Android In-App Billing v3 Library

This is a simple, straight-forward implementation of the Android v4 In-app billing API.

It supports: In-App Product Purchases (both non-consumable and consumable) and Subscriptions.

Maintainers Wanted

This project is looking for maintainers.

For now only pull requests of external contributors are being reviewed, accepted and welcomed. No more bug fixes or new features will be implemented by the Anjlab team.

If you are interesting in giving this project some ❤️, please chime in!

v4 API Upgrade Notice

Originally this was Google's v2 Billing API implementation, for those who interested all source code kept safe here.

If you got your app using this library previously, here is the Migration Guide.

Getting Started

• You project should build against Android 4.0 SDK at least.

• Add this Android In-App Billing v3 Library to your project:

  • If you guys are using Eclipse, download latest jar version from the releases section of this repository and add it as a dependency
  • If you guys are using Android Studio and Gradle, add this to you build.gradle file:

repositories {
  mavenCentral()
}
dependencies {
  implementation 'com.anjlab.android.iab.v3:library:2.0.3'
}

• Create instance of BillingProcessor class and implement callback in your Activity source code. Constructor will take 3 parameters:
  • Context
  • Your License Key from Google Developer console. This will be used to verify purchase signatures. You can pass NULL if you would like to skip this check (You can find your key in Google Play Console -> Your App Name -> Services & APIs)
  • IBillingHandler Interface implementation to handle purchase results and errors (see below)

public class SomeActivity extends Activity implements BillingProcessor.IBillingHandler {
  BillingProcessor bp;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    bp = new BillingProcessor(this, "YOUR LICENSE KEY FROM GOOGLE PLAY CONSOLE HERE", this);
    bp.initialize();
    // or bp = BillingProcessor.newBillingProcessor(this, "YOUR LICENSE KEY FROM GOOGLE PLAY CONSOLE HERE", this);
    // See below on why this is a useful alternative
  }
 
  // IBillingHandler implementation
 
  @Override
  public void onBillingInitialized() {
    /*
    * Called when BillingProcessor was initialized and it's ready to purchase 
    */
  }
 
  @Override
  public void onProductPurchased(String productId, PurchaseInfo purchaseInfo) {
    /*
    * Called when requested PRODUCT ID was successfully purchased
    */
  }
 
  @Override
  public void onBillingError(int errorCode, Throwable error) {
    /*
    * Called when some error occurred. See Constants class for more details
    * 
    * Note - this includes handling the case where the user canceled the buy dialog:
    * errorCode = Constants.BILLING_RESPONSE_RESULT_USER_CANCELED
    */
  }
 
  @Override
  public void onPurchaseHistoryRestored() {
    /*
    * Called when purchase history was restored and the list of all owned PRODUCT ID's 
    * was loaded from Google Play
    */
  }
}

• Call purchase method for a BillingProcessor instance to initiate purchase or subscribe to initiate a subscription:

bp.purchase(YOUR_ACTIVITY, "YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE");
bp.subscribe(YOUR_ACTIVITY, "YOUR SUBSCRIPTION ID FROM GOOGLE PLAY CONSOLE HERE");

• That's it! A super small and fast in-app library ever!

• And don't forget to release your BillingProcessor instance!

@Override
public void onDestroy() {
  if (bp != null) {
    bp.release();
  }  
  super.onDestroy();
}

Instantiating a BillingProcessor with late initialization

The basic new BillingProcessor(...) actually binds to Play Services inside the constructor. This can, very rarely, lead to a race condition where Play Services are bound and onBillingInitialized() is called before the constructor finishes, and can lead to NPEs. To avoid this, we have the following:

bp = BillingProcessor.newBillingProcessor(this, "YOUR LICENSE KEY FROM GOOGLE PLAY CONSOLE HERE", this); // doesn't bind
bp.initialize(); // binds

Testing In-app Billing

Here is a complete guide. Make sure you read it before you start testing

Check Play Market services availability

Before any usage it's good practice to check in-app billing services availability. In some older devices or chinese ones it may happen that Play Market is unavailable or is deprecated and doesn't support in-app billing.

Simply call static method BillingProcessor.isIabServiceAvailable(context):

boolean isAvailable = BillingProcessor.isIabServiceAvailable(this);
if(!isAvailable) {
  // continue
}

Please notice that calling BillingProcessor.isIabServiceAvailable() (only checks Play Market app installed or not) is not enough because there might be a case when it returns true but still payment won't succeed. Therefore, it's better to call bp.isConnected() after initializing BillingProcessor:

boolean isConnected = billingProcessor.isConnected();
if(isConnected) {
  // launch payment flow
}

or call isSubscriptionUpdateSupported() for checking update subscription use case:

boolean isSubsUpdateSupported = billingProcessor.isSubscriptionUpdateSupported();
if(isSubsUpdateSupported) {
  // launch payment flow
}

Consume Purchased Products

You can always consume made purchase and allow to buy same product multiple times. To do this you need:

bp.consumePurchaseAsync("YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE", new IPurchasesResponseListener());

Restore Purchases & Subscriptions

bp.loadOwnedPurchasesFromGoogleAsync(new IPurchasesResponseListener());

Getting Listing Details of Your Products

To query listing price and a description of your product / subscription listed in Google Play use these methods:

bp.getPurchaseListingDetailsAsync("YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE", new ISkuDetailsResponseListener());
bp.getSubscriptionListingDetailsAsync("YOUR SUBSCRIPTION ID FROM GOOGLE PLAY CONSOLE HERE", new ISkuDetailsResponseListener());

As a result you will get a callback call including List<SkuDetails> data with one SkuDetails object with the following info included:

public final String productId;
public final String title;
public final String description;
public final boolean isSubscription;
public final String currency;
public final Double priceValue;
public final String priceText;

To get info for multiple products / subscriptions on one query, just pass a list of product ids:

bp.getPurchaseListingDetailsAsync(arrayListOfProductIds, new ISkuDetailsResponseListener());
bp.getSubscriptionListingDetailsAsync(arrayListOfProductIds, new ISkuDetailsResponseListener());

where arrayListOfProductIds is a ArrayList<String> containing either IDs for products or subscriptions.

Getting Purchase Info Details

PurchaseInfo object is passed to onProductPurchased method of a handler class. However, you can always retrieve it later calling these methods:

bp.getPurchaseInfo("YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE");
bp.getSubscriptionPurchaseInfo("YOUR SUBSCRIPTION ID FROM GOOGLE PLAY CONSOLE HERE");

As a result you will get a PurchaseInfo object with the following info included:

public final String responseData;
public final String signature;

// PurchaseData contains orderId, productId, purchaseTime, purchaseToken, purchaseState and autoRenewing fields 
public final PurchaseData purchaseData;

Handle Canceled Subscriptions

Call bp.getSubscriptionPurchaseInfo(...) and check the purchaseData.autoRenewing flag. It will be set to False once subscription gets cancelled. Also notice, that you will need to call periodically bp.loadOwnedPurchasesFromGoogleAsync() method in order to update subscription information

Promo Codes Support

You can use promo codes along with this library. Promo codes can be entered in the purchase dialog or in the Google Play app. The URL https://play.google.com/redeem?code=YOUR_PROMO_CODE will launch the Google Play app with the promo code already entered. This could come in handy if you want to give users the option to enter a promo code within your app.

Protection Against Fake "Markets"

There are number of attacks which exploits some vulnerabilities of Google's Play Market. Among them is so-called Freedom attack: Freedom is special Android application, which intercepts application calls to Play Market services and substitutes them with fake ones. So in the end attacked application thinks that it receives valid responses from Play Market.

In order to protect from this kind of attack you should specify your merchantId, which can be found in your Payments Merchant Account. Selecting Settings->Public Profile you will find your unique merchantId

WARNING: keep your merchantId in safe place!

Then using merchantId just call constructor:

public BillingProcessor(Context context, String licenseKey, String merchantId, IBillingHandler handler);

Later one can easily check transaction validity using method:

public boolean isValidPurchaseInfo(PurchaseInfo purchaseInfo);

P.S. This kind of protection works only for transactions dated between 5th December 2012 and 21st July 2015. Before December 2012 orderId wasn't contain merchantId and in the end of July this year Google suddenly changed orderId format.

Proguard

The necessary proguard rules are already added in the library. No further configurations are needed.

The contents in the consumer proguard file contains:

-keep class com.android.vending.billing.**

License

Copyright 2021 AnjLab

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create New Pull Request