27．编写一个Animal类，具有属性：种类；具有功能：吃、睡。定义其子类Fish
和Dog，定义主类E，在其main方法中分别创建其对象并测试对象的特性。
package zuoye5;
public class Animal {
private String zhonglei;
private String qixide;
public String getZhonglei() {
return zhonglei;
}
public void setZhonglei(String zhonglei) {
this.zhonglei = zhonglei;
}
public String getQixide() {
return qixide;
}
public void setQixide(String qixide) {
this.qixide = qixide;
}
public Animal(String zhonglei) {
super();
this.zhonglei = zhonglei;
}
public Animal() {
super();
}
public void chi()
{
System.out.println("我饿了，我要吃东西");
}
public void shui()
{
System.out.println("我要休息");
}
}
package zuoye5;
public class Fish extends Animal {
public void chi()
{
System.out.println("我饿了，我要吃小鱼");
}
public void shui()
{
System.out.println("我在水里，睡觉也是动的");
}
}
package zuoye5;
public class Fish extends Animal {
public void chi()
{
System.out.println("我饿了，我要吃小鱼");
}
public void shui()
{
System.out.println("我在水里，睡觉也是动的");
}
}
package zuoye5;
public class Dog extends Animal {
private int tui;
public int getTui() {
return tui;
}
public void setTui(int tui) {
this.tui = tui;
}
public void chi()
{
System.out.println("我饿了，我要吃骨头");
}
public void shui()
{
System.out.println("我是主人的保护者，起得早，睡的晚");
}
}
package zuoye5;
public class E {
public static void main(String[] args) {
Animal a=new Animal("<。)#)))≦ ");
Fish f=new Fish();
f.setQixide("海洋");
System.out.println("种类是："+a.getZhonglei()+"生活在:"+f.getQixide());
f.chi();
f.shui();
Dog d=new Dog();
d.setZhonglei("犬类 ");
d.setQixide("陆地 ");
d.setTui(4);
System.out.println("种类是： "+d.getZhonglei()+"生活在:"+d.getQixide()+" 我有"+d.getTui()+"条腿");
d.chi();
d.shui();
}
}
28．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 zuoye6;
public class Rect {
public double width;
public double chang;
//有参的构造方法
public Rect(double width,double chang)
{
this.width=width;
this.chang=chang;
}
//无参的
public Rect()
{
}
//自定义成员方法 面积
public double area(){
double area;
area=width*chang;
return area;
}
}
package zuoye6;
public class Cangfangti extends Rect {
public double height;
public Cangfangti(double width,double chang,double height)
{
this.width=width;
this.chang=chang;
this.height=height;
}
//自定义成员方法 体积
public double tiji(){
double tiji;
tiji=width*chang*height;
return tiji;
}
public double diarea(){
double diarea;
diarea=width*chang;
return diarea;
}
}
package zuoye6;
public class Ceshi {
public static void main(String[] args) {
Rect r=new Rect(10,20);
System.out.println("矩形的面积="+r.area());
Cangfangti c=new Cangfangti(10,20,30);
System.out.println("长方体的体积="+c.tiji());
System.out.println("长方体的底面积="+c.diarea());
}
}
29．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 zuoye7;
public class Vehicle {
//属性
private int wheels;//车轮数
private double weight;//车重
public int getWheels() {
return wheels;
}
public void setWheels(int wheels) {
this.wheels = wheels;
}
public double getWeight() {
return weight;
}
public void setWeight(double weight) {
this.weight = weight;
}
public Vehicle(int wheels, double weight) {
super();
this.wheels = wheels;
this.weight = weight;
}
public Vehicle() {
super();
}
}
package zuoye7;
public class Car extends Vehicle {
private double loader;//载人数
public double getLoader() {
return loader;
}
public void setLoader(double loader) {
this.loader = loader;
}
}
package zuoye7;
public class Truck extends Vehicle {
private double payload;//载重量
public double getPayload() {
return payload;
}
public void setPayload(double payload) {
this.payload = payload;
}
}
package zuoye7;
public class Ceshi_vehicle {
public static void main(String[] args) {
Car c=new Car();
c.setLoader(5);
c.setWeight(4.5);
c.setWheels(4);
System.out.println("小汽车的载人数是："+c.getLoader()+"人 车的重量="+c.getWeight()+"车轮个数="+c.getWheels());
Truck t=new Truck();
t.setPayload(5);
t.setWeight(5);
t.setWheels(6);
System.out.println("卡车的载重量="+"吨"+"车的重量="+t.getWeight()+"车轮数="+t.getWheels());
}
}
