用jiana为某公司编写一个工资支付系统，用于计算某一类员工的月薪。该公司共有四类员工：领固定月薪的（SalariedEmployee）；计时取酬的（HourlyEmployee，如果一月工时超过160小时，则还需对额外的工时支付加班费）；按销售额提成（CommissionEmployee）的和带底薪并按销售额提成的（BasePlusCommissionEmployee），其继承层次结构如下所示。已知每类员工均有表示员工工号、姓名和出生年月的属性，和用于计算员工月薪的方法。创建一个Employee变量数组，保存Employee类层次结构中每个具体类对象的引用，对每个Employee显示其工号、姓名、出生年月和月收入，如果当月是Employee的生日所在的月份，则还另发给他100月作为红包。

好的，我理解了您的问题。下面是一个用 Java 语言实现的工资支付系统，该系统包含了 SalariedEmployee、HourlyEmployee、CommissionEmployee 和 BasePlusCommissionEmployee 四个类，并且实现了您的要求：

import java.util.Calendar;
import java.util.GregorianCalendar;

abstract class Employee {
    private String employeeId;
    private String name;
    private int birthYear;
    private int birthMonth;
    private int birthDay;

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

    public String getEmployeeId() {
        return employeeId;
    }

    public String getName() {
        return name;
    }

    public int getBirthYear() {
        return birthYear;
    }

    public int getBirthMonth() {
        return birthMonth;
    }

    public int getBirthDay() {
        return birthDay;
    }

    public abstract double getMonthlySalary();

    public void printEmployeeInfo() {
        System.out.println("Employee ID: " + employeeId);
        System.out.println("Name: " + name);
        System.out.println("Birth Date: " + birthYear + "/" + birthMonth + "/" + birthDay);
        System.out.println("Monthly Salary: " + getMonthlySalary());
        if (isBirthday()) {
            System.out.println("Happy Birthday! You get a red envelope of $100.");
        }
        System.out.println();
    }

    private boolean isBirthday() {
        Calendar today = new GregorianCalendar();
        int todayMonth = today.get(Calendar.MONTH) + 1;
        return todayMonth == birthMonth;
    }
}

class SalariedEmployee extends Employee {
    private double monthlySalary;

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

    public double getMonthlySalary() {
        return monthlySalary;
    }
}

class HourlyEmployee extends Employee {
    private double hourlyWage;
    private double hoursWorked;

    public HourlyEmployee(String employeeId, String name, int birthYear, int birthMonth, int birthDay, double hourlyWage, double hoursWorked) {
        super(employeeId, name, birthYear, birthMonth, birthDay);
        this.hourlyWage = hourlyWage;
        this.hoursWorked = hoursWorked;
    }

    public double getMonthlySalary() {
        double overtimePay = 0;
        if (hoursWorked > 160) {
            overtimePay = (hoursWorked - 160) * hourlyWage * 1.5;
        }
        return hoursWorked * hourlyWage + overtimePay;
    }
}

class CommissionEmployee extends Employee {
    private double commissionRate;
    private double grossSales;

    public CommissionEmployee(String employeeId, String name, int birthYear, int birthMonth, int birthDay, double commissionRate, double grossSales) {
        super(employeeId, name, birthYear, birthMonth, birthDay);
        this.commissionRate = commissionRate;
        this.grossSales = grossSales;
    }

    public double getMonthlySalary() {
        return commissionRate * grossSales;
    }
}

class BasePlusCommissionEmployee extends CommissionEmployee {
    private double baseSalary;

    public BasePlusCommissionEmployee(String employeeId, String name, int birthYear, int birthMonth, int birthDay, double commissionRate, double grossSales, double baseSalary) {
        super(employeeId, name, birthYear, birthMonth, birthDay, commissionRate, grossSales);
        this.baseSalary = baseSalary;
    }

    public double getMonthlySalary() {
        return super.getMonthlySalary() + baseSalary;
    }
}

public class PayrollSystem {
    public static void main(String[] args) {
        Employee[] employees = new Employee[4];
        employees[0] = new SalariedEmployee("001", "Alice", 1980, 6, 1, 3000);
        employees[1] = new HourlyEmployee("002", "Bob", 1985, 10, 15, 20, 180);
        employees[2] = new CommissionEmployee("003", "Charlie", 1990, 5, 20, 0.15, 10000);
        employees[3] = new BasePlusCommissionEmployee("004", "David", 1995, 8, 8, 0.1, 8000, 1500);

        for (Employee employee : employees) {
            employee.printEmployeeInfo();
        }
    }
}

在这个系统中，抽象类 `Employee` 定义了员工的基本属性和方法，其中 `getMonthlySalary()` 方法是抽象的，需要在具体子类中实现。四个具体子类分别实现了不同类型员工的月薪计算方法。

在 `main()` 方法中，我们创建了一个 `Employee` 类型的数组，存放了四个具体类型的员工对象。然后遍历这个数组，对每个员工调用 `printEmployeeInfo()` 方法，输出员工的基本信息和月收入，并判断是否为员工的生日月份，如果是则额外发放 $100 的红包。