java练习：编写工资系统，实现不同类型员工(多态)的按月发放工资。如果当月出现某个Employee对象的生日，则将该雇员的工资增加100元。

1、员工类Employee：

public abstract class Employee {
    //姓名
    private String name;
    //工号
    private String num;
    //生日
    private MyDate birthday;

    //构造方法
    public Employee(String name,String num,MyDate birthday){
        this.name = name;
        this.num = num;
        this.birthday = birthday;
    }
    //无参构造   不写也行
    public Employee() {

    }

    //抽象类方法
    public abstract double earnings();

    @Override
    public String toString() {
        return "name:"+name+",num:"+num+",birthday:"+birthday;
    }

    public MyDate getBirthday() {
        return birthday;
    }

    public String getName() {
        return name;
    }
}

2、小时工HourlyEmployee：

public class HourlyEmployee extends Employee{
    //小时工   按小时结算工资

    //每小时的工资
    private double wage;
    //时间
    private double hour;

    public HourlyEmployee(String name,String num,MyDate birthday,double wage,double hour){
        //super继承父类
        super(name, num, birthday);
        this.wage = wage;
        this.hour = hour;
    }

    //重写父类Employee的earnings（）方法
    @Override
    public double earnings() {
        return wage * hour;
    }

    @Override
    public String toString() {
        return super.toString()+this.earnings();
    }
}

3、正式员工SalariedEmployee：

public class SalariedEmployee extends Employee{
    //正式员工  按每月发工资
    private double monthlySalary;

   public SalariedEmployee(String name,String num,MyDate birthday,double monthlySalary){
       super(name, num, birthday);
       this.monthlySalary = monthlySalary;
   }

   public SalariedEmployee(){
   }

    //重写父类Employee的earnings（）方法
    @Override
    public double earnings() {
        return monthlySalary;
    }

    @Override
    public String toString() {
        return super.toString() + ",薪水："+this.earnings();
    }
}

4、日期类MyDate：

public class MyDate {
    private int year;
    private int month;
    private int day;
    //对年月日进行赋值
    public MyDate(int year,int month,int day){
        this.year = year;
        this.month = month;
        this.day = day;
    }

    @Override
    public String toString() {
        return year + "年" + month + "月" + day + "日";
    }

    //因为需要获取员工是否生日
    //所以需要调用getMonth（）方法
    public int getMonth() {
        return month;
    }
}

5、财务系统类PayrollSystem：

import java.util.Arrays;

public class PayrollSystem {
    //创建数组  用于存储员工信息
    private Employee[] employees;

    public PayrollSystem(){
    }

    @Override
    public String toString() {
        return  Arrays.toString(employees);
    }
    //有参构造
    public PayrollSystem(Employee[] employees){
        this.employees = employees;
    }

    //获取数组
    public Employee[] getEmployees() {
        return employees;
    }
    //更改数组
    public void setEmployees(Employee[] employees) {
        this.employees = employees;
    }


}

6、测试类EmployeeTest：

import java.util.Scanner;

public class EmployeeTest {
    public static void main(String[] args) {
        //创建一个PayrollSystem好比创建一个财务系统
        //用于存储员工信息
        PayrollSystem payrollSystem = new PayrollSystem();
        MyDate e1B = new MyDate(2000,10,1);
        Employee e1 = new SalariedEmployee("张三","A001",e1B,5000.0);
        Employee e2 = new SalariedEmployee("李四","A002",e1B,5000.0);
        //创建数组  给它赋值  将他赋给payroSystem的数组赋值
        Employee[] employees = {e1,e2};
        //将他赋给payrollSystem的数组
        payrollSystem.setEmployees(employees);
        Scanner scanner = new Scanner(System.in);
        while (true){
            System.out.println("功能列表：" +
                    "1、列出员工信息" +
                    "2、输入月份" +
                    "3、退出");
            System.out.print("请输入要执行的命令：");
            int s1 = scanner.nextInt();
            if(s1 == 1){
                for (int i = 0;i 
写的比较匆忙，后期再完善一下