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" ><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)){ session.setAttribute("uname", uname); request.getRequestDispatcher("index.jsp").forward(request,response); } else{ 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");
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>
<h1>登陆失败！！</h1>
<%response.setHeader("refresh", "3;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>
<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)){ session.setAttribute("uname", uname); request.getRequestDispatcher("index.jsp").forward(request,response); } else{ 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");
if(uname==null)
response.sendRedirect("login.jsp");
%>
欢迎你<%=uname %>
<a href="logout.jsp">退出登录</a>
<form action="buy.jsp" method="post">
选择要购买的商品:<br>
<input type="checkbox" name="bookname" value = "商品1">商品1<br>
<input type="checkbox" name="bookname" value = "商品2">商品2<br>
<input type="checkbox" name="bookname" value = "商品3">商品3<br>
<input type="submit" value="购买">
</form>
</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("cart");
if(books==null){
books=new ArrayList();
session.setAttribute("cart", books);
}
request.setCharacterEncoding("utf-8");
String bookname=request.getParameter("bookname");
books.add(bookname);
%>
购物车中有：
<%
for(int i=0;i<books.size();i++){
out.print(books.get(i).toString()+"<br>");
}
%>
</body>
</html>
