How to insert multiple different objects (classes) in a TreeView using javaFX

I am trying to create a TableView in which there are different classes/object types per level.
My TreeView would look something like this, where Object A.1 would be the first instance of Class A, Object A.2 the second, etc..

>RootItem
    >Object A.1
        >Object B.1
        >Object B.2
        >Object C.1
    >Object A.2
        >Object B.3
            >Object D.1

I only need to display the name of the objects (ie the toString method), but I also need the objects to be more than just Strings, so I can access the other attributes at a later point (ie if the user double clicks on an object).

How would this have to be implemented?
Is there maybe another approach I didn't think of?

import java.io.IOException;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class SOTest extends Application{
public static void main(String[] args) throws IOException  {
launch(args);
}
@Override
public void start(Stage stage) throws Exception {
//Creating tree items
TreeItem<Parent> root1 = new TreeItem<Parent>(new A("A.1"));
TreeItem<Parent> item1 = new TreeItem<Parent>(new B("B.1"));
TreeItem<Parent> item2 = new TreeItem<Parent>(new B("B.2"));
TreeItem<Parent> item3 = new TreeItem<Parent>(new C("C.1"));
root1.setExpanded(true);
root1.getChildren().addAll(item1, item2, item3);
TreeItem<Parent> root2 = new TreeItem<Parent>(new A("A.2"));
item1 = new TreeItem<Parent>(new B("B.3"));
TreeItem<Parent> subItem = new TreeItem<Parent>(new D("D.1"));
item1.getChildren().add(subItem);
root2.getChildren().addAll(item1);
TreeItem base = new TreeItem("Root Node");
base.setExpanded(true);
base.getChildren().addAll(root1, root2);
//Creating a TreeView item
TreeView view = new TreeView(base);
view.setPrefHeight(300);
VBox pane = new VBox(10);
pane.setPadding(new Insets(5, 5, 5, 50));
pane.getChildren().addAll(view);
//Setting the stage
Group node = new Group(pane);
Scene scene = new Scene(node, 595, 320);
stage.setTitle("Diff Object Tree Structure");
stage.setScene(scene);
stage.show();
}
}
abstract class Parent{
protected String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String toString() {
return name;
}
}
class A extends Parent{
public A(String name) {
this.name = name;
}
public B b;
public C c;
}
class B extends Parent{
public B(String name) {
this.name = name;
}
public D d;
}
class C extends Parent{
public C(String name) {
this.name = name;
}
}
class D extends Parent{
public D(String name) {
this.name = name;
}
}