1.实现如下类之间的继承关系，并编写Music类来测试这些类。
package workhome0922休息;
public class People {
protected double height;
protected double weight;
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
public double getWeight() {
return weight;
}
public void setWeight(double weight) {
this.weight = weight;
}
//方法
public void speakHello()
{
System.out.print("我是一个人"+" ");
}
public void averageHeight()
{
System.out.print("我有身高"+" ");
}
public void averageWeight()
{
System.out.println("我有体重"+" ");
}
}
package workhome0922休息;
public class ChinaPeople extends People {
public void speakHello()
{
System.out.print("中国人"+" ");
}
public double averageHeight(double height)
{
// return height;
this.height=height;//为什么要把height赋给父类的height？？？？？？
return this.height;
}
public double averageWeight(double weight)
{
this.weight=weight;
return this.weight;
}
public void chinaGongFu()
{
System.out.println("中国功夫"+"太极拳");
}
}
package workhome0922休息;
public class AmericanPeople extends People {
public void speakHello()
{
System.out.print("美国人");
}
public double averageHeight(double height)
{
this.height=height;
return this.height;
}
public double averageWeight(double weight)
{
this.weight=weight;
return this.weight;
}
public void americanBoxing()
{
System.out.println("美国功夫："+"直拳");
}
}
package workhome0922休息;
public class Peopletest {
public static void main(String[] args) {
//实例化人
People p=new People();
p.speakHello();
p.averageHeight();
p.averageWeight();
//实例化中国人
ChinaPeople c=new ChinaPeople();
c.speakHello();
System.out.print(""+"身高:"+c.averageHeight(171.2));
System.out.print(" "+"体重:"+c.averageWeight(125)+" ");
c.chinaGongFu();
//实例化美国人
AmericanPeople a=new AmericanPeople();
a.speakHello();
System.out.print(" "+"身高:"+a.averageHeight(180));
System.out.print(" "+"体重:"+a.averageWeight(160)+" ");
a.americanBoxing();
}
}
2.创建如下三个类：（People类中的三个方法分别输出一些信息，ChinaPeople
和AmericanPeople类重写父类的三个方法）。
package workhome0922休息;
public class Instrument {
//方法-输出:弹奏乐器
public void play()
{
System.out.println("弹奏乐器");
}
}
package workhome0922休息;
public class Wind extends Instrument {
//方法1-输出：弹奏Wind
public void play()
{
System.out.println("弹奏Wind");
}
//方法2-输出：调用Wind的play2
public void play2()
{
System.out.println("调用Wind的play2");
}
}
package workhome0922休息;
public class Brass extends Instrument {
//方法1-输出：弹奏brass
public void play()
{
System.out.println("弹奏brass");
}
//方法2-输出：调用brass的play2
public void play2()
{
System.out.println("调用brass的play2");
}
}
package workhome0922休息;
public class Music {
//调用对象i的play方法
public static void tune(Instrument i)
{
i.play();
}
public static void main(String[] args) {
Wind w=new Wind();
Music.tune(w);
w.play2();
Brass b=new Brass();
Music.tune(b);
}
}
3.编写一个Java应用程序，该程序包括3个类：Monkey类、People类和主类E。
要求：
(1) Monkey类中有个构造方法：Monkey (String s)，并且有个public void speak()
方法，在speak方法中输出“咿咿呀呀......”的信息。
(2)People类是Monkey类的子类，在People类中重写方法speak(),在speak方法
中输出“小样的，不错嘛！会说话了！”的信息。
(3)在People类中新增方法void think()，在think方法中输出“别说话！认真思考！”的信息。
(4)在主类E的main方法中创建Monkey与People类的对象类测试这2个类的功能。
package workhome2;
public class Monkey {
//构造方法
Monkey(String s)
{
super();
System.out.println(s+1);
}
Monkey(int ss)
{
System.out.println(ss);
}
//方法
public void speak()
{
System.out.println("咿咿呀呀......");
}
}
package workhome2;
public class People extends Monkey {
//继承构造方法
public People(String s) {
super(s);
System.out.println(s+10);
}
//重写父类方法speak
public void speak()
{
System.out.println("小样的，不错嘛！会说话了");
}
//新增方法
public void think()
{
System.out.println("别说话！认真思考！");
}
}
package workhome2;
public class E {
public static void main(String[] args) {
//创建Monkey对象
Monkey m=new Monkey("10");
m.speak();
//创建People对象
People p=new People("10");
p.speak();
p.think();
}
}
4.定义类Human，具有若干属性和功能；定义其子类Man、Woman；
在主类Test中分别创建子类、父类和上转型对象，并测试其特性。
package workhome3;
public class Human {
//人的属性
public String leg;
public String foot;
public String getLeg() {
return leg;
}
public void setLeg(String leg) {
this.leg = leg;
}
public String getFoot() {
return foot;
}
public void setFoot(String foot) {
this.foot = foot;
}
//人的方法
public void run()
{
System.out.println("可以跑");
}
public void jump()
{
System.out.println("可以跳");
}
public int Int(int a)
{
a=a+1;
return a;
}
}
package workhome3;
public class Man extends Human {
//男人的方法
public void run()
{
System.out.println("可以跑快");
}
public void jump()
{
System.out.println("可以跳高");
}
public void eat()
{
System.out.println("吃饭睡觉打豆豆");
}
}
package workhome3;
public class Woman extends Human {
//女人的方法
public void run()
{
System.out.println("可以跑慢");
}
public void jump()
{
System.out.println("可以跳矮");
}
}
package workhome3;
public class humantest {
public static void main(String[] args) {
//向上转型
Human h1=new Man();
h1.setFoot("人有两条腿");
System.out.println(h1.getFoot());
h1.run();
System.out.println(h1.Int(10));
//向下转型
Man m1=(Man)h1;
m1.setFoot("男人有两条比女人长的腿");
System.out.println(m1.getFoot());
m1.jump();
System.out.println(m1.Int(10));
m1.eat();
}
}
6.按要求编写一个Java应用程序：
（1）定义一个类，描述一个矩形，包含有长、宽两种属性，和计算面积方法。
（2）编写一个类，继承自矩形类，同时该类描述长方体，具有长、宽、高属性，和计算体积的方法。
（3）编写一个测试类，对以上两个类进行测试，创建一个长方体，定义其长、宽、高，输出其底面积和体积。
package workhome4;
public class jivxing {
// 包含有长、宽两种属性，和计算面积方法。
private double chang;
private double kuan;
public double getChang() {
return chang;
}
public void setChang(double chang) {
this.chang = chang;
}
public double getKuan() {
return kuan;
}
public void setKuan(double kuan) {
this.kuan = kuan;
}
//方法
public double mianji(double chang,double kuan)
{
this.chang=chang;
this.kuan =kuan;
return this.chang*this.kuan;
}
}
package workhome4;
public class jivxing2 extends jivxing {
private double gao;
public double getGao() {
return gao;
}
public void setGao(double gao) {
this.gao = gao;
}
public double tiji(double chang,double kuan,double gao)
{
this.gao=gao;
return super.mianji(chang, kuan)*this.gao;
}
}
package workhome4;
public class test {
public static void main(String[] args) {
// TODO Auto-generated method stub
jivxing2 j=new jivxing2();
System.out.println(j.mianji(1, 2));
System.out.println(j.tiji(1, 2, 3));
}
}
7.
编写一个Java应用程序，设计一个汽车类Vehicle，包含的属性有车轮个数
wheels和车重weight。小车类Car是Vehicle的子类，其中包含的属性有载人数
loader。卡车类Truck是Car类的子类，其中包含的属性有载重量payload。每个
类都有构造方法和输出相关数据的方法。最后，写一个测试类来测试这些类的功
能。
package workhome4;
public class Vehicle {
//wheels和车重weight
private int wheel;//轮胎数量
private double weight;//车重
public int getWheel() {
return wheel;
}
public void setWheel(int wheel) {
this.wheel = wheel;
}
public double getWeight() {
return weight;
}
public void setWeight(double weight) {
this.weight = weight;
}
//构造方法
public Vehicle(int wheel,double weight)
{
super();
this.wheel=wheel;
this.weight=weight;
}
//方法
public void vv()
{
System.out.print("轮胎数："+this.wheel+" "+"车重："+this.weight+" ");
}
}
package workhome4;
public class Car extends Vehicle {
private int loader;//载人数
public int getLoader() {
return loader;
}
public void setLoader(int loader) {
this.loader = loader;
}
public Car(int wheel,double weight,int loader) {
super(wheel,weight);
this.loader=loader;
}
//方法
public void cc()
{
System.out.println();
super.vv();
System.out.print("和载人数"+this.loader+" ");
}
}
package workhome4;
public class Truck extends Car {
private double payload;//载重量
public double getPayload() {
return payload;
}
public void setPayload(double payload) {
this.payload = payload;
}
public Truck(int wheel, double weight, int loader, double payload) {
super(wheel, weight, loader);
this.payload=payload;
}
//方法
public void tt()
{
super.cc();
System.out.println("载重量"+this.payload+" ");
}
}
package workhome4;
public class cartest {
public static void main(String[] args) {
Vehicle v=new Vehicle(4,99999);
v.vv();
Car c=new Car(4,888888,3);
c.cc();
Truck t=new Truck(4,777777,6,90000.888);
t.tt();
}
}
8.编写一个Shape类，具有属性：周长和面积；
定义其子类三角形和矩形，分别具有求周长的方法。
定义主类E，在其main方法中创建三角形和矩形类的对象，
并赋给Shape类的对象a、b，使用对象a、b来测试其特性。
package workhome5;
public interface Shape {
public abstract void zc(int a,int b,int c);
public abstract void mj(int a,int b,int c);
}
package workhome5;
public class sanjiaoxing implements Shape {
@Override
public void zc(int a,int b,int c) {
// TODO Auto-generated method stub
System.out.println("三角形的周长为："+(a+b+c));
}
@Override
public void mj(int a,int b,int c) {
// TODO Auto-generated method stub
System.out.println("三角形的面积为："+a*b/2);
}
}
package workhome5;
public class jvxing implements Shape {
@Override
public void zc(int a, int b,int c) {
// TODO Auto-generated method stub
System.out.println("矩形的周长为："+(a+b)*2);
}
@Override
public void mj(int a, int b, int c) {
// TODO Auto-generated method stub
System.out.println("矩形的面积为："+2*(a+b));
}
}
package workhome5;
public class cheng {
private Shape i;
public Shape getI() {
return i;
}
public void setI(Shape i) {
this.i = i;
}
public void getit()
{
i.mj(3, 2, 1);
i.zc(3, 2, 1);
}
}
package workhome5;
public class test {
public static void main(String[] args) {
// TODO Auto-generated method stub
cheng v=new cheng();
sanjiaoxing a=new sanjiaoxing();
v.setI(a);
v.getit();
jvxing b=new jvxing();
v.setI(b);
v.getit();
}
}
9.
package jiekouhomework;
public interface ShapePara {
// nt getArea()：获得图形的面积。int getCircumference()：获得图形的周长
public abstract double getArea();
public abstract double getCircumference();
}
package jiekouhomework;
public class Circle implements ShapePara {
// adius:public 修饰的double类型radius,表示圆的半径。
// x：private修饰的double型变量x，表示圆心的横坐标。
// y：protected修饰的double型变量y，表示圆心的纵坐标。
public double radius;
private double x;
protected double y;
double PI=3.14;
public double getRadius() {
return radius;
}
public void setRadius(double radius) {
this.radius = radius;
}
// public double getX() {
// return x;
// }
//
// public void setX(double x) {
// this.x = x;
// }
//
// public double getY() {
// return y;
// }
// public void setY(double y) {
// this.y = y;
// }
//构造方法
Circle(double radius)
{
this.radius=radius;
}
//方法
public void setCenter(double x, double y)
{
this.x=x;
this.y=y;
}
@Override
public double getArea() {
// TODO Auto-generated method stub
// System.out.println(PI*radius*radius);
return PI*this.radius*this.radius;
}
@Override
public double getCircumference() {
// TODO Auto-generated method stub
// System.out.println(2*PI*this.radius);
return 2*PI*this.radius;
}
package jiekouhomework;
public class jiehe {
private ShapePara s;
public ShapePara getS() {
return s;
}
public void setS(ShapePara s) {
this.s = s;
}
public void ceshi()
{
s.getArea();
s.getCircumference();
}
}
package jiekouhomework;
public class test {
public static void main(String[] args) {
// TODO Auto-generated method stub
jiehe ss=new jiehe();
Circle cc=new Circle(7);
ss.setS(cc);
System.out.println(cc.getArea());
System.out.println(cc.getCircumference());
} }
