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 com.gyq.chapterOne; public abstract class Shape1 { protected double area; protected double per; protected String color; public Shape1() { } public Shape1(String color) { super(); this.color = color; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public abstract void getArea(); public abstract void getPer(); public abstract void showAll(); }
package com.gyq.chapterOne; import java.awt.Color; public class Rectangle1 extends Shape1{ private int width; private int height; public Rectangle1() { } public Rectangle1(int width, int height,String color) { super(color); this.width = width; this.height = height; } @Override public void getArea() { area = width * height; } @Override public void getPer() { per = (width + height) * 2; } @Override public void showAll() { System.out.println("矩形面积为:"+area+",举行周长为:"+per+",矩形颜色为:"+color); } }
package com.gyq.chapterOne; public class Circle1 extends Shape1{ private int radius; public Circle1() { super(); // TODO Auto-generated constructor stub } public Circle1(int radius,String color) { super(color); this.radius = radius; } @Override public void getArea() { area = radius * radius * 3.14; } @Override public void getPer() { per = 2 * radius * 3.14; } @Override public void showAll() { System.out.println("圆的面积为:"+area+",周长为:"+per+",颜色为:"+color); } }
package com.gyq.chapterOne; public class PolyDeom { public static void main(String[] args) { // TODO Auto-generated method stub Rectangle1 r = new Rectangle1(3, 4, "蓝"); Circle1 c = new Circle1(2, "黄"); r.getArea(); r.getPer(); r.showAll(); c.getArea(); c.getPer(); c.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。
Ÿ 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 : ColaEmployee 的子类,拿固定工资的员工。
Ÿ 属性:月薪
(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。
Ÿ 属性:每小时的工资、每月工作的小时数
(4) SalesEmployee :ColaEmployee 的子类,销售人员,工资由月销售额和提成率决定。
Ÿ 属性:月销售额、提成率
(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 com.gyq.chapterOne; public class ColaEmployee { protected String name; protected int birthday; public ColaEmployee() { } public ColaEmployee(String name, int birthday) { super(); this.name = name; this.birthday = birthday; } public double getSalary(int month) { return 0; } }
package com.gyq.chapterOne; public class SalariedEmployee extends ColaEmployee{ double Salary; public SalariedEmployee() { super(); // TODO Auto-generated constructor stub } public SalariedEmployee(double salary,String name, int birthday) { super(name, birthday); this.Salary = salary; } public double getSalary(int month) { if (super.birthday==birthday) { return Salary + 100; } else { return Salary; } } }
package com.gyq.chapterOne; public class HourlyEmployee extends ColaEmployee{ int hourSalary; int hour; public HourlyEmployee() { super(); // TODO Auto-generated constructor stub } public HourlyEmployee(int hourSalary, int hour,String name, int birthday) { super(name, birthday); this.hourSalary = hourSalary; this.hour = hour; } public double getSalary(int month) { if (super.birthday==birthday) { if (hour>160) { return hourSalary * 160 + hourSalary * (hour - 160) * 1.5 +100; } else { return hourSalary*hour+100; } } else { if (hour>160) { return hourSalary * 160 + hourSalary * (hour - 160) * 1.5; } else { return hourSalary*hour; } } } }
package com.gyq.chapterOne; public class SalesEmployee extends ColaEmployee{ int monthSales; double add; public SalesEmployee() { super(); // TODO Auto-generated constructor stub } public SalesEmployee(int monthSales, double add,String name, int birthday) { super(name, birthday); this.monthSales = monthSales; this.add = add; } public double getSalary(int mon) { if (super.birthday==birthday) { return monthSales*add+100; } else { return monthSales*add; } } }
package com.gyq.chapterOne; import java.time.Month; public class Company { public void getSalary(ColaEmployee a,int month) { System.out.println(a.name + "在" + month + "月的月薪为" + a.getSalary(month) + "元"); } }
package com.gyq.chapterOne; public class TestCompany { public static void main(String[] args) { // TODO Auto-generated method stub ColaEmployee[] a= {new SalariedEmployee(10000,"James",4),new HourlyEmployee(60, 200, "Licy", 10),new SalesEmployee(9000, 1.8, "Coco", 2)}; for (int i = 0; i < a.length; i++) { new Company().getSalary(a[i], 4); } } }
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”);
}
}
(3)类图如下:
(4)要求从控制台输入一个字符串,根据字符串的值来判断创建三种水果中哪个类的对象。
运行结果如图:
package com.gyq.chapterOne; public interface Fruit { }
package com.gyq.chapterOne; public class Apple implements Fruit{ public Apple() { System.out.println("创建了一个苹果对象"); } }
package com.gyq.chapterOne; public class Banana implements Fruit{ public Banana() { System.out.println("创建了一个香蕉对象"); } }
package com.gyq.chapterOne; public class Grape implements Fruit{ public Grape() { System.out.println("创建了一个葡萄对象"); } }
package com.gyq.chapterOne; import java.util.Scanner; public class Gardener { public Fruit create() { System.out.println("请输入你想要创建的水果对象"); Scanner input = new Scanner(System.in); String name = input.next(); Fruit fruit = null; switch (name) { case "苹果": fruit = new Apple(); break; case "香蕉": fruit = new Banana(); break; case "葡萄": fruit = new Grape(); break; } input.close(); return fruit; } }
package com.gyq.chapterOne; public class FruitDeom { public static void main(String[] args) { // TODO Auto-generated method stub Gardener g = new Gardener(); g.create(); } }