1、实现如下类之间的继承关系，并编写Music类来测试这些类。
2、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 xiejie;
public class Monkey {
Monkey(String s ){
}
public void speak() {
System.out.println("咿咿呀呀......");
}
package xiejie;
public class People extends Monkey{
People(String s){
super(s);
}
public void speak() {
System.out.println("小样的，不错嘛！会说话了！");
}
public void think() {
System.out.println("别说话！认真思考！");
}
}
package xiejie;
public class E {
public static void main(String[] args) {
Monkey m = new Monkey("圆圆");
m.speak();
People p = new People("毛毛");
p.speak();
p.think();
}
}
3、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 xiejie;
public class juxing1 {
private double a,b;
public double getb() {
return b;
}
public void setb(double b) {
this.b=b;
}
public double geta() {
return a;
}
public void seta(double a) {
this.a=a;
}
public double s() {
return this.a*this.b;
}
}
package xiejie;
public class changfangti extends juxing1{
private double c;
public double getc() {
return c;
}
public void setc(double c) {
this.c=c;
}
public double v() {
return this.geta()*this.getb()*this.getc();
}
}
package xiejie;
public class Test {
public static void main(String[] args) {
juxing1 j = new juxing1();
j.seta(10);
j.setb(10);
System.out.println("矩形的长为："+j.geta()+"矩形的宽为："+j.getb());
System.out.println("矩形的面积为："+j.s());
changfangti d = new changfangti();
d.seta(5);
d.setb(5);
d.setc(5.2);
System.out.println("长方体的长为："+d.geta()+"长方体的宽为："+d.getb()+"长方体的高为："+d.getc());
System.out.println("长方体的体积为："+d.v());
}
}
4、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 xiejie;
public class Vehicle {
private int wheels;
private double weight;
public int getwheels() {
return wheels;
}
public void setwheels() {
this.wheels=wheels;
}
public double getweight() {
return weight;
}
public void setweight() {
this.weight=weight;
}
public Vehicle(int wheels,double weight) {
super();
this.wheels=wheels;
this.weight=weight;
}
}
package xiejie;
public class Car extends Vehicle{
private int loader;
public int getloader() {
return loader;
}
public void setloader() {
this.loader=loader;
}
public Car(int wheels,double weight,int loader) {
super(wheels,weight);
this.loader=loader;
}
}
package xiejie;
public class Truck extends Car{
private double payload;
public double getpayload() {
return payload;
}
public void setpayload() {
this.payload=payload;
}
public Truck(int wheels, double weight, int loader,double payload) {
super(wheels, weight, loader);
this.payload=payload;
}
package xiejie;
public class TestCar {
public static void main(String[] args) {
Vehicle v = new Vehicle(4,4);
System.out.println("汽车一有"+v.getwheels()+"个轮子，重量为："+v.getweight());
Car c = new Car(4,8,5);
System.out.println("汽车二有"+c.getwheels()+"个轮子，重量为："+c.getweight()+",载客量为："+c.getloader());
Truck t = new Truck(8,8,5,20);
System.out.println("汽车三有"+t.getwheels()+"个轮子，重量为："+t.getweight()+",载客量为："+t.getloader()+",承受重量为："+t.getpayload());
}
}
