Prevent class from exit

We need to keep always running app never been quit, we use onStop to reopen.

@Override

     public void onStop() {

          super.onStop();

     Intent i=new Intent(this,MainActivity.class);

    i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

    i.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

    i.putExtra("ID_TimeLeft",String.valueOf(0));

    startActivity(i);

   }

Second way, create a check function like this.

public static boolean isRunning(Context context) {

     ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);

for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {

         if (myclass.class.getName().equals(service.service.getClassName())){

            return true;

        }

     }

       return false;

}

Add these lines in to above last close bracket.

boolean running=true;

@Override

     public void onWindowFocusChanged(boolean hasFocus) {

          super.onWindowFocusChanged(hasFocus);

          if (!hasFocus) {

               running=isRunning(this);

               if(running==false){

              finish();

          Intent i=new Intent(this,myclass.class);

            startActivity(i);

            running=true;   

   }

Now app will reopen when closed for any reason.