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 duotaishangji; public abstract class Shape { double area; double per; String color; public Shape() { super(); } public Shape(String color) { super(); this.color = color; } public abstract void getArea(); public abstract void getPer(); public abstract void showAll(); public void getColor(String color) { this.color=color; } }
package duotaishangji; public class Rectangle extends Shape { int width; int height; public Rectangle() { super(); } public Rectangle(int width, int height,String color) { super(color); this.width = width; this.height = height; } @Override public void getArea() { // TODO Auto-generated method stub System.out.println("面积是"+width*height); } @Override public void getPer() { // TODO Auto-generated method stub System.out.println("周长是"+2*(width+height)); } @Override public void showAll() { // TODO Auto-generated method stub getArea(); getPer(); } }
package duotaishangji; public class Circle extends Shape { double radius; public Circle() { super(); } public Circle(double radius ,String color) { super(color); this.radius = radius; } @Override public void getArea() { // TODO Auto-generated method stub System.out.println("面积是"+3.14*radius*radius); } @Override public void getPer() { // TODO Auto-generated method stub System.out.println("周长是"+2*radius*3.14); } @Override public void showAll() { // TODO Auto-generated method stub getArea(); getPer(); } }
package duotaishangji; public class PolyDemo { public static void main(String[] args) { // TODO Auto-generated method stub Rectangle r = new Rectangle(); Rectangle r1 = new Rectangle(2,3,"白色"); Circle c = new Circle(); Circle c1 = new Circle(2.5,"白色"); r1.showAll(); c1.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 duojie;
public class ColaEmployee {
String name;
int birthmonth;
public void getSalary(int month) {
System.out.println("月份:"+month);
}
}
package duojie;
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 duojie;
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 duojie;
public class SalesEmployee extends ColaEmployee{
int monthxiaoshou;
int tichenglv;
public void xiaoshouSalar(String name,int monthxiaoshou,int tichenglv,int birthmonth,int month) {
if(month==birthmonth) {
System.out.println(name+"工资是"+(monthxiaoshou*(1+tichenglv)+100));
}else {
System.out.println(name+"工资是"+(monthxiaoshou*(1+tichenglv)));
}
}
}
package duojie;
public class Company {
public void method(ColaEmployee a) {
if(a instanceof HourlyEmployee) {
HourlyEmployee H =(HourlyEmployee)a;
H.hourSalary("张三",30,180,7,7);
}else if(a instanceof SalariedEmployee) {
SalariedEmployee S=(SalariedEmployee)a;
S.gudingSalar("李四", 8, 8, 20000);
}else if(a instanceof SalesEmployee) {
SalesEmployee s = (SalesEmployee)a;
s.xiaoshouSalar("王五",5000,2,6,6);
}
}
}
package duojie;
public class TestCompany {
public static void main(String[] args) {
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”);
}
}
(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。
package jiekou1; public interface Fruit { public void method(); }
package jiekou1; public class Apple implements Fruit{ public Apple(){ System.out.println("创建了一个苹果类的对象"); } @Override public void method() { // TODO Auto-generated method stub new Apple(); } }
package jiekou1; public class Oranges implements Fruit{ public Oranges(){ System.out.println("创建了一个葡萄类的对象"); } @Override public void method() { // TODO Auto-generated method stub new Oranges(); } }
package jiekou1; public class Pear implements Fruit{ public Pear(){ System.out.println("创建了一个香蕉类的对象"); } @Override public void method() { // TODO Auto-genera();ted method stub new Pear(); } }
package jiekou1; import java.util.Scanner; public class test { public static void main(String[] args) { // TODO Auto-generated method stub Scanner a = new Scanner(System.in); String next= a.next(); if(next.equals("苹果")){ new Apple(); }else if(next.equals("葡萄")){ new Oranges(); }else if(next.equals("香蕉")) { new Pear(); }else { System.out.println("没有此类"); } } }