Question

IS it possible to have an activity without UI to perform action?
a.not possible b.wrongquestion c.yes,it is possible d.none of the above

Answer 1

c. yes, it is possible.

In Android you can have an Activity with no UI (for example by using the built‑in theme Theme.NoDisplay). Such an Activity can perform quick work in onCreate/onResume and then call finish(). Example:

Manifest:
<activity android:name=".NoUiActivity"
android:theme="@android:style/Theme.NoDisplay" />

Activity:
public class NoUiActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// do the action here
finish();
}
}

Note: for longer-running or background tasks it's usually better to use a Service or JobScheduler instead of an Activity.