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"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'login.jsp' starting page</title>
</head>
<body>
    <form action="dologin.jsp" method="post" name="login">
        用户名：<input type="text" name="uname" size="20"><br> 
        密&emsp;码：<input type="password" name="upwd" size="20"><br> 
        <input type="button" value="登录" onClick="validate()">
    </form>
    <script type="text/javascript">
        function validate() {
            if (login.uname.value == "") {
                alert("用户名不能为空!");
                return;
            }
            if (login.upwd.value == "") {
                alert("密码不能为空!");
                return;
            }
            login.submit();
        }
    </script>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'dologin.jsp' starting page</title>
</head>
<body>
    <%
        //设置编码
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        //获取请求数据
        String uname = request.getParameter("uname");
        String upwd = request.getParameter("upwd");
        //判断密码和用户名是否相同
        if (uname.equals(upwd)) {
            session.setAttribute("uname",uname);
            request.getRequestDispatcher("main.jsp")
                    .forward(request, response);
        } else {
            response.sendRedirect("no.jsp");
        }
    %>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

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

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

</head>

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

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'main.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="loginout.jsp">退出登录</a>    
     
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'no.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"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'main.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="loginout.jsp">退出登录</a>
   <br>
   <form action="Buy.jsp">
         <hr>
         是否加入购物车？<br> <input name="item" type="checkbox" value="weilong">
         山楂 $1<br> <input name="item" type="checkbox" value="xizhilang">
         薯片 $2<br> <input name="item" type="checkbox" value="menglong">
         雪糕 $3<br>
         <hr>
         <input type="submit" value="加入购物车">
     </form>    
     
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'Buy.jsp' starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>
  
  <body>
   <h2>购物车</h2>
     <%
         request.setCharacterEncoding("utf-8");
         String itemName[] = request.getParameterValues("item");
         if (itemName == null) {
             out.print("购物车为空");
         } else {
             for (int k = 0; k < itemName.length; k++) {
                 out.print("(" + (k + 1) + ")" + itemName[k] + "<br>");
             }
         }
     %>
  </body>
</html>

posted @ 2022-04-24 14:44 **# 阅读(48) 评论(0) 编辑收藏举报

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