package chapter1;

public class ItemComparer implements Comparable {
	public int compare(Object obj1, Object obj2) {
		if ((obj1 instanceof Item) && (obj2 instanceof Item)) {
			Item item1 = (Item) obj1;
			Item item2 = (Item) obj2;
			return item1.ID.compareTo(item2.ID);
		} else
			return -1;
	}
}