JavaOOP如何通过继承减少代码重复

class Employee {
    protected String name;
    protected String id;
public void work() {
    System.out.println(name + " 正在工作");
}
}
class FullTimeEmployee extends Employee {
public void calculateSalary() {
System.out.println("按月发放工资");
}
}
class PartTimeEmployee extends Employee {
public void calculateSalary() {
System.out.println("按小时结算工资");
}
}

abstract class Shape {
    public abstract double getArea();
public void printInfo() {
    System.out.println("这是一个图形，面积为：" + getArea());
}
}
class Circle extends Shape {
private double radius;
public Circle(double radius) {
    this.radius = radius;
}

public double getArea() {
    return Math.PI * radius * radius;
}
}
class Rectangle extends Shape {
private double width, height;
public Rectangle(double width, double height) {
    this.width = width;
    this.height = height;
}

public double getArea() {
    return width * height;
}
}

class Employee {
    public void clockIn() {
        System.out.println("员工打卡上班");
    }
}
class RemoteEmployee extends Employee {
@Override
public void clockIn() {
System.out.println("远程员工通过系统签到");
}
}