private String getMD5Str(String str) {        MessageDigest messageDigest = null;        try {            messageDigest = MessageDigest.getInstance("MD5");            messageDigest.reset();            messageDigest.update(str.getBytes("UTF-8"));        } catch (NoSuchAlgorithmException e) {            System.out.println("NoSuchAlgorithmException caught!");            System.exit(-1);        } catch (UnsupportedEncodingException e) {            e.printStackTrace();        }        byte[] byteArray = messageDigest.digest();        StringBuffer md5StrBuff = new StringBuffer();        for (int i = 0; i < byteArray.length; i++) {            if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)                md5StrBuff.append("0").append(                        Integer.toHexString(0xFF & byteArray[i]));            else                md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));        }        return md5StrBuff.toString();    }