// Arbitrarily-picked constant integer you define to track a request for payment data activity.

private static final int LOAD_PAYMENT_DATA_REQUEST_CODE = 991;

private static final long SHIPPING_COST_CENTS = 90 * PaymentsUtil.CENTS_IN_A_UNIT.longValue();

// A client for interacting with the Google Pay API.

private PaymentsClient paymentsClient;

private ActivityCheckoutBinding layoutBinding;

private View googlePayButton;

private JSONArray garmentList;

private JSONObject selectedGarment;

/**

* Initialize the Google Pay API on creation of the activity

*

* @see Activity#onCreate(android.os.Bundle)

*/

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

initializeUi();

// Set up the mock information for our item in the UI.

try {

selectedGarment = fetchRandomGarment();

displayGarment(selectedGarment);

} catch (JSONException e) {

throw new RuntimeException("The list of garments cannot be loaded");

}

// Initialize a Google Pay API client for an environment suitable for testing.

// It's recommended to create the PaymentsClient object inside of the onCreate method.

paymentsClient = PaymentsUtil.createPaymentsClient(this);

possiblyShowGooglePayButton();

}

/**

* Handle a resolved activity from the Google Pay payment sheet.

*

* @param requestCode Request code originally supplied to AutoResolveHelper in requestPayment().

* @param resultCode Result code returned by the Google Pay API.

* @param data Intent from the Google Pay API containing payment or error data.

* @see <a href="https://developer.android.com/training/basics/intents/result">Getting a result

* from an Activity</a>

*/

@Override

public void onActivityResult(int requestCode, int resultCode, Intent data) {

switch (requestCode) {

// value passed in AutoResolveHelper

case LOAD_PAYMENT_DATA_REQUEST_CODE:

switch (resultCode) {

case Activity.RESULT_OK:

PaymentData paymentData = PaymentData.getFromIntent(data);

handlePaymentSuccess(paymentData);

break;

case Activity.RESULT_CANCELED:

// The user cancelled the payment attempt

break;

case AutoResolveHelper.RESULT_ERROR:

Status status = AutoResolveHelper.getStatusFromIntent(data);

handleError(status.getStatusCode());

break;

}

// Re-enables the Google Pay payment button.

googlePayButton.setClickable(true);

}

}

private void initializeUi() {

// Use view binding to access the UI elements

layoutBinding = ActivityCheckoutBinding.inflate(getLayoutInflater());

setContentView(layoutBinding.getRoot());

// The Google Pay button is a layout file – take the root view

googlePayButton = layoutBinding.googlePayButton.getRoot();

googlePayButton.setOnClickListener(

new View.OnClickListener() {

@Override

public void onClick(View view) {

requestPayment(view);

}

});

}

private void displayGarment(JSONObject garment) throws JSONException {

layoutBinding.detailTitle.setText(garment.getString("title"));

layoutBinding.detailPrice.setText(

String.format(Locale.getDefault(), "$%.2f", garment.getDouble("price")));

final String escapedHtmlText = Html.fromHtml(

garment.getString("description"), Html.FROM_HTML_MODE_COMPACT).toString();

layoutBinding.detailDescription.setText(Html.fromHtml(

escapedHtmlText, Html.FROM_HTML_MODE_COMPACT));

final String imageUri = String.format("@drawable/%s", garment.getString("image"));

final int imageResource = getResources().getIdentifier(imageUri, null, getPackageName());

layoutBinding.detailImage.setImageResource(imageResource);

}

/**

* Determine the viewer's ability to pay with a payment method supported by your app and display a

* Google Pay payment button.

*

* @see <a href="https://developers.google.com/android/reference/com/google/android/gms/wallet/

* PaymentsClient.html#isReadyToPay(com.google.android.gms.wallet.

* IsReadyToPayRequest)">PaymentsClient#IsReadyToPay</a>

*/

private void possiblyShowGooglePayButton() {

final Optional<JSONObject> isReadyToPayJson = PaymentsUtil.getIsReadyToPayRequest();

if (!isReadyToPayJson.isPresent()) {

return;

}

// The call to isReadyToPay is asynchronous and returns a Task. We need to provide an

// OnCompleteListener to be triggered when the result of the call is known.

IsReadyToPayRequest request = IsReadyToPayRequest.fromJson(isReadyToPayJson.get().toString());

Task<Boolean> task = paymentsClient.isReadyToPay(request);

task.addOnCompleteListener(this,

new OnCompleteListener<Boolean>() {

@Override

public void onComplete(@NonNull Task<Boolean> task) {

if (task.isSuccessful()) {

setGooglePayAvailable(task.getResult());

} else {

Log.w("isReadyToPay failed", task.getException());

}

}

});

}

/**

* If isReadyToPay returned {@code true}, show the button and hide the "checking" text. Otherwise,

* notify the user that Google Pay is not available. Please adjust to fit in with your current

* user flow. You are not required to explicitly let the user know if isReadyToPay returns {@code

* false}.

*

* @param available isReadyToPay API response.

*/

private void setGooglePayAvailable(boolean available) {

if (available) {

googlePayButton.setVisibility(View.VISIBLE);

} else {

Toast.makeText(this, R.string.googlepay_status_unavailable, Toast.LENGTH_LONG).show();

}

}

/**

* PaymentData response object contains the payment information, as well as any additional

* requested information, such as billing and shipping address.

*

* @param paymentData A response object returned by Google after a payer approves payment.

* @see <a href="https://developers.google.com/pay/api/android/reference/

* object#PaymentData">PaymentData</a>

*/

private void handlePaymentSuccess(PaymentData paymentData) {

// Token will be null if PaymentDataRequest was not constructed using fromJson(String).

final String paymentInfo = paymentData.toJson();

if (paymentInfo == null) {

return;

}

try {

JSONObject paymentMethodData = new JSONObject(paymentInfo).getJSONObject("paymentMethodData");

// If the gateway is set to "example", no payment information is returned - instead, the

// token will only consist of "examplePaymentMethodToken".

final JSONObject tokenizationData = paymentMethodData.getJSONObject("tokenizationData");

final String token = tokenizationData.getString("token");

final JSONObject info = paymentMethodData.getJSONObject("info");

final String billingName = info.getJSONObject("billingAddress").getString("name");

Toast.makeText(

this, getString(R.string.payments_show_name, billingName),

Toast.LENGTH_LONG).show();

// Logging token string.

Log.d("Google Pay token: ", token);

} catch (JSONException e) {

throw new RuntimeException("The selected garment cannot be parsed from the list of elements");

}

}

/**

* At this stage, the user has already seen a popup informing them an error occurred. Normally,

* only logging is required.

*

* @param statusCode will hold the value of any constant from CommonStatusCode or one of the

* WalletConstants.ERROR_CODE_* constants.

* @see <a href="https://developers.google.com/android/reference/com/google/android/gms/wallet/

* WalletConstants#constant-summary">Wallet Constants Library</a>

*/

private void handleError(int statusCode) {

Log.e("loadPaymentData failed", String.format("Error code: %d", statusCode));

}

public void requestPayment(View view) {

// Disables the button to prevent multiple clicks.

googlePayButton.setClickable(false);

// The price provided to the API should include taxes and shipping.

// This price is not displayed to the user.

try {

double garmentPrice = selectedGarment.getDouble("price");

long garmentPriceCents = Math.round(garmentPrice * PaymentsUtil.CENTS_IN_A_UNIT.longValue());

long priceCents = garmentPriceCents + SHIPPING_COST_CENTS;

Optional<JSONObject> paymentDataRequestJson = PaymentsUtil.getPaymentDataRequest(priceCents);

if (!paymentDataRequestJson.isPresent()) {

return;

}

PaymentDataRequest request =

PaymentDataRequest.fromJson(paymentDataRequestJson.get().toString());

// Since loadPaymentData may show the UI asking the user to select a payment method, we use

// AutoResolveHelper to wait for the user interacting with it. Once completed,

// onActivityResult will be called with the result.

if (request != null) {

AutoResolveHelper.resolveTask(

paymentsClient.loadPaymentData(request),

this, LOAD_PAYMENT_DATA_REQUEST_CODE);

}

} catch (JSONException e) {

throw new RuntimeException("The price cannot be deserialized from the JSON object.");

}

}

private JSONObject fetchRandomGarment() {

// Only load the list of items if it has not been loaded before

if (garmentList == null) {

garmentList = Json.readFromResources(this, R.raw.tshirts);

}

// Take a random element from the list

int randomIndex = Math.toIntExact(Math.round(Math.random() * (garmentList.length() - 1)));

try {

return garmentList.getJSONObject(randomIndex);

} catch (JSONException e) {

throw new RuntimeException("The index specified is out of bounds.");

}

}