第八周作业

1.登陆
输入用户名密码,判断用户名和密码相同,登陆成功,session中保存用户的用户名,进入主页main.jsp,主页有一个退出按钮,点击,回到登陆页login.jsp。要求:退出登录后,如果在浏览器直接输入主页main.jsp,访问不了,直接跳到登陆页。

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
<head>


<title>My JSP 'index.jsp' starting page</title>

</head>

<body>
<script type="text/javascript">
        function validate(){
            if(loginForm.uname.value==""){
                alert("账号不能为空!");
                return;
            }
            if(loginForm.upwd.value==""){
                alert("密码不能为空!");
                return;
            }
            loginForm.submit();
        }
    </script>


    <form name="loginForm" action="dologin.jsp" method="post">
        
    用户名:<input type="text" name="uname" ><br> 
    密码: <input  type="password" name="upwd" >
    
        <input type="button" value="登录" onClick="validate()">    
    </form>

</body>
</html>

  

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
    request.setCharacterEncoding("utf-8");
    String uname = request.getParameter("uname");
    String upwd = request.getParameter("upwd");
    if (uname.equals(upwd)){
        //转发到ok页面,但是url没变
        session.setAttribute("uname", uname);
        request.getRequestDispatcher("main.jsp").forward(request,response);
    }
    else{
        //重定向回login.jsp,浏览器url也变
        response.sendRedirect("no.jsp");
    }

  

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
  <head>    
    <title>My JSP 'index.jsp' starting page</title>
  </head>  
  <body> 
   
  <% 
  String uname=(String)session.getAttribute("uname");
  //如果他是空,说明没登陆,直接访问该页面了
  if(uname==null)
      response.sendRedirect("login.jsp");  
   %> 
  
  欢迎你<%=uname %>
  
  <a href="logout.jsp">退出登录</a>

  
  
  </body>
</html>

  

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
<head>


<title>My JSP 'index.jsp' starting page</title>

</head>

<body>
    <%
    
    session.invalidate();
    response.setHeader("refresh", "5;url=login.jsp");
    
     %>
退出成功
</body>
</html>

  

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
<head>


<title>My JSP 'index.jsp' starting page</title>

</head>

<body>
    <h1>登陆失败!!</h1>
    <%response.setHeader("refresh", "5;url=login.jsp");%>

</body>
</html>

  

 

 

 

 

 

 2.购物车
和上一题一起,在main.jsp中做一个购物车,里面显示3个商品名和价格 每一个后面有一个加入购物车按钮,
main.jsp中有一个按钮(或者超链接)可以显示购物车。(选作:在购物车中加删除按钮删除商品)

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>

    <%
        String uname = (String) session.getAttribute("uname");
        //如果他是空,说明没登陆,直接访问该页面了
        if (uname == null)
            response.sendRedirect("login.jsp");
    %>

    欢迎你<%=uname%>

    <a href="logout.jsp">退出登录</a>
    <hr>
    商品展示:
    <br>
    <hr>
    <form action="show.jsp" method="post">
        请选择要加入购物车的商品:<br> <input type="checkbox" name="list" value="苹果">
        苹果 ¥9.9<br> <input type="checkbox" name="list" value="橙子">
        橙子 ¥7.88<br> <input type="checkbox" name="list" value="橘子">
        橘子 ¥6.88<br>
        <hr>
        <input type="submit" value="加入购物车">

    </form>


</body>
</html>

  

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
<head>


<title>My JSP 'index.jsp' starting page</title>

</head>

<body>
    <h2>购物车添加的商品有:</h2>
    <%
        request.setCharacterEncoding("utf-8");
        String listName[] = request.getParameterValues("list");
        if (listName == null) {
            out.print("购物车为空!");
        } else {
            for (int i = 0; i < listName.length; i++) {
                out.print("(" + (i + 1) + ")" + listName[i] + "<br>");
            }
        }
    %>
</body>
</html>

  

 

 

 

posted @ 2022-04-23 22:59  计算机1904李傲  阅读(12)  评论(0编辑  收藏  举报