Java toString()在多继承关系中的应用

package com.test.javaSe;abstract class Person {private int age;private String name;public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public void say() {};public abstract void run();@Overridepublic String toString() {// TODO Auto-generated method stubreturn this.name + " " + this.age;}}abstract class Student extends Person {String schoolName;public abstract int getPropertityes();public String getSchoolName() {return schoolName;}public void setSchoolName(String schoolName) {this.schoolName = schoolName;}@Overridepublic String toString() {// TODO Auto-generated method stubreturn super.toString() + " " + this.schoolName;}}class Graduate extends Student {    int classId;public int getClassId() {return classId;}public void setClassId(int classId) {this.classId = classId;}@Overridepublic void run() {// TODO Auto-generated method stubSystem.out.println("run.....");}@Overridepublic int getPropertityes() {// TODO Auto-generated method stubreturn 0;}@Overridepublic String toString() {// TODO Auto-generated method stubreturn super.toString()+" "+this.classId;}}public class AbstractTest {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubPerson p = new Graduate();Graduate g = new Graduate();g.setAge(22);g.setName("ctl");g.setSchoolName("kjxy");g.setClassId(2010151430);p = g;System.out.println(p);//ctl 22 kjxy 2010151430}}