黑马prince

导航

第八周作业

1.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"%>
<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"%>
<%
    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>
    <%
     
    session.invalidate();
    response.setHeader("refresh", "5;url=login.jsp");
     
     %>
退出登录成功
</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></title>
    
  </head>
  
  <body>
   <%
        String uname = (String) session.getAttribute("uname");
        if (uname == null)
            response.sendRedirect("login.jsp");
    %>
    商品展示：
    <br> 欢迎购买玩具：
    <br>
    <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="荔枝"  <br> 
        <input type="checkbox" name="list" value="桃子"> <br> 
        <input type="checkbox" name="list" value="西瓜"> <br>
        <input type="submit" value="加入购物车">

    </form>
  </body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
  <head>    
    <title></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 on 2022-04-24 20:51  HumbleSwag  阅读(17)  评论(0)    收藏  举报