Java购物车

小组成员

班级	成员1	成员2	成员3
网络1912	黄雨冰	陈璧君	甘梨梨

GITEE仓

地址：https://gitee.com/huang-yubing/javacode

• 小组分工：
• 黄雨冰：前期调查，代码实现
• 陈璧君：代码规范，代码实现
• 甘梨梨：UML类图，代码实现

前期调查

---

系统功能结构图

---

流程图

UML类图

运行效果

• 商城
  
• 加购商品
  
• 进入购物车结算
  
• 删除商品
  • 删除一个
    
    结算验证 少了5元 成功删除一个
  • 删除全部
    
    结算验证 总价为0 全部删除选择的商品

---

DAO

• 购物车DAO

public interface CartDao {

	public boolean add(Commodity e,int count);//加入购物车
	public boolean remove(Integer id);//将商品移除
	public void diplayAll();//输出购物车内商品条目
	public double checkout();//输出总金额
	public boolean delete(Integer id);//删除条目
}

• 货架DAO

public interface ShelfDao {
	public void addCommodity(Commodity e);//添加商品
	public boolean deleteCommodity(Commodity e);//删除商品
	public void showCommodity();//展示货架上的商品
	public Commodity getItemById(Integer id);//根据id找商品
}

关键代码

商品类

• 以商品Commodity作为父类，其子类分别有食品类，书籍类以及数码类。

/**
 * 商品类
 * @author 
 *
 */
public class Commodity {
	private Integer id;//编号
	private String name;//名字
	private Double price;//价格
	private String description;//类别
	private int inventory;//库存
	
	public Commodity() {
		
	}

	public Commodity(Integer id, String name,Double price) {
		this.id = id;
		this.name = name;
		this.price=price;
	}
	
	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

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

	public Double getPrice() {
		return price;
	}

	public void setPrice(Double price) {
		this.price = price;
	}

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public int getInventory() {
		return inventory;
	}

	public void setInventory(int inventory) {
		this.inventory = inventory;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {  //只比较id,id相同则说明两个商品相同
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Commodity other = (Commodity) obj;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		return true;
	}

	@Override
	public String toString() {
		return "Commodity [id=" + id + ", name=" + name + ", price=" + price + ", description=" + description + "]";
	}

	
	

}
/**
 * 食品类
 * @author 98295
 *
 */
class Food extends Commodity{
	private String shelfLife;//保质期
	private String date="生产日期见包装";//生产日期见包装
	//private String information;//其他信息
	
	/**
	 * 构造函数
	 */
	public Food() {
		
	}
	public Food(Integer id, String name,Double price,String shelfLife,int inventory) {
		this.setId(id);
		this.setName(name);
		this.setPrice(price);
		this.setDescription("Food");
		this.setInventory(inventory);
		this.shelfLife=shelfLife;	
		
	}
	
	public String getShelfLife() {
		return shelfLife;
	}
	public void setShelfLife(String shelfLife) {
		this.shelfLife = shelfLife;
	}
	public String getDate() {
		return date;
	}
	public void setDate(String date) {
		this.date = date;
	}
	@Override
	public String toString() {
		return "Food [id: " + this.getId() + ", name: " + this.getName() + ", price: " + this.getPrice() + ", shelfLife: " + shelfLife + ", date: " + date+", inventory: "+this.getInventory();
	}
	
	
	
}
/**
 * 书籍类
 * @author 98295
 *
 */
class Book extends Commodity{
	private String author;//作者
	private String press;//出版社
	
	public Book() {
		
	}
	public Book(Integer id, String name,Double price,String author,String press,int inventory) {
		this.setId(id);
		this.setName(name);
		this.setPrice(price);
		this.setDescription("Book");
		this.setInventory(inventory);
		this.author=author;	
		this.press=press;
		
	}
	
	
	public String getAuthor() {
		return author;
	}
	public void setAuthor(String author) {
		this.author = author;
	}
	public String getPress() {
		return press;
	}
	public void setPress(String press) {
		this.press = press;
	}
	@Override
	public String toString() {
		return "Book [id: " + this.getId() + ", name: " + this.getName() + ", price: " + this.getPrice() +", author: " + author + ", press: " + press+", inventory: "+this.getInventory() ;
	}
	
	
}

/**
 * 电子产品类
 * @author 98295
 *
 */
class Electronics extends Commodity{
	private String manufacturer;//厂家
	private String productData;//产品数据
	
public Electronics() {
		
	}
	public Electronics(Integer id, String name,Double price,String manufacturer,String productData,int inventory) {
		this.setId(id);
		this.setName(name);
		this.setPrice(price);
		this.setDescription("Electronics");
		this.setInventory(inventory);
		this.manufacturer=manufacturer;
		this.productData=productData;	
	}
	
	public String getManufacturer() {
		return manufacturer;
	}
	public void setManufacturer(String manufacturer) {
		this.manufacturer = manufacturer;
	}
	public String getProductData() {
		return productData;
	}
	public void setProductData(String productData) {
		this.productData = productData;
	}
	@Override
	public String toString() {
		return "Electronics  [id: " + this.getId() + ", name: " + this.getName() + ", price: " + this.getPrice() +", manufacturer: " + manufacturer + ", productData: " + productData+", inventory: "+this.getInventory();
	}
	
}

购物车类

• 对购物车内的商品进行增加，输出，移除，结算。

package shopping;

import java.util.ArrayList;
import java.util.List;

/**
 * 购物车接口的实现
 * 
 * @author
 *
 */
public class CartDaoImpI implements CartDao {
	private ArrayList<ItemEntry> itemList;
	public CartDaoImpI() {
		itemList = new ArrayList<>();
	}

	/**
	 * 结算
	 * 
	 * @return 返回购物车中所有商品的总价
	 */
	public double checkout() {
		double x = 0;
		for (ItemEntry item : itemList) {
			x = x + item.getItem().getPrice() * item.getQty();// 价格*数量
		}
		return x;
	}

	/**
	 * 将商品加入购物车
	 * @param e
	 * @param count
	 * @return
	 */
	public boolean add(Commodity e,int count) {
		if (e == null) {
			return false;
		}
		int index = findById(e.getId());

		if (index == -1) {// 如果不包含该商品的条目
			itemList.add(new ItemEntry(e,count));
		} else {
			itemList.get(index).increase();
		}
		return true;
	}

	/**
	 * 从购物车删除1个该商品
	 * 
	 * @param id
	 * @return 如果id不存在，返回false；
	 */
	public boolean remove(Integer id) {
		if (id == null) {
			System.out.println("商品不存在！");
			return false;
		}
		int index = findById(id);
		if (index == -1) {// 未找到
			System.out.println("商品不存在！");
			return false;
		} else {
			ItemEntry entry = itemList.get(index);
			if (entry.getQty() <= 1) {// 移除相关条目qty<=0，则删除条目
				itemList.remove(index);
			} else {
				entry.decrease();
			}
		}
		System.out.println("商品删除成功！！");

		return true;
	}

	/**
	 * 删除条目
	 * @param id
	 * @return
	 */
	public boolean delete(Integer id) {
		if (id == null) {
			System.out.println("商品不存在！");
			return false;
		}
		int index = findById(id);
		if (index == -1) {// 未找到
			System.out.println("商品不存在！");
			return false;
		} else {
			// 删除条目
			itemList.remove(index);
		}
		System.out.println("商品删除成功！！");

		return true;
	}

	/**
	 * 展示购物车
	 */
	public void diplayAll() {
		for (ItemEntry itemEntry : itemList) {
			System.out.println(itemEntry);
		}
	}

	/**
	 * 通过id在购物车中查找是否已存在相关条目。 声明为private，因为只在本类中使用。
	 * 
	 * @param id
	 * @return 如果包含返回相关条目所在下标，否则返回-1
	 */
	private int findById(Integer id) {
		for (int i = 0; i < itemList.size(); i++) {
			if (itemList.get(i).getItem().getId().equals(id))
				return i;
		}
		return -1;
	}

	private class ItemEntry { // 内部类：购物车条目类
		/**
		 * 商品
		 */
		Commodity item;

		/**
		 * 商品数量
		 */
		Integer qty;

		public ItemEntry(Commodity item,int qty) {
			this.item = item;
			this.qty=qty;
		}

		// 添加
		public void increase() {
			qty++;
		}

		// 减少
		public void decrease() {
			qty--;
		}

		public Commodity getItem() {
			return item;
		}

		public Integer getQty() {
			return qty;
		}

		@Override
		public String toString() {
			return item + ", qty=" + qty + "]";
		}

	}

}

货架商城类

• 对商城卖家进行商品的添加，删除以及展示。

 /**
 * 实现货架接口（上架商品）
 * 
 * @author 98295
 *
 */
public class ShelfDaoImpI implements ShelfDao {

	private ArrayList<Commodity> shelfList;// 货架
	
	public ShelfDaoImpI() {
		shelfList=new  ArrayList<>();
	}
	
	public void addCommodity(Commodity e) {
		// 添加商品
		if (e == null) {
			return;
		}
		int index = findById(e.getId());
		if (index == -1) {// 如果该商品编号不存在，则需创建新的商品
			shelfList.add(e);
		} else {// 存在则增加库存
			shelfList.get(index).setInventory(shelfList.get(index).getInventory() + e.getInventory());
		}
	}

	/**
	 * 根据id找下标
	 * @param id
	 * @return 商品的下标
	 */
	private int findById(Integer id) {
		for (int i = 0; i < shelfList.size(); i++) {
			if (shelfList.get(i).getId().equals(id))
				return i;
		}
		return -1;
	}

	public boolean deleteCommodity(Commodity e) {
		// 删除商品,下架
		if (e.getId() == null)
			return false;
		int index = findById(e.getId());
		if (index == -1) {// 未找到
			return false;
		} else {
			shelfList.remove(index);
		}

		return true;
	}

	public void showCommodity() {
		// 展示货架上的商品

		System.out.println("                                                      商城");
		System.out.println("Food:");
		for(Commodity x:shelfList) {
			if(x.getDescription()=="Food")
			System.out.println(x);
		}
		System.out.println("Book:");
		for(Commodity x:shelfList) {
			if(x.getDescription()=="Book")
			System.out.println(x);
		}
		System.out.println("Electronics:");
		for(Commodity x:shelfList) {
			if(x.getDescription()=="Electronics")
			System.out.println(x);
		}
	}

	/**
	 * 根据id找商品
	 * 
	 * @param id
	 * @return 商品
	 */
	public Commodity getItemById(Integer id) {
		if (id == null)
			return null;
		int index = findById(id);
		if (index == -1) {// 未找到
			return null;
		} else {
			return shelfList.get(index);
		}
	}

}

菜单

package shopping;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		/**
		 * 读入数据:商品编号/商品名称/价格/具体数据/库存
		 */
		Commodity x1 = new Food(1, "apple", 13.0, "30days", 20);
		Commodity x2 = new Book(3, "LittlePrince", 130.0, "Unknown", "Xinhua", 10);
		Commodity x3 = new Electronics(21, "Iphone", 4999.0, "USA", "128G 8G", 3);
		Commodity x4 = new Food(1, "apple", 13.0, "30days", 20);//累加
		Commodity x5 = new Food(34, "Milk tea", 15.0, "2h", 20);
		Commodity x6 = new Book(311, "Anna Karenina", 100.0, "Leo Tolstoy", "Xinhua", 150);
		Commodity x7 = new Food(433, "ice cream", 5.0, "20min", 100);

		CartDao cart = new CartDaoImpI();// 根据需求选择
		ShelfDao shelf = new ShelfDaoImpI();

		// 加入货架
		shelf.addCommodity(x1);
		shelf.addCommodity(x2);
		shelf.addCommodity(x3);
		shelf.addCommodity(x4);
		shelf.addCommodity(x5);
		shelf.addCommodity(x6);
		shelf.addCommodity(x7);

		int choice;

		while (true) {

			shelf.showCommodity();// 展示货架内的商品

			System.out.println("请选择：");
			System.out.println("1.加购商品        /               2.进入购物车                /            其他按键：退出");
			choice = sc.nextInt();
			if (choice == 1) {// 添加商品到购物车
				System.out.println("请选择你要加入购物车的商品id:");
				int input = sc.nextInt();
				if(shelf.getItemById(input)==null) {
					System.out.println("商品不存在！");
					continue;
				}
				System.out.println("请输入你要加购的数量：");
				int n = sc.nextInt();
				if(n>shelf.getItemById(input).getInventory())
				{
					System.out.println("库存不足！！！");
				}else {
				 cart.add(shelf.getItemById(input),n);
				}
				

			} else if (choice == 2) {// 进入购物车
				while (true) {
					cart.diplayAll();// 展示购物车

					System.out.println("请选择：");
					System.out.println("1.删除一个商品        /       2.删除一整个商品的条目        /        3.结算        /             其他按键：退出购物车");
					int nextChoice = sc.nextInt();
					switch (nextChoice) {
					case 1:
						/* 删除-数量减少 */
						System.out.println("请输入需要减少一个数量的商品的id：");
						int in = sc.nextInt();
						cart.remove(in);

						break;
					case 2:
						/* 删除-移除一个条目 */
						System.out.println("请输入需要移除的商品的id");
						int put = sc.nextInt();
						cart.delete(put);

						break;

					case 3:
						System.out.println("总金额为：" + cart.checkout());
						break;

					default:
						break;
					}
					if(nextChoice!=1&&nextChoice!=2&&nextChoice!=3) {
						break;
					}
				}

			} else {
				break;
			}

		}
	}

}

GUI界面

系统运行总界面

登陆界面

加购商品界面

删除商品并结算界面

具体代码详见git