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
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title></title>
<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>
</head>
<body>
<form name="loginForm" action="1.oblogin.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"%>
<html>
<head>
<title></title>
</head>
<body>
<%
String uname=(String)session.getAttribute("uname");if(uname==null)
response.sendRedirect("login.jsp");
%>
<a href="1.out.jsp">退出登录</a> <br>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html><head><title></title></head><body>
登陆失败，请重试！
<%
response.setHeader("refresh", "5;url=login.jsp");
%></body></html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html><head><title></title></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("main.jsp").forward(request, response);
} else {
response.sendRedirect("false.jsp");
}
%>
</body></html><%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html><head><title></title></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("main.jsp").forward(request, response);
} else {
response.sendRedirect("false.jsp");
}
%>
</body></html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title></title>
</head>
<body>
<%
session.invalidate();
response.setHeader("refresh", "5;url=login.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"%><html><head><title></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>
玉米¥10<a href="buy.jsp?sgname=1">购买</a><br>
土豆¥9.9<a href="buy.jsp?sgname=2">购买</a><br>
</body></html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><html><head><title></title></head><body>
<%
ArrayList books = (ArrayList) session.getAttribute("sgs");
if (sgs == null) {
sgs = new ArrayList();
session.setAttribute("sgs",sgs);
}
String sgname = request.getParameter("sgname");
String sg01="玉米,价格：20元";
String sg02="土豆,价格：30元";
if (sgname != null) {
sgname = new String(sgname.getBytes("ISO-8859-1"), "utf-8");
if(sgname.equals("1")){
sgs.add(sg01);
}else{
books.add(book02);
}
}
String delete = request.getParameter("delete");
if (delete != null) {
int i = Integer.parseInt(delete);
sgs.remove(i);
}
%>
购物车中的信息为：
<br>
<%
int i = 0;
for (i = 0; i <sgs.size(); i++) {
%>
<a href="buy.jsp?delete=<%=i%> ">删除</a>
<%
out.println(sgs.get(i) + "<br>");
}
%>
<a href="main.jsp">返回主页面</a></body></html>
