Accessing hidden methods warnings on Android 9+

[b055man]

When using the plugin on Android 10, there are number of warnings issued due to using non-public APIs.

Are there any plans on resolving this (Google at some point may become more restrictive..)?

D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin(14382): on native side observed method: isDeviceConnected
D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin(14382): on native side observed method: connectToDevice
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->objectFieldOffset(Ljava/lang/reflect/Field;)J (greylist,core-platform-api, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->compareAndSwapInt(Ljava/lang/Object;JII)Z (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->getIntVolatile(Ljava/lang/Object;J)I (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden field Lsun/misc/Unsafe;->theUnsafe:Lsun/misc/Unsafe; (greylist, reflection, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->arrayIndexScale(Ljava/lang/Class;)I (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->arrayBaseOffset(Ljava/lang/Class;)I (greylist,core-platform-api, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->getObject(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->getObjectVolatile(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putOrderedObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->getLongVolatile(Ljava/lang/Object;J)J (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putOrderedLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->getObjectVolatile(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putOrderedObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putOrderedLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putOrderedLong(Ljava/lang/Object;JJ)V (greylist, linking, allowed)
W/ra.smartcontro(14382): Accessing hidden method Lsun/misc/Unsafe;->putOrderedObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)```

[mikolak]

@dariuszseweryn could it be from RxAndroidBle or is it from MBA?

[dariuszseweryn]

Nothing in the RxAndroidBle is directly referencing sun.misc.Unsafe class. There are some reflection use-cases that workaround connection issues on older Android versions. They can be viewed here. There is nothing else that I know of.

[b055man]

I think this is exactly related to reflections. Here is a snippet from the pre-launch report from Play Console:

The pre-launch report is from a full app I'm working on, so it is possible that not all of these apply to flutter_ble, but I believe at least some of them do, as they resemble the warnings I observe in the console when there are BLE operations happening.

Any chance to have an SDK-dependant implementation of things in the future that do not use hidden APIs on modern SDKs?

[EDIT] Here's Google approach on this matter - and it looks like this behaviour might be observed on Android 9 onwards: https://developer.android.com/distribute/best-practices/develop/restrictions-non-sdk-interfaces Also, it looks like there are some further changes on the way for Android 11: https://developer.android.com/preview/non-sdk-11