Android Studio In App Purchase Tutorial

This topic describes how to integrate the Google Play Billing Library into your app to berangkat selling products.

This topic includes code examples that are based on the official sample apps on GitHub. See additional resources for a complete list of sample apps and other resources that you can use while integrating.

Life of a purchase

Here’s a typical purchase flow for a one-time purchase or a subscription.

1. Show the user what they can buy.
2. Launch the purchase flow for the user to accept the purchase.
3. Verify the purchase on your server.
4. Give content to the user.
5. Acknowledge delivery of the content. For consumable products, consume the purchase so that the user can’kaki langit buy the item again.

Subscriptions automatically renew berayun-ayun they are canceled. A subscription can go through the following states:

• Active:
  User is in good standing and has access to the subscription.
• Cancelled:
  User has cancelled but still has access until expiration.
• In grace period:
  User experienced a payment issue but still has access while Google is retrying the payment method.
• On hold:
  User experienced a payment issue and no longer has access while Google is retrying the payment method.
• Paused:
  User paused their access and does not have access mencicil they resume.
• Expired:
  User has cancelled and lost access to the subscription. The user is considered
  churned
  at expiration.

Initialize a connection to Google Play

The first step to integrate with Google Play’s billing system is to add the Google Play Billing Library to your app and initialize a connection.

Add the Google Play Billing Library dependency

Add the Google Play Billing Library dependency to your app’s
build.gradle
file as shown:

dependencies {     def billing_version = "5.0.0"      implementation "com.android.billingclient:billing:$billing_version" }

dependencies {     val billing_version = "5.0.0"      implementation("com.android.billingclient:billing:$billing_version") }

If you’re using Kotlin, the Google Play Billing Library KTX module contains Kotlin extensions and coroutines support that enable you to write idiomatic Kotlin when using the Google Play Billing Library. To include these extensions in your project, add the following dependency to your app’s
build.gradle
file as shown:

dependencies {     def billing_version = "5.0.0"      implementation "com.android.billingclient:billing-ktx:$billing_version" }
          

dependencies {     val billing_version = "5.0.0"      implementation("com.android.billingclient:billing-ktx:$billing_version") }
          

Initialize a BillingClient

Once you’ve added a dependency on the Google Play Billing Library, you need to initialize a
BillingClient
instance.
BillingClient
is the main interface for communication between the Google Play Billing Library and the rest of your app.
BillingClient
provides convenience methods, both synchronous and asynchronous, for many common billing operations. It’s strongly recommended that you have one active
BillingClient
connection open at one time to avoid multiple
PurchasesUpdatedListener
callbacks for a single event.

To create a
BillingClient, use
newBuilder(). You can pass any context to
newBuilder(), and
BillingClient
uses it to get an application context. That means you don’tepi langit need to worry about memory leaks. To receive updates on purchases, you must also call
setListener(), passing a reference to a
PurchasesUpdatedListener. This listener receives updates for all purchases in your app.

private val purchasesUpdatedListener =    PurchasesUpdatedListener { billingResult, purchases ->        // To be implemented in a later section.    }  private var billingClient = BillingClient.newBuilder(context)    .setListener(purchasesUpdatedListener)    .enablePendingPurchases()    .build()
          

private PurchasesUpdatedListener purchasesUpdatedListener = new PurchasesUpdatedListener() {     @Override     public void onPurchasesUpdated(BillingResult billingResult, List<Purchase> purchases) {         // To be implemented in a later section.     } };  private BillingClient billingClient = BillingClient.newBuilder(context)     .setListener(purchasesUpdatedListener)     .enablePendingPurchases()     .build();
          

Connect to Google Play

After you have created a
BillingClient, you need to establish a connection to Google Play.

To connect to Google Play, call
startConnection(). The connection process is asynchronous, and you must implement a
BillingClientStateListener
to receive a callback once the setup of the client is complete and it’s ready to make further requests.

You must also implement retry logic to handle lost connections to Google Play. To implement retry logic, override the
onBillingServiceDisconnected()
callback method, and make sure that the
BillingClient
calls the
startConnection()
method to reconnect to Google Play before making further requests.

The following example demonstrates how to start a connection and test that it’s ready to use:

billingClient.startConnection(object : BillingClientStateListener {     override fun onBillingSetupFinished(billingResult: BillingResult) {         if (billingResult.responseCode ==  BillingResponseCode.OK) {             // The BillingClient is ready. You can query purchases here.         }     }     override fun onBillingServiceDisconnected() {         // Try to restart the connection on the next request to         // Google Play by calling the startConnection() method.     } })
          

billingClient.startConnection(new BillingClientStateListener() {     @Override     public void onBillingSetupFinished(BillingResult billingResult) {         if (billingResult.getResponseCode() ==  BillingResponseCode.OK) {             // The BillingClient is ready. You can query purchases here.         }     }     @Override     public void onBillingServiceDisconnected() {         // Try to restart the connection on the next request to         // Google Play by calling the startConnection() method.     } });
          

Show products available to buy

After you have established a connection to Google Play, you are ready to query for your available products and display them to your users.

Querying for product details is an important step before displaying your products to your users, as it returns localized product information. For subscriptions, ensure your product display follows all Play policies.

To query for in-app product details, call
queryProductDetailsAsync().

To handle the result of the asynchronous operation, you must also specify a listener which implements the
ProductDetailsResponseListener
interface. You can then override
onProductDetailsResponse(), which notifies the listener when the query finishes, as shown in the following example:

val queryProductDetailsParams =     QueryProductDetailsParams.newBuilder()         .setProductList(             ImmutableList.of(                 Product.newBuilder()                     .setProductId("product_id_example")                     .setProductType(ProductType.SUBS)                     .build()))         .build()  billingClient.queryProductDetailsAsync(queryProductDetailsParams) {     billingResult,     productDetailsList ->       // check billingResult       // process returned productDetailsList } )
          

QueryProductDetailsParams queryProductDetailsParams =     QueryProductDetailsParams.newBuilder()         .setProductList(             ImmutableList.of(                 Product.newBuilder()                     .setProductId("product_id_example")                     .setProductType(ProductType.SUBS)                     .build()))         .build();  billingClient.queryProductDetailsAsync(     queryProductDetailsParams,     new ProductDetailsResponseListener() {         public void onProductDetailsResponse(BillingResult billingResult,                 List<ProductDetails> productDetailsList) {             // check billingResult             // process returned productDetailsList         }     } )
          

When querying for product details, pass an instance of
QueryProductDetailsParams
that specifies a list of product ID strings created in Google Play Console along with a
ProductType. The
ProductType
can be either
ProductType.INAPP
for one-time products or
ProductType.SUBS
for subscriptions.

Querying with Kotlin extensions

If you’re using Kotlin extensions, you can query for in-app product details by calling the
queryProductDetails()
extension function.

queryProductDetails()
leverages Kotlin coroutines so that you don’ufuk need to define a separate listener. Instead, the function suspends mencicil the querying completes, after which you can process the result:

        suspend fun processPurchases() {     val productList = ArrayList<String>()     productList.add("product_id_example")      val params = QueryProductDetailsParams.newBuilder()     params.setProductList(productList)         .setType(ProductType.SUBS)      // leverage queryProductDetails Kotlin extension function     val productDetailsResult = withContext(Dispatchers.IO) {         billingClient.queryProductDetails(params.build())     }      // Process the result. }
        
      

Process the result

The Google Play Billing Library stores the query results in a
List
of
ProductDetails
objects. You can then call a variety of methods on each
ProductDetails
object in the list to view relevant information about an in-app product, such as its price or description. To view the available product detail information, see the list of methods in the
ProductDetails
class.

Before offering an item for sale, check that the user does not already own the item. If the user has a consumable that is still in their item library, they must consume the item before they can buy it again.

Before offering a subscription, verify that the user is not already subscribed. Also note the following:

• queryProductDetailsAsync()
  returns subscription product details and a maximum of 50 offers per subscription.
• queryProductDetailsAsync()
  returns only offers for which the user is eligible. If the user attempts to purchase an offer for which they’re ineligible (for example, if the app is displaying an outdated list of eligible offers), Play informs the user that they are ineligible, and the user can choose to purchase the base plan instead.

Launch the purchase flow

To menginjak a purchase request from your app, call the
launchBillingFlow()
method from your app’s main thread. This method takes a reference to a
BillingFlowParams
object that contains the relevant
ProductDetails
object obtained from calling
queryProductDetailsAsync(). To create a
BillingFlowParams
object, use the
BillingFlowParams.Builder
class.

// An activity reference from which the billing flow will be launched. val activity : Activity = ...;  val productDetailsParamsList = listOf(     BillingFlowParams.ProductDetailsParams.newBuilder()         // retrieve a value for "productDetails" by calling queryProductDetailsAsync()         .setProductDetails(productDetails)         // to get an offer token, call ProductDetails.subscriptionOfferDetails()         // for a list of offers that are available to the user         .setOfferToken(selectedOfferToken)         .build() )  val billingFlowParams = BillingFlowParams.newBuilder()     .setProductDetailsParamsList(productDetailsParamsList)     .build()  // Launch the billing flow val billingResult = billingClient.launchBillingFlow(activity, billingFlowParams)
          

// An activity reference from which the billing flow will be launched. Activity activity = ...;  ImmutableList
              productDetailsParamsList =     ImmutableList.of(         ProductDetailsParams.newBuilder()              // retrieve a value for "productDetails" by calling queryProductDetailsAsync()             .setProductDetails(productDetails)             // to get an offer token, call ProductDetails.getSubscriptionOfferDetails()             // for a list of offers that are available to the user             .setOfferToken(selectedOfferToken)             .build()     );  BillingFlowParams billingFlowParams = BillingFlowParams.newBuilder()     .setProductDetailsParamsList(productDetailsParamsList)     .build();  // Launch the billing flow BillingResult billingResult = billingClient.launchBillingFlow(activity, billingFlowParams);
            
          

The
launchBillingFlow()
method returns one of several response codes listed in
BillingClient.BillingResponseCode. Be sure to check this result to ensure there were no errors launching the purchase flow. A
BillingResponseCode
of
OK
indicates a successful launch.

On a successful call to
launchBillingFlow(), the system displays the Google Play purchase screen. Figure 1 shows a purchase screen for a subscription:

Google Play calls
onPurchasesUpdated()
to deliver the result of the purchase operation to a listener that implements the
PurchasesUpdatedListener
interface. The listener is specified using the
setListener()
method when you initialized your client.

You must implement
onPurchasesUpdated()
to handle possible response codes. The following example shows how to override
onPurchasesUpdated():

override fun onPurchasesUpdated(billingResult: BillingResult, purchases: List<Purchase>?) {    if (billingResult.responseCode == BillingResponseCode.OK && purchases != null) {        for (purchase in purchases) {            handlePurchase(purchase)        }    } else if (billingResult.responseCode == BillingResponseCode.USER_CANCELED) {        // Handle an error caused by a user cancelling the purchase flow.    } else {        // Handle any other error codes.    } }
          

@Override void onPurchasesUpdated(BillingResult billingResult, List<Purchase> purchases) {     if (billingResult.getResponseCode() == BillingResponseCode.OK         && purchases != null) {         for (Purchase purchase : purchases) {             handlePurchase(purchase);         }     } else if (billingResult.getResponseCode() == BillingResponseCode.USER_CANCELED) {         // Handle an error caused by a user cancelling the purchase flow.     } else {         // Handle any other error codes.     } }
          

A successful purchase generates a Google Play purchase success screen similar to figure 2.

A successful purchase also generates a purchase token, which is a unique identifier that represents the user and the product ID for the in-app product they purchased. Your apps can store the purchase token locally, though we recommend passing the token to your secure backend peladen where you can then verify the purchase and protect against fraud. This process is further described in the following section.

The user is also emailed a receipt of the transaction containing an Order ID or a unique ID of the transaction. Users receive an email with a unique Titipan ID for each one-time product purchase, and also for the initial subscription purchase and subsequent recurring automatic renewals. You can use the Pesanan ID to manage refunds in the Google Play Console.

Indicate a personalized price

If your app can be distributed to users in the European Union, use the
setIsOfferPersonalized()
method to disclose to users that an item’s price was personalized using automated decision-making.

You must consult Art. 6 (1) (ea) CRD of the Consumer Rights Directive (2011/83/EU) to determine if the price you are offering to users is personalized.

setIsOfferPersonalized()
takes a boolean input. When
true, the Play UI includes the disclosure. When
false, the UI omits the disclosure. The default value is
false.

See the Consumer Help Center for more information.

Processing purchases

Once a user completes a purchase, your app then needs to process that purchase. In most cases, your app is notified of purchases through your
PurchasesUpdatedListener. but there are cases where your app is made aware of calling
BillingClient.queryPurchasesAsync()
as described in Fetching purchases.

Your app should process a purchase in the following way:

1. Verify the purchase.
2. Give content to the user, and acknowledge delivery of the content. Optionally, mark the item as consumed so that the user can buy the item again.

To verify a purchase, first check that the purchase state is
PURCHASED. If the purchase is
PENDING, then you should process the purchase as described in Handling pending transactions. For purchases received from
onPurchasesUpdated()
or
queryPurchasesAsync(), you should further verify the purchase to ensure legitimacy before your app grants entitlement. To learn how to properly verify a purchase, see Verify purchases before granting entitlements.

Once you’ve verified the purchase, your app is ready to grant entitlement to the user. After granting entitlement, your app must then acknowledge the purchase. This acknowledgement communicates to Google Play that you have granted entitlement for the purchase.

The process to grant entitlement and acknowledge the purchase depends on whether the purchase is a non-consumable, a consumable, or a subscription.

For consumables, the
consumeAsync()
method fulfills the acknowledgement requirement and indicates that your app has granted entitlement to the user. This method also enables your app to make the one-time product available for purchase again.

To indicate that a one-time product has been consumed, call
consumeAsync()
and include the purchase token that Google Play should make available for repurchase. You must also pass an object that implements the
ConsumeResponseListener
interface. This object handles the result of the consumption operation. You can override the
onConsumeResponse()
method, which the Google Play Billing Library calls when the operation is complete.

The following example illustrates consuming a product using the associated purchase token:

suspend fun handlePurchase(purchase: Purchase) {     // Purchase retrieved from BillingClient#queryPurchasesAsync or your PurchasesUpdatedListener.     val purchase : Purchase = ...;      // Verify the purchase.     // Ensure entitlement was not already granted for this purchaseToken.     // Grant entitlement to the user.      val consumeParams =         ConsumeParams.newBuilder()             .setPurchaseToken(purchase.getPurchaseToken())             .build()     val consumeResult = withContext(Dispatchers.IO) {         client.consumePurchase(consumeParams)     } }
          

void handlePurchase(Purchase purchase) {     // Purchase retrieved from BillingClient#queryPurchasesAsync or your PurchasesUpdatedListener.     Purchase purchase = ...;      // Verify the purchase.     // Ensure entitlement was not already granted for this purchaseToken.     // Grant entitlement to the user.      ConsumeParams consumeParams =         ConsumeParams.newBuilder()             .setPurchaseToken(purchase.getPurchaseToken())             .build();      ConsumeResponseListener listener = new ConsumeResponseListener() {         @Override         public void onConsumeResponse(BillingResult billingResult, String purchaseToken) {             if (billingResult.getResponseCode() == BillingResponseCode.OK) {                 // Handle the success of the consume operation.             }         }     };      billingClient.consumeAsync(consumeParams, listener); }
          

To acknowledge non-consumable purchases, use either
BillingClient.acknowledgePurchase()
from the Google Play Billing Library or Product.Purchases.Acknowledge from the Google Play Developer Jago merah. Before acknowledging a purchase, your app should check whether it was already acknowledged by using the
isAcknowledged()
method in the Google Play Billing Library or the
acknowledgementState
field in the Google Developer Api.

The following example shows how to acknowledge a purchase using the Google Play Billing Library:

val client: BillingClient = ... val acknowledgePurchaseResponseListener: AcknowledgePurchaseResponseListener = ...  suspend fun handlePurchase() {     if (purchase.purchaseState === PurchaseState.PURCHASED) {         if (!purchase.isAcknowledged) {             val acknowledgePurchaseParams = AcknowledgePurchaseParams.newBuilder()                     .setPurchaseToken(purchase.purchaseToken)             val ackPurchaseResult = withContext(Dispatchers.IO) {                client.acknowledgePurchase(acknowledgePurchaseParams.build())             }         }      } }
          

BillingClient client = ... AcknowledgePurchaseResponseListener acknowledgePurchaseResponseListener = ...  void handlePurchase(Purchase purchase) {     if (purchase.getPurchaseState() == PurchaseState.PURCHASED) {         if (!purchase.isAcknowledged()) {             AcknowledgePurchaseParams acknowledgePurchaseParams =                 AcknowledgePurchaseParams.newBuilder()                     .setPurchaseToken(purchase.getPurchaseToken())                     .build();             client.acknowledgePurchase(acknowledgePurchaseParams, acknowledgePurchaseResponseListener);         }     } }
          

Subscriptions are handled similarly to non-consumables. You can acknowledge a subscription Acknowledgement using either
BillingClient.acknowledgePurchase()
from the Google Play Billing Library or
Purchases.Subscriptions.Acknowledge
from the Google Play Developer Jago merah. All initial subscription purchases need to be acknowledged. Subscription renewals do not need to be acknowledged. For more information on when subscriptions need to be acknowledged, see the Sell subscriptions topic.

Fetching purchases

Listening to purchase updates using a
PurchasesUpdatedListener
is titinada sufficient to ensure your app processes all purchases. It’s possible that your app might not be aware of all the purchases a user has made. Here are some scenarios where your app could lose track or be unaware of purchases:

• Network Issues during the purchase: A user makes a successful purchase and receives confirmation from Google, but their device loses network connectivity before their device receives notification of the purchase through the
  PurchasesUpdatedListener.
• Multiple devices: A user buys an item on one device and then expects to see the item when they switch devices.
• Handling purchases made outside your app: Some purchases, such as promotion redemptions, can be made outside of your app.

To handle these situations, be sure that your app calls
BillingClient.queryPurchasesAsync()
in your
onResume()
method to ensure that all purchases are successfully processed as described in processing purchases.

The following example shows how to fetch for a user’s subscription purchases. Note that
queryPurchasesAsync()
returns only active subscriptions and non-consumed one-time purchases.

val params = QueryPurchasesParams.newBuilder()                .setProductType(ProductType.SUBS)  // uses queryPurchasesAsync Kotlin extension function val purchasesResult = billingClient.queryPurchasesAsync(params.build())  // check purchasesResult.billingResult // process returned purchasesResult.purchasesList, e.g. display the plans user owns
          

billingClient.queryPurchasesAsync(     QueryPurchasesParams.newBuilder()       .setProductType(ProductType.SUBS)       .build(),     new PurchasesResponseListener() {       public void onQueryPurchasesResponse(BillingResult billingResult, List
              purchases) {         // check billingResult         // process returned purchase list, e.g. display the plans user owns        }     } );
            
          

Fetching purchase history

queryPurchaseHistoryAsync()
returns the most recent purchase made by the user for each product, even if that purchase is expired, canceled, or consumed.

If you’re using Kotlin extensions, you can use the
queryPurchaseHistory()
extension function.

val params = QueryPurchaseHistoryParams.newBuilder()                .setProductType(ProductType.SUBS)  // uses queryPurchaseHistory Kotlin extension function val purchaseHistoryResult = billingClient.queryPurchaseHistory(params.build())  // check purchaseHistoryResult.billingResult // process returned purchaseHistoryResult.purchaseHistoryRecordList, e.g. display purchase
          

billingClient.queryPurchaseHistoryAsync(     QueryPurchaseHistoryParams.newBuilder()         .setProductType(ProductType.SUBS)         .build(),     new PurchaseHistoryResponseListener() {       public void onPurchaseHistoryResponse(         BillingResult billingResult, List
              purchasesHistoryList) {           // check billingResult           // process returned purchase history list, e.g. display purchase history         }     } );
            
          

Handling purchases made outside your app

Some purchases, such as promotion redemptions, can happen outside of your app. When a user makes a purchase outside of your app, they expect your app to show an in-app message, or use some kind of notification mechanism to let the user know that the app correctly received and processed the purchase. Some acceptable mechanisms are:

• Show an in-app popup.
• Deliver the message to an in-app message box, and clearly stating that there is a new message in the in-app message box.
• Use an OS notification message.

Keep in mind that it is possible for your app to be in any state when your app recognizes the purchase. It is even possible for your app to not even be installed when the purchase was made. Users expect to receive their purchase when they resume the app, regardless of the state in which the app is.

You must detect purchases regardless of the state in which the app is when the purchase was made. However, there are some exceptions where it may be acceptable to titinada immediately notify the user that the item was received. For example:

• During the action part of a game, where showing a message may distract the user. In this case, you must notify the user after the action part is over.
• During cutscenes, where showing a message may distract the user. In this case, you must notify the user after the cutscene is over.
• During the initial tutorial and user setup parts of the game. We recommend you notify new users of the reward immediately after they open the game or during initial user set up. However, it is acceptable to wait until the main game sequence is available to notify the user.

Always keep the user in mind when deciding when and how to notify your users of purchases made outside of your app. Any time a user doesn’horizon immediately receive a notification, they may get confused, and may stop using your app, contact user support, or complain about it on social media. Note:
PurchasesUpdatedListener
is registered with your application context to handle purchase updates, including purchases initiated outside of your app. This means that if your application process does not exist, your
PurchasesUpdatedListener
would titinada be notified. This is why your app should call
BillingClient.queryPurchasesAsync()
in the
onResume()
method as mentioned in Fetch Purchases.

Handling pending transactions

Google Play supports
pending transactions, or transactions that require one or more additional steps between when a user initiates a purchase and when the payment method for the purchase is processed. Your app should not grant entitlement to these types of purchases until Google notifies you that the user’s payment method was successfully charged.

For example, a user can create a
PENDING
purchase of an in-app item by choosing cash as their form of payment. The user can then choose a physical store where they will complete the transaction and receive a code through both notification and email. When the user arrives at the physical store, they can redeem the code with the cashier and pay with cash. Google then notifies both you and the user that cash has been received. Your app can then grant entitlement to the user.

Your app must support pending transactions by calling
enablePendingPurchases()
as part of initializing your app.

When your app receives a new purchase, either through your
PurchasesUpdatedListener
or as a result of calling
queryPurchasesAsync(), use the
getPurchaseState()
method to determine whether the purchase state is
PURCHASED
or
PENDING.

If your app is running when the user completes the purchase, your
PurchasesUpdatedListener
is called again, and the
PurchaseState
is now
PURCHASED. At this point, your app can process the purchase using the kalimantang method for processing one-time purchases. Your app should also call
queryPurchasesAsync()
in your app’s
onResume()
method to handle purchases that have transitioned to the
PURCHASED
state while your app was not running.

Your app can also use Cak benar-time developer notifications with pending purchases by listening for
OneTimeProductNotifications. When the purchase transitions from
PENDING
to
PURCHASED, your app receives a
ONE_TIME_PRODUCT_PURCHASED
notification. If the purchase is cancelled, your app receives a
ONE_TIME_PRODUCT_CANCELED
notification. This can happen if your customer does titinada complete payment in the required timeframe. When receiving these notifications, you can use the Google Play Developer API, which includes a
PENDING
state for
Purchases.products.

You can find detailed steps on how to test this scenario at Test pending purchases.

Handling multi-quantity purchases

Supported in versions 4.0 and higher of the Google Play Billing Library, Google Play allows customers to purchase more than one of the same in-app product in one transaction by specifying a quantity from the purchase cart. Your app is expected to handle multi-quantity purchases and grant entitlement based on the specified purchase quantity.

To honor multi-quantity purchases, your app’s provisioning logic needs to check for an item quantity. You can access a
quantity
field from one of the following APIs:

• getQuantity()
  from the Google Play Billing Library.
• Purchases.products.quantity
  from the Google Play Developer Jago merah.

Once you’ve added logic to handle multi-quantity purchases, you then need to enable the multi-quantity feature for the corresponding product on the in-app product management page in the Google Play Developer Console.