java編程思想之接口泛型

接口也可以做泛型編程，例如要實現一個接口Iterface，用到java生成器Gernerator，Iterable，還有迭代器iterator

要實現泛型，必須要實現一個類型，這裏就拿車作爲一個基類，然後擴展其他的子類，在寫代碼前需要明確一點

：java裏面的for循環會去自動尋找iterator迭代器的方法，並尋找next（）和hasnext（）方法，知道hasnext（）方法

返回false爲止，代碼如下：

package com;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.Random;

public class PeopleGernerator implements Gernerator<People>,Iterable<People> {
	private Class[] types={America.class,Australia.class,Chinese.class};
	private Random rand=new Random(47);//隨機生成器
	public PeopleGernerator(){}
	private int size=0;
	public PeopleGernerator(int cnt)
	{
		size=cnt;
	}
	@Override
	public People next() {
		// TODO Auto-generated method stub
		try{
			return (People) types[rand.nextInt(types.length)].newInstance(); 
		}catch (Exception e) {
			throw new RuntimeException(e);
			// TODO: handle exception
		}
	}
	class PeopleIterator implements Iterator<People>
	{
		private int count=size;
		@Override
		public boolean hasNext() {
			return count>0;
			// TODO Auto-generated method stub
		}

		@Override
		public People next() {
			// TODO Auto-generated method stub
		count--;
		return PeopleGernerator.this.next();
		}

		@Override
		public void remove() {
			// TODO Auto-generated method stub
			throw new UnsupportedOperationException();
		}
	}
	public Iterator<People> iterator()
	{
		return new PeopleIterator();
	}
	public static void main(String args[])
	{
		PeopleGernerator E=new PeopleGernerator();
		for(int i=0;i<5;i++)
		{
			System.out.println(E.next());
		}
		
		PeopleGernerator k=new PeopleGernerator(10);
		System.out.println(k.next());
		
		for(People c:new PeopleGernerator(5) )
		{
			System.out.println(c);
		}
		

	}
}

結果如下：

Chinese 1
Chinese 2
Australia 3
Chinese 4
Australia 5
Chinese 6
Chinese 7
Australia 8
Chinese 9
Australia 10