#319 增加“退款结果通知“处理方法，并优化调整微信支付相关代码

weixin-java-common/src/main/java/me/chanjar/weixin/common/util/crypto/WxCryptUtil.java

@@ -47,7 +47,6 @@ public class WxCryptUtil {
   protected String appidOrCorpid;
 
   public WxCryptUtil() {
-    super();
   }
 
   /**
@@ -106,7 +105,7 @@ public class WxCryptUtil {
   private static String genRandomStr() {
     String base = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
     Random random = new Random();
-    StringBuffer sb = new StringBuffer();
+    StringBuilder sb = new StringBuilder();
     for (int i = 0; i < 16; i++) {
       int number = random.nextInt(base.length());
       sb.append(base.charAt(number));
@@ -148,12 +147,11 @@ public class WxCryptUtil {
     String encryptedXml = encrypt(genRandomStr(), plainText);
 
     // 生成安全签名
-    String timeStamp = Long.toString(System.currentTimeMillis() / 1000l);
+    String timeStamp = Long.toString(System.currentTimeMillis() / 1000L);
     String nonce = genRandomStr();
 
     String signature = SHA1.gen(this.token, timeStamp, nonce, encryptedXml);
-    String result = generateXml(encryptedXml, signature, timeStamp, nonce);
-    return result;
+    return generateXml(encryptedXml, signature, timeStamp, nonce);
   }
 
   /**
@@ -194,9 +192,7 @@ public class WxCryptUtil {
       byte[] encrypted = cipher.doFinal(unencrypted);
 
       // 使用BASE64对加密后的字符串进行编码
-      String base64Encrypted = base64.encodeToString(encrypted);
-
-      return base64Encrypted;
+      return base64.encodeToString(encrypted);
     } catch (Exception e) {
       throw new RuntimeException(e);
     }
@@ -228,8 +224,7 @@ public class WxCryptUtil {
     }
 
     // 解密
-    String result = decrypt(cipherText);
-    return result;
+    return decrypt(cipherText);
   }
 
   /**