如何根据所选项目在BottomNavigationView上加载片段？

<com.google.android.material.bottomnavigation.BottomNavigationView
    android:id="@+id/bottomNavigationView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:menu="@menu/bottom_navigation_menu" />

BottomNavigationView bottomNavigationView = findViewById(R.id.bottomNavigationView);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        Fragment fragment;
        switch (item.getItemId()) {
            case R.id.menu_item_project1:
                fragment = new Project1Fragment();
                break;
            case R.id.menu_item_project2:
                fragment = new Project2Fragment();
                break;
            // 添加其他项目对应的片段
            default:
                return false;
        }
        getSupportFragmentManager().beginTransaction().replace(R.id.fragmentContainer, fragment).commit();
        return true;
    }
});

<FrameLayout
    android:id="@+id/fragmentContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />