package com.wxd.shopping;

public class Item {
  private int id; //商品id
  private String name;//商品名稱(chēng)
  private String city;//商品產(chǎn)地
  private double price;//商品價(jià)格
  private int number;//商品數(shù)量
  private String picture;//商品圖片地址

  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 double getPrice() {
    return price;
  }

  public void setPrice(double 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;
  }

  /**
   * 重寫(xiě)hashCode方法，使得在購(gòu)物車(chē)添加商品的時(shí)候，如果id和名稱(chēng)相同就判定為同一件商品
   * @return
   */
  @Override
  public int hashCode() {
    return (this.getId()+this.getName()).hashCode();
  }

  /**
   * 重寫(xiě)equals方法，判斷是否為同一個(gè)對(duì)象
   * @param obj
   * @return
   */
  @Override
  public boolean equals(Object obj) {
    if(this==obj){
      return true;
    }
    if(obj instanceof Item){
      Item i= (Item) obj;
      if(this.getId()==i.getId()&&this.getName().equals(i.getName())){
        return true;
      }else{
        return false;
      }
    }else{
      return false;
    }
  }

  @Override
  public String toString() {
    return "Item{" +
        "id=" + id +
        ", name='" + name + '\'' +
        ", city='" + city + '\'' +
        ", price=" + price +
        ", number=" + number +
        ", picture='" + picture + '\'' +
        '}';
  }

  //有參構(gòu)造
  public Item(int id, String name, String city, double price, int number, String picture) {
    this.id = id;
    this.name = name;
    this.city = city;
    this.price = price;
    this.number = number;
    this.picture = picture;
  }
  //無(wú)參構(gòu)造
  public Item() {
  }
}

package com.wxd.shopping;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

//購(gòu)物車(chē)
public class Cart {
  //購(gòu)買(mǎi)商品的集合
  private HashMap<Item,Integer> goods;
  //購(gòu)物車(chē)的總金額
  private double totalPrice;

  //構(gòu)造方法初始化數(shù)據(jù)
  public Cart(){
    goods=new HashMap<Item,Integer>();
    totalPrice=0.0;
  }
  public HashMap<Item, Integer> getGoods() {
    return goods;
  }

  public void setGoods(HashMap<Item, Integer> goods) {
    this.goods = goods;
  }

  public double getTotalPrice() {
    return totalPrice;
  }

  public void setTotalPrice(double totalPrice) {
    this.totalPrice = totalPrice;
  }
  //添加商品進(jìn)購(gòu)物車(chē)的方法
  public boolean addGoodsInCart(Item item,int number){
    if(goods.containsKey(item)){
      goods.put(item,goods.get(item)+number);
    }else{
      goods.put(item,number);
    }
    calTotalPrice();//重新計(jì)算購(gòu)物車(chē)的總金額
    return true;
  }
  //刪除商品的方法
  public boolean removeGoodsFromCart(Item item){
    goods.remove(item);
    calTotalPrice();//重新計(jì)算購(gòu)物車(chē)的總金額
    return true;
  }
  //統(tǒng)計(jì)購(gòu)物車(chē)的總金額
  public double calTotalPrice(){
    double sum=0.0;
    Set<Item> keys=goods.keySet();
    Iterator<Item> iterator = keys.iterator();
    while (iterator.hasNext()){
      Item i = iterator.next();
      sum+=i.getPrice()*goods.get(i);
    }
    this.setTotalPrice(sum);//設(shè)置購(gòu)物車(chē)的總金額
    return this.getTotalPrice();
  }

  //測(cè)試的main方法
  public static void main(String[] args) {
    //先創(chuàng)建兩個(gè)商品對(duì)象
    Item i1=new Item(1,"耐克","溫州",300.0,500,"001.jpg");
    Item i2=new Item(2,"阿迪","廣州",500.0,500,"001.jpg");
    Item i3=new Item(1,"耐克","溫州",300.0,500,"001.jpg");
    Cart c=new Cart();
    c.addGoodsInCart(i1,1);
    c.addGoodsInCart(i2,2);
    //再次購(gòu)買(mǎi)耐克鞋
    c.addGoodsInCart(i3,3);
    //遍歷購(gòu)買(mǎi)商品的集合
    HashMap<Item, Integer> goods = c.getGoods();
    Set<Map.Entry<Item, Integer>> entries = goods.entrySet();
    for(Map.Entry<Item, Integer> itemEntry:entries){
      System.out.println(itemEntry.toString());
    }
    System.out.println("購(gòu)物車(chē)總金額:"+c.getTotalPrice());
  }
}