本部分中的页面介绍了如何通过 App Engine API 访问 Datastore。使用这些 API 的应用只能在 App Engine 中运行，并且必须升级到推荐的 Google Cloud API 才能迁移到较新版本的 App Engine 运行时环境。推荐的 Datastore API 包含在 Google Cloud 客户端库中，让应用可在 App Engine 中以及其他支持 Java 8 的环境中运行。
搭配使用 Objectify 与 Datastore
您可以使用 Objectify 访问 Datastore，而不是使用 App Engine API 或 Google Cloud API 来访问。Objectify 是 Cloud Datastore 的开源 API，可提供比 App Engine API 和 Google Cloud API 更高的抽象级层。使用早期版本的 Objectify 的应用只能在 App Engine 中运行，但使用版本 6 及更高版本的应用可以在 App Engine 以及其他支持 Java 8 的环境中运行。
[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["很难理解","hardToUnderstand","thumb-down"],["信息或示例代码不正确","incorrectInformationOrSampleCode","thumb-down"],["没有我需要的信息/示例","missingTheInformationSamplesINeed","thumb-down"],["翻译问题","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC)：2025-08-20。"],[[["\u003cp\u003eThis API is designed for first-generation runtimes and is relevant when upgrading to second-generation runtimes.\u003c/p\u003e\n"],["\u003cp\u003eApps using these App Engine APIs can only run in App Engine and must upgrade to the recommended Google Cloud APIs before migrating to newer runtimes.\u003c/p\u003e\n"],["\u003cp\u003eThe Google Cloud Client Library is the recommended API for Datastore and allows apps to run in App Engine and other environments.\u003c/p\u003e\n"],["\u003cp\u003eObjectify, an open-source API, offers a higher-level abstraction for accessing Datastore, and version 6 or later can run in multiple environments.\u003c/p\u003e\n"],["\u003cp\u003eWhile Objectify is mentioned, Google Cloud Platform does not provide direct support for this third-party library.\u003c/p\u003e\n"]]],[],null,["# Using App Engine APIs with Datastore\n\n| This API is supported for first-generation runtimes and can be used when [upgrading to corresponding second-generation runtimes](/appengine/docs/standard/\n| java-gen2\n|\n| /services/access). If you are updating to the App Engine Java 11/17 runtime, refer to the [migration guide](/appengine/migration-center/standard/migrate-to-second-gen/java-differences) to learn about your migration options for legacy bundled services.\n\n\u003cbr /\u003e\n\n[Datastore](/datastore/docs)\nis a NoSQL document database built for automatic scaling, high performance, and\nease of application development.\n\nThe pages in this section describe how to access Datastore with\n*App Engine APIs* . Apps that use these APIs can only run in\nApp Engine and will need to upgrade to the\n[recommended Google Cloud APIs](/datastore/docs/reference/libraries#client-libraries-install-java)\nbefore migrating to newer App Engine runtimes. The recommended APIs for\nDatastore are in the Google Cloud Client Library and enable your\napp to run in App Engine as well as other environments that support Java 8.\n\nUsing Objectify with Datastore\n------------------------------\n\nInstead of using App Engine APIs or Google Cloud APIs, you can use Objectify\nto access Datastore.\n[Objectify](https://github.com/objectify/objectify/wiki)\nis an open-source API for Cloud Datastore that provides a higher-level of\nabstraction than App Engine APIs and Google Cloud APIs. While apps that use\nearlier versions of Objectify can only run in App Engine, apps that\nuse version 6 and later can run in App Engine as well as other\nenvironments that support Java 8.\n\nIf you plan to use Objectify, it's recommended that you use version 6\nor later.\n| **Note:** The use of Objectify is shown for reference only. Google Cloud Platform does not provide support for the Objectify library, which is a third-party library."]]
