新手小白，花了很长时间，请多多指教

package com.demo;
import java.util.Scanner;
import java.util.Arrays;

public class Initial {

public static void main(String[] args) {
    // TODO Auto-generated method stub
System.out.println("******欢迎使用嗒嗒租车系统******");
System.out.println("您是否要租车：1是  非1否");
Scanner input=new Scanner(System.in);
int num=input.nextInt();
if(num==1){
 System.out.println("您可租车的类型及价目表："); 
 System.out.println("序号             汽车名称              租金                   容量");
 System.out.println("1.     奥迪A4    500元/天        载人：4人");
 System.out.println("2.     马自达6    400元/天        载人：4人");
 System.out.println("3.     皮卡雪6    450元/天        载人：4人，载货：2吨");
 System.out.println("4.     金龙                   800元/天        载人：20人");
 System.out.println("5.     松花江               400元/天        载货：4吨");
 System.out.println("6.     依维柯              1000元/天        载人：20吨");
 System.out.println("请输入要租车的数量：");
 int cheshu=input.nextInt();
 Manned aodi=new Aodi();
 Manned mazida=new Mazida();
 Manned jinlong=new Jinlong();
 Manned pika=new Pika();
 Carry songhua=new Songhua();
 Carry yiwei=new Yiwei();
 String[] allName=new String[cheshu];
 int allRent=0;
 int allManned=0;
 int allCarry=0;
 int xuhao;
 for(int i=1;i<=cheshu;i++){
     System.out.println("请输入第"+i+"辆车的序号");
     xuhao=input.nextInt();
     switch(xuhao){
     case 1:
         System.out.println("您选择的是"+aodi.getName());
         System.out.println();
         allName[i-1]=aodi.getName();
         allRent+=aodi.getRent();
         allManned+=aodi.getManned();
         allCarry+=aodi.getCarry();
         break;
     case 2:
         System.out.println("您选择的是"+mazida.getName());
         System.out.println();
         allName[i-1]=mazida.getName();
         allRent+=mazida.getRent();
         allManned+=mazida.getManned();
         allCarry+=mazida.getCarry();
         break;
     case 3:
         System.out.println("您选择的是"+pika.getName());
         System.out.println();
         allName[i-1]=pika.getName();
         allRent+=pika.getRent();
         allManned+=pika.getManned();
         allCarry+=pika.getCarry();
         break;
     case 4:
         System.out.println("您选择的是"+jinlong.getName());
         System.out.println();
         allName[i-1]=jinlong.getName();
         allRent+=jinlong.getRent();
         allManned+=jinlong.getManned();
         allCarry+=jinlong.getCarry();
         break;
     case 5:
         System.out.println("您选择的是"+songhua.getName());
         System.out.println();
         allName[i-1]=songhua.getName();
         allRent+=songhua.getRent();
         allManned+=songhua.getManned();
         allCarry+=songhua.getCarry();
         break;
     case 6:
         System.out.println("您选择的是"+yiwei.getName());
         System.out.println();
         allName[i-1]=yiwei.getName();
         allRent+=yiwei.getRent();
         allManned+=yiwei.getManned();
         allCarry+=yiwei.getCarry();
         break;
     }
 }
 System.out.println("请输入租车天数");
 int day=input.nextInt();
 int cost=allRent*day;
 System.out.println("******您的总账单******");
 System.out.println("您所需要的车为："+Arrays.toString(allName));
 System.out.println("总车数为："+cheshu);
 System.out.println("租车天数为："+day);
 System.out.println("总金额为:"+cost+"元          载人总数:"+allManned+"人          载客总量："+allCarry+"吨");

}else{
    System.out.println("欢迎下次使用嗒嗒租车系统！");
    System.exit(0);
}

}

}

---

package com.demo;

public abstract class Manned {
public abstract String getName();
public abstract int getRent();
public abstract int getManned();
public abstract int getCarry();
}

---

package com.demo;

public interface Carry {
public String getName();
public int getRent();
public int getManned();
public int getCarry();

}

---

package com.demo;

public class Aodi extends Manned {

private String name="奥迪A4";
private int rent=500;
private int manned=4;
private int carry=0;
public String getName() {
    return name;
}

public int getRent() {
    return rent;
}

public int getManned() {
    return manned;
}

public int getCarry() {
    return carry;
}

}

---

package com.demo;

public class Mazida extends Manned {
private String name="马自达6";
private int rent=400;
private int manned=4;
private int carry=0;
public String getName() {
return name;
}

public int getRent() {
    return rent;
}

public int getManned() {
    return manned;
}

public int getCarry() {
    return carry;
}   

}

---

package com.demo;

public class Pika extends Manned implements Carry{
private String name="皮卡雪6";
private int rent=450;
private int manned=4;
private int carry=2;
public String getName() {
return name;
}

public int getRent() {
    return rent;
}

public int getManned() {
    return manned;
}

public int getCarry() {
    return carry;
}

}

---

package com.demo;

public class Songhua implements Carry {
private String name="松花江";
private int rent=400;
private int manned=0;
private int carry=4;
public String getName() {
return name;
}
public int getRent() {
return rent;
}
public int getManned() {
return manned;
}
public int getCarry() {
return carry;
}
}

---

package com.demo;

public class Yiwei implements Carry {
private String name="依维柯";
private int rent=1000;
private int manned=0;
private int carry=20;
public String getName() {
return name;
}
public int getRent() {
return rent;
}
public int getManned() {
return manned;
}
public int getCarry() {
return carry;
}
}

---

package com.demo;

public class Jinlong extends Manned {
private String name="金龙";
private int rent=800;
private int manned=20;
private int carry=0;
public String getName() {
return name;
}
public int getRent() {
return rent;
}
public int getManned() {
return manned;
}
public int getCarry() {
return carry;
}
}

---

显示结果如图：