第八次

2022-04-23 16:04:27 作者：互联网

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>
  </head>
   <script type="text/javascript">
    function v() {
        if (loginForm.uname.value=="") {
            alert("账号不能为空！");
            return;
        }
        if (loginForm.password.value=="") {
            alert("密码不能为空！");
            return;
        }
        loginForm.submit();
    }
    </script>
  <body>
  <form name="loginForm" action="m.jsp" method="post">
  账号：<input type="text" name="uname"><br>
  密码：<input type="password" name="password"> <br> 
  <input type="submit" value="登录" onclick="v()">
  </form>  
  </body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
 </head>
  <body>
   <%
        request.setCharacterEncoding("utf-8");
        String uname = request.getParameter("uname");
        String password = request.getParameter("password");
        if (uname.equals(password)) {
            session.setAttribute("uname", uname);
            request.getRequestDispatcher("J.jsp").forward(request, response);
        } else {
            response.sendRedirect("q.jsp");
        }
    %>
 </body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
 </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("index.jsp");
   %>
    欢迎<br>
  <a href="n.jsp">退出登录</a> <br>
 </body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
 </head>
 <%String src=request.getParameter("id"); %>
  <body>
  登陆失败，请重试
    <%
      response.setHeader("refresh", "5;url=index.jsp");
    %>
 </body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
 </head>
  <body>
 <%
    session.invalidate();
    response.setHeader("refresh", "5;url=index.jsp");
  %>
退出成功!
 </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>main</title>
    
  </head>
  
  <body>
    <h1>登陆成功！</h1>

    <%
        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");
            
    %>
    
    <form action="show.jsp" method="post">
        商品：<br> <br>
    苹果 5.45<input type="checkbox" name="item" value="苹果">加入购物车 <br> 
    梨 4.34 <input type="checkbox" name="item" value="梨"> 加入购物车 <br> 
    香蕉 4.56<input type="checkbox" name="item" value="香蕉"> 加入购物车<br><br>
    <input type="submit" value="加入购物车">
    </form>
    
    
    
    <form name="form1" action="logout.jsp" method="post">
    <input type="submit" value="退出登录">
    </form>
    
    
   
</body>
</html>

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

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>    
    <title>show</title>
    
  </head>
  
  <body>
    <%
    request.setCharacterEncoding("utf-8");
    String itemName[]=request.getParameterValues("item");
    if(itemName==null){
    out.print("未添加购物车");
    }
    else{
    for(int i=0;i<itemName.length;i++){
    out.print("("+(i+1)+")"+itemName[i]+"<br>");
    }
    }
     %>
  </body>
</html>

标签：购物车,jsp,登陆,按钮,main,loginForm,第八次
来源： https://www.cnblogs.com/Astra1208/p/16182602.html