1、登录页面代码
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
session.invalidate();
%>
<form action="panduan.jsp"method="post">
用户名：<input type="text" name="user"><br>
密    码：<input type="password" name="mima"><br>
<input type="submit" value="登录">
</form>
</body>
</html>
2、判断提交数据代码
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
String nm=request.getParameter("user");
String mm=request.getParameter("mima");
if(nm!=""&&mm!="")
{
if(nm.equals("lisi")&&mm.equals("123"))
{
session.setAttribute("user", nm);
response.sendRedirect("zhuye.jsp");
}
else
{
out.print("请输入正确的用户名和密码！");
%>
<br>
<a href="denglu1.jsp">点击返回登录页</a>
<%
}
}
else
{
out.print("您输入的用户名或密码为空！");
%>
<br>
<a href="denglu1.jsp">点击返回登录页</a>
<%
}
%>
</body>
</html>
3、主页代码
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
Object ob=session.getAttribute("user");
if(ob!=null)
{
out.print("欢迎您，"+ob.toString());
}
else
{
out.print("连接超时，请3秒后重新登录！");
response.setHeader("refresh", "3;URL=denglu1.jsp");
}
%>
<br>
<a href="denglu1.jsp">退出当前用户！</a>
</body>
</html>
4、运行结果
【1】输入为空时，运行结果
【2】输入错误时运行结果
【4】输入正确时运行结果
