行为变更：以 Android 14 或更高版本为目标平台的应用

与以前的版本一样，Android 14 包含一些行为变更，这些变更可能会影响您的应用。以下行为变更仅影响以 Android 14（API 级别 34）或更高版本为目标平台的应用。如果您的应用以 Android 14 或更高版本为目标平台，您应该修改自己的应用以适当地支持这些行为（如果适用）。

此外，请务必查看对 Android 14 上运行的所有应用都有影响的行为变更列表（无论应用的 targetSdkVersion 如何）。

核心功能

前台服务类型是必需的

如果您的应用以 Android 14（API 级别 34）或更高版本为目标平台，则必须为应用中的每项前台服务指定至少一个前台服务类型。您应该选择一个能够代表应用用例的前台服务类型。系统需要特定类型的前台服务满足特定用例。

注意：Android 14 针对运行状况和远程消息传递用例引入了前台服务类型。系统还为简短服务、特殊用例和系统豁免保留新的类型。

如果应用中的用例与这些类型均不相关，强烈建议您迁移逻辑以使用 WorkManager 或用户发起的数据传输作业。

在 BluetoothAdapter 中强制执行 BLUETOOTH_CONNECT 权限

对于以 Android 14（API 级别 34）或更高版本为目标平台的应用，Android 14 会在调用 BluetoothAdapter getProfileConnectionState() 方法时强制执行 BLUETOOTH_CONNECT 权限。

此方法已需要 BLUETOOTH_CONNECT 权限，但未被强制执行。请确保您的应用在应用的 AndroidManifest.xml 文件中声明 BLUETOOTH_CONNECT（如以下代码段所示），并在调用 getProfileConnectionState 之前检查用户是否已授予权限。

<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />

OpenJDK 17 更新

Android 14 continues the work of refreshing Android's core libraries to align with the features in the latest OpenJDK LTS releases, including both library updates and Java 17 language support for app and platform developers.

A few of these changes can affect app compatibility:

• Changes to regular expressions: Invalid group references are now disallowed to more closely follow the semantics of OpenJDK. You might see new cases where an IllegalArgumentException is thrown by the java.util.regex.Matcher class, so make sure to test your app for areas that use regular expressions. To enable or disable this change while testing, toggle the DISALLOW_INVALID_GROUP_REFERENCE flag using the compatibility framework tools.
• UUID handling: The java.util.UUID.fromString() method now does more strict checks when validating the input argument, so you might see an IllegalArgumentException during deserialization. To enable or disable this change while testing, toggle the ENABLE_STRICT_VALIDATION flag using the compatibility framework tools.
• ProGuard issues: In some cases, the addition of the java.lang.ClassValue class causes an issue if you try to shrink, obfuscate, and optimize your app using ProGuard. The problem originates with a Kotlin library that changes runtime behaviour based on whether Class.forName("java.lang.ClassValue") returns a class or not. If your app was developed against an older version of the runtime without the java.lang.ClassValue class available, then these optimizations might remove the computeValue method from classes derived from java.lang.ClassValue.

JobScheduler 增强回调和网络行为

Since its introduction, JobScheduler expects your app to return from onStartJob or onStopJob within a few seconds. Prior to Android 14, if a job runs too long, it stops and fails silently. If your app targets Android 14 (API level 34) or higher and exceeds the granted time on the main thread, the app triggers an ANR with the error message "No response to onStartJob" or "No response to onStopJob". Consider migrating to WorkManager, which provides support for asynchronous processing or migrating any heavy work into a background thread.

JobScheduler also introduces a requirement to declare the ACCESS_NETWORK_STATE permission if using setRequiredNetworkType or setRequiredNetwork constraint. If your app does not declare the ACCESS_NETWORK_STATE permission when scheduling the job and is targeting Android 14 or higher, it will result in a SecurityException.

Tiles 发布 API

对于以 14 及更高版本为目标平台的应用，TileService#startActivityAndCollapse(Intent) 已废弃，现在会在调用时抛出异常。如果您的应用从功能块启动 activity，请改用 TileService#startActivityAndCollapse(PendingIntent)。

隐私权

拥有对照片和视频的部分访问权限

Android 14 introduces Selected Photos Access, which allows users to grant apps access to specific images and videos in their library, rather than granting access to all media of a given type.

This change is only enabled if your app targets Android 14 (API level 34) or higher. If you don't use the photo picker yet, we recommend implementing it in your app to provide a consistent experience for selecting images and videos that also enhances user privacy without having to request any storage permissions.

If you maintain your own gallery picker using storage permissions and need to maintain full control over your implementation, adapt your implementation to use the new READ_MEDIA_VISUAL_USER_SELECTED permission. If your app doesn't use the new permission, the system runs your app in a compatibility mode.

用户体验

安全的全屏 intent 通知

With Android 11 (API level 30), it was possible for any app to use Notification.Builder.setFullScreenIntent to send full-screen intents while the phone is locked. You could auto-grant this on app install by declaring USE_FULL_SCREEN_INTENT permission in the AndroidManifest.

Full-screen intent notifications are designed for extremely high-priority notifications demanding the user's immediate attention, such as an incoming phone call or alarm clock settings configured by the user. For apps targeting Android 14 (API level 34) or higher, apps that are allowed to use this permission are limited to those that provide calling and alarms only. The Google Play Store revokes default USE_FULL_SCREEN_INTENT permissions for any apps that don't fit this profile. The deadline for these policy changes is May 31, 2024.

This permission remains enabled for apps installed on the phone before the user updates to Android 14. Users can turn this permission on and off.

You can use the new API NotificationManager.canUseFullScreenIntent to check if your app has the permission; if not, your app can use the new intent ACTION_MANAGE_APP_USE_FULL_SCREEN_INTENT to launch the settings page where users can grant the permission.

安全

对隐式 intent 和待处理 intent 的限制

对于以 Android 14（API 级别 34）或更高版本为目标平台的应用，Android 会通过以下方式限制应用向内部应用组件发送隐式 intent：

• 隐式 intent 只能传送到导出的组件。应用必须使用显式 intent 传送到未导出的组件，或将该组件标记为已导出。
• 如果应用通过未指定组件或软件包的 intent 创建可变待处理 intent，系统会抛出异常。

这些变更可防止恶意应用拦截意在供应用内部组件使用的隐式 intent。

例如，下面是可以在应用的清单文件中声明的 intent 过滤器：

<activity
    android:name=".AppActivity"
    android:exported="false">
    <intent-filter>
        <action android:name="com.example.action.APP_ACTION" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</activity>

如果应用尝试使用隐式 intent 启动此 activity，则系统会抛出异常：

Kotlin

// Throws an exception when targeting Android 14.
context.startActivity(Intent("com.example.action.APP_ACTION"))

Java

// Throws an exception when targeting Android 14.
context.startActivity(new Intent("com.example.action.APP_ACTION"));

如需启动非导出的 activity，应用应改用显式 intent：

Kotlin

// This makes the intent explicit.
val explicitIntent =
        Intent("com.example.action.APP_ACTION")
explicitIntent.apply {
    package = context.packageName
}
context.startActivity(explicitIntent)

Java

// This makes the intent explicit.
Intent explicitIntent =
        new Intent("com.example.action.APP_ACTION")
explicitIntent.setPackage(context.getPackageName());
context.startActivity(explicitIntent);

在运行时注册的广播接收器必须指定导出行为

Apps and services that target Android 14 (API level 34) or higher and use context-registered receivers are required to specify a flag to indicate whether or not the receiver should be exported to all other apps on the device: either RECEIVER_EXPORTED or RECEIVER_NOT_EXPORTED, respectively. This requirement helps protect apps from security vulnerabilities by leveraging the features for these receivers introduced in Android 13.

Exception for receivers that receive only system broadcasts

If your app is registering a receiver only for system broadcasts through Context#registerReceiver methods, such as Context#registerReceiver(), then it shouldn't specify a flag when registering the receiver.

更安全的动态代码加载

如果您的应用以 Android 14（API 级别 34）或更高版本为目标平台，并使用动态代码加载 (DCL) 功能，则必须将所有动态加载的文件标记为只读。否则，系统会抛出异常。我们建议应用尽可能避免动态加载代码，因为这样做会大大增加应用因代码注入或代码篡改而遭到入侵的风险。

如果必须动态加载代码，请使用以下方法，在动态文件（例如 DEX、JAR 或 APK 文件）打开并写入任何内容之前立即将其设为只读：

Kotlin

val jar = File("DYNAMICALLY_LOADED_FILE.jar")
val os = FileOutputStream(jar)
os.use {
    // Set the file to read-only first to prevent race conditions
    jar.setReadOnly()
    // Then write the actual file content
}
val cl = PathClassLoader(jar, parentClassLoader)

Java

File jar = new File("DYNAMICALLY_LOADED_FILE.jar");
try (FileOutputStream os = new FileOutputStream(jar)) {
    // Set the file to read-only first to prevent race conditions
    jar.setReadOnly();
    // Then write the actual file content
} catch (IOException e) { ... }
PathClassLoader cl = new PathClassLoader(jar, parentClassLoader);

处理已存在的动态加载文件

为防止系统对现有动态加载的文件抛出异常，我们建议您先删除并重新创建文件，然后再尝试在应用中重新动态加载这些文件。重新创建文件时，请按照上述指南在写入时将文件标记为只读。或者，您可以将现有文件重新标记为只读，但在这种情况下，我们强烈建议您先验证文件的完整性（例如，对照可信值检查文件的签名）以保护应用免遭恶意操作的影响。

针对从后台启动 activity 的其他限制

For apps targeting Android 14 (API level 34) or higher, the system further restricts when apps are allowed to start activities from the background:

• When an app sends a PendingIntent using PendingIntent#send() or similar methods, the app must opt in if it wants to grant its own background activity launch privileges to start the pending intent. To opt in, the app should pass an ActivityOptions bundle with setPendingIntentBackgroundActivityStartMode(MODE_BACKGROUND_ACTIVITY_START_ALLOWED).
• When a visible app binds a service of another app that's in the background using the bindService() method, the visible app must now opt in if it wants to grant its own background activity launch privileges to the bound service. To opt in, the app should include the BIND_ALLOW_ACTIVITY_STARTS flag when calling the bindService() method.

These changes expand the existing set of restrictions to protect users by preventing malicious apps from abusing APIs to start disruptive activities from the background.

压缩路径遍历

对于以 Android 14（API 级别 34）或更高版本为目标平台的应用，Android 会通过以下方式防止 Zip 路径遍历漏洞：如果 zip 文件条目名称包含“..”或以“/”开头，则 ZipInputStream.getNextEntry() 会抛出 ZipException。ZipFile(String)

应用可以通过调用 dalvik.system.ZipPathValidator.clearCallback() 选择停用此验证。

每个 MediaProjection 拍摄会话都需要征得用户同意

For apps targeting Android 14 (API level 34) or higher, a SecurityException is thrown by MediaProjection#createVirtualDisplay in either of the following scenarios:

• Your app caches the Intent that is returned from MediaProjectionManager#createScreenCaptureIntent, and passes it multiple times to MediaProjectionManager#getMediaProjection.
• Your app invokes MediaProjection#createVirtualDisplay multiple times on the same MediaProjection instance.

Your app must ask the user to give consent before each capture session. A single capture session is a single invocation on MediaProjection#createVirtualDisplay, and each MediaProjection instance must be used only once.

Handle configuration changes

If your app needs to invoke MediaProjection#createVirtualDisplay to handle configuration changes (such as the screen orientation or screen size changing), you can follow these steps to update the VirtualDisplay for the existing MediaProjection instance:

1. Invoke VirtualDisplay#resize with the new width and height.
2. Provide a new Surface with the new width and height to VirtualDisplay#setSurface.

Register a callback

Your app should register a callback to handle cases where the user doesn't grant consent to continue a capture session. To do this, implement Callback#onStop and have your app release any related resources (such as the VirtualDisplay and Surface).

If your app doesn't register this callback, MediaProjection#createVirtualDisplay throws an IllegalStateException when your app invokes it.

更新后的非 SDK 限制

Android 14 includes updated lists of restricted non-SDK interfaces based on collaboration with Android developers and the latest internal testing. Whenever possible, we make sure that public alternatives are available before we restrict non-SDK interfaces.

If your app does not target Android 14, some of these changes might not immediately affect you. However, while you can currently use some non-SDK interfaces (depending on your app's target API level), using any non-SDK method or field always carries a high risk of breaking your app.

If you are unsure if your app uses non-SDK interfaces, you can test your app to find out. If your app relies on non-SDK interfaces, you should begin planning a migration to SDK alternatives. Nevertheless, we understand that some apps have valid use cases for using non-SDK interfaces. If you cannot find an alternative to using a non-SDK interface for a feature in your app, you should request a new public API.

如需详细了解此 Android 版本中的变更，请参阅 Android 14 中有关限制非 SDK 接口的更新。如需全面了解有关非 SDK 接口的详细信息，请参阅对非 SDK 接口的限制。