第八周
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"%>
<%
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></title>
</head>
<body>
<form action="MyJsp.jsp" method="post" name="login">
用户名：<input type="text" name="uname" size="20"><br>
密 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"%>
<%
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></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("b.jsp")
.forward(request, response);
} else {
response.sendRedirect("c.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></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("text.jsp");
}
%>
欢迎你<%=uname%><br>
<a href="a.jsp">退出登录</a>
<br>
</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></title>
</head>
<body>
<%
session.invalidate();//结束会话
response.setHeader("refresh", "5;url=text.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></title>
</head>
<body>
<h1>登陆失败！！</h1>
<%response.setHeader("refresh", "5;url=text.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>third</title>
</head>
<body>
<h2>登陆成功！</h2>
<%
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("Two.jsp");
%>
<form action="t.jsp" method="post">
商品：<br> <br>
草莓 10.30<input type="checkbox" name="item" value="草莓">加入购物车 <br>
梨 5.41 <input type="checkbox" name="item" value="梨"> 加入购物车 <br>
香蕉 8.50<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="t.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>Two</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>
