行為變更：指定 Android 14 以上版本的應用程式

和先前版本一樣，Android 14 也包含可能會影響應用程式的行為變更。以下行為變更僅適用於指定 Android 14 (API 級別 34) 以上版本的應用程式。如果您的應用程式指定 Android 14 以上版本，建議您視情況修改應用程式，以支援這些行為。

此外，無論應用程式的 targetSdkVersion 為何，請務必查看對所有 Android 14 應用程式有影響的行為變更清單。

核心功能

必須提供前景服務類型

If your app targets Android 14 (API level 34) or higher, it must specify at least one foreground service type for each foreground service within your app. You should choose a foreground service type that represents your app's use case. The system expects foreground services that have a particular type to satisfy a particular use case.

If a use case in your app isn't associated with any of these types, it's strongly recommended that you migrate your logic to use WorkManager or user-initiated data transfer jobs.

在 BluetoothAdapter 中強制執行 BLUETOOTH_CONNECT 權限

針對指定 Android 14 (API 級別 34) 以上版本的應用程式呼叫 BluetoothAdapter getProfileConnectionState() 方法，Android 14 會強制執行 BLUETOOTH_CONNECT 權限。

這個方法已要求 BLUETOOTH_CONNECT 權限，但未強制執行。請務必在應用程式的 AndroidManifest.xml 檔案中宣告 BLUETOOTH_CONNECT，如以下程式碼片段所示，並在呼叫 getProfileConnectionState 之前檢查使用者是否已授予權限。

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

OpenJDK 17 更新

Android 14 持續更新 Android 核心程式庫，以便與最新版 OpenJDK LTS 中的功能保持一致，其中包括程式庫更新以及應用程式與平台開發人員的 Java 17 語言支援。

以下部分變更可能會影響應用程式相容性：

  • 規則運算式的變更：系統現在不允許無效的群組參照，以便更符合 OpenJDK 的語義學。您可能會發現 java.util.regex.Matcher 類別擲回 IllegalArgumentException 的新案例，因此請務必就使用規則運算式的應用程式層面進行測試。如要在測試時啟用或停用這項變更，請使用相容性架構工具切換 DISALLOW_INVALID_GROUP_REFERENCE 標記。
  • UUID 處理：從現在起，java.util.UUID.fromString() 方法在驗證輸入引數時會執行更嚴格的檢查，因此反序列化程序期間可能會出現 IllegalArgumentException。如要在測試時啟用或停用這項變更，請使用相容性架構工具切換 ENABLE_STRICT_VALIDATION 標記。
  • ProGuard 問題：在某些情況下，新增 java.lang.ClassValue 類別之後，當您嘗試使用 ProGuard 縮減、模糊處理及最佳化應用程式時，可能會出現問題。問題出在 Kotlin 程式庫，因為此程式庫會根據 Class.forName("java.lang.ClassValue") 是否傳回類別來變更執行階段的行為。如果您的應用程式是在缺乏 java.lang.ClassValue 類別的情況下，按照舊版執行階段開發，則這些最佳化做法可能會在類別中移除衍生自 java.lang.ClassValue 的 computeValue 方法。

JobScheduler 會強化回呼和網路行為

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, the job is stopped 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".

This ANR may be a result of 2 scenarios: 1. There is work blocking the main thread, preventing the callbacks onStartJob or onStopJob from executing and completing within the expected time limit. 2. The developer is running blocking work within the JobScheduler callback onStartJob or onStopJob, preventing the callback from completing within the expected time limit.

To address #1, you will need to further debug what is blocking the main thread when the ANR occurs, you can do this using ApplicationExitInfo#getTraceInputStream() to get the tombstone trace when the ANR occurs. If you're able to manually reproduce the ANR, you can record a system trace and inspect the trace using either Android Studio or Perfetto to better understand what is running on the main thread when the ANR occurs. Note that this can happen when using JobScheduler API directly or using the androidx library WorkManager.

To address #2, consider migrating to WorkManager, which provides support for wrapping any processing in onStartJob or onStopJob in an asynchronous 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.

圖塊啟動 API

針對指定 14 以上版本為目標的應用程式，TileService#startActivityAndCollapse(Intent) 已遭淘汰，現在呼叫時會擲回例外狀況。如果您的應用程式從資訊方塊啟動活動，請使用 TileService#startActivityAndCollapse(PendingIntent)。

隱私權

相片和影片的部分存取權

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.

使用者體驗

安全的全螢幕意圖通知

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.

安全性

隱含和待處理意圖的限制

For apps targeting Android 14 (API level 34) or higher, Android restricts apps from sending implicit intents to internal app components in the following ways:

  • Implicit intents are only delivered to exported components. Apps must either use an explicit intent to deliver to unexported components, or mark the component as exported.
  • If an app creates a mutable pending intent with an intent that doesn't specify a component or package, the system throws an exception.

These changes prevent malicious apps from intercepting implicit intents that are intended for use by an app's internal components.

For example, here is an intent filter that could be declared in your app's manifest file:

<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>

If your app tried to launch this activity using an implicit intent, an ActivityNotFoundException exception would be thrown:

Kotlin

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

Java

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

To launch the non-exported activity, your app should use an explicit intent instead:

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);

已註冊執行階段的廣播接收器必須指定匯出行為

應用程式和服務若以 Android 14 (API 級別 34) 以上版本為目標版本，並使用已註冊使用情境的接收器，必須利用 RECEIVER_EXPORTED 或 RECEIVER_NOT_EXPORTED 標記，指定應否將接收器匯出至裝置上其他所有應用程式。透過 Android 13 針對這些接收器引進的功能，上述要求有助於避免應用程式出現安全漏洞。

僅接收系統廣播訊息的接收器除外

如果應用程式僅透過 Context#registerReceiver 方法 (例如 Context#registerReceiver())，為系統廣播訊息註冊接收器，則註冊接收器時不應指定標記。

更安全的動態程式碼載入

If your app targets Android 14 (API level 34) or higher and uses Dynamic Code Loading (DCL), all dynamically-loaded files must be marked as read-only. Otherwise, the system throws an exception. We recommend that apps avoid dynamically loading code whenever possible, as doing so greatly increases the risk that an app can be compromised by code injection or code tampering.

If you must dynamically load code, use the following approach to set the dynamically-loaded file (such as a DEX, JAR, or APK file) as read-only as soon as the file is opened and before any content is written:

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);

Handle dynamically-loaded files that already exist

To prevent exceptions from being thrown for existing dynamically-loaded files, we recommend deleting and recreating the files before you try to dynamically load them again in your app. As you recreate the files, follow the preceding guidance for marking the files read-only at write time. Alternatively, you can re-label the existing files as read-only, but in this case, we strongly recommend that you verify the integrity of the files first (for example, by checking the file's signature against a trusted value), to help protect your app from malicious actions.

從背景啟動活動的額外限制

針對以 Android 14 (API 級別 34) 以上版本為目標版本的應用程式，系統會進一步限制應用程式可從背景啟動活動的情況：

  • 當應用程式使用 PendingIntent#send() 或類似方法傳送 PendingIntent 時，如果應用程式要自行授予背景活動啟動權限，以便啟動待處理意圖，則須在當前階段選擇加入。如要選擇加入，應用程式應透過 setPendingIntentBackgroundActivityStartMode(MODE_BACKGROUND_ACTIVITY_START_ALLOWED) 傳遞 ActivityOptions 組合。
  • 如果開放瀏覽權限的應用程式使用 bindService() 方法，在背景中綁定另一個應用程式的服務，則開放瀏覽權限的應用程式必須在當前階段選擇加入，才可將其背景活動啟動權限授予該綁定的服務。如要選擇加入，應用程式在呼叫 bindService() 方法時，應納入 BIND_ALLOW_ACTIVITY_STARTS 標記。

這些變更會擴大現有的限制組合，避免惡意應用程式濫用 API 而從背景啟動干擾活動，進而為使用者提供保護。

Zip Path Traversal

針對指定 Android 14 (API 級別 34) 以上版本的應用程式，Android 會透過下列方式避免 Zip Path Traversal 安全漏洞：如果 ZIP 檔案的項目名稱包含「..」或以「/」開頭，則 ZipFile(String) 和 ZipInputStream.getNextEntry() 會擲回 ZipException。

應用程式可透過呼叫 dalvik.system.ZipPathValidator.clearCallback()，選擇不採用此驗證。

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 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.

如要進一步瞭解此 Android 版本中的變更，請參閱「Android 14 的非 SDK 介面限制更新內容」。如要進一步瞭解非 SDK 介面的一般資訊，請參閱「非 SDK 介面的限制」。