购物车的代码
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>showCart</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<table>
<tr>
<th>书籍名称</th>
<th>价格</th>
<th>数量</th>
<th>小计</th>
</tr>
<c:forEach items="${cart.cart}" var="item">
<tr>
<td>${item.value.bookInfo.bookname}</td>
<td>${item.value.bookInfo.price}</td>
<td>${item.value.count}</td>
<td>${item.value.tmoney}</td>
</tr>
</c:forEach>
<tr>
<td> </td><td> </td><td> </td> <td>总计：${cart.total}</td>
</tr>
<tr><td> </td><td><a href="${pageContext.request.contextPath}/index.jsp">继续购买</a></td></tr>
</table>
</body>
</html>
---servlet代码
package org.xiaoai.web.action;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.xiaoai.entity.BookInfo;
import org.xiaoai.entity.CartBean;
import org.xiaoai.servers.BookInfoServices;
import org.xiaoai.servers.impl.BookInfoServicesImpl;
public class CartServlet extends HttpServlet {
BookInfoServices se=new BookInfoServicesImpl();
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String way=request.getParameter("method");
if("addCart".equals(way)){
this.addCart(request, response);
}
}
//添加到购物车
public void addCart(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String id=request.getParameter("id");
BookInfo bookInfo=se.abookInfo(new Integer(id));
HttpSession session=request.getSession();
CartBean cart=(CartBean)session.getAttribute("cart");
if(cart==null){
cart=new CartBean();
session.setAttribute("cart", cart);
}
cart.addBookInfo(bookInfo);
response.sendRedirect(request.getContextPath()+"/"+"showCart.jsp");
}
}
--相关的实体
--cartBean
package org.xiaoai.entity;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
*购物车
*/
public class CartBean {
//定义集合存储购买的物品
private Map<Integer,CartItem> cart=new HashMap<Integer,CartItem>();
//总价
private double total;
public Map<Integer, CartItem> getCart() {
return cart;
}
public void setCart(Map<Integer, CartItem> cart) {
this.cart = cart;
}
public double getTotal() {
double total = 0.0d;
Set<Integer> keys = cart.keySet();
Iterator<Integer> it = keys.iterator();
while(it.hasNext()){
Integer key = it.next();
// 获得对应Item
CartItem item = cart.get(key);
total += item.getTmoney();
}
return total;
}
public void setTotal(double total) {
this.total = total;
}
//添加到购物车的物品进行判断
public void addBookInfo(BookInfo bookInfo){
if(cart!=null){
//判断该物品是否存在
if(cart.containsKey(bookInfo.getBookid())){
//表示此书已经存在
CartItem item=cart.get(bookInfo.getBookid());
item.setCount(item.getCount()+1);
}else{
//书籍不存在
CartItem item=new CartItem();
item.setCount(1);
item.setBookInfo(bookInfo);
cart.put(bookInfo.getBookid(), item);
}
}
}
}
--cartItem代码
package org.xiaoai.entity;
import java.text.DecimalFormat;
/**
*封装购物车信息
*/
public class CartItem {
//书籍信息
private BookInfo bookInfo=new BookInfo();
//书籍购买的数量
private Integer count;
//小计
private double tmoney;
public BookInfo getBookInfo() {
return bookInfo;
}
public void setBookInfo(BookInfo bookInfo) {
this.bookInfo = bookInfo;
}
public Integer getCount() {
return count;
}
public void setCount(Integer count) {
this.count = count;
}
public double getTmoney() {
DecimalFormat format=new DecimalFormat("0.00");
String dou=format.format(count*bookInfo.getPrice());
return new Double(dou);
}
public void setTmoney(double tmoney) {
this.tmoney = tmoney;
}
}