I'm trying to write a system-updater application, which uses the UpdateEngine of Android 7+. However, I can't seem to get access to it from my java code, since the class and its methods are marked with @SystemApi.
I integrated my application into the AOSP tree, but I can't start a successful compile from my application directory: When i run mm in the app dir, I directly get the following error:
The import android.os.UpdateEngine cannot be resolved
This also happens if I just add the import statement to an already existing aosp system-app, e.g.
What is the correct way to use UpdateEngine (or actually any other @SystemApi) from an application? I don't want to change the android api by removing all the SystemApi and break compatibility.
Of course I find the solution right after posting the question...
In case someone else stumbles upon this in the future - The problem was that I had the following SDK version defined in my Android.mk:
LOCAL_SDK_VERSION := current
System APIs (and thus UpdateEngine) became accessible after changing the sdk version as follows:
LOCAL_SDK_VERSION := system_current
来源：https://stackoverflow.com/questions/44941221/accessing-androids-updateengine-or-other-systemapi-classes-from-application-co