用java代码写一个简单的网上购物车程序

需求：1、写一个商品类，有商品编号、商品名称、商品分类、商品单价属性。2、写一个商品条目信息类，有商品和数量两个属性，有商品总价格方法。

3、写一个购物车类，有添加商品方法、查看订单信息，删除商品，修改商品，清空购物车，求购物车中所有商品总金额方法。4、写一个测试类，测试上述方法。

商品类：

public class Product { private int productId;// 商品编号 private String productName;// 商品名称 private String category;// 商品分类 private double price;// 单价 public Product() {// 无参构造 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; } }商品条目信息类：

public class ProductItem { private Product product;//购买的商品 private int count;//商品数量 public double totalMoney(){//小计 double price=product.getPrice();//获取商品单价 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; } }
购物车类：

import java.util.Collection; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; public class ShoppingCart {//购物车 //key：商品编号 value:商品条目 private Map map=new LinkedHashMap(); 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(){//查看订单信息 Collection productItems = map.values(); Iterator iterator = productItems.iterator(); while(iterator.hasNext()){ ProductItem productItem = iterator.next(); Product product = productItem.getProduct(); System.out.println("商品编号："+product.getProductId()+",商品名称：" +product.getProductName()+",单价："+product.getPrice()+",数量："+productItem.getCount() +",小计："+productItem.totalMoney()); } } public boolean deleteProduct(int productId){//删除商品 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){//删除该商品 deleteProduct(productId); return true; } } return false; } public void clearCart(){//清空购物车 map.clear(); } public double totalAllMoney(){//商品总钱数 double total=0; Collection productItems = map.values(); Iterator iterator = productItems.iterator(); while(iterator.hasNext()){ ProductItem productItem = iterator.next(); double money=productItem.totalMoney(); total+=money; } return total; } }
测试类：

public class ShoppingCartTest { public static void main(String[] args) { ShoppingCart cart=new ShoppingCart(); Product p1=new Product(101,"华硕笔记本","笔记本",4599); Product p2=new Product(102,"苹果","水果",5.9); Product p3=new Product(103,"彩电","家电",2799); Product p4=new Product(104,"秋裤","服装",128); Product p5=new Product(105,"华为手机","手机",2998); Product p6=new Product(101,"华硕笔记本","笔记本",4599);//测试买两件商品的情况 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("商品编号为："+p2.getProductId()+"的商品删除成功！"); }else{ System.out.println("删除失败"); } cart.showAll(); System.out.println("############"); boolean flag2=cart.modifyProduct(p3.getProductId(), 2); if(flag2){ System.out.println("商品编号为："+p3.getProductId()+"的商品修改成功！"); }else{ System.out.println("修改失败"); } cart.showAll(); //cart.clearCart(); //cart.showAll(); System.out.println("商品总价钱为："+cart.totalAllMoney()); } } 运行效果图：