Библиотека для совершения покупок внутри приложений (Android In-App Billing v.3)

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.util.Log;

import org.solovyev.android.checkout.ActivityCheckout;
import org.solovyev.android.checkout.BillingRequests;
import org.solovyev.android.checkout.Checkout;
import org.solovyev.android.checkout.EmptyRequestListener;
import org.solovyev.android.checkout.Inventory;
import org.solovyev.android.checkout.ProductTypes;
import org.solovyev.android.checkout.Purchase;
import org.solovyev.android.checkout.RequestListener;
import org.solovyev.android.checkout.ResponseCodes;
import org.solovyev.android.checkout.Sku;

import java.util.Locale;

import javax.annotation.Nonnull;


public abstract class InAppTemplateActivity extends Activity {

	public final static String SKU = "sku_1";

	private Inventory.Request mInventoryRequest;

	private final InventoryCallback mInventoryCallback = new InventoryCallback();

	private ActivityCheckout mCheckout;

	private Inventory mInventory;


	@Override
	protected void onCreate(@Nullable Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);


		mCheckout = Checkout.forActivity(this, application.inApp.getBilling());

		mCheckout.start(new Checkout.Listener() {
			public void onReady(@Nonnull BillingRequests requests) {
				Log.i(this.getClass().toString(), "Checkout onReady");
			}

			public void onReady(@Nonnull BillingRequests requests, @Nonnull String product, boolean billingSupported) {
			}
		});

		mCheckout.createPurchaseFlow(new PurchaseListener());

		mInventory = mCheckout.makeInventory();


		mInventoryRequest = Inventory.Request.create();
		// load purchase info
		mInventoryRequest.loadAllPurchases();
		// load SKU details
		mInventoryRequest.loadSkus(ProductTypes.IN_APP, "android.test.purchased", SKU);


		reloadInventory();
	}

	@Override
	protected void onDestroy() {
		mCheckout.stop();
		mCheckout = null;

		mInventory = null;

		super.onDestroy();
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		mCheckout.onActivityResult(requestCode, resultCode, data);
		super.onActivityResult(requestCode, resultCode, data);
	}

	protected void purchase(final String sku) {
		mCheckout.whenReady(new Checkout.EmptyListener() {
			@Override
			public void onReady(BillingRequests requests) {
				requests.purchase(ProductTypes.IN_APP, sku, null, mCheckout.getPurchaseFlow());
			}
		});
	}

	private void reloadInventory() {
		mInventory.load(mInventoryRequest, mInventoryCallback);
	}

	private void consume(final Purchase purchase) {
		mCheckout.whenReady(new Checkout.EmptyListener() {
			@Override
			public void onReady(@Nonnull BillingRequests requests) {
				requests.consume(purchase.token, new RequestListener<Object>() {
					@Override
					public void onSuccess(@Nonnull Object result) {
						Log.i(this.getClass().toString(), "Consume onSuccess");

						consumed();

						reloadInventory();
					}

					@Override
					public void onError(int response, @Nonnull Exception e) {
						// it is possible that our data is not synchronized with data on Google Play => need to handle some errors
						if (response == ResponseCodes.ITEM_NOT_OWNED) {
							Log.i(this.getClass().toString(), "ERROR: ITEM_NOT_OWNED");

							consumed();
						} else {
							Log.e(this.getClass().toString(), "ERROR: " + e.toString());
						}

						reloadInventory();
					}

					private void consumed() {
						// если нужно, сделать что-то после потребления покупки
					}
				});
			}
		});
	}

	// Чтобы в оплате проходили Static Responses (у них нет токена) нужно заменить дефолтный PurchaseVerifier на свой,
	// например, такой:
/*	class MyPurchaseVerifier implements PurchaseVerifier {

		@Nonnull
		private final String mPublicKey;

		public MyPurchaseVerifier(@Nonnull String publicKey) {
			mPublicKey = publicKey;
		}

		@Override
		public void verify(@Nonnull List<Purchase> purchases, @Nonnull RequestListener<List<Purchase>> listener) {
			final List<Purchase> verifiedPurchases = new ArrayList<Purchase>(purchases.size());
			for (Purchase purchase : purchases) {
				if ("android.test.purchased;android.test.canceled;android.test.refunded;android.test.item_unavailable".contains(purchase.sku)) {
					verifiedPurchases.add(purchase);
				} else if (Security.verifyPurchase(mPublicKey, purchase.data, purchase.signature)) {
					verifiedPurchases.add(purchase);
				} else {
					if (isEmpty(purchase.signature)) {
						Log.e(this.getClass().toString(), "Cannot verify purchase: " + purchase + ". Signature is empty");
					} else {
						Log.e(this.getClass().toString(), "Cannot verify purchase: " + purchase + ". Wrong signature");
					}
				}
			}
			listener.onSuccess(verifiedPurchases);
		}
	}*/
	// И вернуть его в new Billing.DefaultConfiguration() 
	/*
	@Nonnull
	@Override
	public PurchaseVerifier getPurchaseVerifier() {
		return new MyPurchaseVerifier(getPublicKey());
	}
	*/

	private class PurchaseListener extends EmptyRequestListener<Purchase> {
		@Override
		public void onSuccess(@Nonnull Purchase purchase) {
			Log.i(this.getClass().toString(), "Purchase onSuccess");

			purchased();

			reloadInventory();
		}

		@Override
		public void onError(int response, @Nonnull Exception e) {
			// it is possible that our data is not synchronized with data on Google Play => need to handle some errors
			if (response == ResponseCodes.ITEM_ALREADY_OWNED) {
				Log.i(this.getClass().toString(), "ERROR: ITEM_ALREADY_OWNED");

				purchased();
			} else {
				Log.e(this.getClass().toString(), "ERROR: " + e.toString());
			}

			reloadInventory();
		}

		private void purchased() {
			// сделать что-то после покупки
		}
	}

	private class InventoryCallback implements Inventory.Callback {
		@Override
		public void onLoaded(Inventory.Products products) {
			final Inventory.Product product = products.get(ProductTypes.IN_APP);

			if (!product.supported) {
				// billing is not supported, user can't purchase anything. Don't show ads in this case
				Log.e(this.getClass().toString(), "billing_not_supported");
				return;
			}

			for (Sku sku : product.getSkus()) {
				Log.i(this.getClass().toString(),
						String.format(Locale.US, "SKU: id = %s, title = %s, price = %s, currency = %s",
								sku.id,
								sku.title,
								sku.detailedPrice.amount/1000000,
								sku.detailedPrice.currency
						)
				);

				final Purchase purchase = product.getPurchaseInState(sku, Purchase.State.PURCHASED);
				if (purchase != null) {
					Log.i(this.getClass().toString(), String.format(Locale.US, "Куплено - SKU: id = %s", sku.id));

					if (purchase.token != null) {
						// token есть только у непотреблённых покупок

						Log.i(this.getClass().toString(),
								String.format(Locale.US, "Необходимо потребить товар - SKU: id = %s, token = %s, Google Wallet Order ID = %s, payload = %s",
										sku.id,
										purchase.token,
										purchase.orderId != null ? purchase.orderId : "null",// У static responses orderId отсутствует
										purchase.payload
								)
						);

						consume(purchase);
					}
				}
			}
		}
	}
}