TreeSetTest.java

package treeSet;

import java.util.Comparator;
import java.util.NavigableSet;
import java.util.SortedSet;
import java.util.TreeSet;

/**
 * This program sorts a set of item by comparing their descriptions.
 *
 * @author Cay Horstmann
 * @version 1.12 2015-06-21
 */
public class TreeSetTest {
    public static void main(String[] args) {
        SortedSet<Item> parts = new TreeSet<>();
        parts.add(new Item("Toaster", 1234));
        parts.add(new Item("Widget", 4562));
        parts.add(new Item("Modem", 9912));
        System.out.println(parts);

        NavigableSet<Item> sortedByDescription = new TreeSet<>(
                Comparator.comparing(Item::getDescription)
        );
        sortedByDescription.addAll(parts);
        System.out.println(sortedByDescription);
    }
}