#截图：
代码：
// Product.java
package entity;
public class Product {
private Integer id;
private String name;
private Float price;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Float getPrice() {
return price;
}
public void setPrice(Float price) {
this.price = price;
}
}
//ProductInCart.java
package entity;
public class ProductInCart extends Product {
private Integer count;
private Float total;
public Integer getCount() {
return count;
}
public void setCount(Integer count) {
this.count = count;
}
public Float getTotal() {
return total;
}
public void setTotal(Float total) {
this.total = total;
}
}
//CartUtil.java
package util;
import java.util.ArrayList;
import java.util.List;
import entity.Product;
import entity.ProductInCart;
public class CartUtil{
private List<ProductInCart>ps=new ArrayList<ProductInCart>();// 得到购物车中的所有商品
public List<ProductInCart>Getlists(){
return ps;
}
public void addItem(int id) {
Product _p=ProductUtil.find(id);
if(_p!=null) {
if(ps.size()==0) {
ProductInCart newp=new ProductInCart();
newp.setId(_p.getId());
newp.setName(_p.getName());
newp.setPrice(_p.getPrice());
newp.setCount(1);
newp.setTotal(_p.getPrice());
ps.add(newp);
}
else {
int i=0;
for(;i<ps.size();i++) {
ProductInCart temp=(ProductInCart)ps.get(i);
if(temp.getName().equals(_p.getName())) {
temp.setCount(temp.getCount()+1);
temp.setTotal(_p.getPrice()*temp.getCount());
break;
}
}
if(i>=ps.size()) {
ProductInCart newp=new ProductInCart();
//Product _p=ProductUtil.find(id);
newp.setId(_p.getId());
newp.setName(_p.getName());
newp.setPrice(_p.getPrice());
newp.setCount(1);
newp.setTotal(_p.getPrice());
ps.add(newp);
}
}
}
}
// 根据页面传来的id参数将一件对应商品添加到购物车
public void delete(int id) {// 根据页面传来的id参数将一件对应商品从购物车中删除
for(int i=0;i<ps.size();i++) {
ProductInCart temp=(ProductInCart)ps.get(i);
if(temp.getId().equals(id)) {
if(temp.getCount()>1) {
temp.setCount(temp.getCount()-1);
temp.setTotal(temp.getPrice()*temp.getCount());
break;
}
else if(temp.getCount()==1) {
ps.remove(i);
}
}
}
}
public void clear() { // 清空购物车中的全部商品
ps.clear();
}
public float calcTotalPrice() {// 计算购物车中全部商品的总价
float totals=0f;
for(int i=0;i<ps.size();i++) {
ProductInCart temp=(ProductInCart)ps.get(i);
totals+=temp.getTotal();
}
return totals;
}
}
//ProductUtil.java
package util;
import java.util.ArrayList;
import java.util.List;
import entity.Product;
public class ProductUtil {
private static List<Product> products;//顺序存储
private static Float[] prices= {1F,2F,3F};
private static String[] names= {"手机","笔记本","手表"};
static {
products=new ArrayList<Product>();//声明成数组
for(int i=0;i<names.length;i++) {
Product p=new Product();
p.setId(i+1);//设置id
p.setName(names[i]);//设置商品名称
p.setPrice(prices[i]);//设置商品价格
products.add(p);
}
}
public List<Product> getAll(){
return products;
}
public static Product find(int id) {
for(Product p:products) {
if(p.getId()==id) {//如果找到，则返回此行数组
return p;
}
}
return null;
}
}
//cart.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ page import="entity.ProductInCart"%>
<%@ page import="entity.Product"%>
<%@ page import="util.ProductUtil"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head >
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" >
<!-- 4不支持默认图标 要用3 -->
<link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdn.staticfile.org/popper.js/1.12.5/umd/popper.min.js"></script>
</head>
<jsp:useBean id="CartUtil" class="util.CartUtil" scope="session"/>
<%
String action=request.getParameter("action");
if("add".equals(action)){
String id=request.getParameter("id");
CartUtil.addItem(Integer.parseInt(id));
}
else if("del".equals(action)){
String id=request.getParameter("id");
CartUtil.delete(Integer.parseInt(id));
}
else if("clear".equals(action)){
CartUtil.clear();
}
List<ProductInCart> productsincart=CartUtil.Getlists();
if(productsincart==null||productsincart.size()==0){
out.write("<button type='button' class='btn btn-outline-danger'>购物车为空！！！</button>");
} else{
%>
<body>
<table class="table">
<div class="col-sm-1">
<a type="button" class="btn btn-danger" href="${pageContext.request.contextPath }/product.jsp">
<span class="glyphicon glyphicon-arrow-left" >继续购物</span>
</a>
</div>
<thead>
<tr class="table-primary">
<th scope="col">id</th>
<th scope="col">商品名称</th>
<th scope="col">单价</th>
<th scope="col">数量</th>
<th scope="col">小计</th>
<th scope="col">删除</th>
</tr>
</thead>
<tbody>
<% for(ProductInCart pic:productsincart){
out.write("<tr class='table-success'>");
out.write("<td>"+pic.getId()+"</td>");
out.write("<td>"+pic.getName()+"</td>");
out.write("<td>"+pic.getPrice()+"</td>");
out.write("<td>"+pic.getCount()+"</td>");
out.write("<td>"+pic.getTotal()+"</td>");
%>
<td><a href="cart.jsp?action=del&id=<%= pic.getId()%>"><span class="glyphicon glyphicon-minus-sign"></span></a></td>
<%
out.write("</tr>");
}%>
<tr><td ></td><td></td><td></td><td></td>
<td ><font style="font-size:30px;color:red">总计：</font><%=CartUtil.calcTotalPrice()%></td>
<td><a href="cart.jsp?action=clear"><button type="button" class="btn btn-outline-danger">清空购物车</button></a></td>
</tr>
<% }%>
</tbody>
</table>
</body>
</html>
//product.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="entity.Product"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head >
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" >
<!-- 4不支持默认图标 要用3 -->
<link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdn.staticfile.org/popper.js/1.12.5/umd/popper.min.js"></script>
</head>
<jsp:useBean id="ProductUtil" class="util.ProductUtil" scope="application"/>
<body>
<div >
<a href="cart.jsp">
<button type="button" class="btn btn-outline-danger">
<span class="glyphicon glyphicon-shopping-cart">查看购物车</span>
</button>
</a>
</div>
<table class="table">
<thead>
<tr class="table-primary">
<th scope="col">id</th>
<th scope="col">商品名称</th>
<th scope="col">单价</th>
<th scope="col">加入购物车</th>
</tr>
</thead>
<tbody>
<% List<Product> products=ProductUtil.getAll();
for(Product p:products){
out.write("<tr class='table-success'>");
out.write("<td>"+p.getId()+"</td>");
out.write("<td>"+p.getName()+"</td>");
out.write("<td>"+p.getPrice()+"</td>");
%>
<td>
<a href="cart.jsp?action=add&id=<%= p.getId()%>">
<span class="glyphicon glyphicon-shopping-cart"></span>
</a>
</td>
<%
out.write("</tr>");
}
%>
</tbody>
</table>
</body>
</html>
