onFragmentInteraction (fragment 구분 확인)

MainActivity

public void onFragmentInteraction(Fragment  fragment) {
   if (fragment instanceof  BlankTwoFragment){
       Toast.makeText(MainActivity.this, "BlankTwoFragment", Toast.LENGTH_SHORT).show();
   }
    else if (fragment instanceof  BlankFragment) {
       Toast.makeText(MainActivity.this, "BlankFragment", Toast.LENGTH_SHORT).show();
   }
}

interface OnFragmentInteractionListener

interface OnFragmentInteractionListener {    
    void onFragmentInteraction(Fragment fragment);
}