一、cart.jsp页面
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<base href="http://${pageContext.request.serverName }:${pageContext.request.serverPort }${pageContext.request.contextPath }/" />
<title>Insert title here</title>
<script type="text/javascript" src="script/jquery-1.7.2.js"></script>
<script type="text/javascript">
$(function(){
//★给全部删除链接加入点击事件
$(".delete").click(function(){
if(!window.confirm("你确定要删除该购物项吗？")){
return false; //不让链接提交
}
});
//给全部显示书的数量的输入框加入失去焦点的事件
$(".count").blur(function(){
var count =this.value;//得到输入框中的数值
if(isNaN(count)){
count=1;
}
count=count*1;//→转为number类型
if(count<=0){
count=1;
}
var bookId=this.id;//this代表了当前的输入框中的内容
//在这里须要在其变化之前保存下来以便于在function中使用
var inputEle=this; //它是一个dom对象
//window.location.href = "${pageContext.request.contextPath}/client/CartServlet?method=update&count="+count+"&bookId="+bookId;
//★改动购物项图书数量的Ajax处理★ 这个时候须要发送Ajax请求
var path="client/CartServlet"; //上面加了base标签
var params={method:"update",count:count,bookId:bookId};
//data的数据类型{count:2,itemPrice:20,totalCount:5,totalPrice:50}
var success=function(data){//→须要更新四处
//得到总数量
$("#totalCount").html(data.totalCount);
//得到总价
$("#totalPrice").html(data.totalPrice);
//更新购物项中的图书数量
inputEle.value=data.count;//将数据放进去
//得到小计
$(inputEle).parent().parent().find(".itemPrice").html(data.itemPrice);
}
$.post(path,params,success,"json");
});
//给<button>+</button>加入点击事件
$(".increase").click(function(){
//得到 数量首先,先找button的父元素，再找子元素
var $countEle=$(this).parent().find("input");
var count=$countEle.val();//得到文本框中的值
count=count*1+1;//转为number类型后再做运算\
//获取书的id
var bookId=$countEle.attr("id");
//如今改为发送Ajax请求
var path="client/CartServlet";
var params={method:"update",count:count,bookId:bookId};
var success=function(data){
$("#totalCount").html(data.totalCount);
$("#totalPrice").html(data.totalPrice);
//更新书的数量
$countEle.val(data.count);
//得到小计
$countEle.parents("tr").find(".itemPrice").html(data.itemPrice);
};
$.post(path,params,success,"json");
});
//给<button>-</button>加入点击事件
$(".decrease").click(function(){
//得到数量
var $countEle = $(this).parent().find("input");
var count = $countEle.val();//链式调用
count = count*1-1;
if(count<=1){
count=1;
}
//书的id
var bookId = $countEle.attr("id");
//请求
//window.location.href = "${pageContext.request.contextPath}/client/CartServlet?method=update&count="+count+"&bookId="+bookId;
//改为Ajax请求。。。。
var path="client/CartServlet";
var params={method:"update",count:count,bookId:bookId};
var success=function(data){
$("#totalCount").html(data.totalCount);
$("#totalPrice").html(data.totalPrice);
//更新书的数量
$countEle.val(data.count);
//找当前行的小计
$countEle.parents("tr").find(".itemPrice").html(data.itemPrice);
};
$.post(path,params,success,"json");
});
});
</script>
</head>
<body>
<center>
<h2>我的购物车</h2>
<c:choose>
<c:when test="${empty CART || empty CART.map }">
购物车里面还没有书，马上去<a href="client/BookClientServlet?
method=getPageInCondition">购物</a>
</c:when>
<c:otherwise>
<table border="1" cellpadding="10" cellspacing="0">
<tr>
<td>书名</td>
<td>单位价格</td>
<td>数量</td>
<td>小计</td>
<td>操作</td>
</tr>
<c:forEach items="${CART.map }" var="entry">
<tr>
<td>${entry.value.book.bookName}</td>
<td>${entry.value.book.price}</td>
<td>
<button class="decrease" <%-- ${entry.value.count<=1 ?
‘disabled="false"‘ : ‘‘} --%>>-</button>
<input id="${entry.key}" class="count" type="text" value="${entry.value.count}" style="width: 30px;"/>
<button class="increase">+</button>
</td>
<td ><span class="itemPrice">${entry.value.itemPrice}</span></td>
<td><a class="delete" href="client/CartServlet?method=delete&bookid=${entry.key}">删除</a></td>
</tr>
</c:forEach>
<tr>
<td><a id="clear" href="client/CartServlet?method=clear" >清空购物车</a></td>
<td><a
href="client/BookClientServlet?method=getPageInCondition">继续购物</a></td>
<td>共<span id="totalCount">${CART.totalCount }</span>本书</td>
<td>总价:<span id="totalPrice">${CART.totalPrice }</span>元</td>
<td><a href="client/OrderServlet?method=listAllAddress">去结算</a></td>
</tr>
</table>
</c:otherwise>
</c:choose>
</center>
</body>
</html>
package com.atguigu.bookstore.servlet.client;
import com.atguigu.bookstore.bean.Book;
import com.atguigu.bookstore.fun.Cart;
import com.atguigu.bookstore.service.impl.BookServiceImpl;
import com.atguigu.bookstore.service.impl.CartServiceImpl;
import com.atguigu.bookstore.service.inter.BookService;
import com.atguigu.bookstore.service.inter.CartService;
import com.atguigu.bookstore.servlet.BaseServlet;
import com.atguigu.bookstore.utils.WebUtils;
import com.google.gson.Gson;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CartServlet extends BaseServlet {
private static final long serialVersionUID = 1L;
CartService cartService=new CartServiceImpl();
BookService bookService=new BookServiceImpl();
protected void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("add....");
String bookid = request.getParameter("bookid");
Book book = bookService.getBookById(bookid);
Cart cart = WebUtils.getCart(request);
cartService.add(book, cart);
//要得到这种数据{"bookName":"java", "totalCount": 2} 怎么得？
String bookName = book.getBookName();
int totalCount = cart.getTotalCount();
//使用Gson能够得到以上类型的数据,可是须要一个源，这个仅仅有map和
//src是一个一般对象或map对象。在这里仅仅能用map对象。由于假设是一般对象，所须要一个类中包括不了这2种属性，还得又一次定义类，挺麻烦的
//而src是map对象时就不须要在又一次定义类了，
Map<String, Object>map=new HashMap<String, Object>();
map.put("bookName", bookName); //取数据的时候是data.bookName;
map.put("totalCount", totalCount);
String jsonStr=new Gson().toJson(map);
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(jsonStr);
}
protected void delete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("delete...");
String bookid = request.getParameter("bookid");
Cart cart = WebUtils.getCart(request);
cartService.deleteItem(Integer.parseInt(bookid), cart);
WebUtils.myForward(request, response, "/client/book/cart.jsp");
}
protected void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("update....");
String count = request.getParameter("count");
String bookId = request.getParameter("bookId");
Map<String, Object>map=cartService.updateCount(Integer.parseInt(bookId),
Integer.parseInt(count), WebUtils.getCart(request));
// WebUtils.myForward(request, response, "/client/book/cart.jsp"); //不用这种方式了
//要返回的数据类型：{count:2,itemPrice:20,totalCount:5,totalPrice:50}，那么怎样得到呢？能够更改updateCount方法，使其返回一个map集合
String json = new Gson().toJson(map);
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(json);
}
protected void clear(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("clear....");
cartService.clear(WebUtils.getCart(request));
WebUtils.myForward(request, response, "/client/book/cart.jsp");
}
}
<span style="white-space:pre"> </span>@Override
public Map<String, Object> updateCount(int BookId, int count, Cart cart) {
Map<String, Object>map=new HashMap<String, Object>();
CartItem cartItem = cart.getMap().get(BookId);
cartItem.setCount(count);
//{count:2,itemPrice:20,totalCount:5,totalPrice:50}，
map.put("count", count);
map.put("itemPrice", cartItem.getItemPrice());
map.put("totalCount", cart.getTotalCount());
map.put("totalPrice", cart.getTotalPrice());
return map;
}原文：http://www.cnblogs.com/cynchanpin/p/6971335.html