How to restart service after the app is killed from recent tasks

Question

I have created a service to fetch current location of the device in periodic intervals. I want the service to run in the background even if the app is cleared from recently

Answer 1

I use android 9 and the solution works partially for me. I had a case with foreground service (working 24/7), which I wanted to restart after the application was crashed. When the event uncaughtExceptionHandler was caught, the application got frozen besides public void onTaskRemoved(Intent rootIntent) { event doesn't work anymore in latest Android versions (I suppose O+). My application has only one activity with fragments if you need solution for more activities just use this link. To solve that problem I've added a function which checks if the activity is working (to kill it) and some instructions to kill the process:

class MyApplication : Application() {

    private var currentActivity: Activity? = null

    override fun onCreate() {
        super.onCreate()
        StorageManager.init()

        this.registerActivityLifecycleCallbacks(object : ActivityLifecycleCallbacks {
            override fun onActivityPaused(activity: Activity) {

            }

            override fun onActivityStarted(activity: Activity) {
                currentActivity = activity
            }

            override fun onActivityDestroyed(activity: Activity) {
            }

            override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {
            }

            override fun onActivityStopped(activity: Activity) {
                currentActivity = null
            }

            override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
            }

            override fun onActivityResumed(activity: Activity) {
            }
        })

        Thread.setDefaultUncaughtExceptionHandler { _, e ->
            // Close current activity
            currentActivity?.finish()

            val service : PendingIntent? = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                // Start service in Oreo and latest
                PendingIntent.getForegroundService(
                    applicationContext,
                    8888,
                    Intent(applicationContext, SensorService::class.java),
                    PendingIntent.FLAG_ONE_SHOT)
            } else {
                // Start service in Nougat and older
                PendingIntent.getService(
                    applicationContext,
                    8888,
                    Intent(applicationContext, MyService::class.java),
                    PendingIntent.FLAG_ONE_SHOT)
            }

            // The great solution introduced by @cgr
            val alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager
            alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, 1000, service)

            // Kill the current application process to avoid freezing activity
            android.os.Process.killProcess(android.os.Process.myPid())
            exitProcess(10)
        }
    }
}

Add to manifest: