迭代器模式

package iterator;
/***
 * 
 * 自定义迭代器接口
 * @author zw
 *
 */
public interface MyIterator {
	void first();
	void next();
	boolean hasNext();
	boolean isFirst();
	Object getObj();
}

package iterator;

import java.util.ArrayList;
import java.util.List;

/***
 * 自定义聚合类
 * @author zw
 *
 */
public class CMA {
	private List<Object> list = new ArrayList<Object>();

	
	public void addObject(Object obj) {
		this.list.add(obj);
	}
	public void removeObject(int index) {
		this.list.remove(index);
	}

	public List<Object> getList() {
		return list;
	}

	public void setList(List<Object> list) {
		this.list = list;
	}
	
	//获得迭代器对象
	public MyIterator createIterator() {
		return new ConcreteIterator();
	}
	
	
	//使用内部类定义迭代器，可以直接使用外部类的属性
	class ConcreteIterator implements MyIterator{
		
		private int cursor;//定义游标用于记录遍历时的位置
		
		@Override
		public void first() {
			// TODO Auto-generated method stub
			cursor = 0;
		}

		@Override
		public void next() {
			// TODO Auto-generated method stub
			if(cursor<list.size()) {
				cursor++;
			}
		}

		@Override
		public boolean hasNext() {
			// TODO Auto-generated method stub
			if(cursor<list.size()) {
				return true;
			}
			return false;
		}

		@Override
		public boolean isFirst() {
			// TODO Auto-generated method stub
			return cursor==0?true:false;
		}

		@Override
		public Object getObj() {
			// TODO Auto-generated method stub
			return list.get(cursor);
		}
		
	}
	
}

package iterator;

public class Client {
	public static void main(String[] args) {
		CMA cma = new CMA();
		cma.addObject("zzz");
		cma.addObject("ccc");
		cma.addObject("mmm");
		
		
		MyIterator iter = cma.createIterator();
		while(iter.hasNext()) {
			System.out.println(iter.getObj());
			iter.next();
		}
		
	}
}