Вот код:

package sample;

import javafx.beans.Observable;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;
import javafx.collections.ObservableList;
import javafx.util.Callback;

import java.util.List;

/**
 * Created by IDEA on 28/07/15.
 */
public class ListUpdateTest {
    public static void main(String[] args) {
        Callback<IntegerProperty, Observable[]> extractor = (IntegerProperty p) -> {
            System.out.println("The extractor is called.");
            Observable[] res = new Observable[]{p};
            System.out.println("Result from extractor: " + res);
            return res;
        };
        ObservableList<IntegerProperty> list = FXCollections.observableArrayList(extractor);
        System.out.printf("Before adding");
        IntegerProperty p1 = new SimpleIntegerProperty(10);
        IntegerProperty p2 = new SimpleIntegerProperty(20);
        list.addAll(p1, p2);
        System.out.println("After adding");
        list.addListener(new ListChangeListener<IntegerProperty>() {
            @Override
            public void onChanged(Change<? extends IntegerProperty> c) {
                System.out.println("List is " + c.getList());
                while (c.next()) {
                    if (c.wasUpdated()) {
                        System.out.println("An update is detected.");
                        int start = c.getFrom();
                        int end = c.getTo();
                        System.out.println(
                                String.format("Updated range: %d to %d",
                                        start, end)
                        );
                        List<? extends IntegerProperty> updatedElementsList;
                        updatedElementsList = c.getList().subList(start, end);
                        System.out.println("Updated elements: " + updatedElementsList);
                    }
                }
            }
        });
        p1.set(100);
    }
}

Что такоеextractor и зачем нам это здесь?