JAVA 中的MessageDigest类和Mac类的使用

MD5加密：
 try{
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update("abc".getBytes());
            System.out.println("md5(abc)=" + byte2str(md5.digest()));
        }catch (NoSuchAlgorithmException e){

        }

public static String signString(String source, String accessSecret) throws InvalidKeyException, IllegalStateException {
        try {
            Mac mac = Mac.getInstance("HmacSHA1");
            mac.init(new SecretKeySpec(accessSecret.getBytes("UTF-8"), "HmacSHA1"));
            byte[] signData = mac.doFinal(source.getBytes("UTF-8"));
            return Base64Helper.encode(signData);
        } catch (NoSuchAlgorithmException var5) {
            throw new RuntimeException("HMAC-SHA1 not supported.");
        } catch (UnsupportedEncodingException var6) {
            throw new RuntimeException("UTF-8 not supported.");
        }
    }