使用cookie技术实现大型网站购物网站的商品浏览记录

下面我们用cookie技术来做一个商品浏览记录的案例，

第一步：先建一个jsp的页面，用来模拟数据库，存储商品的列表

代码如下：

jsp页面：

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@page import="java.util.*"%>
<!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>Insert title here</title>
</head>
<body>
<h1>商品列表</h1>
<ul>
	<li><a href="/myday07/addcookie?id=1">java基础</a></li>
	<li><a href="/myday07/addcookie?id=2">javaweb</a></li>
	<li><a href="/myday07/addcookie?id=3">DHTML</a></li>
	<li><a href="/myday07/addcookie?id=4">数据库</a></li>
	<li><a href="/myday07/addcookie?id=5">Struts</a></li>
	<li><a href="/myday07/addcookie?id=6">Spring</a></li>
	<li><a href="/myday07/addcookie?id=7">Hibernate</a></li>
</ul>
<h1>最近访问记录</h1><h5><a href="/myday07/clearcookie">清空数据</a> </h5>
<%
	String[] arr = {"java基础","javaweb","DHTML","数据库","Struts","Spring","Hibernate"};
	// 获得所有cookie
	Cookie[] cookies = request.getCookies();

	// 在cookie中查找商品浏览记录
	String visitlist = null;
	if(cookies!=null){
		for (Cookie cookie : cookies) {
			if (cookie.getName().equals("visitlist")) {
				visitlist = cookie.getValue();
				break;
			}
		}
		
		if(visitlist==null){ // 商品列表不存在
			out.println("无");
		}else{
			String[] existIds = visitlist.split(",");
			for(String existId:existIds){
				int id = Integer.parseInt(existId);
				out.println(arr[id-1]+"<br/>");
			}
		}
	}
%>
<hr/>
</body>
</html>
第二步：使用addCookie页面来处理商品的浏览记录请求，并记下商品的访问记录，代码如下： 
package cn.itcast.cookie;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class addCookie extends HttpServlet {

	// 获得用户当前访问商品，更新到商品浏览记录列表
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// 自动刷新
		response.setHeader("refresh", "2;url=/myday07/products1.jsp");

		// 1、获得当前用户浏览商品id
		String id = request.getParameter("id");
		// 2、获得用户浏览记录列表
		Cookie[] cookies = request.getCookies();
		// 查找访问记录列表 name:visitlist ----- 1,3,5,6
		String visitlist = null;
		if (cookies != null) { // 存在cookie
			for (Cookie cookie : cookies) {
				if (cookie.getName().equals("visitlist")) {
					visitlist = cookie.getValue();
					break;
				}
			}
			if (visitlist == null) {
				// 列表不存在,当前商品第一件商品
				Cookie cookie = new Cookie("visitlist", id);
				cookie.setMaxAge(60 * 60);
				response.addCookie(cookie);
				response.getWriter().println("add success");
			} else {
				// 3、判断当前商品是否已经在列表中
				String[] existIds = visitlist.split(",");
				for (String exsitId : existIds) {
					if (exsitId.equals(id)) { // id存在在列表中
						response.getWriter().println("add success");
						return;
					}
				}
				// 4、如果当前商品不在列表中，添加到列表
				Cookie cookie = new Cookie("visitlist", visitlist + "," + id);
				cookie.setMaxAge(60 * 60);
				response.addCookie(cookie);
				response.getWriter().println("add success");
			}
		} else {
			// 表示 并没有该站点的任何cookie
			Cookie cookie = new Cookie("visitlist", id);
			cookie.setMaxAge(60 * 60);//设置cookie的有效期为1个小时
			response.addCookie(cookie);
			response.getWriter().println("add success");
		}
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
} }
第三步：写一个清除访问记录的界面，clear页面，clearCookie页面，代码如下：
 
这个的原理就是设置cookie的有效期，让他的有效期设置为0，这样cookie就会被清除 
package cn.itcast.cookie;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class clearCookie extends HttpServlet
{

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException
	{
		Cookie cookie=new Cookie("visitlist","");
		cookie.setMaxAge(0);
		response.addCookie(cookie);
		response.sendRedirect("/myday07/products1.jsp");
		

	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException
	{
		doGet(request, response);
	}

}
posted @ 2012-10-04 11:09  Andye  阅读(2319)  评论(1)  编辑  收藏  举报