save CountDown in android studio -

my app has text view , button, when touch button, countdown start when close the app , open again countdown return 0 again. how can save countdown? shared preferences?

here code:

public class mainactivity extends activity {     button b1;     textview tv1;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          tv1 = (textview) findviewbyid(r.id.tv1);         b1 = (button) findviewbyid(r.id.b1);     }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu         // adds items action bar if present.         getmenuinflater().inflate(r.menu.menu_main, menu);         return true;     }      @override     public boolean onoptionsitemselected(menuitem item) {         // handle action bar item clicks here. action bar         // automatically handle clicks on home/up button, long         // specify parent activity in androidmanifest.xml.         int id = item.getitemid();          //noinspection simplifiableifstatement         if (id == r.id.action_settings) {             return true;         }          return super.onoptionsitemselected(item);     }      public void a(view view){         new countdowntimer(10000, 1000) {             public void ontick(long millisuntilfinished) {                 tv1.settext("la cuenta llega 0 en: " + millisuntilfinished / 1000);             }             public void onfinish() {                 tv1.settext("listo!");             }         }.start();     } } 

yes definitely. sharedpreferences right solution you. when close app (ondestroy) persist value through sharedpreferences.editor object whereas when app starts (oncreate) load it.

examples here:

https://developer.android.com/training/basics/data-storage/shared-preferences.html