获取淘宝参数签名

public static String getSign(String secret, Map<String, String> params) {
        if (secret == null || "".equals(secret) || params == null)
            throw new RuntimeException("secret or params is null or blank, please check...");
        StringBuilder sb = new StringBuilder();//.append(secret);
        String result = null;
        try {
            // Set<String> sortedKeys = new TreeSet<String>();
            String[] keys = params.keySet().toArray(new String[0]);
            Arrays.sort(keys);
            // sortedKeys.addAll(keys);
            for (String key : keys) {
                String KeyValue = params.get(key);
                sb.append(key).append(KeyValue);
            }
            byte[] bytes = encryptHMAC(sb.toString(), secret);
            //MessageDigest md = MessageDigest.getInstance("MD5");
            result = byteTohex(bytes);

        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return result;
    }

    private static byte[] encryptHMAC(String data, String secret)throws IOException {
        byte[] bytes = null;
        try {
            SecretKey secretKey = new SecretKeySpec(secret.getBytes("UTF-8"),"HmacMD5");
            Mac mac = Mac.getInstance(secretKey.getAlgorithm());
            mac.init(secretKey);
            bytes = mac.doFinal(data.getBytes("UTF-8"));
        } catch (GeneralSecurityException e) {
            e.printStackTrace();
        }
        return bytes;
    }

    public static String byteTohex(byte[] b) {
        StringBuffer sb = new StringBuffer();
        String stmp = "";

        for (int n = 0; n < b.length; n++) {
            stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));

            if (stmp.length() == 1)
                sb.append("0").append(stmp);
            else
                sb.append(stmp);
        }

        return sb.toString().toUpperCase();
    }