private String byteToHex (byte[] bytes) {
      String returnData = "";
      if (bytes != null) {
         returnData = Hex.encodeHexString(bytes).toUpperCase();
      }
      return returnData;
   }
******************************************************************************************
From BLOB to Hexadecimal String for Mysql Copy
@return string representation of blob
*******************************************************************************************
src/main/java/org/replicadb/manager/MySQLManager.java