<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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">
<title></title>
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery-1.11.1.min.js"></script>
<script type="text/javascript">
$(function(){
//判断session里是否已经有shoppingCart
var isHasCart = "${sessionScope.shoppingCart == null}";
//如果session里没有shoppingCart，说明是第一次来到这个页面
if(isHasCart == "true"){
$("#cartstatus").hide();
}else{
$("#cartstatus").show();
$("#bookName").text("${sessionScope.shoppingCart.bookName}");
$("#totalBookNum").text("${sessionScope.shoppingCart.totalBookNum}");
$("#totalMoney").text("${sessionScope.shoppingCart.totalMoney}");
}
$("a").click(function(){
$("#cartstatus").show();
var url = this.href;
var args = {"time":new Date()};
$.getJSON(url, args, function(data){
$("#bookName").text(data.bookName);
$("#totalBookNum").text(data.totalBookNum);
$("#totalMoney").text(data.totalMoney);
});
return false;
});
})
</script>
</head>
<body>
<!--
1.获取当前页面所有的a结点，并为每一个a结点都添加onclick响应事件，同时取消其默认行为。
2.准备发送ajax请求：url（a结点的href属性值） args（时间戳）
3.响应为一个JSON对象，包括：bookName totalBookNum totalMoney
4.把对应的属性添加到对应的位置
-->
<div id="cartstatus">
您已将<span id="bookName"></span>加入到购物车中，购物车中的书有<span id="totalBookNum"></span>本，总价是<span id="totalMoney"></span>元
</div>
<br/>
Java<a href="${pageContext.request.contextPath}/addToCart?id=Java&price=100">加入购物车</a>
<br/>
Oracle<a href="${pageContext.request.contextPath}/addToCart?id=Oracle&price=150">加入购物车</a>
<br/>
Struts2<a href="${pageContext.request.contextPath}/addToCart?id=Struts2&price=180">加入购物车</a>
<br/>
</body>
</html>ShoppingCartItem.java
public class ShoppingCartItem {
private int number;
private String bookName;
private int price;
//...
}ShoppingCart.java 购物车
public class ShoppingCart {
//key:书名 value:ShoppingCartItem对象
private Map<String, ShoppingCartItem> items = new HashMap<String, ShoppingCartItem>();
private String bookName;
public void addToCart(String bookName, int price) {
this.bookName = bookName;
if (items.containsKey(bookName)) {
ShoppingCartItem shoppingCartItem = items.get(bookName);
shoppingCartItem.setNumber(shoppingCartItem.getNumber() + 1);
}else{
ShoppingCartItem shoppingCartItem = new ShoppingCartItem();
shoppingCartItem.setBookName(bookName);
shoppingCartItem.setNumber(1);
shoppingCartItem.setPrice(price);
items.put(bookName, shoppingCartItem);
}
}
public int getTotalBookNum() {
int total = 0;
for (ShoppingCartItem item:items.values()) {
total += item.getNumber();
}
return total;
}
public int getTotalMoney() {
int money = 0;
for (ShoppingCartItem item:items.values()) {
money += item.getNumber() * item.getPrice();
}
return money;
}
public String getBookName() {
return bookName;
}
}addToCart.java servlet
String bookName = request.getParameter("id");
int price = Integer.parseInt(request.getParameter("price"));
ShoppingCart shoppingCart = (ShoppingCart) request.getSession().getAttribute("shoppingCart");
if (shoppingCart == null) {
shoppingCart = new ShoppingCart();
request.getSession().setAttribute("shoppingCart", shoppingCart);
}
shoppingCart.addToCart(bookName, price);
StringBuilder result = new StringBuilder();
result.append("{")
//必须用双引号
.append("\"bookName\":\"" + bookName + "\"")
.append(",")
.append("\"totalBookNum\":" + shoppingCart.getTotalBookNum())
.append(",")
.append("\"totalMoney\":" + shoppingCart.getTotalMoney())
.append("}");
response.setContentType("text/javascript");
response.getWriter().print(result.toString());本文出自 “阿凡达” 博客，请务必保留此出处http://shamrock.blog.51cto.com/2079212/1561834
原文：http://shamrock.blog.51cto.com/2079212/1561834