protected void handlePrivateKey(@Nonnull final VersionedChecksummedBytes key) {
      final Address address =
          new Address(
              Constants.NETWORK_PARAMETERS, ((DumpedPrivateKey) key).getKey().getPubKeyHash());

      handlePaymentIntent(PaymentIntent.fromAddress(address, null));
    }
    @Override
    public void parse() {
      if (input.startsWith("MINTCOIN:-")) {
        try {
          final byte[] serializedPaymentRequest = Qr.decodeBinary(input.substring(9));

          parseAndHandlePaymentRequest(serializedPaymentRequest);
        } catch (final IOException x) {
          log.info("i/o error while fetching payment request", x);

          error(R.string.input_parser_io_error, x.getMessage());
        } catch (final PaymentProtocolException.PkiVerificationException x) {
          log.info("got unverifyable payment request", x);

          error(R.string.input_parser_unverifyable_paymentrequest, x.getMessage());
        } catch (final PaymentProtocolException x) {
          log.info("got invalid payment request", x);

          error(R.string.input_parser_invalid_paymentrequest, x.getMessage());
        }
      } else if (input.startsWith("mintcoin:")) {
        try {
          final BitcoinURI bitcoinUri = new BitcoinURI(null, input);
          final Address address = bitcoinUri.getAddress();
          if (address != null && !Constants.NETWORK_PARAMETERS.equals(address.getParameters()))
            throw new BitcoinURIParseException("mismatched network");

          handlePaymentIntent(PaymentIntent.fromBitcoinUri(bitcoinUri));
        } catch (final BitcoinURIParseException x) {
          log.info("got invalid bitcoin uri: '" + input + "'", x);

          error(R.string.input_parser_invalid_bitcoin_uri, input);
        }
      } else if (PATTERN_BITCOIN_ADDRESS.matcher(input).matches()) {
        try {
          final Address address = new Address(Constants.NETWORK_PARAMETERS, input);

          handlePaymentIntent(PaymentIntent.fromAddress(address, null));
        } catch (final AddressFormatException x) {
          log.info("got invalid address", x);

          error(R.string.input_parser_invalid_address);
        }
      } else if (PATTERN_DUMPED_PRIVATE_KEY_UNCOMPRESSED.matcher(input).matches()
          || PATTERN_DUMPED_PRIVATE_KEY_COMPRESSED.matcher(input).matches()) {
        try {
          final VersionedChecksummedBytes key =
              new DumpedPrivateKey(Constants.NETWORK_PARAMETERS, input);

          handlePrivateKey(key);
        } catch (final AddressFormatException x) {
          log.info("got invalid address", x);

          error(R.string.input_parser_invalid_address);
        }
      } else if (PATTERN_BIP38_PRIVATE_KEY.matcher(input).matches()) {
        try {
          final VersionedChecksummedBytes key =
              new BIP38PrivateKey(Constants.NETWORK_PARAMETERS, input);

          handlePrivateKey(key);
        } catch (final AddressFormatException x) {
          log.info("got invalid address", x);

          error(R.string.input_parser_invalid_address);
        }
      } else if (PATTERN_TRANSACTION.matcher(input).matches()) {
        try {
          final Transaction tx =
              new Transaction(Constants.NETWORK_PARAMETERS, Qr.decodeDecompressBinary(input));

          handleDirectTransaction(tx);
        } catch (final IOException x) {
          log.info("i/o error while fetching transaction", x);

          error(R.string.input_parser_invalid_transaction, x.getMessage());
        } catch (final ProtocolException x) {
          log.info("got invalid transaction", x);

          error(R.string.input_parser_invalid_transaction, x.getMessage());
        }
      } else {
        cannotClassify(input);
      }
    }
  public static PaymentIntent parsePaymentRequest(@Nonnull final byte[] serializedPaymentRequest)
      throws PaymentProtocolException {
    try {
      if (serializedPaymentRequest.length > 50000)
        throw new PaymentProtocolException(
            "payment request too big: " + serializedPaymentRequest.length);

      final Protos.PaymentRequest paymentRequest =
          Protos.PaymentRequest.parseFrom(serializedPaymentRequest);

      final String pkiName;
      final String pkiCaName;
      if (!"none".equals(paymentRequest.getPkiType())) {
        final KeyStore keystore = new TrustStoreLoader.DefaultTrustStoreLoader().getKeyStore();
        final PkiVerificationData verificationData =
            PaymentProtocol.verifyPaymentRequestPki(paymentRequest, keystore);
        pkiName = verificationData.displayName;
        pkiCaName = verificationData.rootAuthorityName;
      } else {
        pkiName = null;
        pkiCaName = null;
      }

      final PaymentSession paymentSession = PaymentProtocol.parsePaymentRequest(paymentRequest);

      if (paymentSession.isExpired())
        throw new PaymentProtocolException.Expired(
            "payment details expired: current time "
                + new Date()
                + " after expiry time "
                + paymentSession.getExpires());

      if (!paymentSession.getNetworkParameters().equals(Constants.NETWORK_PARAMETERS))
        throw new PaymentProtocolException.InvalidNetwork(
            "cannot handle payment request network: " + paymentSession.getNetworkParameters());

      final ArrayList<PaymentIntent.Output> outputs = new ArrayList<PaymentIntent.Output>(1);
      for (final PaymentProtocol.Output output : paymentSession.getOutputs())
        outputs.add(PaymentIntent.Output.valueOf(output));

      final String memo = paymentSession.getMemo();

      final String paymentUrl = paymentSession.getPaymentUrl();

      final byte[] merchantData = paymentSession.getMerchantData();

      final byte[] paymentRequestHash =
          Hashing.sha256().hashBytes(serializedPaymentRequest).asBytes();

      final PaymentIntent paymentIntent =
          new PaymentIntent(
              PaymentIntent.Standard.BIP70,
              pkiName,
              pkiCaName,
              outputs.toArray(new PaymentIntent.Output[0]),
              memo,
              paymentUrl,
              merchantData,
              null,
              paymentRequestHash);

      if (paymentIntent.hasPaymentUrl() && !paymentIntent.isSupportedPaymentUrl())
        throw new PaymentProtocolException.InvalidPaymentURL(
            "cannot handle payment url: " + paymentIntent.paymentUrl);

      return paymentIntent;
    } catch (final InvalidProtocolBufferException x) {
      throw new PaymentProtocolException(x);
    } catch (final UninitializedMessageException x) {
      throw new PaymentProtocolException(x);
    } catch (final FileNotFoundException x) {
      throw new RuntimeException(x);
    } catch (final KeyStoreException x) {
      throw new RuntimeException(x);
    }
  }