这是问题：
假设该卡具有有效的PIN码，并且银行账户中有100个单位。 每个视频都有租金“费用”。您需要扫描篮子列表并计算ATM交易的总额。您可以假设银行帐户中总有足够的单位来支付此练习的租金费用。 Video Kiosk代码的一个版本将包含以下步骤：
•为视频标题创建链接列表，并选择5个项目
•创建一个空的链接列表（篮子）来存储客户选择
•提供菜单驱动的选择过程
完成选择过程
将篮子清单的内容带到自动柜员机并付款
Vkiosk.java
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Scanner;
public class VKiosk {
private static LinkedList VTable=new LinkedList();
private static LinkedList Basket=new LinkedList();
private static double rentCost=0;
private static int j=1;
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// declaring scanner name as "typeNumber"
Scanner typeNumber = new Scanner(System.in);
System.out.println("::: Welcome to My Java Program To model an ATM machine :::");
showVideoList();
System.out.print("Input the serial number of video to buy: ");
buyVideo();
System.out.println("Your total amount of Cost: "+ rentCost);
MMachine buy = new MMachine();
buy.Txn(rentCost);
}
public static double buyVideo(){
Scanner typeNumber = new Scanner(System.in);
String title=typeNumber.nextLine();
String amount=null;
for(int i=0;i<VTable.size();i++){
String videoDetails=VTable.get(i).toString();
if(videoDetails.toLowerCase().contains(title.toLowerCase())){
Basket.add(VTable.get(i));
for(int j=videoDetails.length()-2;j>=0;j--){
if(videoDetails.charAt(j)==' '){
break;
}
amount=videoDetails.substring(j, videoDetails.length()-1);
}
VTable.remove(i);
}
}
rentCost=Double.parseDouble(amount);
return rentCost;
}
public static void VideoList(){
Video vTable1=new Video("BladeRunner", 1, 5);
Video vTable2=new Video("Wages of Fear", 2, 4);
Video vTable3=new Video("Grease", 3, 5);
Video vTable4=new Video("Mama Mia", 4, 4);
Video vTable5=new Video("L'Illusionniste", 5, 6);
VTable.add(vTable1);
VTable.add(vTable2);
VTable.add(vTable3);
VTable.add(vTable4);
VTable.add(vTable5);
}
public static void showVideoList(){
System.out.println();
System.out.println("********************************************************************");
System.out.println("List of the Videos are: ");
System.out.println("********************************************************************");
System.out.println("Serial No Video Detetails");
VideoList();
for(int i=0; i<VTable.size(); i++){
System.out.println( j+" "+VTable.get(i));
j++;
}
System.out.println();
}
}
Video.java
public class Video{
private String title;
private int serial;
private double cost;
public Video(String title, int serial, double cost)
{
this.title = title;
this.serial = serial;
this.cost = cost;
}
public String getTitle() {return title;}
public int getSerial() {return serial;}
public double getCost() {return cost;}
public String getVideo() {
return "title:" + title + " Serial: " + serial + " Cost: " + cost;
}
// Upgrade output of toString ()
@Override
public String toString() {
return "["+getVideo()+"]";
}
}
我成功只购买一件商品，需要通过Linked List Basket购买多件商品。
答案 0 :(得分：1)
只有一次购买的原因是你没有一个循环试图购买（或租赁;命名有点混乱）附加选择。还有一些static类变量使程序更复杂一些。以下是一些建议。
主要方法
添加循环以收集其他输入。此外，删除static double rentCost并移至main方法（同样，更改buyVideo以返回成本而不是更新实例变量）。添加方法以继续收集输入。
private static boolean purchaseAnother(Scanner stdin)
{
while (true) {
System.out.println();
System.out.println("Purchase another (y/n): ");
String chk = stdin.nextLine();
if (chk != null && chk.trim().length() > 0) {
if (chk.toLowerCase().equals("y")) { return true; }
if (chk.toLowerCase().equals("n")) { return false; }
}
}
}
/**
* @param args
* the command line arguments
*/
public static void main(String[] args)
{
// declaring scanner name as "typeNumber"
Scanner typeNumber = new Scanner(System.in);
System.out.println(
"::: Welcome to My Java Program To model an ATM machine :::");
boolean buyMore = true;
// **ADD: initialize the video list only once
VideoList();
// **USE LOCAL VARIABLE FOR COST
double rentCost = 0.0d;
while (buyMore) {
showVideoList();
System.out.print("Input the serial number of video to buy: ");
//**ACCUMULATE THE TOTAL COST
rentCost += buyVideo();
System.out.printf("Current total $%.2f", rentCost);
// SEE IF WISH TO KEEP GOING IF THERE IS ANYTHING LEFT TO RENT
buyMore = (! VTable.isEmpty() && purchaseAnother(typeNumber));
}
// actually make a purchase
// ADD STATEMENT, but this might be in the MMachine class; unknown
System.out.printf("Charging $%.2f to the Debit Card%n", rentCost);
MMachine buy = new MMachine();
buy.Txn(rentCost);
System.out.println("Have a nice day!");
}
BuyVideo方法
更改退还租金金额;不要更新实例变量
public static double buyVideo()
{
Scanner typeNumber = new Scanner(System.in);
String title = typeNumber.nextLine();
String amount = null;
for (int i = 0; i < VTable.size(); i++) {
String videoDetails = VTable.get(i).toString();
if (videoDetails.toLowerCase().contains(title.toLowerCase())) {
Basket.add(VTable.get(i));
for (int j = videoDetails.length() - 2; j >= 0; j--) {
if (videoDetails.charAt(j) == ' ') {
break;
}
amount = videoDetails.substring(j,
videoDetails.length() - 1);
}
// ** ADD LINE TO INDICATE ACTION
System.out.println("Purchasing: " + VTable.remove(i).getTitle());
}
}
// ** CHANGE TO USE A LOCAL VARIABLE AND RETURN IT
double videoRentCost = Double.parseDouble(amount);
return videoRentCost;
}
showVideoList方法
删除VideoList()来电 - 仅在main()方法中初始化租借列表一次。另外，请考虑稍微清理输出格式。
public static void showVideoList()
{
System.out.println();
System.out.println(
"********************************************************************");
System.out.println("List of the Videos are: ");
System.out.println(
"********************************************************************");
// **USE PRINTF TO GIVE BETTER FORMATTING
System.out.printf("%10s %53s%n","Serial No","Video Details");
for (int i = 0; i < VTable.size(); i++) {
// **USE SIMILAR FORMATTING OUTPUT
System.out.printf("%10d %53s%n", VTable.get(i).getSerial(), VTable.get(i));
}
System.out.println();
}
此更改将提供如下演示文稿：
********************************************************************
List of the Videos are:
********************************************************************
Serial No Video Details
1 [title:BladeRunner Serial: 1 Cost: 5.0]
2 [title:Wages of Fear Serial: 2 Cost: 4.0]
3 [title:Grease Serial: 3 Cost: 5.0]
4 [title:Mama Mia Serial: 4 Cost: 4.0]
5 [title:L'Illusionniste Serial: 5 Cost: 6.0]