行了加密，商戶需要用商戶祕鑰進行解密後才能獲得結果通知的內容

2、解密方式

解密步驟如下： 
（1）對加密串A做base64解碼，得到加密串B
（2）對商戶key做md5，得到32位小寫key* ( key設定路徑：微信商戶平臺(pay.weixin.qq.com)-->賬戶設定-->API安全-->金鑰設定 )
（3）用key*對加密串B做AES-256-ECB解密（PKCS7Padding）

3、介面連結

在申請退款介面中上傳引數“notify_url”以開通該功能
如果連結無法訪問，商戶將無法接收到微信通知。 
通知url必須為直接可訪問的url，不能攜帶引數。示例：notify_url：“https://pay.weixin.qq.com/wxpay/pay.action”

4、通知引數

以下欄位在return_code為SUCCESS的時候有返回：

以下為返回的加密欄位：

5、返回引數

商戶處理退款通知引數後同步返回給微信引數：

6、程式碼實現

6.1基礎類

WeChatConfig配置類，主要包含微信的配置資訊

package com.hisap.xql.api.common.wechat;
 
/**
 * @Author: QijieLiu
 * @Description: 微信配置資訊
 * @Date: Created in 16:47 2018/8/14
 */
public class WeChatConfig {
	 public static String APP_ID = "xxxxxx";
	 public static String MCH_ID = "xxxxxx";
	 public static String MCH_KEY = "xxxxxx";
	 public static String APP_SECRET = "xxxxxx";
	 public static String UNIFIEDORDER_URL = "https://api.mch.weixin.qq.com/pay/unifiedorder";
	 public static String NOTIFY_URL = "http://xxx.xxx.xxx.xxx:8080/XqlApi/wechatpay/paynotify";
	 public static String REFUND_URL = "https://api.mch.weixin.qq.com/secapi/pay/refund";
	 public static String REFUND_NOTIFY_URL = "http://xxx.xxx.xxx.xxx:8080/XqlApi/wechatpay/refundnotify";
	 public static String TRADE_TYPE = "APP";
	 public static String CERT_URL="E:\\cert\\apiclient_cert.p12";
}

ResponseJson基礎類，主要與APP前端進行互動

package com.hisap.xql.api.common.bean;
 
public class ResponseJson {
	// 結果碼
	private String code;
	// 結果說明
	private String message;
	// 內容
	private Object data;
 
	public String getCode() {
		return code;
	}
 
	public void setCode(String code) {
		this.code = code;
	}
 
	public String getMessage() {
		return message;
	}
 
	public void setMessage(String message) {
		this.message = message;
	}
 
	public Object getData() {
		return data;
	}
 
	public void setData(Object data) {
		this.data = data;
	}
 
}

6.2工具類

MD5Utils類

package com.hisap.xql.api.common.utils;
 
import java.security.MessageDigest;
 
/**
 * @Author: QijieLiu
 * @Description: MD5加密工具
 * @Date: Created in 09:39 2018/8/17
 */
public class MD5Utils {
	 
	public final static String MD5(String s) {
		char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
		try {
			byte[] btInput = s.getBytes();
			// 獲得MD5摘要演算法的 MessageDigest 物件
			MessageDigest mdInst = MessageDigest.getInstance("MD5");
			// 使用指定的位元組更新摘要
			mdInst.update(btInput);
			// 獲得密文
			byte[] md = mdInst.digest();
			// 把密文轉換成十六進位制的字串形式
			int j = md.length;
			char str[] = new char[j * 2];
			int k = 0;
			for (int i = 0; i < j; i++) {
				byte byte0 = md[i];
				str[k++] = hexDigits[byte0 >>> 4 & 0xf];
				str[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(str);
		}
		catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
 
	private static String byteArrayToHexString(byte b[]) {
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++)
			resultSb.append(byteToHexString(b[i]));
 
		return resultSb.toString();
	}
 
	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n += 256;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}
 
	public static String MD5Encode(String origin, String charsetname) {
		String resultString = null;
		try {
			resultString = new String(origin);
			MessageDigest md = MessageDigest.getInstance("MD5");
			if (charsetname == null || "".equals(charsetname))
				resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
			else
				resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
		}
		catch (Exception exception) {
		}
		return resultString;
	}
 
	private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
 
	public static void main(String[] asd) {
		String con = "hello kitty";
		String str = MD5Encode(con, "UTF-8");
		System.out.println(str.toUpperCase());
	}
}

CommonUtil類

package com.hisap.xql.api.common.wechat;
 
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.KeyStore;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
 
import javax.net.ssl.SSLContext;
 
import org.apache.http.Consts;
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.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
 
import com.hisap.xql.api.common.utils.MD5Utils;
 
package com.data.wechat;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.KeyStore;
import java.security.Security;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import javax.net.ssl.SSLContext;

import org.apache.http.Consts;
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.bouncycastle.jce.provider.BouncyCastleProvider;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;

import com.data.util.MD5Utils;



/**
 * @Author: QijieLiu
 * @Description: 微信支付工具類
 * @Date: Created in 19:39 2018/8/21
 */
public class CommonUtil {
	// 微信引數配置
	public static String API_KEY = WeChatConfig.MCH_KEY;

	// 隨機字串生成
	public static String getRandomString(int length) { // length表示生成字串的長度
		String base = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		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();
	}

	// 請求xml組裝
	public static String getRequestXml(SortedMap<String, Object> 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 key = (String) entry.getKey();
			String value = entry.getValue().toString();
			if ("attach".equalsIgnoreCase(key) || "body".equalsIgnoreCase(key)
					|| "sign".equalsIgnoreCase(key)) {
				sb.append("<" + key + ">" + "<![CDATA[" + value + "]]></" + key
						+ ">");
			} else {
				sb.append("<" + key + ">" + value + "</" + key + ">");
			}
		}
		sb.append("</xml>");
		return sb.toString();
	}

	// 生成簽名
	public static String createSign(String characterEncoding,
			SortedMap<String, Object> parameters) {
		StringBuffer sb = new StringBuffer();
		Set es = parameters.entrySet();
		Iterator it = es.iterator();
		while (it.hasNext()) {
			Map.Entry entry = (Map.Entry) it.next();
			String k = (String) entry.getKey();
			Object v = entry.getValue();
			if (null != v && !"".equals(v) && !"sign".equals(k)
					&& !"key".equals(k)) {
				sb.append(k + "=" + v + "&");
			}
		}
		sb.append("key=" + API_KEY);
		System.out.println(sb.toString());
		String sign = MD5Utils.MD5Encode(sb.toString(), characterEncoding)
				.toUpperCase();
		return sign;
	}

	/**
	 * 驗證回撥簽名
	 * 
	 * @param packageParams
	 * @param key
	 * @param charset
	 * @return
	 */
	public static boolean isTenpaySign(Map<String, String> map) throws UnsupportedEncodingException {
		String charset = "utf-8";
		String signFromAPIResponse = map.get("sign");
		if (signFromAPIResponse == null || signFromAPIResponse.equals("")) {
			System.out.println("API返回的資料簽名資料不存在，有可能被第三方篡改!!!");
			return false;
		}
		System.out.println("伺服器回包裡面的簽名是:" + signFromAPIResponse);
		// 過濾空 設定 TreeMap
		SortedMap<String, String> packageParams = new TreeMap<String, String>();
		for (String parameter : map.keySet()) {
			String parameterValue = map.get(parameter);
			String v = "";
			if (null != parameterValue) {
				v = parameterValue.trim();
			}
			packageParams.put(parameter, v);
		}

		StringBuffer sb = new StringBuffer();
		Set es = packageParams.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 (!"sign".equals(k) && null != v && !"".equals(v)) {
				sb.append(k + "=" + v + "&");
			}
		}
		sb.append("key=" + API_KEY);
		// 將API返回的資料根據用簽名演算法進行計算新的簽名，用來跟API返回的簽名進行比較

		// 算出簽名
		String resultSign = "";
		String tobesign = sb.toString();
		if (null == charset || "".equals(charset)) {
			resultSign = MD5Utils.MD5Encode(tobesign, charset)
					.toUpperCase();
		} else {
			resultSign = MD5Utils.MD5Encode(tobesign, charset)
					.toUpperCase();
		}
		String tenpaySign = ((String) packageParams.get("sign")).toUpperCase();
		return tenpaySign.equals(resultSign);
	}

	// 請求方法
	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);
			// 設定請求方式（GET/POST）
			conn.setRequestMethod(requestMethod);
			conn.setRequestProperty("content-type",
					"application/x-www-form-urlencoded");
			// 當outputStr不為null時向輸出流寫資料
			if (null != outputStr) {
				OutputStream outputStream = conn.getOutputStream();
				// 注意編碼格式
				outputStream.write(outputStr.getBytes("UTF-8"));
				outputStream.close();
			}
			// 從輸入流讀取返回內容
			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);
			}
			// 釋放資源
			bufferedReader.close();
			inputStreamReader.close();
			inputStream.close();
			inputStream = null;
			conn.disconnect();
			return buffer.toString();
		} catch (ConnectException ce) {
			System.out.println("連線超時：{}" + ce);
		} catch (Exception e) {
			System.out.println("https請求異常：{}" + e);
		}
		return null;
	}

	// 退款的請求方法
	public static String httpsRequest2(String requestUrl, String requestMethod,
			String outputStr) throws Exception {
		KeyStore keyStore = KeyStore.getInstance("PKCS12");
		StringBuilder res = new StringBuilder("");
		FileInputStream instream = new FileInputStream(new File(
				WeChatConfig.CERT_URL));
		try {
			keyStore.load(instream, "".toCharArray());
		} finally {
			instream.close();
		}

		// Trust own CA and all self-signed certs
		SSLContext sslcontext = SSLContexts.custom()
				.loadKeyMaterial(keyStore, "1313329201".toCharArray()).build();
		// Allow TLSv1 protocol only
		SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
				sslcontext, new String[] { "TLSv1" }, null,
				SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
		CloseableHttpClient httpclient = HttpClients.custom()
				.setSSLSocketFactory(sslsf).build();
		try {

			HttpPost httpost = new HttpPost(
					"https://api.mch.weixin.qq.com/secapi/pay/refund");
			httpost.addHeader("Connection", "keep-alive");
			httpost.addHeader("Accept", "*/*");
			httpost.addHeader("Content-Type",
					"application/x-www-form-urlencoded; charset=UTF-8");
			httpost.addHeader("Host", "api.mch.weixin.qq.com");
			httpost.addHeader("X-Requested-With", "XMLHttpRequest");
			httpost.addHeader("Cache-Control", "max-age=0");
			httpost.addHeader("User-Agent",
					"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0) ");
			StringEntity entity2 = new StringEntity(outputStr, Consts.UTF_8);
			httpost.setEntity(entity2);
			System.out.println("executing request" + httpost.getRequestLine());

			CloseableHttpResponse response = httpclient.execute(httpost);

			try {
				HttpEntity entity = response.getEntity();

				System.out.println("----------------------------------------");
				System.out.println(response.getStatusLine());
				if (entity != null) {
					System.out.println("Response content length: "
							+ entity.getContentLength());
					BufferedReader bufferedReader = new BufferedReader(
							new InputStreamReader(entity.getContent()));
					String text = "";
					res.append(text);
					while ((text = bufferedReader.readLine()) != null) {
						res.append(text);
						System.out.println(text);
					}

				}
				EntityUtils.consume(entity);
			} finally {
				response.close();
			}
		} finally {
			httpclient.close();
		}
		return res.toString();

	}

	// xml解析
	public static Map doXMLParse(String strxml) throws JDOMException,
			IOException {
		strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");

		if (null == strxml || "".equals(strxml)) {
			return null;
		}

		Map m = new HashMap();

		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);
		}

		// 關閉流
		in.close();

		return m;
	}

	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();
	}
	
	public static String getRefundDecrypt(String reqInfoSecret, String key) {
        String result = "";
        try {
            Security.addProvider(new BouncyCastleProvider());
            sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
            byte[] bt = decoder.decodeBuffer(reqInfoSecret);
            String b = new String(bt);
            String md5key = MD5Utils.MD5(key).toLowerCase();
            SecretKey secretKey = new SecretKeySpec(md5key.getBytes(), "AES");
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            byte[] resultbt = cipher.doFinal(bt);
            result = new String(resultbt,"UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
	
	public static String setXML(String return_code, String return_msg) {
		return "<xml><return_code><![CDATA[" + return_code
				+ "]]></return_code><return_msg><![CDATA[" + return_msg
				+ "]]></return_msg></xml>";

	}
}

6.3業務類

WeChatPayController類

package com.hisap.xql.api.controller;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.hisap.xql.api.common.bean.ResponseJson;
import com.hisap.xql.api.common.constant.CodeMsg;
import com.hisap.xql.api.common.utils.CommonUtil;
import com.hisap.xql.api.common.utils.WeChatPayCommonUtil;
import com.hisap.xql.api.common.wechat.WeChatNotifyResult;
import com.hisap.xql.api.service.WeChatPayService;


/**
 * @Author: QijieLiu
 * @Description: 微信支付
 * @Date: Created in 16:27 2018/8/14
 */
@Controller
@RequestMapping("/wechatpay")
public class WeChatPayController {
	private static final Logger logger = 
			LoggerFactory.getLogger(WeChatPayController.class);
	
	@Autowired
	private WeChatPayService weChatPayService;
	
	@RequestMapping("/refundnotify")
	@ResponseBody
    public void refundnotify(HttpServletRequest request,HttpServletResponse response) throws IOException {
		PrintWriter writer = response.getWriter();
        try{
        	String notityXml = parseRequst(request);
        	logger.info("微信退款結果通知介面請求資料json:" + notityXml);
        	ResponseJson responseJson = weChatPayService.refundnotify(notityXml);
        	logger.info("微信退款結果通知介面響應資料json:" + JSON.toJSONString(responseJson, SerializerFeature.WriteNullStringAsEmpty));
        	if(responseJson.getCode().equals(CodeMsg.SUCCESS_CODE)){
        		String notifyStr = WeChatPayCommonUtil.setXML("SUCCESS", "OK"); 
        		writer.write(notifyStr); 
        		writer.flush();
        	}else{
        		String notifyStr = WeChatPayCommonUtil.setXML("FAIL", responseJson.getMessage()); 
        		writer.write(notifyStr); 
        		writer.flush();
        	}
        }catch (Exception e) {
        	e.printStackTrace();
			logger.error("微信退款結果通知介面服務端異常,異常資訊---" + e.getMessage(), e);
        }
        finally{
        	writer.close();
        }
    }
	
	public static String parseRequst(HttpServletRequest request) throws UnsupportedEncodingException {
		request.setCharacterEncoding("utf-8");
		String body = "";
		try {
			ServletInputStream inputStream = request.getInputStream();
 
			BufferedReader br = new BufferedReader(new InputStreamReader(inputStream, "utf-8")); // 設定編碼格式“utf-8”否則獲取中文為亂碼
			while (true) {
				String info = br.readLine();
				if (info == null) {
					break;
				}
				if (body == null || "".equals(body)) {
					body = info;
				} else {
					body += info;
				}
			}
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return body;
	}

}

WeChatPayService介面類

package com.hisap.xql.api.service;

import java.math.BigDecimal;

import com.hisap.xql.api.common.bean.ResponseJson;
import com.hisap.xql.api.common.wechat.WeChatNotifyResult;

/**
 * @Author: QijieLiu
 * @Description: 微信支付
 * @Date: Created in 16:35 2018/8/14
 */
public interface WeChatPayService {
	ResponseJson refundnotify(String notityXml) throws Exception;
}

WeChatPayServiceImpl介面實現類

package com.hisap.xql.api.service.impl;

import java.io.File;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.UUID;

import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.httpclient.NameValuePair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.hisap.xql.api.common.bean.ResponseJson;
import com.hisap.xql.api.common.constant.CodeMsg;
import com.hisap.xql.api.common.utils.Collections3;
import com.hisap.xql.api.common.utils.CommonUtil;
import com.hisap.xql.api.common.utils.DateUtil;
import com.hisap.xql.api.common.utils.StringUtil;
import com.hisap.xql.api.common.utils.TenpayHttpClient;
import com.hisap.xql.api.common.utils.VersionUtil;
import com.hisap.xql.api.common.utils.WeChatPayCommonUtil;
import com.hisap.xql.api.common.wechat.WeChatConfig;
import com.hisap.xql.api.common.wechat.WeChatNotifyResult;
import com.hisap.xql.api.common.wechat.WeChatRefundResult;
import com.hisap.xql.api.common.wechat.WeChatUniteOrderResult;
import com.hisap.xql.api.common.wechat.WeChatUtil;
import com.hisap.xql.api.dao.XqlOrderGoodsMapper;
import com.hisap.xql.api.dao.XqlOrderMapper;
import com.hisap.xql.api.dao.XqlWxRefundLogMapper;
import com.hisap.xql.api.model.XqlOrder;
import com.hisap.xql.api.model.XqlOrderGoods;
import com.hisap.xql.api.model.XqlOrderGoodsExample;
import com.hisap.xql.api.model.XqlVersion;
import com.hisap.xql.api.model.XqlWxRefundLog;
import com.hisap.xql.api.model.XqlWxRefundLogExample;
import com.hisap.xql.api.service.CommonService;
import com.hisap.xql.api.service.ErpInterfaceService;
import com.hisap.xql.api.service.WeChatPayService;
import com.hisap.xql.api.service.XqlOrderService;
import com.lijing.wechatpay.conn.PaymentTools;
import com.lijing.wechatpay.impl.PayImpl;
import com.lijing.wechatpay.util.PayMD5;

/**
 * @Author: QijieLiu
 * @Description: 微信支付
 * @Date: Created in 16:47 2018/8/14
 */
@Service
public class WeChatPayServiceImpl implements WeChatPayService {
	private static final Logger logger = LoggerFactory
			.getLogger(WeChatPayServiceImpl.class);
	
	@Autowired
	CommonService commonService;

	@Autowired
	XqlOrderService xqlOrderServiceImpl;
	
	@Autowired
	ErpInterfaceService erpInterfaceServiceImpl;

	@Autowired
	XqlOrderGoodsMapper xqlOrderGoodsMapper;
	
	@Autowired
	XqlWxRefundLogMapper xqlWxRefundLogMapper;

	public WeChatPayServiceImpl() {
		// TODO Auto-generated constructor stub
	}

	
	/**
	 * 退款結果通知
	 * 
	 * @param characterEncoding
	 * @param parameters
	 * @return
	 */
	@Override
	public ResponseJson refundnotify(String notityXml) throws Exception {
		ResponseJson responseJson = new ResponseJson();
		logger.info("微信退款結果通知請求資料xml:" + notityXml);
		Map<String, Object> refundnotifyMap = CommonUtil.doXMLParse(notityXml);
		if(refundnotifyMap.get("return_code").toString().equals("SUCCESS")){
			String req_info = refundnotifyMap.get("req_info").toString();
			String req_info_decrypt = CommonUtil.getRefundDecrypt(req_info, WeChatConfig.MCH_KEY);
			logger.info("微信退款結果通知解密後請求資料xml:" + req_info_decrypt);
			if(StringUtil.isEmpty(req_info_decrypt)){
				responseJson = CommonUtil.createResponseJson("40004099", "微信退款結果通知解密失敗", null);
			}
			//新增對應的業務邏輯
			Map<String, Object> refundnotifyDecryptMap = WeChatUtil.parseXmlToMap(req_info_decrypt);
			XqlWxRefundLog xqlWxRefundLog = new XqlWxRefundLog();
			xqlWxRefundLog.setReturnCode(StringUtil.convertNullToBlank(refundnotifyMap.get("return_code")));
			xqlWxRefundLog.setReturnMsg(StringUtil.convertNullToBlank(refundnotifyMap.get("return_msg")));
			xqlWxRefundLog.setAppid(StringUtil.convertNullToBlank(refundnotifyMap.get("appid")));
			xqlWxRefundLog.setMchId(StringUtil.convertNullToBlank(refundnotifyMap.get("mch_id")));
			xqlWxRefundLog.setNonceStr(StringUtil.convertNullToBlank(refundnotifyMap.get("nonce_str")));
			xqlWxRefundLog.setTransactionId(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("transaction_id")));
			xqlWxRefundLog.setOutTradeNo(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("out_trade_no")));
			xqlWxRefundLog.setRefundId(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("refund_id")));
			xqlWxRefundLog.setOutRefundNo(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("out_refund_no")));
			xqlWxRefundLog.setTotalFee(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("total_fee")));
			xqlWxRefundLog.setSettlementTotalFee(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("settlement_total_fee")));
			xqlWxRefundLog.setRefundFee(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("refund_fee")));
			xqlWxRefundLog.setSettlementRefundFee(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("settlement_refund_fee")));
			xqlWxRefundLog.setRefundStatus(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("refund_status")));
			xqlWxRefundLog.setSuccessTime(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("success_time")));
			xqlWxRefundLog.setRefundRecvAccout(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("refund_recv_accout")));
			xqlWxRefundLog.setRefundAccount(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("refund_account")));
			xqlWxRefundLog.setRefundRequestSource(StringUtil.convertNullToBlank(refundnotifyDecryptMap.get("refund_request_source")));
			
			XqlWxRefundLogExample xqlWxRefundLogExample = new XqlWxRefundLogExample();
			XqlWxRefundLogExample.Criteria criteria = xqlWxRefundLogExample.createCriteria();
			criteria.andTransactionIdEqualTo(xqlWxRefundLog.getTransactionId());
			int xqlWxRefundLogCount = xqlWxRefundLogMapper.countByExample(xqlWxRefundLogExample);
			if(xqlWxRefundLogCount >0){
				responseJson = CommonUtil.createResponseJson(
						CodeMsg.SUCCESS_CODE, CodeMsg.SUCCESS_MSG, new JSONObject());
			}else{
				xqlWxRefundLogMapper.insertSelective(xqlWxRefundLog);
				responseJson = CommonUtil.createResponseJson(
						CodeMsg.SUCCESS_CODE, CodeMsg.SUCCESS_MSG, new JSONObject());
			}
		}
		
		return responseJson;
	}

}

微信官方回撥之後，返回引數如下：

<xml>
  <return_code><![CDATA[SUCCESS]]></return_code>
  <return_msg><![CDATA[OK]]></return_msg>
</xml>

退款解密的時候，我一開始報如下錯誤

Exception in thread "main" java.security.NoSuchAlgorithmException: Cannot find any provider supporting AES/ECB/PKCS7Padding
 at javax.crypto.Cipher.getInstance(Cipher.java:524)

網上百度了一下，發現是因為某些國家的進口管制限制，Java釋出的執行環境包中的加解密有一定的限制。比如預設不允許256位金鑰的AES加解密，解決方法就是修改策略檔案，  從官方網站下載JCE無限制許可權策略檔案，注意自己JDK的版本別下錯了。將local_policy.jar和US_export_policy.jar這兩個檔案替換%JRE_HOME%\lib\security和%JDK_HOME%\jre\lib\security下原來的檔案，注意先備份原檔案。本人已經親自測試過，可以使用，請放心下載。