快餐订餐模拟器
快餐订餐模拟器
提问于 2019-08-17 08:45:57
我最近一直在尝试学习OOP，并制作了一个简单的程序，通过使用9位键盘来添加、删除和支付从菜单上订购的项目来模拟某种驱动器体验。
据我所知，每件事都是按我的意思运作的。我觉得我的一些课程可能做得太多了，总体来说，这个程序可以简化。
我不确定的事情之一是Customer类，因为它只包含名称字符串。似乎客户应该能够做一些诸如支付等事情。
另一方面，Order类似乎做了太多的事情。
请告诉我你的想法，以及你会采取什么不同的做法。
这是密码，谢谢你抽出时间！
主要班：
/*******************************************************************************
* Title: Fast Food Simulator
* Author: Some Dude
* Date: 7/14/2019
* Purpose: Learning basic OOP design
*
* Description:
* ! A simple program that simulates placing an order at a drive-thru
* using a keypad for input.
*
* ! User can add/delete items from their order, and pay for the items
******************************************************************************/
package com.company;
import java.util.Scanner;
public class Main
{
private static Scanner scanner = new Scanner(System.in);
private static Menu mainMenu = new Menu();
private static Customer newCustomer;
private static Order customerOrder = new Order();
private static Keypad driveThruKeypad = new Keypad();
/* Main Function Here! */
public static void main(String[] args)
{
CustomerMessages.displayGreeting();
getCustomerName();
CustomerMessages.displayKeypadInstructions();
getOrder();
customerOrder.payForOrder();
CustomerMessages.goodbye();
}
/***************************************************************************
*! While the order is active,
*! Show menu
*! Display order (if they have actually ordered something)
*! Get keypad input from customer
*! Allows user to add/delete items from their order
**************************************************************************/
private static void getOrder()
{
char itemSelection = '0';
while (itemSelection != '#')
{
mainMenu.displayMenu();
if (customerOrder.getItemCount() > 0)
customerOrder.displayOrder(newCustomer.getCustomerName());
itemSelection = driveThruKeypad.getKeypadEntry();
if (driveThruKeypad.deleteBtnPressed(itemSelection))
deleteItem();
else
customerOrder.addItem(mainMenu.getMenuItemName(itemSelection),
mainMenu.getMenuItemPrice(itemSelection));
}
}
/***************************************************************************
* Prompts user to select an item to delete, then deletes it
* only if the item has actually been ordered
**************************************************************************/
private static void deleteItem()
{
char itemSelection = 0;
System.out.println("What Item would you like to delete?");
itemSelection = driveThruKeypad.getKeypadEntry();
customerOrder.removeItem(mainMenu.getMenuItemName(itemSelection),
mainMenu.getMenuItemPrice(itemSelection));
}
/***************************************************************************
* Prompts the customer to enter their name, then initializes the Customer
* instance *newCustomer* using the name given by customer
**************************************************************************/
private static void getCustomerName()
{
System.out.println("Please enter your name");
newCustomer = new Customer(scanner.nextLine());
}
}客户类别：
/*******************************************************************************
* Title: Fast Food Simulator
* Author: Some Dude
* Date: 7/14/2019
* Purpose: Class for a customer, will hold name, and maybe a member id later
******************************************************************************/
package com.company;
public class Customer
{
private String customerName;
Customer(String name)
{
this.customerName = name;
}
public String getCustomerName()
{
return customerName;
}
}键盘级
/*******************************************************************************
* Title: Keypad
* Author: Some Dude
* Date: 7/14/2019
*
*
* Description:
* ! Interface for a 9 digit keypad
******************************************************************************/
package com.company;
import java.util.Scanner;
public class Keypad
{
private Scanner keypadReader = new Scanner(System.in);
/* Control buttons */
private final char SUBMIT_BUTTON = '#';
private final char DELETE_BUTTON = '-';
/* User defined button ranges */
private final char minNumberInput = '0';
private final char maxNumberInput = '9';
/***************************************************************************
*! Gets input from user until the button pressed was a valid button
* on the keypad (Valid buttons are defined up top)
**************************************************************************/
char getKeypadEntry()
{
char keypadEntry = '0';
boolean inputIsValid = false;
while (!inputIsValid)
{
System.out.println("Enter a keypad option: ");
keypadEntry = keypadReader.next().charAt(0);
inputIsValid = validateKeypadEntry(keypadEntry);
}
return keypadEntry;
}
/***************************************************************************
*! Checks user input to make sure it's valid
**************************************************************************/
private boolean validateKeypadEntry(char keypadInput)
{
if ((keypadInput >= minNumberInput) && (keypadInput <= maxNumberInput))
return true;
else
return (keypadInput == SUBMIT_BUTTON) || (keypadInput == DELETE_BUTTON);
}
/* Checks to see if the '#' button was pressed */
public boolean orderCompleteBtnPressed(int input)
{
return input == SUBMIT_BUTTON;
}
/* Checks to see if the '-' button was pressed */
public boolean deleteBtnPressed(int input)
{
return input == DELETE_BUTTON;
}
}订单类别：
/*******************************************************************************
* Title: Order
* Author: Some Dude
* Date: 7/14/2019
* Purpose: Handles everything that has to do with the order
*
* Description: Handles everything that has to do with the order such as ->
*! Adding/deleting order items
*! Accepting payment for the order
*! Keeping track of subtotal(no tax), and grandTotal(After tax)
*! Keeping track of items in the order
******************************************************************************/
package com.company;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;
public class Order
{
/* Scanner used for keypad input */
private Scanner scanner = new Scanner(System.in);
private final double STATE_TAX = 0.10;
/* Order total before/after tax */
private double subTotal;
private double grandTotal;
/* Counter for items ordered and list to hold item names*/
private int itemCount;
private ArrayList orderItems;
public Order()
{
this.itemCount = 0;
this.subTotal = 0.00;
this.grandTotal = 0.00;
this.orderItems = new ArrayList<>();
}
/***************************************************************************
*! Add and item to the order, increment itemCount, increase price
**************************************************************************/
void addItem(String itemName, double itemPrice)
{
if ((!itemName.equals("")) && (itemPrice > 0.00))
{
this.orderItems.add(itemName);
this.itemCount++;
this.subTotal += itemPrice;
System.out.println(itemName + " Added to your order");
updateGrandTotal();
}
}
/***************************************************************************
*! If item has actually been ordered, delete it, else, show err message
**************************************************************************/
void removeItem(String itemName, double itemPrice)
{
if (this.orderItems.contains(itemName))
{
this.orderItems.remove(itemName);
this.itemCount -= 1;
this.subTotal -= itemPrice;
System.out.println(itemName + " Deleted from your order");
updateGrandTotal();
}
else
System.out.println(itemName + " is not in your order");
}
double getGrandTotal()
{
return this.grandTotal;
}
public double getSubTotal()
{
return this.subTotal;
}
public int getItemCount()
{
return itemCount;
}
private void setSubTotal(double amount)
{
this.subTotal = amount;
}
/* Adds the tax rate to the order */
private void updateGrandTotal()
{
this.grandTotal =
this.subTotal + (this.subTotal * this.STATE_TAX);
}
/* Checks to see if item is in orderItems list */
private boolean findOrderItem(String itemName)
{
return this.orderItems.contains(itemName);
}
/* Displays the order details to the user */
public void displayOrder(String customerName)
{
System.out.println(
"************************************************************");
System.out.printf("%s's order details:\n", customerName);
System.out.printf("Items ordered: %d\n", itemCount);
System.out.println(Arrays.toString(this.orderItems.toArray()));
System.out.printf("Price before tax: $%.2f\n", subTotal);
System.out.printf("Grand total: $%.2f\n", grandTotal);
System.out.println(
"************************************************************");
}
/* While order is not paid for, get money from customer */
public void payForOrder()
{
double cashRecieved = 0.00;
while (grandTotal != 0.00)
{
/* Round grandTotal to 2nd decimal place */
grandTotal = round2Decimals(grandTotal);
System.out.printf("Your total is $%.2f\n", grandTotal);
System.out.println("Enter your payment amount");
cashRecieved = scanner.nextDouble();
if (cashRecieved > 0)
grandTotal -= cashRecieved;
if (grandTotal < 0.00)
calculateChange();
}
}
/* Calculates the change due (Only used when grandTotal is < 0.00) */
private void calculateChange()
{
double changeDue = 0.00;
changeDue = (0.00 - grandTotal);
grandTotal = 0.00;
changeDue = round2Decimals(changeDue);
System.out.println("Your change is " + changeDue);
}
/* Returns a double rounded to the 2nd value (2.222 = 2.22) */
private double round2Decimals(double num)
{
return (double) Math.round(num * 100) / 100;
}
}客户消息类：
/*******************************************************************************
* Title: Customer Messages
* Author: Some Dude
* Date: 7/14/2019
*
* Purpose: Stores all of the general messages that the company would
* want to show on the screen
******************************************************************************/
package com.company;
public class CustomerMessages
{
public static void displayGreeting()
{
System.out.println("Welcome to some burger joint!");
}
public static void goodbye()
{
System.out.println("Thank you for eating at some burger joint!\n" +
"Please come again!");
}
/* Shows the instructions for the keypad */
public static void displayKeypadInstructions()
{
System.out.println("\n");
System.out.println(
"************************************************************");
System.out.println("~Keypad Instructions~");
System.out.println("To add an item to your order, please press the " +
"keypad number that matches the item number on the screen");
System.out.println("To delete an item from your order, press the '-' " +
"key on the keypad");
System.out.println("To submit your order, press the '#' key on the " +
"keypad");
System.out.println(
"************************************************************");
}
}菜单类：
/*******************************************************************************
* Title: Menu
* Author: Some Dude
* Date: 7/14/2019
*
* Purpose: Interface for the main menu
*
* Description:
* ! Shows the current menu
* ! Keeps track of how many menu items are available
* ! Keeps track of menu item prices and names
******************************************************************************/
package com.company;
public class Menu
{
/* Menu Prices */
private final double CHEESEBURGER_PRICE = 5.25;
private final double FRENCH_FRIES_PRICE = 2.00;
private final double DRINK_PRICE = 1.00;
/* Menu Items */
private final String CHEESEBURGER = "Cheeseburger";
private final String FRIES = "Fries";
private final String DRINK= "Drink";
/* The amount of items currently on the menu */
private final int totalMenuItems = 3;
/* Displays menu options and prices */
void displayMenu()
{
System.out.println("***************************");
System.out.println("~Menu~");
System.out.println("1) Cheeseburger $" + CHEESEBURGER_PRICE);
System.out.println("2) Fries $" + FRENCH_FRIES_PRICE);
System.out.println("3) Drink $" + DRINK_PRICE);
System.out.println("***************************");
}
public double getCheeseburgerPrice()
{
return CHEESEBURGER_PRICE;
}
public double getFrenchFriesPrice()
{
return FRENCH_FRIES_PRICE;
}
public double getDrinkPrice()
{
return DRINK_PRICE;
}
public int getTotalMenuItems()
{
return totalMenuItems;
}
/***************************************************************************
* Returns the name of the item that matches the item selection number,
* Return blank string if menu item doesn't exist
**************************************************************************/
public String getMenuItemName(char itemSelection)
{
switch (itemSelection)
{
case '1':
return CHEESEBURGER;
case '2':
return FRIES;
case '3':
return DRINK;
default:
return "";
}
}
/***************************************************************************
* Returns the price of the item that matches the itemSelection number
* Return 0.00 if item doesn't exist
**************************************************************************/
double getMenuItemPrice(char itemSelection)
{
switch (itemSelection)
{
case '1':
return CHEESEBURGER_PRICE;
case '2':
return FRENCH_FRIES_PRICE;
case '3':
return DRINK_PRICE;
default:
return 0.00;
}
}
}回答 2
Code Review用户
回答已采纳
发布于 2019-08-17 17:14:33
- 从总体上看，您的代码看起来非常干净，我认为您的类之间的逻辑分离非常清楚。
- 不要用双倍的钱，因为有精确的问题。考虑使用BigDecimal。这样，您还可以避免使用像
round2Decimals这样的草率功能。 - 在Keypad类上，应该注入扫描器依赖项。
public class Keypad
{
private Scanner keypadReader;
public Order(Scanner keypadReader)
{
this.itemCount = 0;
this.subTotal = 0.00;
this.grandTotal = 0.00;
this.orderItems = new ArrayList<>();
this.keypadReader = keypadReader;
}
// ...
}- 为什么在注释前加上
!符号？这没有任何用处，应该删除。 - 使用预增量：
this.itemCount -= 1;\to--this.itemCount;。 - 您的菜单类可能无法处理，比方说，5或6个以上的配料。您可能希望创建一个以名称和价格作为属性的
Dish类。 CustomerMessages类应该是static。- 考虑使用JavaDoc：
/**
* @author Some Dude
* @since 7/14/2019
*
* Interface for the main menu:
* - Shows the current menu
* - Keeps track of how many menu items are available
* - Keeps track of menu item prices and names
*/- 避免长
/**********..。备注。只要/*或/**(对于JavaDoc)就够了。 - 看看Liskov替代原则。这里相当大的例子不是使用
ArrayLists作为属性，而是简单地使用Lists：
private List orderItems; // No longer ArrayList!!!!
public Order()
{
this.itemCount = 0;
this.subTotal = 0.00;
this.grandTotal = 0.00;
this.orderItems = new ArrayList<>();
}- 不要对单行注释使用多行注释：
/* Menu Items */\to// Menu items - 检查类中的静态函数(即
void displayMenu()应该是静态的，CHEESEBURGER_PRICE和其他神奇的数字/字符串也应该是静态的)。
Code Review用户
发布于 2019-08-18 17:21:12
你好，我提议的更改涉及类Menu，因为每次您修改菜单(添加或删除菜单项)时，都必须定义一个新方法来获取新菜单项的名称和价格，或者您必须删除使用已删除项的方法。为了避免这个问题，我建议您的解决方案是在类的代码之上创建一个名为MenuItem的新类：
class MenuItem {
private String name;
private Double price;
public MenuItem(String name, Double price) {
this.name = name;
this.price = price;
}
public String getName() {
return name;
}
public Double getPrice() {
return price;
}
@Override
public String toString() {
return String.format("%s $%.2f", name, price);
}
}您可以检查我是否重写了toString方法:该方法将返回一个字符串，其价格限制在前两位数，如奶酪汉堡，$5,25。现在，Menu类将包含一个ArrayList of MenuItem对象，它位于类的代码之上：
public class Menu {
private List items;
public Menu() {
this.items = new ArrayList();
this.items.add(new MenuItem("Cheeseburger", 5.25));
this.items.add(new MenuItem("Fries", 2.00));
this.items.add(new MenuItem("Drink", 1.00));
}
public void displayMenu()
{
System.out.println("***************************");
System.out.println("~Menu~");
int i = 1;
for (MenuItem item : items) {
System.out.println(String.format("%d) %s", i++, item));
}
System.out.println("***************************");
}
public MenuItem getMenuItem(int itemSelection) {
return items.get(itemSelection);
}
}您可以看到，现在可以从菜单中添加或删除元素。我将参数itemSelection的类型从char修改为int，否则菜单将被限制为从1项到9项。
public class Main {
public static void main(String[] args) {
Menu menu = new Menu();
menu.displayMenu();
int itemSelection = 1;
MenuItem item = menu.getMenuItem(--itemSelection); //menu displayed and arraylist differs for one position
System.out.println(item); //it will print Cheeseburger $5,25
System.out.println(item.getName()); //it will print Cheeseburger
System.out.println(item.getPrice()); //it will print 5.25
}如果菜单从1开始，则必须记住减少从客户中选择的菜单项，以匹配类菜单中的arrayList。
页面原文内容由Code Review提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://codereview.stackexchange.com/questions/226306
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