有限多例

完整设计模式目录见：https://blog.youkuaiyun.com/u013523089/article/details/82852049

有限多例：只能产生固定数量的实例
实现：通过类内部懒加载生成指定数量的实例，并防止new来创建实例

package com.zhaowd.test.designPattern.multitionPattern有限多例;
import java.util.ArrayList;
import java.util.List;
public class Emperor {
	public int aaa;
	//订单多例数量
	private static final int count = 2;
	//用来装单例
	private static List<Emperor> list = new ArrayList<Emperor>();
	private static List<String> listName = new ArrayList<String>();
	//强制不让new
	private Emperor(String name) {
		listName.add(name);
	}
	static {
		for(int i = 0; i < count ; i ++) {
			list.add(new Emperor("皇帝" + i));
		}
	}
	public static Emperor getInstance(int i) {
		return list.get(i);
	}
	public static List<String> getListName() {
		return listName;
	}
}


public static void main(String[] args) {
	Emperor.getInstance(0).aaa=10;
	Emperor.getInstance(1).aaa=20;
	
	System.out.println(Emperor.getInstance(Emperor.getListName().indexOf("皇帝0")).aaa);
	System.out.println(Emperor.getInstance(Emperor.getListName().indexOf("皇帝1")).aaa);
}