迭代模式
迭代模式：
????????? 此模式的思想是有一个数据集合，我们写出一个算法集合，使用算法集合内的各个算法，来迭代数据集合，获得一些数据。
????????? 最常见的就是? List?、Set 等我们常常使用的集合，采用迭代器（Iterator）进行获取集合内的元素。
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以下模仿写了一个实现
package com.mkf.pattern;public interface Iterator {public Object previous();public boolean hasPrevious();public Object next();public boolean hsNext();public Object first();public boolean isFirst();public Object last();public boolean isLast();}package com.mkf.pattern;public interface Collection {public Iterator getIterator();public Object get(int i);public int size();}package com.mkf.pattern.impl;import com.mkf.pattern.Collection;import com.mkf.pattern.Iterator;public class MyIterator implements Iterator {private Collection collection;private int pos = -1;public MyIterator(Collection collection) {this.collection = collection;}@Overridepublic Object first() {pos = 0;return collection.get(pos);}@Overridepublic boolean isFirst() {if (pos == 0) {return true;}return false;}@Overridepublic Object last() {pos = collection.size() - 1;return collection.get(pos);}@Overridepublic boolean isLast() {if (pos == collection.size() - 1) {return true;}return false;}@Overridepublic Object next() {if (pos < collection.size() - 1) {pos++;}return collection.get(pos);}@Overridepublic boolean hsNext() {if (pos < collection.size() - 1) {return true;}return false;}@Overridepublic boolean hasPrevious() {if (pos > 0) {return true;}return false;}@Overridepublic Object previous() {if (pos > 0) {pos--;}return collection.get(pos);}}package com.mkf.pattern.impl;import com.mkf.pattern.Collection;import com.mkf.pattern.Iterator;public class MyCollection implements Collection {public String[] str = { "A", "B", "C", "D", "E", "F", "G" };@Overridepublic Object get(int i) {return str[i];}@Overridepublic Iterator getIterator() {return new MyIterator(this);}@Overridepublic int size() {return str.length;}}package com.mkf;import com.mkf.pattern.Collection;import com.mkf.pattern.Iterator;import com.mkf.pattern.impl.MyCollection;public class TestIterator {/** * @param args */public static void main(String[] args) {Collection collection = new MyCollection();Iterator iterator = collection.getIterator();while(iterator.hsNext()){System.out.print(iterator.next());System.out.print("\t");}}}?运行结果为：
A?B?C?D?E?F?G?