java實現網上購物車程序

public class Product { 
  private int productId;// 商品編號 
  private String productName;// 商品名稱 
  private String category;// 商品分類 
  private double price;// 單價 
 
  public Product() {// 無參構造 
    super(); 
  } 
 
  public Product(int productId, String productName, String category, 
      double price) { 
    super(); 
    this.productId = productId; 
    this.productName = productName; 
    this.category = category; 
    this.price = price; 
  } 
 
  public String toString() { 
    return "Product [productId=" + productId + ", productName=" 
        + productName + ", category=" + category + ", price=" + price 
        + "]"; 
  } 
 
  public int getProductId() { 
    return productId; 
  } 
 
  public void setProductId(int productId) { 
    this.productId = productId; 
  } 
 
  public String getProductName() { 
    return productName; 
  } 
 
  public void setProductName(String productName) { 
    this.productName = productName; 
  } 
 
  public String getCategory() { 
    return category; 
  } 
 
  public void setCategory(String category) { 
    this.category = category; 
  } 
 
  public double getPrice() { 
    return price; 
  } 
 
  public void setPrice(double price) { 
    this.price = price; 
  } 
 
} 

public class ProductItem { 
  private Product product;//購買的商品 
  private int count;//商品數量 
  public double totalMoney(){//小計 
    double price=product.getPrice();//獲取商品單價 
    return price*count; 
  } 
   
  public ProductItem() { 
    super(); 
  } 
 
  public ProductItem(Product product, int count) { 
    super(); 
    this.product = product; 
    this.count = count; 
  } 
 
  public Product getProduct() { 
    return product; 
  } 
  public void setProduct(Product product) { 
    this.product = product; 
  } 
  public int getCount() { 
    return count; 
  } 
  public void setCount(int count) { 
    this.count = count; 
  } 
   
} 

import java.util.Collection; 
import java.util.Iterator; 
import java.util.LinkedHashMap; 
import java.util.Map; 
public class ShoppingCart {//購物車 
  //key：商品編號 value:商品條目 
  private Map<Integer,ProductItem> map=new LinkedHashMap<Integer,ProductItem>(); 
   
  public void addProduct(Product p){//添加商品 
    int productId=p.getProductId(); 
    if(map.containsKey(productId)){ 
      ProductItem productItem=map.get(productId); 
      productItem.setCount(productItem.getCount()+1); 
    }else{ 
      map.put(productId, new ProductItem(p,1)); 
    } 
  } 
  public void showAll(){//查看訂單信息 
    Collection<ProductItem> productItems = map.values(); 
    Iterator<ProductItem> iterator = productItems.iterator(); 
    while(iterator.hasNext()){ 
      ProductItem productItem = iterator.next(); 
      Product product = productItem.getProduct(); 
      System.out.println("商品編號："+product.getProductId()+",商品名稱：" 
      +product.getProductName()+",單價："+product.getPrice()+",數量："+productItem.getCount() 
      +",小計："+productItem.totalMoney()); 
    } 
  } 
  public boolean deleteProduct(int productId){//刪除商品 
    if(map.containsKey(productId)){ 
      map.remove(productId); 
      return true; 
    } 
    return false; 
  } 
  public boolean modifyProduct(int productId,int count){//修改 
    if(map.containsKey(productId)){ 
      if(count>=1){ 
        ProductItem productItem = map.get(productId); 
        productItem.setCount(count); 
        return true; 
      }else if(count==0){//刪除該商品 
        deleteProduct(productId); 
        return true; 
      }   
    } 
    return false; 
  } 
   
  public void clearCart(){//清空購物車 
    map.clear(); 
  } 
   
  public double totalAllMoney(){//商品總錢數 
    double total=0; 
    Collection<ProductItem> productItems = map.values(); 
    Iterator<ProductItem> iterator = productItems.iterator(); 
    while(iterator.hasNext()){ 
      ProductItem productItem = iterator.next(); 
      double money=productItem.totalMoney(); 
      total+=money; 
    } 
    return total; 
  } 
} 

public class ShoppingCartTest { 
 
  public static void main(String[] args) { 
    ShoppingCart cart=new ShoppingCart(); 
    Product p1=new Product(101,"華碩筆記本","筆記本",4599); 
    Product p2=new Product(102,"蘋果","水果",5.9); 
    Product p3=new Product(103,"彩電","家電",2799); 
    Product p4=new Product(104,"秋褲","服裝",128); 
    Product p5=new Product(105,"華為手機","手機",2998); 
    Product p6=new Product(101,"華碩筆記本","筆記本",4599);//測試買兩件商品的情況 
    cart.addProduct(p1); 
    cart.addProduct(p2); 
    cart.addProduct(p3); 
    cart.addProduct(p4); 
    cart.addProduct(p5); 
    cart.addProduct(p6); 
    cart.showAll(); 
    System.out.println("############"); 
    boolean flag=cart.deleteProduct(p2.getProductId()); 
    if(flag){ 
      System.out.println("商品編號為："+p2.getProductId()+"的商品刪除成功！"); 
    }else{ 
      System.out.println("刪除失敗"); 
    } 
    cart.showAll(); 
    System.out.println("############"); 
    boolean flag2=cart.modifyProduct(p3.getProductId(), 2); 
    if(flag2){ 
      System.out.println("商品編號為："+p3.getProductId()+"的商品修改成功！"); 
    }else{ 
      System.out.println("修改失敗"); 
    } 
    cart.showAll(); 
     
    //cart.clearCart(); 
    //cart.showAll(); 
    System.out.println("商品總價錢為："+cart.totalAllMoney()); 
 
  } 
 
}