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 nbnb; public abstract class Shape { double area; double per; String color; public Shape(){ } public abstract double getArea() ; public abstract double getPer() ; public abstract double showAll() ; public void setColor(String color) { this.color = color; } }
package nbnb; public class Rectangle extends Shape { double width; double height; public Rectangle() { } public Rectangle(double width, double height, String color) { super(); this.width = width; this.height = height; this.color = color; } @Override public double getArea() { return area = width * height; } @Override public double getPer() { return per = (width + height) * 2; } @Override public double showAll() { System.out.println("矩形面积为:" + area + ",周长为:" + per + ",颜色:" + color); return height; } }
package nbnb; public class Circle extends Shape{ double radius; public Circle() { } public Circle(double radius, String color) { this.color = color; this.radius = radius; } @Override public double getArea() { return area = radius * radius * 3.14; } @Override public double getPer() { return per = 2 * radius * 3.14; } @Override public double showAll() { System.out.println("圆的面积为:" + area + ",周长为:" + per + ",颜色:" + color); return radius; } }
package nbnb; public class PolyDome { public static void main(String[] args) { // TODO Auto-generated method stub Circle circle = new Circle(2, "break"); Rectangle rectangle = new Rectangle(3, 5, "red"); circle.getArea(); circle.getPer(); circle.showAll(); rectangle.getArea(); rectangle.getPer(); rectangle.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。
- 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。
- 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。
- 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。
- 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 as; public class ColaEmployee { String name; int birthmonth; public void getSalary(int month) { System.out.println("月份:"+month); } }
package as; public class HourlyEmployee extends ColaEmployee{ int hoursal; int mouthhour; public void hourSalary(String name,int hoursal,int mouthhour,int birthmonth,int month) { if(month==birthmonth) { if(mouthhour<=160 && mouthhour>0) { System.out.println(name+"工资是"+(hoursal*mouthhour)+100); }else { System.out.println(name+"工资是"+(((mouthhour-160)*hoursal+(hoursal*160))+100)); } }else { if(mouthhour<=160 && mouthhour>0) { System.out.println(name+"工资是"+(hoursal*mouthhour)); }else { System.out.println(name+"工资是"+(((mouthhour-160)*hoursal+(hoursal*160)))); } } } }
package as; public class SalariedEmployee extends ColaEmployee{ int monthmoney; public void gudingSalar(String name,int month,int birthday, int monthmoney) { if(month==birthday) { System.out.println(name+"工资是"+(monthmoney+100)); }else { System.out.println(name+"工资是"+monthmoney); } } }
package as; public class Company { public void method(ColaEmployee a) { if(a instanceof HourlyEmployee) { HourlyEmployee H =(HourlyEmployee)a; H.hourSalary("1",20,30,16,23); }else if(a instanceof SalariedEmployee) { SalariedEmployee S=(SalariedEmployee)a; S.gudingSalar("2",100,2,9); }else if(a instanceof SalesEmployee) { SalesEmployee s = (SalesEmployee)a; s.xiaoshouSalar("3",96,3,7,6); } } }
package as; public class TestCompany { public static void main(String[] args) { // TODO Auto-generated method stub Company C = new Company(); HourlyEmployee c= new HourlyEmployee(); C.method(c); SalariedEmployee s = new SalariedEmployee(); C.method(s); SalesEmployee m = new SalesEmployee(); C.method(m);
}
}
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 as; import java.util.Scanner; interface Fruit{ } class Apple implements Fruit { public Apple() { System.out.println("创建了一个苹果对象"); } } class Banana implements Fruit { public Banana() { System.out.println("创建了一个香蕉对象"); } } class Putao implements Fruit { public Putao() { System.out.println("创建了一个葡萄对象"); } } class Gardener{ public Fruit create() { 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 Putao(); break; } input.close(); return fruit; } }
package as; public class Test { public static void main(String[] args) { // TODO Auto-generated method stub Gardener g = new Gardener(); g.create(); } }