Java设计模式_Iterator(迭代容器)

方法一:

采用ArrayList类实现.

/**

* 此数组类可动态扩展（方法一）

* @author tfq

*

*/

public class ArrayList {

Object[] objects=new Object[10];

int index=0;

/**

* 父类引用指向子类对象

* @param o

*/

public void add(Object o){

if(index==objects.length){

Object[] newObjects=new Object[objects.length*2];

System.arraycopy(objects, 0, newObjects, 0, objects.length);

objects=newObjects;

}

objects[index]=o;

index++;

}

/**

* 获取数组的长度

* @return

*/

public int size(){

return index;

}

}

/*

*

*辅助类

/

public class Dog {

private int id;

public Dog(int id){

super();

this.id=id;

}

}

public class Test {

public static void main(String[] args) {

ArrayList arr=new ArrayList();

for(int i=0;i<1000;i++){

arr.add((Object)new Dog(10));

}

System.out.println(arr.size());

}

}

打印出数组的长度:1000

方法二:

采用动态链表方式

public class LinkedList {

Node head=null;

Node tail=null;

int index=0;

public void add(Object o){

Node n=new Node(o,null);

if(head==null){

head=n;

tail=n;

}

tail.setNext(n);

tail=n;

index++;

}

public int size(){

return index;

}

}

///结点类

public class Node {

private Object data;

private Node next;

public Node(Object data, Node next) {

super();

this.data = data;

this.next = next;

}

public Object getData() {

return data;

}

public void setData(Object data) {

this.data = data;

}

public Node getNext() {

return next;

}

public void setNext(Node next) {

this.next = next;

}

}

public class Test {

public static void main(String[] args) {

LinkedList lkl=new LinkedList();

for(int i=0;i<1000;i++){

lkl.add((Object)new Dog(10));

}

System.out.println(lkl.size());

}

}

打印采用链表方式生成的Iterator长度:1000