JSP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。
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>
<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" ><br>
    
        <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>
    <h1>登陆失败！！</h1>
    <%response.setHeader("refresh", "1;url=login.jsp");%>

</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", "1;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>
    
    <%
        String uname = (String) session.getAttribute("uname");
        if (uname == null)
            response.sendRedirect("login.jsp");
    %>

    欢迎你<%=uname%>
    <a href="logout.jsp">退出登录</a>
    <br>
    水浒传¥20<a href="buy.jsp?bookname=1">购买</a><br>
           西游记¥30<a href="buy.jsp?bookname=2">购买</a><br>


</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
    <%
        ArrayList books = (ArrayList) session.getAttribute("books");
        if (books == null) {
            books = new ArrayList();
            session.setAttribute("books", books);
        }
        String bookname = request.getParameter("bookname");
        String book01="水浒传,价格：20元";
        String book02="西游记,价格：30元";
        if (bookname != null) {
            bookname = new String(bookname.getBytes("ISO-8859-1"), "utf-8");
            if(bookname.equals("1")){
                books.add(book01);
            }else{
                books.add(book02);
            }
        }
        String delete = request.getParameter("delete");
        if (delete != null) {
            int i = Integer.parseInt(delete);
            books.remove(i);
            
        }
    %>
    购物车中的信息为：
    <br>
    <%
        int i = 0;
        for (i = 0; i < books.size(); i++) {
    %>
    <a href="buy.jsp?delete=<%=i%> ">删除</a>
    <%
        out.println(books.get(i) + "<br>");
        }
    %>
    <a href="main.jsp">返回主页面</a>
</body>
</html>

 

 

 

 

posted @ 2022-04-20 18:12  计算机1901金皓楠  阅读(16)  评论(0)  编辑  收藏  举报