新增arraylist，然后添加类到arraylist中，最后取出arraylist中的类

import java.util.*;

public class Dog {
    String name;
    
    public void eat() {
        System.out.println("吃骨头");
    }
    
    public static void main(String[] args) {
        //在这里写代码
          ArrayList<Dog> myList = new ArrayList<Dog>();
          Dog aDog = new Dog();
          myList.add(aDog);
          Dog newD = myList.get(0);
          newD.eat();
    }
}