Template:Json API HMAC Block- Java

   public static void generateHmacHeaders(HttpURLConnection connection, String applicationId, String applicationPassword, String accountId, String userId) throws Exception{
       final SimpleDateFormat d = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss (z)");
       d.setTimeZone(TimeZone.getTimeZone("GMT"));
       final String timestampString = d.format(new Date());
       final String message = 
          (applicationId == null ? "" : applicationId) + ":" + 
          (applicationPassword == null ? "" : applicationPassword) + ":" + 
          (accountId == null ? "" : accountId) + ":" + 
          (userId == null ? "" : userId) + ":" + 
          timestampString;
       final String auth = "HMAC " + hmacSha1ToBase64(message, apiSecret); //note space after HMAC
       connection.setRequestProperty("updox-timestamp", timestampString);  
       connection.setRequestProperty("Authorization", auth);
   }
   
   public static String hmacSha1ToBase64(String value, String key) throws Exception{
       byte[] keyBytes = key.getBytes();
       SecretKeySpec signingKey = new SecretKeySpec(keyBytes, "HmacSHA1");
       Mac mac = Mac.getInstance("HmacSHA1");
       mac.init(signingKey);
       byte[] rawHmac = mac.doFinal(value.getBytes());
       byte[] base64Bytes = Base64.encodeBase64(rawHmac);
       return new String(base64Bytes, "UTF-8");
   }