How can I implement Fragments on my Drawer menu

Question

I’m trying to use the example of NavigationDrawer android Studio. I even managed to understand the code, I remake it in my project, but I can’t change the Fragments when some menu item is triggered, Android Studio does not point any error in the code but Fragment is not called, Activity code:

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_stalking_app);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);



        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_login, menu);
        return true;
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {

        int id = item.getItemId();

        Toast.makeText(StalkingApp.this, item.getTitle(), Toast.LENGTH_LONG).show();

        Fragment fragment = null;

        Class fragmentClass;

        fragmentClass = Fragment1.class;

        if (id == R.id.nav_procurar) {
            // Handle the camera action
            fragmentClass = Fragment1.class;
        } else if (id == R.id.nav_feed) {
            fragmentClass = Fragment1.class;
        } else if (id == R.id.nav_perfil) {
            fragmentClass = Fragment1.class;
        } else if (id == R.id.nav_fotos) {
            fragmentClass = Fragment1.class;
        } else if (id == R.id.nav_ferramentas) {
            fragmentClass = Fragment1.class;
        } else if (id == R.id.nav_sair) {
            fragmentClass = Fragment1.class;
        }


        try {
            fragment = (Fragment) fragmentClass.newInstance();
        } catch (Exception e) {
            e.printStackTrace();
        }

        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.fragmentContainer, fragment).commit();

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

}

Code of my Fragment:

public class Fragment1 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        if (container == null) {
            return null;
        }

        return (RelativeLayout) inflater.inflate(R.layout.tab_layout_a, container, false);
    }

}

My container:

<LinearLayout
        android:id="@+id/fragmentContainer"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="vertical" >
    </LinearLayout>

He doesn’t return even a mistake, someone can help me?