java抽象类练习题

package com.test;/* * 2、定义一个抽象的"Role"类，有姓名，年龄，性别等成员变量1）要求尽可能隐藏所有变量(能够私有就私有,能够保护就不要公有)，再通过GetXXX()和SetXXX()方法对各变量进行读写。具有一个抽象的play()方法，该方法不返回任何值，同时至少定义两个构造方法。Role类中要体现出this的几种用法。2）从Role类派生出一个"Employee"类，该类具有Role类的所有成员（构造方法除外），并扩展salary成员变量，同时增加一个静态成员变量“职工编号（ID）”。同样要有至少两个构造方法，要体现出this和super的几种用法，还要求覆盖play()方法，并提供一个final sing()方法。3）"Manager"类继承"Employee"类，有一个final成员变量"vehicle"在main()方法中制造Manager和Employee对象,并测试这些对象的方法。 * */abstract class Role {private String name;private int age;private String sex;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public abstract void play ();public Role (){}public Role (String name, int age, String sex){this.name = name;this.age = age;this.sex = sex;}}class Employee extends Role {private double salary;public double getSalary() {return salary;}public void setSalary(double salary) {this.salary = salary;}private static String ID;public static String getID() {return ID;}public static void setID(String iD) {ID = iD;}public Employee () {}public Employee (String name, int age, String sex, double salary, String ID) {super(name, age, sex);this.salary = salary;this.ID = ID;}@Overridepublic void play() {// TODO Auto-generated method stubSystem.out.println("员工编号"+this.getID());}final void sing() {System.out.println("员工姓名"+this.getName()+"员工性别"+this.getSex()+"员工年龄"+this.getAge()+"员工工资"+this.getSalary());}}class Manager extends Employee {final String vehicle;public Manager (String name, int age, String sex, double salary, String ID, String vehicle) {super(name, age, sex, salary, ID);this.vehicle = "保时捷";}}public class Demo2 {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubEmployee e = new Employee("张三", 27, "男", 3000,"001");e.play();e.sing();Manager m = new Manager("李四", 29, "男", 4000, "002", "");m.play();m.sing();System.out.println("坐车"+m.vehicle);}}