我的代码中有没有问题，我的listview没有显示任何东西？

List<String> dataList = new ArrayList<>();
dataList.add("Item 1");
dataList.add("Item 2");
dataList.add("Item 3");

ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, dataList);
listView.setAdapter(adapter);

<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

dataList.add("New Item");
adapter.notifyDataSetChanged();

if (adapter.getCount() == 0) {
    Log.d("ListView", "No items to display");
}

public class MainActivity extends AppCompatActivity {
    private ListView listView;
    private ArrayAdapter<String> adapter;
    private List<String> dataList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = findViewById(R.id.listView);
        dataList = new ArrayList<>();
        dataList.add("Item 1");
        dataList.add("Item 2");
        dataList.add("Item 3");

        adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, dataList);
        listView.setAdapter(adapter);
    }
}