迭代器模式

Iterator.java

import static com.mceiba.util.Print.*;
interface Selector{
	boolean end();
	Object current();
	void next();
}
public class Iterator{
	private Object[] items;
	private int next = 0;
	public Iterator(int size) { items = new Object[size]; }
	public void add(Object obj){
		if(next < items.length) items[next++] = obj;
	}
	private class IteratorSelector implements Selector{
		private int i = 0;
		public boolean end() { return i == items.length; }
		public Object current() { return items[i]; }
		public void next() { if(i < items.length) i++; }
	}
	public Selector selector() { return new IteratorSelector(); }
	public static void main(String[] args){
		Iterator iterator = new Iterator(10);
		for(int i=0; i<10; i++)
			iterator.add(Integer.toString(i));
		Selector selector = iterator.selector();
		while(!selector.end()){
			print(selector.current()+" ");
			selector.next();
		}
		println();
	}
}