How I should know that the app is in not running?

Question

I have an android app that starts playing music right after the splash screen all the time while the user interacts with the app, using a singleton class for MediaPlayer, which is working perfectly, but I want to stop the music when the app exits or user switched to the other app, unfortunately which is not working properly, and I have to kill the app from the recent task to stop the music

Answer 1

If you have multiple activities while user is running the application, use LifecycleObserver to observe the state change in application class.

implementation "androidx.lifecycle:lifecycle-extensions:2.4.0"

Application Class

public class MyApplication extends Application implements LifecycleObserver {

@Override
public void onCreate() {
    super.onCreate();

    ProcessLifecycleOwner.get().getLifecycle().addObserver(this);
}

// Application level lifecycle events

@OnLifecycleEvent(Lifecycle.Event.ON_START)
public void onEnteredForeground() {
    //Log.d(TAG,"Application did enter foreground");
}

@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
public void onEnteredBackground() {
   // Log.d(TAG,"Application did enter background");
}

}

For more info refer to - Handling lifecycle with Lifecycle Observers

Answer 2

use onPause() then make it stop playing music, after that onResume or onStart to play the music if user is back to app