【Java案例】基于控制台的购书系统

向右看齐 2024-03-30 17:41 18阅读 0赞

**案例介绍：**

（1）输出所有图书的信息：包括每本书的编号、书名、单价、库存。

（2）顾客购买书时，根据提示输入购买书的数量。

（3）购买完毕后输出顾客的订单信息，包括：订单号、订单明细、订单总额。

![9844161a5e6143bca3a16a449f7f8cc0.png][]

**运行结果：**

![067851256343443189b61f02ebb4e68a.png][]

**//Book**

class Book{ //Book类，用于存放图书的基本信息
        private int id; //编号
        private String name; //书名
        private double price; //价格
        private int storage; //库存
        //有参构造函数
        public Book(int id,String name,double price,int storage)
        {
            this.id = id;
            this.name = name;
            this.price = price;
            this.storage = storage;
        }
        public int getId() //获取书籍编号
        {
            return id;
        }
        public String getName() //获取书名
        {
            return name;
        }
        public double getPrice() //获取价格
        {
            return price;
        }
        public int getStorage() //获取库存
        {
            return storage;
        }
        public int decreaseStorage(int decrement) //获取实际购买数量
        {
            if(this.storage < decrement)
            {
                decrement = this.storage;
            }
            this.storage -= decrement;
            return decrement;
        }
    }

**//OrderItem**

class OrderItem{
        private Book book; //图书Book类对象
        private int num; //订购数量
        //有参构造函数
        public OrderItem(Book book,int num)
        {
            this.book = book;
            this.num = num;
        }
        public Book getBook() //获取图书对象
        {   
            return book;    
        }   
        public int getNum() //获取订购图书数量
        {   
            return num;    
        }   
    }

**//Order**

//Order类，用于存放订单信息
    class Order{
        private String orderID; //订单ID
        private OrderItem[] items; //订单项数组
        private double total; //订单总额
        //构造函数
        public Order(String orderID)
        {
            this.orderID = orderID;
            this.items = new OrderItem[3];
        }
        public String getOrderID() //获取订单号     
        {   
            return orderID; 
        }   
        public OrderItem[] getItems() //获取订单列表  
        {   
            return items;   
        }   
        public double getTotal() //获取订单总额
        {
            calTotal();
            return total;
        }
        public void setItem(OrderItem item,int i) //指定一个订单项
        {
            this.items[i] = item;
        }
        public void calTotal() //计算订单总额
        {
            double total = 0;
            for(OrderItem item :items)
            {
                total += item.getNum() * item.getBook().getPrice();
            }
            this.total = total;
        }
    }

**//BuyBooks：outBooks()、buyBooks()、outOrder()**

public class BuyBooks {
        public static void main(String[] args)
        {
            Book[] books = new Book[3];
            outBooks(books); //模拟从数据库中读取图书信息并输出
            Order order = buyBooks(books); //顾客购买图书
            outOrder(order); //输出订单信息
        }
        //模拟从数据库中读取图书信息并输出
        public static void outBooks(Book[] books)
        {
            books[0] = new Book(1,"Java教程",30.6,30);
            books[1] = new Book(2,"JSP教程",42.1,40);
            books[2] = new Book(3,"SSH架构",47.3,15);
            System.out.println("\t图书列表");
            System.out.println("图书编号\t图书名称\t\t图书单价\t库存数量");
            System.out.println("---------------------------------------");
            for(Book book : books)
            {
                System.out.println(book.getId()+"\t\t"+book.getName()+"\t\t"+book.getPrice()+"\t\t"+book.getStorage());
            }
            System.out.println("---------------------------------------");
        }
        //顾客购买图书
        public static Order buyBooks(Book[] books)
        {
            Scanner scanner = new Scanner(System.in);
    
            Order order = new Order("00001");
            OrderItem item = null;
            for(int i=0;i<3;i++)
            {
                System.out.print("请输入购买 "+books[i].getName()+" 图书数量：");
                int buyNum = scanner.nextInt();
                if(buyNum<0)
                {
                    buyNum=0;
                    System.out.println("购买数量输入错误，实际购买数量为 0");
                }
                else if (buyNum>books[i].getStorage())
                {
                    System.out.println("购买数量超出库存，实际购买数量为 "+books[i].getStorage());
                }
                buyNum = books[i].decreaseStorage(buyNum);
                item = new OrderItem(books[i],buyNum);
                order.setItem(item,i);
                if(i<2)
                {
                    System.out.println("请继续购买图书。");
                }
            }
            return order;
        }
        //输出订单信息
        public static void outOrder(Order order)
        {
            System.out.println("\n\t图书订单");
            System.out.println("图书订单号："+order.getOrderID());
            System.out.println("图书名称\t购物数量\t图书单价");
            System.out.println("---------------------------------------");
            OrderItem[] items = order.getItems();
            for(OrderItem item : items)
            {
                System.out.println(item.getBook().getName()+"\t\t"+item.getNum()+"\t"+item.getBook().getPrice());
            }
            System.out.println("---------------------------------------");
            System.out.println("订单总额：\t\t"+order.getTotal());
        }
    }

**完整代码：**

import java.util.Scanner;
    
    class Book{ //Book类，用于存放图书的基本信息
        private int id; //编号
        private String name; //书名
        private double price; //价格
        private int storage; //库存
        //有参构造函数
        public Book(int id,String name,double price,int storage)
        {
            this.id = id;
            this.name = name;
            this.price = price;
            this.storage = storage;
        }
        public int getId()          {   return id;      }   //获取书籍编号
        public String getName()     {   return name;    }   //获取书名
        public double getPrice()    {   return price;   }   //获取价格
        public int getStorage()     {   return storage; }   //获取库存
    
        public int decreaseStorage(int decrement) //获取实际购买数量
        {
            if(this.storage < decrement)
            {
                decrement = this.storage;
            }
            this.storage -= decrement;
            return decrement;
        }
    }
    class OrderItem{
        private Book book; //图书Book类对象
        private int num; //订购数量
        //有参构造函数
        public OrderItem(Book book,int num)
        {
            this.book = book;
            this.num = num;
        }
        public Book getBook()   {   return book;    }   //获取图书对象
        public int getNum()     {   return num;     }   //获取订购图书数量
    }
    //Order类，用于存放订单信息
    class Order{
        private String orderID; //订单ID
        private OrderItem[] items; //订单项数组
        private double total; //订单总额
        //构造函数
        public Order(String orderID)
        {
            this.orderID = orderID;
            this.items = new OrderItem[3];
        }
        public String getOrderID()      {   return orderID; }   //获取订单号
        public OrderItem[] getItems()   {   return items;   }   //获取订单列表
        public double getTotal() //获取订单总额
        {
            calTotal();
            return total;
        }
        public void setItem(OrderItem item,int i) //指定一个订单项
        {
            this.items[i] = item;
        }
        public void calTotal() //计算订单总额
        {
            double total = 0;
            for(OrderItem item :items)
            {
                total += item.getNum() * item.getBook().getPrice();
            }
            this.total = total;
        }
    }
    
    public class BuyBooks {
        public static void main(String[] args)
        {
            Book[] books = new Book[3];
            outBooks(books); //模拟从数据库中读取图书信息并输出
            Order order = buyBooks(books); //顾客购买图书
            outOrder(order); //输出订单信息
        }
        //模拟从数据库中读取图书信息并输出
        public static void outBooks(Book[] books)
        {
            books[0] = new Book(1,"Java教程",30.6,30);
            books[1] = new Book(2,"JSP教程",42.1,40);
            books[2] = new Book(3,"SSH架构",47.3,15);
            System.out.println("\t图书列表");
            System.out.println("图书编号\t图书名称\t\t图书单价\t库存数量");
            System.out.println("---------------------------------------");
            for(Book book : books)
            {
                System.out.println(book.getId()+"\t\t"+book.getName()+"\t\t"+book.getPrice()+"\t\t"+book.getStorage());
            }
            System.out.println("---------------------------------------");
        }
        //顾客购买图书
        public static Order buyBooks(Book[] books)
        {
            Scanner scanner = new Scanner(System.in);
    
            Order order = new Order("00001");
            OrderItem item = null;
            for(int i=0;i<3;i++)
            {
                System.out.print("请输入购买 "+books[i].getName()+" 图书数量：");
                int buyNum = scanner.nextInt();
                if(buyNum<0)
                {
                    buyNum=0;
                    System.out.println("购买数量输入错误，实际购买数量为 0");
                }
                else if (buyNum>books[i].getStorage())
                {
                    System.out.println("购买数量超出库存，实际购买数量为 "+books[i].getStorage());
                }
                buyNum = books[i].decreaseStorage(buyNum);
                item = new OrderItem(books[i],buyNum);
                order.setItem(item,i);
                if(i<2)
                {
                    System.out.println("请继续购买图书。");
                }
            }
            return order;
        }
        //输出订单信息
        public static void outOrder(Order order)
        {
            System.out.println("\n\t图书订单");
            System.out.println("图书订单号："+order.getOrderID());
            System.out.println("图书名称\t购物数量\t图书单价");
            System.out.println("---------------------------------------");
            OrderItem[] items = order.getItems();
            for(OrderItem item : items)
            {
                System.out.println(item.getBook().getName()+"\t\t"+item.getNum()+"\t"+item.getBook().getPrice());
            }
            System.out.println("---------------------------------------");
            System.out.println("订单总额：\t\t"+order.getTotal());
        }
    }

[9844161a5e6143bca3a16a449f7f8cc0.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/ed9bc8eac1534fd9b6844d0dcfe34510.png
[067851256343443189b61f02ebb4e68a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/2928e3850ce6487ca77ac514a9cb9f16.png