关于多态的问题，如何解决？

有同学可以帮我看一下我写的是否正确嘛

题目：完成一个多态作为参数的使用的demo

自由发挥，做出demo，注意两种方式

1，子类重写父类抽象方法

2，子类自带的方法（强制转换）

代码：package com.dmd;

public class Person {
public String name;
public int age;

public Person(String name,int age){
    this.name=name;
    this.age=age;
}

public Person(){

}


public void getInfo(){
    System.out.println(name);
    System.out.println(age);
}

}

package com.dmd;

public class Student extends Person{
String school;

public Student(String name,int age,String school){
    super(name,age);
    this.school=school;
}


public Student(){
}


public void study() {
    System.out.println("好好学习，天天向上！");
}


public void getInfo() {
    super.getInfo();
    System.out.println(school);

}



public static void main(String[] args) {
    Person p=new Person();
    p.name="person";
    p.age=40;
    p.getInfo();

    Student s=new Student();
    s.name="student";
    s.age=20;
    s.school="清华大学";
    s.getInfo();
    s.study();

}

}

 
public abstract class Person {
public String name;
public int age;

public Person(String name,int age){
    this.name=name;
    this.age=age;
}
 
public Person(){
} 
 
public void getInfo(){
    System.out.println(name);
    System.out.println(age);
}
public abstract void eat();
}

package a;

public class Student extends Person{
String school;

public Student(String name,int age,String school){
    super(name,age);
    this.school=school;
}
 
 
public Student(){
}
 
 
public void study() {
    System.out.println("好好学习，天天向上！");
}
 
 
public void getInfo() {
    super.getInfo();
    System.out.println(school);
 
}
 
 
 
public static void main(String[] args) {
    Person p=new Student();
    p.name="person";
    p.age=40;
    p.getInfo();
     Student s= (Student)p;
    s.name="student";
    s.age=20;
    s.school="清华大学";
    s.getInfo();
    s.study();
 
}


@Override
public void eat() {
    // TODO Auto-generated method stub
    System.out.println("学生吃饭");
}
}