/**
 *先使用HmacSHA256簽名，再使用Base64編碼,最後進行URL 編碼
 *signatureReqStr : 待加密data
 * secretKey : 密鑰
 */
public static String getSignature(String signatureReqStr,String secretKey){
    Mac sha256_HMAC ;
    String result = "";
    try {
        sha256_HMAC = Mac.getInstance("HmacSHA256");
        SecretKeySpec secret_key = new SecretKeySpec(secretKey.getBytes(), "HmacSHA256");
        sha256_HMAC.init(secret_key);
        result = Base64.encodeBase64String(sha256_HMAC.doFinal(signatureReqStr.getBytes()));
        result = URLEncoder.encode(result);
    } catch (InvalidKeyException e) {
        e.printStackTrace();
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    }
    return result;
}

HmacSHA256簽名加Base64編碼加URL編碼