CryptoDataFormat cryptoFormat = new CryptoDataFormat("AES/GCM/NoPadding", secretKey);
         cryptoFormat.setInitializationVector(iv); // it should set the iv based on the info from paramSpec.. 
         cryptoFormat.setShouldInlineInitializationVector(true);
         cryptoFormat.setAlgorithmParameterSpec(paramSpec);

      if (mode == ENCRYPT_MODE || mode == DECRYPT_MODE) {
            if (iv != null) {
                cipher.init(mode, key, new IvParameterSpec(iv));
            } else if (parameterSpec != null) {
                cipher.init(mode, key, parameterSpec);
            } else {
                cipher.init(mode, key);
            }
        }