How to find the desired fragment after changing the screen orientation?

Question

Android

Hello.
I have one activity and let's say 100 fragments.
After rotating the screen, how to display that fragment, the same fragment that was displayed before the device was rotated?
I do something like this in Activity:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        ...

        Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.my_layout);

        if (fragment instanceof MyFragment1) {
            goToMyFragment1();
        } else if (fragment instanceof MyFragment2) {
             goToMyFragment2();
        } else if (fragment instanceof MyFragment3) {
             ...
        }
    }

This is probably the wrong approach, especially with a large number of fragments. How to do it right? Thanks