最新作业~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~··

1、设计四个类，分别是：（知识点：抽象类及抽象方法）

（1）Shape表示图形类，有面积属性area、周长属性per，颜色属性color，有两个构造方法（一个是默认的、一个是为颜色赋值的），还有3个抽象方法，分别是：getArea计算面积、getPer计算周长、showAll输出所有信息，还有一个求颜色的方法getColor。

（2）2个子类：

1）Rectangle表示矩形类，增加两个属性，Width表示长度、height表示宽度，重写getPer、getArea和showAll三个方法，另外又增加一个构造方法（一个是默认的、一个是为高度、宽度、颜色赋值的）。

2）Circle表示圆类，增加1个属性，radius表示半径，重写getPer、getArea和showAll三个方法，另外又增加两个构造方法（为半径、颜色赋值的）。

（3）一个测试类PolyDemo，在main方法中，声明创建每个子类的对象，并调用2个子类的showAll方法。

package chap3;

public abstract class Shape {
    protected double area;
    protected double per;
    protected String color;

    public Shape() {
    }

    public Shape(String color) {
        this.color = color;
    }

    public abstract double getArea();

    public abstract double getPer();

    public abstract void showAll();

    public String getcolor() {
        return this.color;
    }

}

package chap3;

public class Rectangle extends Shape {
    int weigth;
    int height;

    public Rectangle() {
    }

    public Rectangle(int weigth, int height, String color) {
        super();
        this.weigth = weigth;
        this.height = height;
        this.color = color;
    }

    public double getArea() {
        this.area = weigth * height;
        return this.area;
    }

    public double getPer() {
        this.per = 2 * (weigth + height);
        return this.per;
    }

    public void showAll() {
        System.out.println("该矩形长为" + this.weigth + ",宽为" + this.height + ",周长为" + this.getPer() + ",面积为"
                + this.getArea() + ",颜色为" + this.getcolor());

    }
}

package chap3;

public class Circle extends Shape {
    double radius;
    double pi = Math.PI;

    public Circle() {
    }

    public Circle(double radius, String color) {
        this.radius = radius;
        this.color = color;
    }

    public double getArea() {
        double area = pi * radius * radius;
        return area;
    }

    public double getPer() {
        double per = 2 * pi * radius;
        return per;
    }

    public void showAll() {
        System.out.println(
                "半径为" + this.radius + "的圆,周长为" + this.getPer() + ",面积为" + this.getArea() + ",颜色为" + this.getcolor());
    }

}

package chap3;

public class PolyDemo {
    public static void main(String[] args) {
        Rectangle a = new Rectangle(2, 5, "yellow");
        Circle b = new Circle(2, "black");
        a.showAll();
        b.showAll();
    }
}

2、Cola公司的雇员分为以下若干类：(知识点：多态)

(1) ColaEmployee ：这是所有员工总的父类，属性：员工的姓名,员工的生日月份。

(2) SalariedEmployee ： ColaEmployee 的子类，拿固定工资的员工。

(3) HourlyEmployee ：ColaEmployee 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。

(4) SalesEmployee ：ColaEmployee 的子类，销售人员，工资由月销售额和提成率决定。

(5) 定义一个类Company，在该类中写一个方法，调用该方法可以打印出某月某个员工的工资数额，写一个测试类TestCompany,在main方法，把若干各种类型的员工放在一个ColaEmployee 数组里，并单元出数组中每个员工当月的工资。

package chap3;

public class ColaEmployee {
    String name;
    int month;
    
    public ColaEmployee() {
        super();
        // TODO Auto-generated constructor stub
    }

    public ColaEmployee(String name, int month) {
        super();
        this.name = name;
        this.month = month;
    }
    
    public double getSalary(int month) {
        return 0;
    }
}

package chap3;

public class SalesEmployee extends ColaEmployee{
    private int monthSales;
    private double royaltyRate;

    public SalesEmployee(String name, int month, int monthSales, double royaltyRate) {
        super(name, month);
        this.monthSales = monthSales;
        this.royaltyRate = royaltyRate;
    }

    public double getSalary(int month) {
        if (super.month == month) {
            return monthSales * royaltyRate + 100;
        } else {
            return monthSales * royaltyRate;
        }
    }
}

package chap3;

public class Company {
    public void getSalary(ColaEmployee c, int month) {
        System.out.println(c.name + "在" + month + "月的月薪为" + c.getSalary(month) + "元");
    }
}

package chap3;

public class TestCompany {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ColaEmployee[] cel= {new SalariedEmployee("jack", 6, 10000),new HourlyEmployee("按小时拿工资的员工", 10, 50, 200),new SalesEmployee("销售人员", 6, 20000, 0.8)};
        for (int i = 0; i < cel.length; i++) {
            new Company().getSalary(cel[i], 8);
        }
    }

}

package chap3;

public class HourlyEmployee extends ColaEmployee{
    private int hourSalary;
    private int num;
    
    public HourlyEmployee(String name,int month,int hourSalary, int num) {
        super(name,month);
        this.hourSalary = hourSalary;
        this.num = num;
    }
    public double getSalary(int month) {
        if (super.month == month) {
            if (num>160) {
                return hourSalary * 160 + hourSalary * (num - 160) * 1.5 +100;
            } else {
                return hourSalary * num + 100;
            }
        } else {
            if (num >160) {
                return hourSalary * 160 + hourSalary * (num - 160) * 1.5;
            } else {
                return hourSalary * num;
            }
        }
    }
}

3、利用接口实现动态的创建对象：（知识点：接口）

（1）创建4个类

1苹果

2香蕉

3葡萄

4园丁

（2）在三种水果的构造方法中打印一句话.

以苹果类为例

class apple

{

public apple()

{

System.out.println(“创建了一个苹果类的对象”);

}

package chap3;

public class apple implements Fruit {
    public apple() {
        System.out.println("创建了一个苹果类对象");
    }

}

package chap3;

public interface Fruit {

}

package chap3;

public class banana implements Fruit {
    public banana() {
        System.out.println("创建了一个香蕉类对象");
    }
}

package chap3;

public class grape implements Fruit {
    public grape() {
        System.out.println("创建了一个葡萄类对象");
    }

}

package chap3;

import java.util.Scanner;

public class gardener {
    public void creater() {
        Scanner input = new Scanner(System.in);
        String a = input.next();
        if (a.equals("苹果")) {
            new apple();
        } else if (a.equals("香蕉")) {
            new banana();
        } else if (a.equals("葡萄")) {
            new grape();
        } else {
            System.out.println("请重新运行");
        }
    }

    public static void main(String[] args) {
        new gardener().creater();
    }
}