车的轮胎数 重量

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 zuoye;

public class Vehicle 
{
    private int wheels;
    private double weight;
    Vehicle()
    {
    weight=1;wheels=4;
    }
    Vehicle(int geshu, double chezhong)
    {
    wheels=geshu;
    weight=chezhong;
    }
    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 void shuchu(){
    System.out.println("轮子"+wheels+"个，"+"车重"+weight);
    }
}

{
    private int loader;
    Car1()
    {
    loader=4;
    }
    Car1(int zaike)
    {
    loader=zaike;
    }
    Car1(int geshu, double chezhong,int zaike)
    {
    super(geshu,chezhong);
    loader=zaike;
    }
    public void showData(){
    System.out.println("轮子"+getWheels()+"个"+"自重"+getWeight());
    System.out.println("载客人数："+loader+"人");
    }
    public int getLoader() {
    return loader;
    }
    public void setLoader(int loader) {
    this.loader = loader;
    }
}

package zuoye;

public class Truck extends Car1
{
    private double payload;
    Truck()
    {
    payload=500;
    }
    Truck(double zaizhong)
    {
    payload=zaizhong;
    }
    Truck(int zaike,double zaizhong)
    {
    super(zaike);
    payload=zaizhong;
    }
    Truck(int lun, double chezhong,int zaike,double zaizhong)
    {
    super(lun,chezhong,zaike);
    payload=zaizhong;
    }
    public void showData(){
    System.out.println("轮子"+getWheels()+"个"+"自重"+getWeight());
    System.out.println("载客人数："+getLoader()+"人");
    System.out.println("载重："+payload);
    }
}

package zuoye;

public class ceshi2 {

    public static void main(String[] args) 
    {
        Truck t=new Truck();
        t.showData();
        t=new Truck(500);
        t.showData();
        t=new Truck(20,500);
        t.showData();
        t=new Truck(20,21,22,500);
        t.showData();

    }

}