MD5加密

MD5 加密分好多位，下列是32位

 /**
     * 32位MD5
     *
     * @param plain
     * @return
     */
    public String encryption(String plain) {
        String re_md5 = new String();
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(plain.getBytes());
            byte b[] = md.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));
            }

            return re_md5 = buf.toString();

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();

            return re_md5;
        }

    }