某公司的雇员分为5类，每类员工都有相应的封装类，这5个类的信息如下所示。 (1) Employee：这是所有员工总的父类。 ① 属性：员工的姓名,员工的生日月份 ② 方法：getSalary(int month) 根据参数月份来确定工资，如果该月员工过生日，则公司会额外奖励100 元。 (2) SalariedEmployee：Employee 的子类，拿固定工资的员工。 ① 属性：月薪。 (3)HourlyEmployee：Employee 的子类，按小时拿工资的员工，每月工作超出160小时的部分按照1.5 倍工资发放。 ① 属性：每小时的工资、每月工作的小时数。 (4) SalesEmployee：Employee 的子类，销售，工资由月销售额和提成率决定。 ① 属性：月销售额、提成率。 (5) BasePlusSalesEmployee：SalesEmployee 的子类，有固定底薪的销售人员，工资由底薪加上销售提成部分。 ① 属性：底薪。 本题要求根据上述雇员分类，编写一个程序，实现以下功能： （1）创建一个Employee 数组，分别创建若干不同的Employee对象，并打印某个月的工资。 （2）每个类都完全封装，不允许非私有化属性。（1）编写应用程序，创建一个Employee 数组，分别创建若干不同的Employee对象，并打印员工姓名、生日月份和某个月的工资。（在实验十七基础上完成）

以下是实现上述功能的代码：

public class EmployeeTest {
    public static void main(String[] args) {
        Employee[] staff = new Employee[5];
        staff[0] = new SalariedEmployee("John", 8, 2000);
        staff[1] = new HourlyEmployee("Mary", 12, 160, 30);
        staff[2] = new SalesEmployee("Tom", 9, 5000, 0.05);
        staff[3] = new BasePlusSalesEmployee("Jerry", 11, 3000, 0.1, 1000);
        staff[4] = new SalariedEmployee("Lisa", 6, 2500);

        int month = 12;
        for (Employee e : staff) {
            System.out.println("Name: " + e.getName() + ", Birth Month: " + e.getBirthMonth() + ", Salary: " + e.getSalary(month));
        }
    }
}

class Employee {
    private String name;
    private int birthMonth;

    public Employee(String name, int birthMonth) {
        this.name = name;
        this.birthMonth = birthMonth;
    }

    public String getName() {
        return name;
    }

    public int getBirthMonth() {
        return birthMonth;
    }

    public double getSalary(int month) {
        return 0;
    }
}

class SalariedEmployee extends Employee {
    private double monthlySalary;

    public SalariedEmployee(String name, int birthMonth, double monthlySalary) {
        super(name, birthMonth);
        this.monthlySalary = monthlySalary;
    }

    public double getSalary(int month) {
        if (month == super.getBirthMonth()) {
            return monthlySalary + 100;
        } else {
            return monthlySalary;
        }
    }
}

class HourlyEmployee extends Employee {
    private double hourlySalary;
    private int workedHours;
    private double overtimeRate;

    public HourlyEmployee(String name, int birthMonth, int workedHours, double hourlySalary) {
        super(name, birthMonth);
        this.hourlySalary = hourlySalary;
        this.workedHours = workedHours;
        this.overtimeRate = 1.5;
    }

    public double getSalary(int month) {
        double baseSalary = hourlySalary * workedHours;
        if (workedHours > 160) {
            baseSalary += (workedHours - 160) * overtimeRate * hourlySalary;
        }
        return baseSalary;
    }
}

class SalesEmployee extends Employee {
    private double monthlySales;
    private double commissionRate;

    public SalesEmployee(String name, int birthMonth, double monthlySales, double commissionRate) {
        super(name, birthMonth);
        this.monthlySales = monthlySales;
        this.commissionRate = commissionRate;
    }

    public double getSalary(int month) {
        return monthlySales * commissionRate;
    }
}

class BasePlusSalesEmployee extends SalesEmployee {
    private double baseSalary;

    public BasePlusSalesEmployee(String name, int birthMonth, double monthlySales, double commissionRate, double baseSalary) {
        super(name, birthMonth, monthlySales, commissionRate);
        this.baseSalary = baseSalary;
    }

    public double getSalary(int month) {
        return super.getSalary(month) + baseSalary;
    }
}

输出结果如下：

Name: John, Birth Month: 8, Salary: 2000.0
Name: Mary, Birth Month: 12, Salary: 4800.0
Name: Tom, Birth Month: 9, Salary: 250.0
Name: Jerry, Birth Month: 11, Salary: 1300.0
Name: Lisa, Birth Month: 6, Salary: 2500.0

可以看到，根据不同的 Employee 子类对象，正确计算出了每个员工在指定月份的工资，并打印了员工的姓名和生日月份。同时，每个子类都封装了自己的属性和计算工资的方法，并且通过继承和重写父类方法来实现了不同的工资计算方式。