处理退款回调

src/main/java/com/sczx/pay/utils/WXPayUtil.java

@@ -22,6 +22,26 @@ import java.io.StringWriter;
 import java.security.MessageDigest;
 import java.security.SecureRandom;
 import java.util.*;
+import javax.xml.bind.annotation.XmlRootElement;
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.Unmarshaller;
+import java.io.StringReader;
+import org.apache.commons.codec.binary.Base64;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.crypto.Cipher;
+import javax.crypto.spec.SecretKeySpec;
+import javax.crypto.spec.IvParameterSpec;
+import java.security.Security;
+import javax.crypto.BadPaddingException;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.InvalidAlgorithmParameterException;
 
 public class WXPayUtil {
     
@@ -164,4 +184,60 @@ public class WXPayUtil {
         Map<String, String> data = xmlToMap(xmlString);
         return isSignatureValid(data, key);
     }
+
+
+    /**
+     * 将XML字符串转换为指定类型的实体对象
+     *
+     * @param xmlString XML字符串
+     * @param clazz 实体类Class
+     * @param <T> 实体类型
+     * @return 实体对象
+     * @throws Exception 转换异常
+     */
+    public static <T> T xmlToEntity(String xmlString, Class<T> clazz) throws Exception {
+        JAXBContext context = JAXBContext.newInstance(clazz);
+        Unmarshaller unmarshaller = context.createUnmarshaller();
+        return clazz.cast(unmarshaller.unmarshal(new StringReader(xmlString)));
+    }
+
+
+    public static String decryptReqInfo(String reqInfo, String apiKey) throws Exception {
+        try {
+            // 步骤1: 对加密串A做base64解码，得到加密串B
+            byte[] encryptedData = Base64.decodeBase64(reqInfo);
+
+            // 步骤2: 对商户key做md5，得到32位小写key*
+            String key = DigestUtils.md5Hex(apiKey).toLowerCase();
+
+            // 步骤3: 用key*对加密串B做AES-256-ECB解密（PKCS7Padding)
+            byte[] decryptedData = decrypt(encryptedData, key);
+
+            return new String(decryptedData, "UTF-8");
+        } catch (Exception e) {
+            logger.error("解密微信退款通知req_info失败", e);
+            throw new Exception("解密失败: " + e.getMessage(), e);
+        }
+    }
+
+    /**
+     * AES解密方法
+     *
+     * @param encryptedData 加密数据
+     * @param key 解密密钥
+     * @return 解密后的字节数组
+     * @throws Exception 解密异常
+     */
+    private static byte[] decrypt(byte[] encryptedData, String key) throws Exception {
+        try {
+            SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
+            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
+            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
+            return cipher.doFinal(encryptedData);
+        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException |
+                IllegalBlockSizeException | BadPaddingException e) {
+            logger.error("AES解密失败", e);
+            throw new Exception("AES解密失败: " + e.getMessage(), e);
+        }
+    }
 }