1 import java.util.*;
2
3 public class SixDuo {
4 public void eat(){
5 System.out.println("狗狗吃骨头");
6 }
7 public static void main(String[] args){
8 ArrayList<Object> myAL = new ArrayList<Object>();
9 SixDuo Dogc = new SixDuo();
10 Object obj = new Object();
11 myAL.add(Dogc); //加入myAL
12 myAL.add(obj);
13 Object o = myAL.get(0); //取出在myAL里排第一位的Dogc
14 SixDuo d1 = (SixDuo)o; //将类型转换成SixDuo
15 d1.eat();
16 if(o instanceof SixDuo){ //为了防止o取出的不一定是SixDuo类型而进行判断
17 SixDuo d2 = (SixDuo) o;
18 d2.eat();
19 }
20 }
21
22 }
