设计模式＝＝迭代器模式（Iterator）
/* * 迭代器模式（Iterator） * * 类似于集合中的Iterator，使用迭代器来统一不同集合对象的遍历方式， * 隐藏内部细节，用一个抽象迭代器，每个具体的集合类来实现特有的迭代器。 */package model;public class TestIterator { public static void main(String[] args) { Stack s = new Stack(); s.push("Liucy"); s.push("Huxz"); s.push("George"); LinkedList l = new LinkedList(); l.addFirst("Liucy"); l.addFirst("Huxz"); l.addFirst("George"); print(l.iterator()); } public static void print(Itr it) { while (it.hasNext()) { System.out.println(it.next()); } }}interface Itr { boolean hasNext(); Object next();}class Stack { Object[] os = new Object[10]; int index = 0; private void expand() { Object[] os2 = new Object[os.length * 2]; System.arraycopy(os, 0, os2, 0, os.length); os = os2; } public void push(Object o) { if (index == os.length) expand(); os[index] = o; index++; } public Object pop() { index--; Object o = os[index]; os[index] = null; return o; } private class StackItr implements Itr { int cursor = 0; public boolean hasNext() { return cursor < index; } public Object next() { return os[cursor++]; } } public Itr iterator() { return new StackItr(); }}class LinkedList { private class Node { Object o; Node next; public Node(Object o) { this.o = o; } public void setNext(Node next) { this.next = next; } public Node getNext() { return this.next; } } Node head; public void addFirst(Object o) { Node n = new Node(o); n.setNext(head); head = n; } public Object removeFirst() { Node n = head; head = head.getNext(); return n.o; } class LinkedListItr implements Itr { Node currentNode = head; public boolean hasNext() { return this.currentNode != null; } public Object next() { Node n = currentNode; currentNode = currentNode.getNext(); return n.o; } } public Itr iterator() { return new LinkedListItr(); }}?