3.1. Managed API Compatibility

The managed Dalvik bytecode execution environment is the primary vehicle for Android applications. The Android application programming interface (API) is the set of Android platform interfaces exposed to applications running in the managed runtime environment.

Device implementations:

  • [C-0-1] MUST provide complete implementations, including all documented behaviors, of any documented API exposed by the Android SDK or any API decorated with the “@SystemApi” marker in the upstream Android source code.

  • [C-0-2] MUST support/preserve all classes, methods, and associated elements marked by the TestApi annotation (@TestApi).

  • [C-0-3] MUST NOT omit any managed APIs, alter API interfaces or signatures, deviate from the documented behavior, or include no-ops, except where specifically allowed by this Compatibility Definition.

  • [C-0-4] MUST still keep the APIs present and behave in a reasonable way, even when some hardware features for which Android includes APIs are omitted. See section 7 for specific requirements for this scenario.

  • [C-0-5] MUST restrict the use of 3rd-party app usage of hidden APIs, defined as APIs in the android namespace decorated with the @hidden annotation but not with a @SystemAPI or @TestApi, as described in the SDK documents and ship with each and every hidden API on the same restricted lists as provided via the light-greylist, dark-greylist, and blacklist files in the prebuilts/runtime/appcompat/ path for the appropriate API level branch in the AOSP. However they:

    • MAY, if a hidden API is absent or implemented differently on the device implementation, move the hidden API into the blacklist or omit it from all restricted lists (i.e. light-grey, dark-grey, black).
    • MAY, if a hidden API does not already exist in the AOSP, add the hidden API to any of the restricted lists (i.e. light-grey, dark-grey, black).
    • MAY implement a dynamic update mechanism that moves a hidden API from a restricted list into a less restrictive list, except for the whitelist.

3.1.1. Android Extensions

Android includes the support of extending the managed APIs while keeping the same API level version.

  • [C-0-1] Android device implementations MUST preload the AOSP implementation of both the shared library ExtShared and services ExtServices with versions higher than or equal to the minimum versions allowed per each API level. For example, Android 7.0 device implementations, running API level 24 MUST include at least version 1.

3.1.2. Android Library

Due to Apache HTTP client deprecation, device implementations:

  • [C-0-1] MUST NOT place the org.apache.http.legacy library in the bootclasspath.
  • [C-0-2] MUST add the org.apache.http.legacy library to the application classpath only when the app satisfies one of the following conditions:
    • Targets API level 28 or lower.
    • Declares in its manifest that it needs the library by setting the android:name attribute of <uses-library> to org.apache.http.legacy.

The AOSP implementation meets these requirements.