PAaS 1 Library

PAaS 1 Library

PAaS 1 is the legacy Java PAaS library distributed as posapplib-1.10.0.jar. Existing integrations may still use it, but new integrations should use PAaS 2 Library unless Westpay advises otherwise.

Main Types

Type	Package	Purpose
CarbonTerminal	se.westpay.posapplib	Main implementation of terminal operations.
PaymentTerminal	se.westpay.posapplib	Interface implemented by CarbonTerminal.
TerminalSettings	se.westpay.posapplib	Terminal ID, hosts, language, and force-login settings.
TransactionRequest	se.westpay.posapplib	Base transaction request.
PurchaseRequest / RefundRequest	se.westpay.posapplib	Transaction-specific request models.
TransactionResponse	se.westpay.posapplib	Transaction result, receipts, and payment details.
TransactionResponseHandler	se.westpay.posapplib	Callback for completed transactions.
CardVerificationHandler	se.westpay.posapplib	Callback for cardholder verification when required.

Lifecycle

1. Create a CarbonTerminal.
2. Build TerminalSettings.
3. Call initialise.
4. Wait for InitialisationResponseHandler.
5. Call doTransaction with a request and response handler.
6. Print or store the preformatted receipts from TransactionResponse.

Initialise

java
PaymentTerminal terminal = new CarbonTerminal();

TerminalSettings settings = new TerminalSettings();
settings.setTerminalId("80000001");
settings.setConfigurationHosts(new String[] { "185.27.171.42:55133" });
settings.setAuthorisationHosts(new String[] { "185.27.171.42:55144" });

boolean accepted = terminal.initialise(
    settings,
    response -> {
        TerminalStatus status = response.getTerminalStatus();
        log("Initialisation completed: " + status);
    },
    notification -> log("Notification: " + notification)
);

Transaction

java
PurchaseRequest request = new PurchaseRequest();
request.setCurrencyId(752);
request.setTotalAmount(10000);
request.setSaleId("sale-1001");

boolean accepted = terminal.doTransaction(
    request,
    response -> {
        if (response.getError() == TransactionError.NONE) {
            print(response.getMerchantReceipt());
            print(response.getCardholderReceipt());
        } else {
            showError(response.getError().toString());
        }
    },
    verification -> true
);

Common Operations

Method	Purpose
doTransaction	Starts a purchase/refund transaction.
abortTransaction	Requests that the current transaction is aborted.
getLastTransactionResult	Retrieves the last known transaction result.
getTerminalStatus	Reads terminal status.
getPrinterStatus	Reads printer state.
enableNavigationBar / disableNavigationBar	Controls Android navigation UI.
checkForUpdates	Checks whether updates are available.
doMaintenance	Starts supported maintenance flow.

Serial Communication Package

The legacy docs also include se.westpay.libserial. This package contains lower-level serial communication helpers such as SerialCommunication, Com.BaudRates, Com.StopBits, Com.DataBits, and Com.Parity. Most PAaS app integrations should stay at the PaymentTerminal abstraction unless a Westpay integration guide specifically requires serial-level access.

Migration Note

PAaS 2 changes the transaction launch model from direct doTransaction callbacks to Android Intent launch/result handling. When migrating:

• Replace doTransaction with createIntentForTransaction plus ActivityResultLauncher.
• Replace legacy response handlers with createTransactionResponseFromIntent.
• Move to se.westpay.paaslib.* packages.
• Revisit receipt printing because PAaS 2 exposes PrintJob for text and bitmap printing.