Develop Reference

Strange NPE deep inside MediaSessionCompat

I have seen similar questions posted about MediaSessionCompat but they are all pretty old, in fact most predate AndroidX and they point at it being fixed in newer versions.
This crash is happening with androidx.media:media:1.2.1 on various phones from Android 8 through 11. It is always MediaSessionImplApi21. Works fine for me on every phone I've tried.
This issue is new for me as of my latest release. The two big changes I made are that I added a progress bar to my MediaStyle notification and that I upgraded to 1.2.1 from 1.0.0.
This is the exception:
Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'android.support.v4.media.session.MediaSessionCompat$Callback android.support.v4.media.session.MediaSessionCompat$MediaSessionImplApi21.getCallback()' on a null object reference
at android.support.v4.media.session.MediaSessionCompat$Callback$MediaSessionCallbackApi21.getSessionImplIfCallbackIsSet(MediaSessionCompat.java:1907)
at android.support.v4.media.session.MediaSessionCompat$Callback$MediaSessionCallbackApi21.onMediaButtonEvent(MediaSessionCompat.java:1597)
at android.media.session.MediaSession$CallbackMessageHandler.handleMessage(MediaSession.java:1471)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7094)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
If my Callback wasn't set them a lot of things wouldn't work.
Also my code looks like this:
MediaSessionCompat mediaSessionCompat = new MediaSessionCompat(context, TAG);
mediaSessionCompat.setCallback(mediaSessionCallback);
So there's really no room to not set the Callback.
Any idea what it could be?
From looking at the code and where it crashed:
private MediaSessionImplApi21 getSessionImplIfCallbackIsSet() {
MediaSessionImplApi21 sessionImpl;
synchronized (mLock) {
sessionImpl = (MediaSessionImplApi21) mSessionImpl.get();
}
return MediaSessionCompat.Callback.this == sessionImpl.getCallback()
? sessionImpl : null;
}
It is crashing on sessionImpl.getCallback(). Which probably means it either got recycled because mSessionImpl is a WeakReference or it was set to null to begin with.

Turns out it was a bug and has now been patched and will hopefully be out on 1.2.2 https://issuetracker.google.com/issues/178694750

Sporadic IllegalArgumentException: Unknown URL content://

Very rarely getting:
Fatal Exception: java.lang.IllegalArgumentException: Unknown URL content://com.example.provider/info
at android.content.ContentResolver.insert(ContentResolver.java:1252)
Fatal Exception: java.lang.IllegalArgumentException: Unknown authority com.example.provider
at android.content.ContentResolver.applyBatch(ContentResolver.java:1247)
Emphasis on rarely. Generally work fine without issue, so the authorities is set up fine, but this is showing up every once in a while for no reason. Are there reasons why the ContentResolver may not be able to find a ContentProvider (i.e. if not set up yet)?

I've had the rare IllegalArgumentException with Unknown URIs issue when I was doing ContentResolver operations in the custom Application object.
For example, I was trying to delete items in my content provider in the application onCreate method which would very occasionally crash:
public class CustomApplication extends Application {
#Override
public void onCreate() {
//..
context.getContentResolver().delete(ReminderEntry.getContentURI(), null, null, null, null);
//..
}
}
Which would sometimes render the following crash:
Fatal Exception: java.lang.RuntimeException: Unable to create application com.myapp.CustomApplication: java.lang.IllegalArgumentException: Unknown URL content://com.myapp.db.CustomContentProvider/reminder
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6431)
at android.app.ActivityThread.access$1800(ActivityThread.java:229)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1887)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7331)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by java.lang.IllegalArgumentException: Unknown URL content://com.myapp.db.CustomContentProvider/reminder
at android.content.ContentResolver.delete(ContentResolver.java:1376)
at com.myapp.ReminderEntryDao.delete(Unknown Source)
at com.myapp.CustomApplication.onCreate(Unknown Source)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1037)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6428)
at android.app.ActivityThread.access$1800(ActivityThread.java:229)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1887)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7331)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
I also saw similar behaviour with a BOOT_COMPLETE receiver. I had about 70 reported crashes with this exception (mostly Infinix devices ~43%, hardly any Samsung Devices) of about 200 000 monthly active users.
I moved this into a background scheduled job and haven't seen the crash since. I was only ever able to reproduce this issue once on a Nexus device that I used but never again.
I suspect perhaps sometimes on some versions of Android on some devices the Application/BOOT_COMPLETE Receiver initializes before the ContentProvider is fully initialized and therefore when it tries to access it, it is not properly set up yet.
There are a couple of stackoverflow posts that do state exactly what is created first and how the OS should behave:
Is the Application class guaranteed to be instantiated before a defined boot receiver is called
But like I said, I've seen otherwise and moving operations out of the classes into background schedulers seems to fix the problem (perhaps it is just because it takes a bit longer to get setup). Hopefully my experience will help you.
Edit: I used the evernote job dispatcher and deferred my ContentResolver operations to the job if required. (but I would assume that deferring the content provider operation to any kind of background processing might fix it as it had a bit more time to get setup - these are just my suspicions of course).
class DeleteRemindersJob extends Job {
#NonNull
#Override
protected Result onRunJob(final Params params) {
cursor = getContext().getContentResolver().delete(ReminderEntry.getContentURI(), null, null, null, null);
//..
return Result.SUCCESS;
}
}

java.lang.NullPointerException IntentService

I'm trying to start a service in a different app that's installed on the device. I get a NullPointerException when using startService
public void notConnected(){
Log.i(TAG,"no connection... reconnecting.");
Intent reset = new Intent("com.famoco.intent.action.TOGGLE_DATA");
Log.i(TAG,"calling " + reset.getAction());
if(reset.getAction().equals("com.famoco.intent.action.TOGGLE_DATA"))
{
startService(reset);
}
else
{
Log.i(TAG,"couldn't start service");
}
}
and this is error log
E/AndroidRuntime: FATAL EXCEPTION: IntentService[MyAppCommService]
Process: com.myapppackage.MyApp, PID: 8583
java.lang.NullPointerException
at android.content.ContextWrapper.startService(ContextWrapper.java:494)
at com.myapppackage.MyApplocation.activity.MyAppActivity.notConnected(MyAppActivity.java:591)
at com.myapppackage.MyApplocation.api.MyAppApi.submitClock(MyAppApi.java:228)
at com.myapppackage.MyApplocation.service.MyAppCommService.submitTags(MyAppCommService.java:52)
at com.myapppackage.MyApplocation.service.MyAppCommService.onHandleIntent(MyAppCommService.java:98)
at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:65)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.os.HandlerThread.run(HandlerThread.java:61)
Turns out my context returned null, I fixed it by getting the context in onCreate and calling myContext.startservice.

You are starting a new Intent. And looking at that Google example, looks like you use the wrong method to start it up.
- you use:
startService(reset);
- try this one:
startActivity(intent);
But that starts an Activity. And you want an service. I don't think you can do that unless you are the developer of that other app. In general, Android Apps don't have access each others code & resources.

Fixed it by returning context in the onCreate() and then calling context.startService()

Getting a lot of crashes from android youtube player api

I am using version 1.2.1 (tried with latest version 1.2.2) of android's youtube player api. It works fine on most of the devices. However now and then, I keep on getting crashes on crashlytics. I am getting the following crashes
Fatal Exception: java.lang.IllegalStateException: android.os.TransactionTooLargeException
at com.google.android.youtube.api.jar.client.RemoteEmbeddedPlayer.x(SourceFile:558)
at bpd.w(SourceFile:576)
at tef.onTransact(SourceFile:390)
at android.os.Binder.transact(Binder.java:395)
at com.google.android.youtube.player.internal.d$a$a.r(Unknown Source)
at com.google.android.youtube.player.internal.s.h(Unknown Source)
at com.google.android.youtube.player.YouTubePlayerView.e(Unknown Source)
at com.google.android.youtube.player.YouTubePlayerSupportFragment.onSaveInstanceState(Unknown Source)
at android.support.v4.app.Fragment.performSaveInstanceState(Fragment.java:1936)
at android.support.v4.app.FragmentManagerImpl.saveFragmentBasicState(FragmentManager.java:1654)
at android.support.v4.app.FragmentManagerImpl.saveAllState(FragmentManager.java:1722)
at android.support.v4.app.Fragment.performSaveInstanceState(Fragment.java:1938)
at android.support.v4.app.FragmentManagerImpl.saveFragmentBasicState(FragmentManager.java:1654)
at android.support.v4.app.FragmentManagerImpl.saveAllState(FragmentManager.java:1722)
at android.support.v4.app.FragmentActivity.onSaveInstanceState(FragmentActivity.java:527)
at com.newshunt.news.activities.NewsBaseActivity.onSaveInstanceState(NewsBaseActivity.java:56)
at com.newshunt.news.activities.NewsDetailsActivity.onSaveInstanceState(NewsDetailsActivity.java:613)
at android.app.Activity.performSaveInstanceState(Activity.java:1388)
at android.app.Instrumentation.callActivityOnSaveInstanceState(Instrumentation.java:1286)
at android.app.ActivityThread.callCallActivityOnSaveInstanceState(ActivityThread.java:4588)
at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:3960)
at android.app.ActivityThread.handleStopActivity(ActivityThread.java:4023)
at android.app.ActivityThread.access$1200(ActivityThread.java:181)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1498)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6117)
at java.lang.reflect.Method.invoke(Method.java)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
Also getting crashes for the following exception.
Fatal Exception: java.lang.IllegalStateException: android.os.DeadObjectException
at com.google.android.apps.youtube.api.jar.a.eo.surfaceDestroyed(SourceFile:236)
at android.view.SurfaceView.updateWindow(SurfaceView.java:589)
at android.view.SurfaceView.onWindowVisibilityChanged(SurfaceView.java:237)
at android.view.View.dispatchDetachedFromWindow(View.java:12854)
at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:2757)
at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:2757)
at android.view.ViewGroup.removeViewInternal(ViewGroup.java:3844)
at android.view.ViewGroup.removeViewInternal(ViewGroup.java:3819)
at android.view.ViewGroup.removeView(ViewGroup.java:3751)
at com.google.android.youtube.player.YouTubePlayerView$1.b(Unknown Source)
at com.google.android.youtube.player.internal.r.h(Unknown Source)
at com.google.android.youtube.player.internal.r$e.onServiceDisconnected(Unknown Source)
at android.app.LoadedApk$ServiceDispatcher.doDeath(LoadedApk.java:1111)
at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1125)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:176)
at android.app.ActivityThread.main(ActivityThread.java:5317)
at java.lang.reflect.Method.invokeNative(Method.java)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(NativeStart.java)
The crash happens to appear in specific versions of youtube application like 5.2.27. Although there are a lot of issues filed for these crashes, there has been no reply from the youtube developers on how to mitigate this issue.
Some of the fellow developers have suggested the following workarounds
1) Use loadVideo instead of cueVideo. But I cannot use this workaround because loadVideo always autoplays the video which is not a requirement of my application. Also someone mentioned that with loadVideo also, this problem is happening although in some different version.
2) Put check in the code to check the youtube application version and then put the specific code. Now the problem with this approach is that I have to check each and every version of youtube app ever released and check which versions are causing the issue which is not a good workaround.
Now is there any fix which I can apply to avoid this issue or are the youtube developers planning to release some jar which internally takes care of all these issues?

I reduced the bug occurrence by putting youtube calls (like youtubePlayer.loadVideo(), cueVideo(), getCurrentTimeMillis() etc.) in a try catch block and catch the IllegalStateException exception then reinitialize youtube player.
To create a new instance of the YoutubePlayer just call the initialize() method in the catch block.
Example:
if (youtubePlayer != null) {
try {
youtubePlayer.loadVideo(videoId);
} catch (IllegalStateException e) {
initialize(API_KEY, this);
}
}
but the bug still occurred , I worked around it by catching these exceptions and restart activity. This uncaught exceptions and to catch them you need to use UncaughtExceptionHandler
example :
private Thread.UncaughtExceptionHandler defaultUEH;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
defaultUEH = Thread.getDefaultUncaughtExceptionHandler();
// setup handler for uncaught exception
Thread.setDefaultUncaughtExceptionHandler(_unCaughtExceptionHandler);
}
private Thread.UncaughtExceptionHandler _unCaughtExceptionHandler =
new Thread.UncaughtExceptionHandler() {
#Override
public void uncaughtException(Thread thread, Throwable ex) {
Log.e(TAG, "uncaughtException: ", ex);
PendingIntent myActivity = PendingIntent.getActivity(getApplicationContext(),
192837, new Intent(getApplicationContext(), MainActivity.class),
PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmManager;
alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP,
15000, myActivity );
System.exit(2);
// re-throw critical exception further to the os (important)
defaultUEH.uncaughtException(thread, ex);
}
};

The android YouTube Player API is not stable, there are known bugs in it. The team from YouTube said that they will release a new version of the library.
For now, the best solution I have found is to build my own library.

Exception in the Android's code while starting the app

In the "Crashes and ANRs" of the Google Play Developer console I've got such a report:
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.AssetManager android.content.res.Resources.getAssets()' on a null object reference
at android.app.LoadedApk.getAssets(LoadedApk.java:590)
at android.app.LoadedApk.makeApplication(LoadedApk.java:646)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5088)
at android.app.ActivityThread.access$1600(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1509)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5944)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1389)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1184)
The device that has this problem is Galaxy S4 and runs Android 5.0
What it can be - there is not a single line from my code, why does it fail?
Thanks a lot!

I've got this in my console too.
It seems this occurs when users start the app when it's currently being updated or just after that.
A possible workaround would be to check if getResources returns null when the application start, and kill it if it does:
public class DevToolsApplication extends Application {
private static final String TAG = "DevToolsApplication";
#Override
public void onCreate() {
super.onCreate();
AppLogger.i(TAG, "app start...");
checkAppReplacingState();
}
private void checkAppReplacingState() {
if (getResources() == null) {
AppLogger.w(TAG, "app is replacing...kill");
Process.killProcess(Process.myPid());
}
}
}
See this for more information
https://issuetracker.google.com/issues/36972466

Make sure that anywhere you call getAssets(), you call it as:
getApplicationContext().getAssets()
It would appear as if you are calling getAssets() in a class that does not have the application context available, hence the fact that it is null.

I've got the same exception while added the below overlay in the AndroidManifest.xml file. Even after removing the Overlay code, landed into the above exception.
<overlay android:targetPackage="com.android.systemui"
android:priority="1"/>
Just close the Android Studio completely. Open the project again. Clean and Build the exception got cleared.