Iterator (Iterator mode) -- (supermarket manager)

This Iterator is used by the cashier. [Html] package patterns. actions. iterator; public interface IteratorList {boolean isEmpty (); // whether [hasNext ()] Object nextMerchandise (); // merchandise: item} [java] package patterns. actions. iterator;/*** check items at the cashier * @ author one **/public class IteratorCheck implements IteratorList {private Supermarket shop; private int total = 0; private int current = 0; iteratorCheck (Supermarket shop) {this. shop = shop; this. total = shop. size (); this. current = 0 ;}@ Override public boolean isEmpty () {return this. current <this. total ;}@ Override public Object nextMerchandise () {if (this. current <this. total) return this. shop. take (this. current ++); return null;} [java] package patterns. actions. iterator;/*** basic Shopping elements * @ author one **/public interface Shopping {public void buy (Object obj ); // buy a new product [add] public IteratorList iteratorList (); // check [iterator]} [java] package patterns. actions. iterator; import java. util. arrayList; import java. util. list;/*** supermarkets provide specific Shopping environments ** @ author one **/public class Supermarket implements Shopping {private List cart = new ArrayList (); // The cart is used as the container @ Override public void buy (Object obj) {cart. add (obj); // put the item to the shopping cart} @ Override public IteratorList iteratorList () {return new IteratorCheck (this);} public int size () {return this. cart. size ();} public Object take (int current) {if (current <this. cart. size () return this. cart. get (current); return null;} [java] package patterns. actions. iterator; public class Client {/*** @ param args */public static void main (String [] args) {Shopping cart = new Supermarket (); cart. buy ("Cola"); cart. buy ("juice"); cart. buy ("sour plum"); IteratorList check = cart. iteratorList (); while (check. isEmpty () {System. out. println (check. nextMerchandise () ;}} output: [html] cola