在Android Studio中，如何使用java代码将片段切换到另一个片段

FragmentB fragmentB = new FragmentB();
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragmentB);
fragmentTransaction.commit();

FragmentA fragmentA = new FragmentA();
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragmentA);
fragmentTransaction.commit();