加密算法使用（二）：使用MD5加密字符串（另：byte數組轉16進制自動補零方法寫法）

    public static void main(String args[]) throws NoSuchAlgorithmException {
        String s = new String("dsajgbqignbopuadhbgnhpjaunaob");
        MessageDigest md5 = MessageDigest.getInstance("MD5");  
        md5.update(s.getBytes());  
        System.out.println(bytes2Hex(md5.digest())); 
        
    }

    private static String bytes2Hex(byte[] bts) {
        String des = "";
        String tmp = null;

        for (int i = 0; i < bts.length; i++) {
            tmp = (Integer.toHexString(bts[i] & 0xFF));
            if (tmp.length() == 1) {
                des += "0";
            }
            des += tmp;
        }
        return des;
    }

 另一種2進制轉16進制的方式

private static String byteToHex(final byte[] hash) {
        Formatter formatter = new Formatter();
        for (byte b : hash)
        {
            formatter.format("%02x", b);
        }
        String result = formatter.toString();
        formatter.close();
        return result;
    }