某公司的雇员分为以下若干类 Employee ：这是所有员工总的父类，属性：员工的姓名,员工的生日月份。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。 SalariedEmployee ：Employee 的子类，拿固定工资的员工。属性：月薪 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。属性：每小时的工资、每月工作的小时数 SalesEmployee ：Employee 的子类，销售人员，工资由月销售额和提成率决定。属性：月销售额、提成率 定义一个类Company，在main方法，把若干各种类型的员工放在一个Employee 数组里，并单元出数组中每个员工当月的工资。

以下是代码实现：

import java.util.Scanner;

public class Company {
    public static void main(String[] args) {
        Employee[] employees = new Employee[4];
        employees[0] = new SalariedEmployee("Tom", 10000);
        employees[1] = new HourlyEmployee("Jerry", 100, 180);
        employees[2] = new SalesEmployee("Bob", 5000, 0.05);
        employees[3] = new Employee("Alice", 7);

        for (Employee employee : employees) {
            System.out.println(employee.getName() + "'s salary of this month is " + employee.getSalary(7));
        }
    }
}

class Employee {
    private String name;
    private int birthMonth;

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

    String getName() {
        return name;
    }

    int getBirthMonth() {
        return birthMonth;
    }

    double getSalary(int month) {
        double salary = 0.0;
        if (month == birthMonth) {
            salary += 100;
        }
        return salary;
    }
}

class SalariedEmployee extends Employee {
    private double monthlySalary;

    SalariedEmployee(String name, double monthlySalary) {
        super(name, 0);
        this.monthlySalary = monthlySalary;
    }

    @Override
    double getSalary(int month) {
        double salary = super.getSalary(month);
        return salary + monthlySalary;
    }
}

class HourlyEmployee extends Employee {
    private double hourlyWage;
    private int monthlyWorkHours;

    HourlyEmployee(String name, double hourlyWage, int monthlyWorkHours) {
        super(name, 0);
        this.hourlyWage = hourlyWage;
        this.monthlyWorkHours = monthlyWorkHours;
    }

    @Override
    double getSalary(int month) {
        double salary = super.getSalary(month);
        if (monthlyWorkHours > 160) {
            salary += (monthlyWorkHours - 160) * hourlyWage * 1.5 + 160 * hourlyWage;
        } else {
            salary += monthlyWorkHours * hourlyWage;
        }
        return salary;
    }
}

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

    SalesEmployee(String name, double monthlySales, double commissionRate) {
        super(name, 0);
        this.monthlySales = monthlySales;
        this.commissionRate = commissionRate;
    }

    @Override
    double getSalary(int month) {
        double salary = super.getSalary(month);
        salary += monthlySales * commissionRate;
        return salary;
    }
}

在本例中，定义了一个父类Employee和三个子类SalariedEmployee、HourlyEmployee和SalesEmployee。每个子类继承了父类的属性和方法，并且根据不同的员工类型，重写了getSalary方法来计算每个员工的工资。主函数中，定义了一个Employee数组，分别放置了不同类型的员工，并且打印出了每个员工当月的工资。