public static String md5(String str,String charsetName) {
   String result = "";
   MessageDigest md5 = null;
   try {
      md5 = MessageDigest.getInstance("MD5");
      md5.update(str.getBytes(charsetName));
   } catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
   } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
   }
   byte 
 
b[] = md5.digest();
   int i;
   StringBuffer buf = new StringBuffer("");
   for (int offset = 0; offset < b.length; offset++) {
      i = b[offset];
      if (i < 0)
         i += 256;
      if (i < 16)
         buf.append("0");
      buf.append(Integer.toHexString(i));
   }
   result = buf.toString();

   return 
 
result;
}