迭代器模式

Author: anxpp

src/com/anxpp/designpattern/iterator/ArrayList.java

@@ -0,0 +1,36 @@
+packagecom.anxpp.designpattern.iterator;
+//方便演示而实现的简陋的数组list
+publicclassArrayList<T> implementsList<T>{
+privateintsize; //存放的元素个数,会默认初始化为0
+privateObject[] defaultList; //使用数组存放元素
+privatestaticfinalintdefaultLength = 10;//默认长度
+publicArrayList(){//默认构造函数
+defaultList = newObject[defaultLength];
+ }
+@Override
+publicIterator<T> iterator(){
+returnnewMyIterator();
+ }
+//添加元素
+@Override
+publicbooleanadd(Tt){
+if(size<=defaultLength){
+defaultList[size++] = t;
+returntrue;
+ }
+returnfalse;
+ }
+//遍历器
+privateclassMyIteratorimplementsIterator<T>{
+privateintnext;
+@Override
+publicbooleanhasNext(){
+returnnext<size;
+ }
+@SuppressWarnings("unchecked")
+@Override
+publicTnext(){
+return (T) defaultList[next++];
+ }
+ }
+}

src/com/anxpp/designpattern/iterator/Iterator.java

@@ -0,0 +1,7 @@
+packagecom.anxpp.designpattern.iterator;
+
+//只是需要遍历一堆数据，那么只需要2个方法就可以了
+publicinterfaceIterator<T>{
+booleanhasNext(); //是否还有下一个元素
+Tnext(); //得到下一个元素
+}

src/com/anxpp/designpattern/iterator/LinkList.java

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+packagecom.anxpp.designpattern.iterator;
+//方便演示而实现的简陋的单向链表list
+publicclassLinkList<T> implementsList<T>{
+privateintsize; //存放的元素个数,会默认初始化为0
+privateNode<T> first; //首节点，默认初始化为null
+@Override
+publicIterator<T> iterator(){
+returnnewMyIterator();
+ }
+@Override
+publicbooleanadd(Tt){
+if(size==0){
+first = newNode<T>(t,null);
+ }
+while(first.next!=null);
+first.next = newNode<T>(t,null);
+returntrue;
+ }
+//链表节点
+privatestaticclassNode<T>{
+Tdata;
+Node<T> next;
+Node(Tdata,Node<T> next){
+this.data = data;
+this.next = next;
+ }
+ }
+//遍历器
+privateclassMyIteratorimplementsIterator<T>{
+privateNode<T> next; //下一个节点
+MyIterator(){
+next = first;
+ }
+@Override
+publicbooleanhasNext(){
+returnnext!=null;
+ }
+@Override
+publicTnext(){
+Tdata = next.data;
+next = next.next;
+returndata;
+ }
+ }
+}

src/com/anxpp/designpattern/iterator/List.java

@@ -0,0 +1,7 @@
+packagecom.anxpp.designpattern.iterator;
+
+//便于介绍，不做多的操作
+publicinterfaceList<T>{
+Iterator<T> iterator(); //返回一个遍历器
+booleanadd(Tt); //添加元素到列表
+}

src/com/anxpp/designpattern/iterator/TestUse.java

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+packagecom.anxpp.designpattern.iterator;
+publicclassTestUse{
+publicstaticvoidmain(Stringargs[]){
+//分别定义两种结构
+List<Integer> array = newArrayList<Integer>();
+List<Integer> link = newLinkList<Integer>();
+//添加数据
+for(inti = 1;i < 8; i++){
+array.add(i);
+link.add(i);
+ }
+//获得迭代器
+Iterator<Integer> ai = array.iterator();
+Iterator<Integer> li = array.iterator();
+//遍历并输出
+while(ai.hasNext())
+System.out.print(ai.next());
+System.out.println();
+while(li.hasNext())
+System.out.print(li.next());
+ }
+}

src/com/anxpp/designpattern/iterator/package-info.java

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+/**
+ * @author Administrator
+ * 迭代器模式--此处未实现remove()方法
+ */
+packagecom.anxpp.designpattern.iterator;