练习模拟登录淘宝后记住用户名及购物车里的商品

1.Login界面

<%@page import="java.net.URLDecoder"%>
<%@page import="jdk.nashorn.api.scripting.URLReader"%>
<%@ 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>Insert title here</title>
</head>
<body>
<%
//提取cookie保存的卡号

//获取所有cookie
Cookie[]cks=request.getCookies();
String username="";
if(cks!=null){
//遍历
for(Cookie c:cks)
{
    if(c.getName().equals("username"))
    {
        username = URLDecoder.decode(c.getValue());
    }
}
}
%>
<form action="Check.jsp" method="post">
用户名：<input type="text" name="user" value="<%=username %>"><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="登录">
</form>
</body>
</html>

2.检查登录界面

<%@page import="java.net.URLEncoder"%>
<%@page import="com.haiqi.test.UserDAO"%>
<%@ 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>Insert title here</title>
</head>
<body>
<%
    String username=request.getParameter("user");//获取的值是与form表单中的文本框的name对应
    String password = request.getParameter("password");
    
    //数据验证
    if(username==null||password==null||
    username.equals("")||password.equals(""))
    {    //带缓存输出
        out.write("请正确登录");
        response.setHeader("refresh", "3;url=Login.jsp");
    }
    else
    {
        //检查登录信息
        UserDAO ud = new UserDAO();
        username = new String(request.getParameter("user").getBytes("ISO-8859-1"),"UTF-8");
        if(ud.CheckLogin(username, password))
        {
            
            //用cookie记住用户名
            Cookie cid = new Cookie("username",URLEncoder.encode(username));
            cid.setMaxAge(10*24*60*60);//设置过期时间
            response.addCookie(cid);
            //保持登录状态
            session.setAttribute("username", username);
            response.sendRedirect("Main.jsp");
            
            
        }
     else
        {
            out.write("登录失败！");
            //跳回登录界面
            response.setHeader("refresh", "2;URL=Login.jsp");
        }
    }
%>
</body>
</html>

3.主界面

<%@page import="com.haiqi.test.UserDAO"%>
<%@ 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>Insert title here</title>
</head>
<body>
淘宝首页<br>
<%
Object obj =session.getAttribute("username");
if(obj == null)
{
    out.print("登录超时或未登录！");
    
    response.setHeader("refresh", "3;url=Login.jsp");
}
else
{
    out.print(obj+",欢迎登录！");
}
%>
<br>
<br>
<a href="Logout.jsp">退出登录</a>
<form action="Main2.jsp" method="post">
请输入你要购买的商品名称<input type="text" name="spname"><br>
<input type="submit" value="加入购物车">


<a href="Login.jsp">退出登录</a>
</body>
</html>




4.退出界面




<%@ 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>Insert title here</title>
</head>
<body>
<%
//销毁session
session.invalidate();
out.print("退出成功！");
response.setHeader("refresh", "2;url=login.jsp");
%>
</body>
</html>




5.UserDAO




package com.haiqi.test;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.mchange.v2.c3p0.ComboPooledDataSource;


public class UserDAO {
    private ComboPooledDataSource cp = new ComboPooledDataSource("helloc3p0");
    public boolean CheckLogin(String username,String password)
    {
        boolean rtn = false;
        try {
                Connection conn = cp.getConnection();
                PreparedStatement ps = conn.prepareStatement("select * from account where a_name=?and a_password=?");
                ps.setString(1, username);
                ps.setString(2, password);
                ResultSet rs = ps.executeQuery();
                rtn=rs.next();
            } 
        catch (SQLException e) 
        {
            
            e.printStackTrace();
        }
        return rtn;
    }

}








6.添加商品页面




<%@page import="java.net.URLEncoder"%>
<%@page import="java.net.URLDecoder"%>
<%@page import="jdk.nashorn.api.scripting.URLReader"%>
<%@ 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>Insert title here</title>
</head>
 
<%
String spname=request.getParameter("spname");
if(spname!=null)
{
    spname=new String(spname.getBytes("ISO-8859-1"),"UTF-8");
//设置cookie
    Cookie cok = new Cookie("spname", URLEncoder.encode(spname) );//利用cookie记住购物车内的物品
//设置cookie的生命周期
    cok.setMaxAge(10*60*24);
//发送cookie
    response.addCookie(cok);
//跳转页面到菜单选择
    response.sendRedirect("thing.jsp");
}
%>

<body>
</body>

</html>




7.购物车页面




<%@page import="java.net.URLDecoder"%>
<%@page import="java.net.URLEncoder"%>
<%@page import="jdk.nashorn.api.scripting.URLReader"%>
<%@ 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>Insert title here</title>
</head>
<body>
<!-- EL表达式 -->
<!--name=${param.name };  -->
添加到购物车的商品
<br>
<%


    Cookie []ck = request.getCookies();
    String spname="";
    if(ck!=null){
    for(Cookie c:ck)
    {   //遍历
        if(c.getName().equals("spname"))
        {
            spname=URLDecoder.decode(c.getValue());
        }
    }
        out.write(spname);
    }
    else
{
    out.write("购物车没添加商品！");
}

%>
<br>
<a href="Main2.jsp">返回购物车</a>
</body>
</html>






        

	      

	    

	  

	  

	    
      
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          原文地址：https://www.cnblogs.com/miracle-0807/p/6015600.html