list中对象、值保存的解释

package com.lee.list;

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

import org.junit.Test;

import com.lee.model.Person;


public class ListAddChangeList {

	/*[com.lee.model.Person@2510bb7, com.lee.model.Person@16d81c91]
	[com.lee.model.Person@2510bb7, com.lee.model.Person@16d81c91]
	[com.lee.model.Person@2510bb7, com.lee.model.Person@16d81c91]
	[null, null]*/
	//实验证明，list保存的是p1 p2 指向的内存地址，这块内存地址的值可以通过p1 p2去修改里边的值
	//但是改变p1 p2的指向并不能改变这块内存地址的值，所以当p1 = null时
	//list保存的p1所指向的内存地址还是不会改变，还是会有值
	@Test
	public void t1(){
		List<Person> list = new ArrayList<Person>();
		Person p1 = new Person("n1",11); 
		Person p2 = new Person("n2", 22); 
		list.add(p1);
		list.add(p2);
		
//		p1 = null;
//		p2 = null;
		
		//System.out.println(list.toString());
		
		print(list);
		p1.setAge(15);
		
		List<Person> list2 = new ArrayList<Person>();
		list2.add(list.get(0));
		list2.add(list.get(1));
		
		list.set(0, null);
		list.set(1, null);
		
		//System.out.println(list2.toString());
		p1.setAge(166);
		p1 = null;
		p2 = null;
		System.out.println("****p1.setAge(16)****");
		print(list2);
//		p1 = null;
//		p2 = null;
		p1.setAge(17);
		System.out.println("***********");
		print(list2);
		//System.out.println(list2.toString());
		
//		list2.set(0, null);
//		list2.set(1, null);
		
		//System.out.println(list2.toString());
		p1.setAge(17);
		print(list2);
	}

	private void print(List<Person> list) {
		for(Person person : list){
			System.out.print(person.getName() + " " + person.getAge() + " ");
		}
		if(list.size() == 0){
			System.out.println("empty");
		}
		System.out.println();
		
	}
	
	
	
}