<%@ 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>登录页</title>
</head>
<body>
<form action="yanzheng.jsp" method="post">
用户：<input type="text" name="userid" width=30 />
密码：<input type="text" name="password" width=30 />
<br>
<input type="submit" value="提交" />
</form>
</body>
</html>
登录页
<%@ 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>登录验证页面</title>
</head>
<body>
<%
String strUserid = request.getParameter("userid");
String strPW = request.getParameter("password");
if(strUserid == null || strUserid.trim().length() == 0) //trim() 去掉空格
{
response.sendRedirect("massage.jsp?msgid=1"); //跳转到massage.jsp 文件中的 msgid=1
}
else if(strPW == null || strPW.trim().length() == 0) //trim() 去掉空格
{
response.sendRedirect("massage.jsp?msgid=2");
}
else
{
//查找用户信息
String strUID = "zhangsan";
String strP = "123456";
if (strUserid.equals(strUID)) //找到账户
{
if(strPW.equals(strP))
{
response.sendRedirect("massage.jsp?msgid=3");
}
else
{
response.sendRedirect("massage.jsp?msgid=4");
}
}
else
{
response.sendRedirect("massage.jsp?msgid=5");
}
}
%>
</body>
</html>
登录验证页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.util.*" %>
<!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>消息页面</title>
</head>
<body>
<%
String strMsgID = request.getParameter("msgid");
if(strMsgID == null || strMsgID.trim().length() == 0)//如果只用后面的 如果放入一个空值，会造成空指针异常，会报错
{
out.print("请正确传递信息");
}
else
{
int iMsgid = Integer.parseInt(strMsgID);
switch(iMsgid) //当错误信息为1时 输出一句话
{
case 1:
out.print("请输入用户代码！");
break;
case 2:
out.print("请输入密码！");
break;
case 3:
out.print("登陆成功！");
break;
case 4:
out.print("密码输入错误！");
break;
case 5:
out.print("用户不存在！");
break;
default:
out.print("传递的msgid错误");
}
}
response.setHeader("refresh","3;URL=login.jsp");
%>
</body>
</html>
消息页面
时间： 2024-10-12 11:57:59