简易购物车实体类的设计

一 购物车类（Cart）的设计

 

 

二 代码

1、Cart类

package entity;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

//购物车类

public class Cart {

    //购买商品的集合

    private HashMap<Items,Integer> goods;

    

    //购物车的总金额

    private double totalPrice;

    //构造方法

    public Cart()

    {

        goods = new HashMap<Items,Integer>();

        totalPrice = 0.0;

    }

    

    

    public HashMap<Items, Integer> getGoods() {

        return goods;

    }

    public void setGoods(HashMap<Items, Integer> goods) {

        this.goods = goods;

    }

    public double getTotalPrice() {

        return totalPrice;

    }

    public void setTotalPrice(double totalPrice) {

        this.totalPrice = totalPrice;

    }

    

    //添加商品进购物车的方法

    public boolean addGoodsInCart(Items item ,int number)

    {

        if(goods.containsKey(item))

        {

            goods.put(item, goods.get(item)+number);

        }

        else

        {

            goods.put(item, number);    

        }

        calTotalPrice(); //重新计算购物车的总金额

        return true;

    }

    

    //删除商品的方法

    public boolean removeGoodsFromCart(Items item)

    {

        goods.remove(item);

        calTotalPrice(); //重新计算购物车的总金额

        return true;

    }

    

    //统计购物车的总金额

    public double calTotalPrice()

    {

        double sum = 0.0;

        Set<Items> keys = goods.keySet(); //获得键的集合

        Iterator<Items> it = keys.iterator(); //获得迭代器对象

        while(it.hasNext())

        {

            Items i = it.next();

            sum += i.getPrice()* goods.get(i);

        }

        this.setTotalPrice(sum); //设置购物车的总金额

        return this.getTotalPrice();

    }

    

    public static void main(String[] args) {

        

        //先创建两个商品对象

        Items i1 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg");

        Items i2 = new Items(2,"李宁运动鞋","广州",300,500,"002.jpg");

        Items i3 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg");

        

        Cart c = new Cart();

        c.addGoodsInCart(i1, 1);

        c.addGoodsInCart(i2, 2);

        //再次购买沃特篮球鞋，购买3双

        c.addGoodsInCart(i3, 3);

        

        

        //变量购物商品的集合

        Set<Map.Entry<Items, Integer>> items= c.getGoods().entrySet();

        for(Map.Entry<Items, Integer> obj:items)

        {

            System.out.println(obj);

        }

        

        

        System.out.println("购物车的总金额："+c.getTotalPrice());

        

    }

    

}

2、Items类

package entity;

 

//商品类

public class Items {

 

        private int id; // 商品编号

        private String name; // 商品名称

        private String city; // 产地

        private int price; // 价格

        private int number; // 库存

        private String picture; // 商品图片

 

        //保留此不带参数的构造方法

        public Items()

        {

                

        }

        

        public Items(int id,String name,String city,int price,int number,String picture)

        {

                this.id = id;

                this.name = name;

                this.city = city;

                this.picture = picture;

                this.price = price;

                this.number = number;

                

        }

        public int getId() {

                return id;

        }

 

        public void setId(int id) {

                this.id = id;

        }

 

        public String getName() {

                return name;

        }

 

        public void setName(String name) {

                this.name = name;

        }

 

        public String getCity() {

                return city;

        }

 

        public void setCity(String city) {

                this.city = city;

        }

 

        public int getPrice() {

                return price;

        }

 

        public void setPrice(int price) {

                this.price = price;

        }

 

        public int getNumber() {

                return number;

        }

 

        public void setNumber(int number) {

                this.number = number;

        }

 

        public String getPicture() {

                return picture;

        }

 

        public void setPicture(String picture) {

                this.picture = picture;

        }

        

        

        

        @Override

        public int hashCode() {

                // TODO Auto-generated method stub

                return this.getId()+this.getName().hashCode();

        }

 

        @Override

        public boolean equals(Object obj) {

                // TODO Auto-generated method stub

                if(this==obj)

                {

                        return true;

                }

                if(obj instanceof Items)

                {

                        Items i = (Items)obj;

                        if(this.getId()==i.getId()&&this.getName().equals(i.getName()))

                        {

                                return true;

                        }

                        else

                        {

                                return false;

                        }

                }

                else

                {

                        return false;

                }

        }

 

        public String toString()

        {

                return "商品编号："+this.getId()+",商品名称："+this.getName();

        }

 

}

 

三 测试结果

商品编号：1,商品名称：沃特篮球鞋=4

商品编号：2,商品名称：李宁运动鞋=2

购物车的总金额：1400.0