您必须对示例中的计费服务客户端代码进行一些更改。
首先，您应该调用服务器以获取将被用于RestoreTransactions或进行购买的随机数，以使事情尽可能安全。
让我们跟随发生的事情。这是Google Play调用的BillingReceiver：
private void purchaseStateChanged(Context context, String signedData, String signature) { Intent intent = new Intent(Consts.ACTION_PURCHASE_STATE_CHANGED); intent.setClass(context, BillingService.class); intent.putExtra(Consts.INAPP_SIGNED_DATA, signedData); intent.putExtra(Consts.INAPP_SIGNATURE, signature); context.startService(intent);}如果查看BillingService.java中的handleCommand，它将处理此意图：
public void handleCommand(Intent intent, int startId) { String action = intent.getAction(); if (Consts.DEBUG) { Log.i(TAG, "handleCommand() action: " + action); } if (Consts.ACTION_/confirm/i_NOTIFICATION.equals(action)) { String[] notifyIds = intent.getStringArrayExtra(Consts.NOTIFICATION_ID); confirmNotifications(startId, notifyIds); } else if (Consts.ACTION_GET_PURCHASE_INFORMATION.equals(action)) { String notifyId = intent.getStringExtra(Consts.NOTIFICATION_ID); getPurchaseInformation(startId, new String[] { notifyId }); } else if (Consts.ACTION_PURCHASE_STATE_CHANGED.equals(action)) { String signedData = intent.getStringExtra(Consts.INAPP_SIGNED_DATA); String signature = intent.getStringExtra(Consts.INAPP_SIGNATURE); purchaseStateChanged(startId, signedData, signature); } else if (Consts.ACTION_RESPONSE_CODE.equals(action)) { long requestId = intent.getLongExtra(Consts.INAPP_REQUEST_ID, -1); int responseCodeIndex = intent.getIntExtra(Consts.INAPP_RESPONSE_CODE, ResponseCode.RESULT_ERROR.ordinal()); ResponseCode responseCode = ResponseCode.valueOf(responseCodeIndex); checkResponseCode(requestId, responseCode); }}然后调用PurchaseStateChanged函数。该功能应由对服务器的调用代替，以创建用于内容传递的会话。应该将Security.java中的代码移植到服务器端，以验证云中的事务。
private void purchaseStateChanged(int startId, String signedData, String signature) { ArrayList<Security.VerifiedPurchase> purchases; purchases = Security.verifyPurchase(signedData, signature); if (purchases == null) { return; } ArrayList<String> notifyList = new ArrayList<String>(); for (VerifiedPurchase vp : purchases) { if (vp.notificationId != null) { notifyList.add(vp.notificationId); } ResponseHandler.purchaseResponse(this, vp.purchaseState, vp.productId, vp.orderId, vp.purchaseTime, vp.developerPayload); } if (!notifyList.isEmpty()) { String[] notifyIds = notifyList.toArray(new String[notifyList.size()]); confirmNotifications(startId, notifyIds); }}确保将公共密钥放在已移植的Security.java文件中的服务器端。
