Java微信支付-退款成功异步回调验签

「爱情、让人受尽委屈。」 2023-06-07 10:33 55阅读 0赞

> [接上一篇Java微信支付-申请退款API，本篇在上篇文章的基础上讲述调用申请退款API后退款成功之后微信异步回调通知][Java_-_API_API]  
> 下文中所需配置、类都在以请查看以上链接内容。

> 在调用微信支付-申请退款API时，会传递`notify_url`这个参数给微信，这个参数是退款成功之后微信端会向此地址进行通知，我们应该在接受到微信发来的通知时进行验签确保安全性。  
> **注意**：`notify_url`必须为外网可访问的url，不能携带参数。测试时可以使用`内网穿透`进行测试，这个东西在此我就不赘述了，需要的朋友自行Google。

/**
     * 微信支付Controller
     * 
     * @create: 2019-10-10 15:40
     * @author: Sun
     */
    @RequestMapping(value = "/wxpay")
    @RestController
    @Slf4j
    public class WxPayController {
        
    
        @Autowired
        private WxPayService wxPayService;
    
        /**
         * 微信退款异步回调接口
         *
         * @return
         */
        @RequestMapping(value = "/refund/async/notify")
        public void refundAsyncNotify(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
        
            log.info("[refundAsyncNotify]");
            
            String resultXml = wxPayService.refundAsyncNotify(httpServletRequest);
    
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(httpServletResponse.getOutputStream());
            bufferedOutputStream.write(resultXml.getBytes());
            bufferedOutputStream.flush();
            bufferedOutputStream.close();
        }
    }

/**
     * 微信支付接口
     * 
     * @create: 2019-10-10 15:40
     * @author: Sun
     */
    public interface WxPayService {
        
    
        /**
         * 微信退款异步通知验证签名
         * @param httpServletRequest
         * @return
         */
        String refundAsyncNotify(HttpServletRequest httpServletRequest);
    }

/**
     * 微信支付实现
     * 
     * @author: Sun
     * @create: 2019-10-10 17:54
     * @version: v1.0
     */
    @Service
    @Slf4j
    public class WxPayServiceImpl implements WxPayService {
        
    
        @Autowired
        private MyWxPayConfig myWxPayConfig;
        @Autowired
        private WxDecodeUtil wxDecodeUtil;
        
        /**
         * 微信响应字段
         */
        private static final String RETURN_CODE = "return_code";
        
    
        @Override
        public String refundAsyncNotify(HttpServletRequest httpServletRequest) {
        
    
            String returnXmlMessage = null;
            String notifyXmlData = null;
    
            try {
        
                notifyXmlData = readXmlFromStream(httpServletRequest);
                Map<String, String> notifyMapData = WXPayUtil.xmlToMap(notifyXmlData);
                log.info("[refundAsyncNotify] [xml转换为map数据成功] [notifyMapData:{}]", notifyMapData);
    
                if (WXPayConstants.SUCCESS.equals(notifyMapData.get(RETURN_CODE))) {
        
                    // 获得加密信息
                    String reqInfo = notifyMapData.get("req_info");
                    // 进行AES解密 获取req_info中包含的相关信息(解密失败会抛出异常)
                    String refundDecryptedData = wxDecodeUtil.decryptData(reqInfo);
                    Map<String, String> reqInfoMap = WXPayUtil.xmlToMap(refundDecryptedData);
                    log.info("[refundAsyncNotify] [reqInfo解密成功] [reqInfoMap:{}]", reqInfoMap);
                    // TODO 订单退款成功后相关业务逻辑...
                    
    				// 组装返回给微信的xml数据
                    returnXmlMessage = setReturnXml(WXPayConstants.SUCCESS, "OK");
                    log.info("[refundAsyncNotify]  [out_trade_no:{}] [out_refund_no:{}] [退款异步消息处理成功:{}]",
                            reqInfoMap.get("out_trade_no"), reqInfoMap.get("out_refund_no"), returnXmlMessage);
                } else {
        
                    returnXmlMessage = setReturnXml(WXPayConstants.FAIL, "return_code不为success");
                }
            } catch (IOException e) {
        
                log.error("[refundAsyncNotify] [读取微信服务器返回流中xml数据时发生异常:{}] ", ExceptionUtils.getStackTrace(e));
                returnXmlMessage = setReturnXml(WXPayConstants.FAIL, "An exception occurred while reading the WeChat server returning xml data in the stream.");
            } catch (Exception e) {
        
                log.error("[refundAsyncNotify [处理异常]] [xml数据:{}] [异常:{}] ", notifyXmlData, ExceptionUtils.getStackTrace(e));
    
                returnXmlMessage = setReturnXml(WXPayConstants.FAIL, "Refund successful, exception occurred during asynchronous notification processing.");
                log.warn("[refundAsyncNotify] [退款异步消息处理失败:{}]", returnXmlMessage);
            }
    
            return returnXmlMessage;
        }
    
        /**
         * 设置返回给微信服务器的xml信息
         *
         * @param returnCode
         * @param returnMsg
         * @return
         */
        private String setReturnXml(String returnCode, String returnMsg) {
        
            return "<xml><return_code><![CDATA[" + returnCode + "]]></return_code><return_msg><![CDATA[" + returnMsg + "]]></return_msg></xml>";
        }
    
        /**
         * 从流中读取微信返回的xml数据
         *
         * @param httpServletRequest
         * @return
         * @throws IOException
         */
        private String readXmlFromStream(HttpServletRequest httpServletRequest) throws IOException {
        
            InputStream inputStream = httpServletRequest.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            final StringBuffer sb = new StringBuffer();
            String line = null;
            try {
        
                while ((line = bufferedReader.readLine()) != null) {
        
                    sb.append(line);
                }
            } finally {
        
                bufferedReader.close();
                inputStream.close();
            }
    
            return sb.toString();
        }
    }

/**
     * 微信解密工具类(AES-256-ECB解密 PKCS7Padding)
     * 解密方式官方文档：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_16&index=10#menu1
     * 解密步骤如下：
     * （1）对加密串A做base64解码，得到加密串B
     * （2）对商户key做md5，得到32位小写key* ( key设置路径：微信商户平台(pay.weixin.qq.com)-->账户设置-->API安全-->密钥设置 )
     * （3）用key*对加密串B做AES-256-ECB解密（PKCS7Padding）
     */
    @Component
    public class WxDecodeUtil {
        
    
        private String algorithm = "AES";
    
        private String algorithmModePadding = "AES/ECB/PKCS7Padding";
    
        private String key;
    
        SecretKeySpec secretKey;
    	
    	private boolean initialized = false;
    
        /**
         * AES解密
         * @param base64Data
         * @return
         * @throws Exception
         */
        public String decryptData(String base64Data) throws Exception {
        
    		initialize();
     
            // 获取解码器实例，"BC"指定Java使用BouncyCastle库里的加/解密算法。
            Cipher cipher = Cipher.getInstance(algorithmModePadding, "BC");
            // 使用秘钥并指定为解密模式初始化解码器
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            // cipher.doFinal(byte[] b)在单部分操作中加密或解密数据，或完成多部分操作。 根据此秘钥的初始化方式，对数据进行加密或解密。
            return new String(cipher.doFinal(Base64.decode(base64Data)));
        }
        
        /**
         * 安全提供者列表中注册解密算法提供者，这个加载过程还挺慢的，有时候要好几秒，只需要加载一次就能一直使用。
         */
        private void initialize() {
        
            if (initialized) {
        
                return;
            }
    
            Security.addProvider(new BouncyCastleProvider());
            initialized = true;
        }
    
    
        /**
         * 构造方法(容器初始化时从配置文件中获取key，在全局中维护一个唯一的SecretKeySpec)
         * @param key
         */
        public WxDecodeUtil(@Value("${wxconfig.key}") String key) {
        
            this.key = key;
            // 转化成JAVA的密钥格式
            secretKey = new SecretKeySpec(WxMd5Util.MD5Encode(key, "UTF-8").toLowerCase().getBytes(), algorithm);
        }
    
    }

[Java_-_API_API]: https://blog.csdn.net/qq_41693150/article/details/102542921