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：
[java] view plain copy 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：
[java] view plain copy 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：
[java] view plain copy 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<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(){//查看订单信息
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<ProductItem> productItems = map.values();
Iterator<ProductItem> iterator = productItems.iterator();
while(iterator.hasNext()){
ProductItem productItem = iterator.next();
double money=productItem.totalMoney();
total+=money;
}
return total;
}
} 测试类：
[java] view plain copy 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()); } }