Android 集成Google支付，目前有两种方式，一种是使用Google Play结算库，另一种是使用AIDL进行应用内购买结算。今天我们来说一下如何使用Google play结算库结算，另一种请见：Android集成Google支付，以及遇到的坑、坑

使用Google Play结算库比使用AIDL相对简单很多，但是Google废弃了一个关键字段developerPayload，下面会说到。

Google支付官方给的demo GitHub地址，可以去拉下来瞅瞅。https://github.com/googlesamples/android-play-billing/tree/master/TrivialDrive_v2

本文只介绍Google结算库的接入，至于Google后台的配置及BASE_64_ENCODED_PUBLIC_KEY获取，可以去Google后台看看。

一：官方API接入方式：Google支付官方API

我们先按Google API接一遍，先了解一下原理，后面有使用demo中的方法接入的Google支付，使用很简单，如果不想看官方API可以直接看第二步，代码是一样的，只不过封装的好一点，demo中把重连什么的都封装好了。

1.首先在app的build.gradle中添加依赖：

  //Google 支付    compile 'com.android.billingclient:billing:1.2'

2.Connect to Google Play

在每次支付之前，都需要链接到Google Play：

1):调用 newBuilder() 方法创建BillingClient类的实例，也就是Play Billing Library client。还必须调用setListener()方法，并将引用传递给PurchasesUpdatedListener的实例，以便接收应用程序启动的购买以及谷歌Play Store启动的购买的更新。

2):建立与Google Play的连接。设置过程是异步的，你必须实现一个BillingClientStateListener，以便在客户端发出进一步请求后接收回调。

3):重写onBillingServiceDisconnected()回调方法，并实现自己的重试策略，以便在客户端丢失连接时处理到谷歌Play的连接丢失。如果要是与Google链接失败，或者在支付过程中断开了，可以在这个方法中重连。其实Demo中已经封装好了，使用很方便。

下面是代码：

// create new Personprivate BillingClient billingClient;...billingClient = BillingClient.newBuilder(activity).setListener(this).build();billingClient.startConnection(new BillingClientStateListener() {    @Override    public void onBillingSetupFinished(@BillingResponse int billingResponseCode) {        if (billingResponseCode == BillingResponse.OK) {            // The billing client 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.    }});

3.查询应用程序内的所有产品信息

去查询应用程序内的所有产品信息，也就是查一下你要购买的产品是否在Google后台配置了。我的产品ID是在应用内写死的，Google后台也配置过了，所以没管这个查询操作。

skuList中添加的是你的产品ID。SkuType是产品类型。SkuType.INAPP(用于一次性产品或奖励产品)或SkuType.SUBS(订阅)。

List skuList = new ArrayList<> ();skuList.add("premium_upgrade");skuList.add("gas");SkuDetailsParams.Builder params = SkuDetailsParams.newBuilder();params.setSkusList(skuList).setType(SkuType.INAPP);billingClient.querySkuDetailsAsync(params.build(),    new SkuDetailsResponseListener() {        @Override        public void onSkuDetailsResponse(int responseCode, List skuDetailsList) {            // Process the result.        }    });

下面是对查询结果的处理：如果请求成功，则响应代码为BillingResponse.OK。

if (responseCode == BillingResponse.OK                    && skuDetailsList != null) {   for (SkuDetails skuDetails : skuDetailsList) {       String sku = skuDetails.getSku();       String price = skuDetails.getPrice();       if ("premium_upgrade".equals(sku)) {           premiumUpgradePrice = price;       } else if ("gas".equals(sku)) {           gasPrice = price;       }   }}

查询到的结果：

4：开始购买应用内产品

（注：有些老手机可能不支持你的产品，比如订阅，你调用isFeatureSupported()方法检查设备是否支持要销售的产品。）

要从应用程序启动购买请求，请从UI线程调用launchBillingFlow()方法：

// Retrieve a value for "skuDetails" by calling querySkuDetailsAsync().BillingFlowParams flowParams = BillingFlowParams.newBuilder()        .setSkuDetails(skuDetails)        .build();int responseCode = billingClient.launchBillingFlow(flowParams);

当您调用launchBillingFlow()方法时，系统将显示Google 购买一次性产品截图：

下面是购买订阅的截图：

5：接受购买成功的回调：

购买完成之后可以拿到Google返回的订单信息，自己做一些处理。还要做消耗操作，如果不消耗，下次不能购买好像。

@Overridevoid onPurchasesUpdated(@BillingResponse int responseCode, List purchases) {    if (responseCode == BillingResponse.OK            && purchases != null) {        for (Purchase purchase : purchases) {            handlePurchase(purchase);        }    } else if (responseCode == BillingResponse.USER_CANCELED) {        // Handle an error caused by a user cancelling the purchase flow.    } else {        // Handle any other error codes.    }}

purchase中就是订单信息。可以从中获取到订单的ID和产品ID等，发给服务器验证。

二：使用官方的Demo

1：还是先导入依赖：

  //Google 支付    compile 'com.android.billingclient:billing:1.2'

2：把Demo中shared-module的billing文件夹中的代码拷到项目中：

https://github.com/googlesamples/android-play-billing/tree/master/TrivialDrive_v2

3:在支付的Activity中：

首先Activity 要 implements BillingProvider

然后在Activity中添加一下方法：

 /**     * Google支付内容**************************************     */ //Google支付    private BillingManager mBillingManager;    private BillingProvider mBillingProvider;    @Override    public BillingManager getBillingManager() {        return mBillingManager;    }    @Override    public boolean isPremiumPurchased() {        return false;    }    /**     * 购买事件     * purchaseId：产品ID     */    public void googlePay(String purchaseId) {        mBillingProvider.getBillingManager().initiatePurchaseFlow(purchaseId,"", BillingClient.SkuType.INAPP);    }    /**     * Handler to billing updates     */    private class UpdateListener implements BillingManager.BillingUpdatesListener {        @Override        public void onBillingClientSetupFinished() {            //通过商品ID，去查询Google后台是否有该ID的商品            final List skuList = new ArrayList<>();            skuList.add(purchaseId);            mBillingProvider.getBillingManager().querySkuDetailsAsync(BillingClient.SkuType.INAPP, skuList, new SkuDetailsResponseListener() {                @Override                public void onSkuDetailsResponse(int responseCode, List skuDetailsList) {                    if (responseCode != BillingClient.BillingResponse.OK) {                                            } else if (skuDetailsList != null && skuDetailsList.size() > 0) {                        for (SkuDetails details : skuDetailsList) {                                                    //获取到所查商品信息                        }                    } else {                        //没有要消耗的产品//                        Toast.makeText(PayActivity.this, "没有要查询的产品", Toast.LENGTH_LONG).show();                    }                }            });        }        @Override        public void onConsumeFinished(String token, @BillingClient.BillingResponse int result) {//            Toast.makeText(PayActivity.this, "消耗完成", Toast.LENGTH_LONG).show();            // Note: We know this is the SKU_GAS, because it's the only one we consume, so we don't            // check if token corresponding to the expected sku was consumed.            // If you have more than one sku, you probably need to validate that the token matches            // the SKU you expect.            // It could be done by maintaining a map (updating it every time you call consumeAsync)            // of all tokens into SKUs which were scheduled to be consumed and then looking through            // it here to check which SKU corresponds to a consumed token.            if (result == BillingClient.BillingResponse.OK) {                // Successfully consumed, so we apply the effects of the item in our                // game world's logic, which in our case means filling the gas tank a bit                //消耗成功//                Toast.makeText(PayActivity.this, "消耗成功", Toast.LENGTH_LONG).show();            } else {//                Toast.makeText(PayActivity.this, "消耗失败", Toast.LENGTH_LONG).show();            }        }        @Override        public void onPurchasesUpdated(List purchaseList) {            for (Purchase purchase : purchaseList) {                //拿到订单信息，做自己的处理，发生到服务端验证订单信息，然后去消耗                                //购买成功，拿着令牌 去消耗//                Toast.makeText(PayActivity.this, "购买成功：" + purchase.getPurchaseToken(), Toast.LENGTH_LONG).show();                // We should consume the purchase and fill up the tank once it was consumed                mBillingProvider.getBillingManager().consumeAsync(purchase.getPurchaseToken());            }        }    }    /**     * Google支付内容**************************************     */

要购买直接调用googlePay()方法，把产品ID传进去，就可以调起Google支付了。

注：Google的BASE_64_ENCODED_PUBLIC_KEY，是在BillingManager.java中添加的，BASE_64_ENCODED_PUBLIC_KEY的获取，是从Google后台获取的。

OK了，就这么多，代码不多。

三：下面我们来说说developerPayload吧

使用AIDL进行应用内购买结算，客户端可以传一个developerPayload作为额外参数传给Google，在用户支付成功之后的订单信息里，也会有这个字段，服务端可以根据这个额外参数来判断是哪个用户购买的，从而进行处理。但是使用Google play结算库结算，不能添加这个字段了，我们可以在Google依赖库中的com/android/billingclient/api/BillingClientImpl.java看到这个字段已经被弃用：第80行和第88行

 @Override  public int launchBillingFlow(Activity activity, BillingFlowParams params) {    if (!isReady()) {      return broadcastFailureAndReturnBillingResponse(BillingResponse.SERVICE_DISCONNECTED);    }    @SkuType String skuType = params.getSkuType();    String newSku = params.getSku();    SkuDetails skuDetails = params.getSkuDetails();    boolean rewardedSku = skuDetails != null && skuDetails.isRewarded();    // Checking for mandatory params fields    if (newSku == null) {      BillingHelper.logWarn(TAG, "Please fix the input params. SKU can't be null.");      return broadcastFailureAndReturnBillingResponse(BillingResponse.DEVELOPER_ERROR);    }    if (skuType == null) {      BillingHelper.logWarn(TAG, "Please fix the input params. SkuType can't be null.");      return broadcastFailureAndReturnBillingResponse(BillingResponse.DEVELOPER_ERROR);    }    // Checking for requested features support    if (skuType.equals(SkuType.SUBS) && !mSubscriptionsSupported) {      BillingHelper.logWarn(TAG, "Current client doesn't support subscriptions.");      return broadcastFailureAndReturnBillingResponse(BillingResponse.FEATURE_NOT_SUPPORTED);    }    boolean isSubscriptionUpdate = (params.getOldSku() != null);    if (isSubscriptionUpdate && !mSubscriptionUpdateSupported) {      BillingHelper.logWarn(TAG, "Current client doesn't support subscriptions update.");      return broadcastFailureAndReturnBillingResponse(BillingResponse.FEATURE_NOT_SUPPORTED);    }    if (params.hasExtraParams() && !mIABv6Supported) {      BillingHelper.logWarn(TAG, "Current client doesn't support extra params for buy intent.");      return broadcastFailureAndReturnBillingResponse(BillingResponse.FEATURE_NOT_SUPPORTED);    }    if (rewardedSku && !mIABv6Supported) {      BillingHelper.logWarn(TAG, "Current client doesn't support extra params for buy intent.");      return broadcastFailureAndReturnBillingResponse(BillingResponse.FEATURE_NOT_SUPPORTED);    }    try {      BillingHelper.logVerbose(          TAG, "Constructing buy intent for " + newSku + ", item type: " + skuType);      Bundle buyIntentBundle;      // If IAB v6 is supported, we always try to use buyIntentExtraParams and report the version      if (mIABv6Supported) {        Bundle extraParams = constructExtraParams(params);        extraParams.putString(BillingHelper.LIBRARY_VERSION_KEY, LIBRARY_VERSION);        if (rewardedSku) {          extraParams.putString(BillingFlowParams.EXTRA_PARAM_KEY_RSKU, skuDetails.rewardToken());          if (mChildDirected == ChildDirected.CHILD_DIRECTED              || mChildDirected == ChildDirected.NOT_CHILD_DIRECTED) {            extraParams.putInt(BillingFlowParams.EXTRA_PARAM_CHILD_DIRECTED, mChildDirected);          }        }        int apiVersion = (params.getVrPurchaseFlow()) ? 7 : 6;        buyIntentBundle =            mService.getBuyIntentExtraParams(                apiVersion,                mApplicationContext.getPackageName(),                newSku,                skuType,                null,                extraParams);      } else if (isSubscriptionUpdate) {        // For subscriptions update we are calling corresponding service method        buyIntentBundle =            mService.getBuyIntentToReplaceSkus(                /* apiVersion */ 5,                mApplicationContext.getPackageName(),                Arrays.asList(params.getOldSku()),                newSku,                SkuType.SUBS,                /* developerPayload */ null);      } else {        buyIntentBundle =            mService.getBuyIntent(                /* apiVersion */ 3,                mApplicationContext.getPackageName(),                newSku,                skuType,                /* developerPayload */ null);      }      int responseCode = BillingHelper.getResponseCodeFromBundle(buyIntentBundle, TAG);      if (responseCode != BillingResponse.OK) {        BillingHelper.logWarn(TAG, "Unable to buy item, Error response code: " + responseCode);        return broadcastFailureAndReturnBillingResponse(responseCode);      }      // Launching an invisible activity that will handle the purchase result      Intent intent = new Intent(activity, ProxyBillingActivity.class);      intent.putExtra(ProxyBillingActivity.KEY_RESULT_RECEIVER, onPurchaseFinishedReceiver);      PendingIntent pendingIntent = buyIntentBundle.getParcelable(RESPONSE_BUY_INTENT_KEY);      intent.putExtra(RESPONSE_BUY_INTENT_KEY, pendingIntent);      // We need an activity reference here to avoid using FLAG_ACTIVITY_NEW_TASK.      // But we don't want to keep a reference to it inside the field to avoid memory leaks.      // Plus all the other methods need just a Context reference, so could be used from the      // Service or Application.      activity.startActivity(intent);    } catch (RemoteException e) {      String msg =          "RemoteException while launching launching replace subscriptions flow: "              + "; for sku: "              + newSku              + "; try to reconnect";      BillingHelper.logWarn(TAG, msg);      return broadcastFailureAndReturnBillingResponse(BillingResponse.SERVICE_DISCONNECTED);    }    return BillingResponse.OK;  }

developerPayload已经写死为null了，很气人，不能用了。并且Google开发人员也明确说出以后也不会开通这个字段。请看https://issuetracker.google.com/issues/63381481

所以，在集成的时候，要特别注意这一点。

当然也有人自己开发了对Payload支持的Demo：https://github.com/DimaDake/billing

他就是把Google Play结算库中的代码全部拉出来，然后把developerPayload的重新添加上。这个demo的其他代码没细看，我是没使用这个demo，毕竟支付是和钱有关的，还是用Google Play的官方SDK比较好。

ok，集成好，就可以购买测试了。测试过程这里不细说了，可以看另一篇文章Android集成Google支付，以及遇到的坑、坑

Google支付V3.0集成，使用Google play结算库结算，弃用developerPayload字段