How to implement arraylist into the ListView?

TigerTN :

I'm just getting started with JavaFX which i find pretty cool , so i m trying to implement the arraylist of an ToDListItem class into the listView of my FXML file

i've tried to add items in my arraylist which is todoitems , then set it all into the listView which has an id 'ToDoList' in my FXML file but it seems nothing happpend when the UI display

package sample;
import javafx.fxml.FXML;
import javafx.scene.control.ListView;
import javafx.scene.control.SelectionMode;
import sample.ToDoList.ToDoItem;

import java.time.LocalDate;
import java.time.Month;
import java.util.ArrayList;
import java.util.List;

public class Controller {
    private List<ToDoItem> todoitems;

    @FXML
    private ListView ToDoList ;

    public void intialize(){
        ToDoItem item1= new ToDoItem("Going to Sea","Going to Sea with thamer and kais",
                LocalDate.of(2020, Month.JUNE,16));
        ToDoItem item2= new ToDoItem("JavaFx","Getting ready for real programming real world stuff",
                LocalDate.of(2020, Month.JULY,14));
        ToDoItem item3= new ToDoItem("Sleep & Chill","Going to Watch Youtube Later & Chill",
                LocalDate.of(2020, Month.JANUARY,13));

        todoitems= new ArrayList<>();

        todoitems.add(item1);
        todoitems.add(item2);
        todoitems.add(item3);

        ToDoList.getItems().setAll(todoitems);
        ToDoList.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
    }
}

FXML file.

<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.control.ListView?>
<BorderPane fx:controller="sample.Controller"  xmlns:fx="http://javafx.com/fxml">
  <left>
      <ListView fx:id="ToDoList">
      </ListView>
  </left>
</BorderPane>

i didn't get any result when the UI displayed

Oleksandr :

The method should be named initialize but not intialize. I would rather use javafx.fxml.Initializable to avoid misspelling issue.

This is not the recommended approach:

List<T> content = ...
getItems().setAll(content);

The issue with the approach shown above is that the content list is being copied into the items list.

Use:

ObservableList<T> content = ...
listView.setItems(content);

public class Controller {
    private final List<ToDoItem> todoItems = FXCollections.observableArrayList();

    @FXML
    private ListView ToDoList ;

    public void initialize() {
        ToDoList.setItems(todoItems);
        ToDoList.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
        populate();
    }

    private void populate () {
        todoItems.add(new ToDoItem("Going to Sea","Going to Sea with thamer and kais",
                LocalDate.of(2020, Month.JUNE,16)));
        todoItems.add(new ToDoItem("JavaFx","Getting ready for real programming real world stuff",
                LocalDate.of(2020, Month.JULY,14)));
        todoItems.add(new ToDoItem("Sleep & Chill","Going to Watch Youtube Later & Chill",
                LocalDate.of(2020, Month.JANUARY,13)));
    }
}

Make sure that the method ToDoItem.toString is overridden properly.