#788 批量修改所有使用字符串的getBytes方法的地方，显式使用utf-8编码，以免某些场景下出问题

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/bean/notify/WxPayRefundNotifyResult.java

@@ -1,6 +1,7 @@
 package com.github.binarywang.wxpay.bean.notify;
 
 import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
 import javax.crypto.Cipher;
 import javax.crypto.spec.SecretKeySpec;
 
@@ -48,7 +49,7 @@ public class WxPayRefundNotifyResult extends BaseWxPayResult implements Serializ
     String reqInfoString = result.getReqInfoString();
     try {
       final String keyMd5String = DigestUtils.md5Hex(mchKey).toLowerCase();
-      SecretKeySpec key = new SecretKeySpec(keyMd5String.getBytes(), "AES");
+      SecretKeySpec key = new SecretKeySpec(keyMd5String.getBytes(StandardCharsets.UTF_8), "AES");
 
       Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
       cipher.init(Cipher.DECRYPT_MODE, key);

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/bean/result/BaseWxPayResult.java

@@ -4,6 +4,7 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.Serializable;
 import java.math.BigDecimal;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -192,7 +193,7 @@ public abstract class BaseWxPayResult implements Serializable {
       this.xmlDoc = DocumentBuilderFactory
         .newInstance()
         .newDocumentBuilder()
-        .parse(new ByteArrayInputStream(this.xmlString.getBytes("UTF-8")));
+        .parse(new ByteArrayInputStream(this.xmlString.getBytes(StandardCharsets.UTF_8)));
       return xmlDoc;
     } catch (SAXException | IOException | ParserConfigurationException e) {
       throw new RuntimeException("非法的xml文本内容：" + this.xmlString);