写的不好继续学习中。。。。

父类
public class Che {
public String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPicter() {
return picter;
}
public void setPicter(double picter) {
this.picter = picter;
}
public int getHuo() {
return huo;
}
public void setHuo(int huo) {
this.huo = huo;
}
public int getPreson() {
return preson;
}
public void setPreson(int preson) {
this.preson = preson;
}
public double picter;
public int huo;
public int preson;

}
汽车类
public class Qiche extends Che{
public String getName() {
return name;
}

public void setName(String name) {
    this.name = name;
}

public double getPicter() {
    return picter;
}

public void setPicter(double picter) {
    this.picter = picter;
}

public int getPreson() {
    return preson;
}

public void setPreson(int preson) {
    this.preson = preson;
}

String name;
double picter;
 int preson;

Qiche(String name,double picter,int preson){
    this.name=name;
    this.picter=picter;
    this.preson=preson;

}

}
火车类
public class Huoche extends Che {
String name;
double picter;
int huo;

Huoche(String name,double picter,int huo){
    this.name=name;
    this.picter=picter;
    this.huo=huo;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public double getPicter() {
    return picter;
}

public void setPicter(double picter) {
    this.picter = picter;
}

public int getHuo() {
    return huo;
}

public void setHuo(int huo) {
    this.huo = huo;
}

}
皮卡车类
public class Pika extends Che{

String name;
 double picter;
 int huo;
 int preson;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public double getPicter() {
    return picter;
}

public void setPicter(double picter) {
    this.picter = picter;
}

public int getHuo() {
    return huo;
}

public void setHuo(int huo) {
    this.huo = huo;
}

public int getPreson() {
    return preson;
}

public void setPreson(int preson) {
    this.preson = preson;
}

Pika(String name,double picter,int preson,int huo){
    this.name=name;
    this.picter=picter;
    this.preson=preson;
    this.huo=huo;
}

}
测试类主程序
public class Dome {

public static void main(String[] args) {
    TreeMap<Integer, Che> tm = new TreeMap<Integer,Che>();
    Che[] c = {new Qiche("奧迪A4",500.0,4),
               new Qiche("馬自達6",400.0,4),
               new Pika("皮卡雪6",450.0,4,2),
               new Qiche("景龍",800.0,20),     //定義 Che類型的數組容器
               new Huoche("松花江",400.0,4),
               new Huoche("依維柯",1000.0,20)};

    System.out.println("欢迎使用哒哒租车系统:");
    System.out.println("您是否要租车：1是      0否");
    Scanner sa = new Scanner(System.in);
    int a = sa.nextInt();
    if(a==0){
        System.out.println("欢迎下次继续使用！！");
    }else if(a==1){
        System.out.println("您可租車的類型及其價目表");
        System.out.println("序号\t"+"汽车名称\t"+"租金\t"+"容量");
        //遍历数组
        for(int x = 0;x<c.length;x++){
            //判断是否 时 汽车类
                if(c[x] instanceof Qiche){
                System.out.println((x+1)+"\t"+c[x].getName()+"\t"+c[x].getPicter()+"/天\t"+"載人"+c[x].getPreson());
                tm.put(x+1, c[x]); //把这个添加进treemap集合中
                }
                //判断是否是火车类
                else if(c[x] instanceof Huoche){
                    System.out.println((x+1)+"\t"+c[x].getName()+"\t"+c[x].getPicter()+"/天\t"+"载货"+c[x].getHuo()+"頓");
                    tm.put(x+1, c[x]);//把这个添加进treemap集合中
                    }else{
                        System.out.println((x+1)+"\t"+c[x].getName()+"\t"+c[x].getPicter()+"/天\t"+"载货"+c[x].getHuo()+"頓"+"載人"+c[x].getPreson());
                        tm.put(x+1, c[x]);//把这个添加进treemap集合中
                    }   
        }
        double zong =0;
        int ren =0;
        int pikaren =0;//定义这写是为了存储数值
        int huo=0;
        int pikahuo = 0;
        StringBuilder sb1 = new StringBuilder();//存储汽车类的名字
        StringBuilder sb2 = new StringBuilder();//存储火车类的名字
        StringBuilder sb3 = new StringBuilder();//存储皮卡车类的名字
        System.out.println("請輸入租車的數量");
        int shu = sa.nextInt();
        for(int x= 0;x<shu;x++){
            System.out.println("請輸入第"+(x+1)+"的序號");
            int xu = sa.nextInt();
        //遍历 map 集合
            Set<Map.Entry<Integer, Che>> en = tm.entrySet();
            Iterator<Map.Entry<Integer, Che>> it = en.iterator();
            while(it.hasNext()){
                Map.Entry<Integer,Che> mm =  it.next();
                int key = mm.getKey();//得到map集合的键值
                if(xu==key){//判断是否相同
                    Che ch = mm.getValue(); //获得车子的值
                    //判断车子的类型是哪个  车型
                    if(ch instanceof Qiche){
                        sb1.append(ch.getName()+"   ");//存储汽车类的名字
                        ren = ren +ch.getPreson();//计算机车的人数
                        zong = zong + ch.getPicter();//计算 车的金钱
                    }else if(ch instanceof Huoche){
                        sb2.append(ch.getName()+"   ");//存储汽车类的名字
                        zong = zong + ch.getPicter();//计算 车的金钱
                        huo = huo + ch.getHuo();//计算车的货物
                    }else if(ch instanceof Pika){
                        sb3.append(ch.getName()+"   ");//存储汽车类的名字
                        ren = ren +ch.getPreson();
                        zong = zong + ch.getPicter();//计算 车的金钱
                        pikaren = pikaren + ch.getPreson();//计算机车的人数
                        pikahuo = pikahuo + ch.getHuo();//计算车的货物
                    }
                }
            }

        }
        System.out.println("請輸入租車的天數");
        int day = sa.nextInt();
        System.out.println("您的賬單是------------");
    if(sb1.length()!=0){    
    System.out.println("*****可載人的車有：");
    System.out.println(sb1.toString()+"可載人:"+ren+"人");
    }

    if(sb3.length()!=0){
        System.out.println("其中皮卡車有："+sb3.toString()+"可載貨:"+pikahuo+"可載人："+pikaren);
    }
    if(sb2.length()!=0){
        System.out.println("*****可載貨的車有：");
        System.out.println(sb2.toString()+"可載貨:"+huo+"頓");
        System.out.println("總計需要:"+zong*day);
    }
    }else{
        System.out.println("请输入 0 或者 1 ");
    }
}

}