java实现谷歌支付后端验证订单

前段时间公司项目接入了第三方支付谷歌支付，一句话就是前端下单后再调用后端接口检验订单，(其他业务)，校验完就可以去消耗了

网上的教程好多都是先获取code，拿到code后再去获取refresh_token和access_token，使用access_token做为凭证调用google api，获取code时需要登录，登录在后端都不好做了

推荐使用下面的方式

//	packageName为应用程序报名、productId商品id、purchaseToken谷歌返回的收据
	public String checkOrder(String packageName, String productId, String purchaseToken) throws IOException, GeneralSecurityException {
        //使用服务帐户Json文件获取Google凭据
        List<String> scopes = new ArrayList<>();
        scopes.add(AndroidPublisherScopes.ANDROIDPUBLISHER);
        GoogleCredential credential = GoogleCredential.fromStream(new FileInputStream("服务账号json文件路径"))
                .createScoped(scopes);
//        使用谷歌凭据和收据从谷歌获取购买信息
        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
        JsonFactory jsonFactory = new JacksonFactory();
        AndroidPublisher publisher = new AndroidPublisher.Builder(httpTransport, jsonFactory, credential)
                .setApplicationName("应用程序名称").build();
        AndroidPublisher.Purchases purchases = publisher.purchases();
        final AndroidPublisher.Purchases.Products.Get request = purchases.products().get(packageName, productId,purchaseToken);
        final ProductPurchase purchase = request.execute();
        //处理业务
    }

purchase 里面包含以下信息

只说几个关键的字段
orderId -------------------------------谷歌的平台订单号
consumptionState-----------------Inapp产品的消费状态。可能的值为：0。尚未消耗1.已消耗
purchaseState---------------------订单的购买状态。可能的值为：0。已购买1.已取消2.待定
obfuscatedExternalProfileId—透传字段，一般传服务端生成的订单id
后面就是处理自己的业务了，大概说下我这次业务，从谷歌得到交易对象purchase后
1.判断订单是否已购买
2.判断订单是否已消耗
3.如果是已购买未消耗的情况下才继续往下走
4.更新数据库订单记录，通过obfuscatedExternalProfileId透传的订单号查询数据库找到该笔订单
5.通知服务发放道具

下面记录下遇到的问题

出现下面这种情况一般是服务账号没有权限，需要在google play console赋予权限

  "errors": [
   {
    "domain": "androidpublisher",
    "reason": "permissionDenied",
    "message": "The current user has insufficient permissions to perform the requested operation."
   }
  ],
  "code": 401,
  "message": "The current user has insufficient permissions to perform the requested operation."
 }
}

出现下面这种情况 项目没有关联或者关联错了，如果关联了还报这个错误，随便新增一个内购商品，你可以新增完删除掉

{
    "error": {
        "errors": [
            {
                "domain": "androidpublisher",
                "reason": "projectNotLinked",
                "message": "The project id used to call the Google Play Developer API has not been linked in the Google Play Developer Console."
            }
        ],
        "code": 403,
        "message": "The project id used to call the Google Play Developer API has not been linked in the Google Play Developer Console."
    }
}