Android In-App Billing v3 Library

This is a simple, straight-forward implementation of the Android v3 In-app billing API.

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

Getting Started

You project should build against Android 2.2 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 {
       compile 'com.anjlab.android.iab.v3:library:1.0.+'
    }

Open the AndroidManifest.xml of your application and add this permission:

  <uses-permission android:name="com.android.vending.BILLING" />

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);
		// 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, TransactionDetails details) {
		/*
		 * 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
		 */
	}
}

override Activity's onActivityResult method:

  @Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		if (!bp.handleActivityResult(requestCode, resultCode, data))
			super.onActivityResult(requestCode, resultCode, data);
	}

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

Without a developer payload:

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

With a developer payload:

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

IMPORTANT: when you provide a payload, internally the library prepends a string to your payload. For subscriptions, it prepends "subs:\<productId\>:", and for products, it prepends "inapp:\<productId\>:\<UUID\>:". This is important to know if you do any validation on the payload returned from Google Play after a successful purchase.

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():

    boolean isAvailable = BillingProcessor.isIabServiceAvailable();
    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 isOneTimePurchaseSupported() after initializing BillingProcessor:

    boolean isOneTimePurchaseSupported = billingProcessor.isOneTimePurchaseSupported();
    if(isOneTimePurchaseSupported) {
        // 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.consumePurchase("YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE");

Restore Purchases & Subscriptions

	bp.loadOwnedPurchasesFromGoogle();

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.getPurchaseListingDetails("YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE");
    bp.getSubscriptionListingDetails("YOUR SUBSCRIPTION ID FROM GOOGLE PLAY CONSOLE HERE");

As a result you will get a 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.getPurchaseListingDetails(arrayListOfProductIds);
	bp.getSubscriptionListingDetails(arrayListOfProductIds);

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

As a result you will get a List<SkuDetails> which contains objects described above.

Getting Purchase Transaction Details

As a part or 1.0.9 changes, TransactionDetails object is passed to onProductPurchased method of a handler class. However, you can always retrieve it later calling these methods:

    bp.getPurchaseTransactionDetails("YOUR PRODUCT ID FROM GOOGLE PLAY CONSOLE HERE");
    bp.getSubscriptionTransactionDetails("YOUR SUBSCRIPTION ID FROM GOOGLE PLAY CONSOLE HERE");

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

    public final String productId;
    public final String orderId;
    public final String purchaseToken;
    public final Date purchaseTime;
    
    // containing the raw json string from google play and the signature to
    // verify the purchase on your own server
    public final PurchaseInfo purchaseInfo;

Handle Canceled Subscriptions

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

Promo Codes Support

You can use promo codes along with this library, they are supported with one extra notice. According to this issue there is currently a bug in Google Play Services, and it does not respect Developer Payload token made by this library, causing a security validation fault (BILLING_ERROR_INVALID_DEVELOPER_PAYLOAD error code). While Google engineers are working on fixing this (lets hope so, you can also leave a feedback on this issue to make them work faster).

Still, there are couple of workarounds you can use:

Handle BILLING_ERROR_INVALID_DEVELOPER_PAYLOAD error code in your onBillingError implementation. You can check out #156 for a suggested workaround. This does not look nice, but it works.
Avoid using promo codes in a purchase dialog, prefer entering these codes in Google Play's App Redeem promo code menu. One way to do this is to distribute your promo codes in form of a redeem link (https://play.google.com/redeem?code=YOURPROMOCODE) instead of just a YOURPROMOCODE values. You can find a sample on how to bundle it inside your app here.

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 isValid(TransactionDetails transactionDetails);

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.

License

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

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

RealAndyLawton/android-inapp-billing-v3