使用Cookie和Session完成SimpleShop 

 1 package com.yxfyg.servlet;
 2 
 3 import java.io.IOException;
 4 import java.util.LinkedHashMap;
 5 import java.util.Map;
 6 
 7 import javax.servlet.ServletException;
 8 import javax.servlet.http.Cookie;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 import javax.servlet.http.HttpSession;
13 
14 import com.yxfyg.util.CookieUtil;
15 
16 public class ShoppingServlet extends HttpServlet {
17 
18     @Override
19     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
20 
21         String id = req.getParameter("id");
22         Cookie[] cookies = req.getCookies();
23         Cookie cookie = CookieUtil.findCookie(cookies, "history");
24         if (cookie != null) {
25             String ids = cookie.getValue();
26             ids = id + "#" + ids;
27             cookie.setValue(ids);
28             cookie.setMaxAge(60 * 60 * 24 * 7);
29             cookie.setPath("/SimpleShop");
30             resp.addCookie(cookie);
31         } else {
32             Cookie history = new Cookie("history", id);
33             history.setMaxAge(60 * 60 * 24 * 7);
34             history.setPath("/SimpleShop");
35             resp.addCookie(history);
36         }
37 
38         HttpSession session = req.getSession();
39         Map<Integer, Integer> map = (Map<Integer, Integer>) session.getAttribute("cart");
40 
41         int index = Integer.parseInt(id);
42 
43         if (map == null) {
44             map = new LinkedHashMap<Integer, Integer>();
45             map.put(index, 1);
46         } else {
47             if (map.containsKey(index)) {
48                 map.put(index, map.get(index) + 1);
49             } else {
50                 map.put(index, 1);
51             }
52         }
53         session.setAttribute("cart", map);
54 
55         resp.sendRedirect("product_list.jsp");
56     }
57 
58     @Override
59     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
60         doGet(req, resp);
61     }
62 }
 1 package com.yxfyg.servlet;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.ServletException;
 6 import javax.servlet.http.Cookie;
 7 import javax.servlet.http.HttpServlet;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10 
11 import com.yxfyg.util.CookieUtil;
12 
13 public class ClearHistory extends HttpServlet{
14     
15     @Override
16     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
17         Cookie history = new Cookie("history", "");
18         history.setMaxAge(0);
19         resp.addCookie(history);
20         resp.sendRedirect("product_list.jsp");
21         
22     }
23     
24     @Override
25     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
26         doGet(req, resp);
27     }
28 }
 1 package com.yxfyg.servlet;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.ServletException;
 6 import javax.servlet.http.HttpServlet;
 7 import javax.servlet.http.HttpServletRequest;
 8 import javax.servlet.http.HttpServletResponse;
 9 import javax.servlet.http.HttpSession;
10 
11 public class ClearCart extends HttpServlet{
12     
13     @Override
14     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
15         HttpSession session = req.getSession();
16         session.invalidate();
17         resp.sendRedirect("product_list.jsp");
18     }
19     
20     @Override
21     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
22         doGet(req, resp);
23     }
24 
25 }
package com.yxfyg.util;

import javax.servlet.http.Cookie;

public class CookieUtil {
    
    public static Cookie findCookie(Cookie[] cookies,String name) {
        
        if(cookies != null) {
            for(Cookie cookie : cookies) {
                if(name.equals(cookie.getName())) {
                    return cookie;
                }
            }
        }
        return null;
    }
    
}
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" import="com.yxfyg.util.*"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>商品列表</title>
</head>
<body>
    <div>
        <a href="ShoppingServlet?id=0">苹果</a><br/>
        <a href="ShoppingServlet?id=1">芒果</a><br/>
        <a href="ShoppingServlet?id=2">柠檬</a><br/>
        <a href="ShoppingServlet?id=3">橙子</a><br/>
        <a href="ShoppingServlet?id=4">草莓</a><br/>
        <a href="ShoppingServlet?id=5">西瓜</a><br/>
    </div>
    
    <div>
        <h3>浏览记录(<a href="ClearHistory">清除浏览记录</a>)</h3>
        <% 
            Cookie[] cookies = request.getCookies();
            Cookie history = CookieUtil.findCookie(cookies,"history");
            if(history == null){
        %>
            <h3>还没有浏览任何商品</h3>
        <%
            }else{
                String[] ids = history.getValue().split("#");
                String[] names = {"苹果","芒果","柠檬","橙子","草莓","西瓜"};
                int[] list = new int[ids.length];
                boolean flag = true;
                for(int i=0;i<ids.length;i++){
                    list[i] = Integer.parseInt(ids[i]);
                }
                for(int i=0;i<ids.length;i++){
                    flag = true;
                    for(int j=0;j<i;j++){
                        if(list[i] == list[j]){
                            flag = false;
                            break;
                        }
                    }
                    if(flag){
        %>
            <a href="ShoppingServlet?id=<%=list[i] %>"><%=names[list[i]] %></a>
        <%
                    }
                }
            }
        %>
    </div>
    <div>
        <h3><a href="cart.jsp">我的购物车</a></h3>
    </div>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" import="java.util.Map"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>购物车</title>
</head>
<body>
    <div>
        <h3>购物车（<a href="ClearCart">清空购物车</a>）</h3>
        <%
            String[] names = {"苹果","芒果","柠檬","橙子","草莓","西瓜"};
            Map<Integer,Integer> map = (Map<Integer,Integer>)session.getAttribute("cart");
            if(map != null){
                for(int index : map.keySet()){
        %>
            <a href="ShoppingServlet?id=<%=index %>"><%=names[index] %></a> 数量：<%=map.get(index) %><br/>
        <%
                }
            }else{
        %>
            <h3>空空如也</h3>
        <%
            }
        %>
    </div>
</body>
</html>

 

posted @ 2020-05-03 16:56  yxfyg  阅读(199)  评论(0)    收藏  举报