JavaSE中继承，多态，接口的练习题

1.建立InstanceTest 类，在类中定义方法method(Person e);
在method中:
(1)根据e的类型调用相应类的getInfo()方法。
(2)根据e的类型执行：
如果e为Person类的对象，输出：
“a person”;
如果e为Student类的对象，输出：
“a student”
“a person ”
如果e为Graduate类的对象，输出：
“a graduated student”
“a student”
“a person”

package com.lhc.exer2;

public class InstanceTest{
   
	public static void main(String[] args) {
   
		InstanceTest test = new InstanceTest();
		test.method(new Person());
		System.out.println("---------------");
		test.method(new Student());
	}
	public void method(Person e) {
   
		System.out.println(e.getInfo());
		if(e instanceof Graduate) {
   
			System.out.println("a graduated student");
			System.out.println("a student");
			System.out.println("a person");
		}else if(e instanceof Student) {
   
			System.out.println("a student");
			System.out.println("a person");
		}else {
   
			System.out.println("a person");
		}
	}
}

class Person {
   
	protected String name = "person";
	protected int age