简单登陆，注册的动态网页

登陆页 login.jsp

<%@ 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>登陆页</title>

<script type="text/javascript">

function check()
{
    var uid = document.getElementById("userid");
    
    if(uid.value =="")
        {
        alert("请输入用户名");
        
        return false;
        }
    if(dlform.password.value == "")
        {
        alert("密码不能为空")
        
        return false;
        }
    return true;
    }
</script>

</head>
<body>

<form id="dlform" action="yanzheng.jsp" method="post" onSubmit="return check();">

用户名：<input id="userid" name="userid" type="text" value="请输入用户名" size="20"/>

密码：<input id="password" name="password" type="password" size="20"/>

<input type="submit" value="登陆" />

<a href="zhuce.jsp">注册新用户</a>

</form>

</body>
</html>

登陆验证页 yanzheng.jsp

<%@ 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>验证页</title>
</head>
<body>

<%
String userid = request.getParameter("userid");

String password = request.getParameter("password");

/* if(userid == null || userid.trim().length() == 0)
{
    response.sendRedirect("cuowutishi.jsp?msgid=1");
}
else if(password == null || password.trim().length() == 0)
{
    response.sendRedirect("cuowutishi.jsp?msgid=2");
}
else
{  */ //查找用户信息
    Object user = application.getAttribute("userxinxi");

        String[] zcuser = user.toString().split("#") ;
    
        String zcuserid = zcuser[0];
        String zcusername = zcuser[1];
        String zcpassword = zcuser[2];
    
         if(userid.equals(zcuserid))
        {
            if(password.equals(zcpassword))
            {
                out.print("欢迎" + zcusername + "登陆成功");
            
            //跳转到系统页面
            }
            else
            {
                response.sendRedirect("cuowutishi.jsp?msgid=3");
            }
            }
        else
        {
            response.sendRedirect("cuowutishi.jsp?msgid=4");
        }
//}

%>

</body>
</html>

注册页面 zhuce.jsp

<%@ 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>注册新用户</title>

<script type="text/javascript">
function check()
{
    if(zcform.zcid.value == "")
        {
        alert("请输入用户名");
        
        return false;
        }
    
    if(zcform.zcname.value == "")
        {
        alert("请输入用户昵称");
        
        return false;
        }
    
    if(zcform.zcpassword.value == "")
        {
        alert("请输入密码");
    
        return false;
        }
    
    if(zcform.qrpassword.value == "")
        {
        alert("请输入确认密码");

        return false;
        }
    if(zcform.qrpassword.value !== zcform.zcpassword.value)
        {
        alert("确认密码与用户密码不一致");
        
        return false;
        }
    
    return true;
    }
</script>

</head>
<body>

<form id= "zcform" action="saveUser.jsp" method="get" onsubmit="return check();">

用户代码：<input id="zcid" name="userid" type="text" size="20" /><br><br>

用户名称：<input id="zcname" name="username" type="text" size="20" /><br><br>

用户密码：<input id="zcpassword" name="password" type="password" size="20" /><br><br>

确认密码：<input id="qrpassword" name="qrpassword" type="password" size="20" /><br><br>

<input type="submit" value="提交" /><br>

<a href="login.jsp">返回登陆页</a>

</form>

</body>
</html>

保存注册信息页面 saveUser.jsp

<%@ 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>保存用户信息</title>
</head>
<body>

<%

String userid = request.getParameter("userid");

String username = new String(request.getParameter("username").getBytes("ISO-8859-1"),"UTF-8");

String password = request.getParameter("password");

/* if(userid == null || userid.trim().length() == 0)
{
    response.sendRedirect("cuowutishi.jsp?msgid=1");
}
else if(password == null || password.trim().length() == 0)
{
    response.sendRedirect("cuowutishi.jsp?msgid=2");
}
else if(username == null || username.trim().length() == 0)
{
    response.sendRedirect("cuowutishi.jsp?msgid=5");
}
else {  */
    Object user = application.getAttribute("userxinxi");
    
    if(user != null)
        {
           response.sendRedirect("cuowutishi.jsp?msgid=7");
        }
    else 
    {
        String userxinxi = userid + "#" + username + "#" + password;
    
        application.setAttribute("userxinxi", userxinxi);
    
        response.sendRedirect("cuowutishi.jsp?msgid=6");
    }
//}

%>

</body>
</html>

错误提示页面 cuowutishi.jsp

<%@ 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>错误信息</title>
</head>
<body>


<%

String strMsgId = request.getParameter("msgid");

if(strMsgId == null || strMsgId.trim().length() == 0)
{
    out.print("请正确传递信息");
}
else
{
    int iMsgid = Integer.parseInt(strMsgId);
            
    switch(iMsgid)
    {
    case 1 :
        
        out.print("您输入正确的用户名");
        
        break;
        
    case 2 :
        
        out.print("您输入正确的密码");
        
        break;
        
    case 3 :
        
        out.print("密码输入错误");
        
        break;
        
    case 4 :
        
        out.print("该用户不存在");
        
        break;
        
    case 5 :
        
        out.print("请正确输入用户昵称");
        
        break;
        
    case 6 :
        
        out.print("提交成功");
        
        break;
    case 7 :
        
          out.print("该用户已存在");
          
          break;
        
    default:
        
        out.print("无法识别传递的信息");
        
        break;
    }
}

response.setHeader("refresh", "3;URL=login.jsp");

%>

</body>
</html>