form 登陆跳转页面练习（未连接数据库）和连接数据库版

<%@ 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>
<style>

.a{500px;height:300px ;border : 1px solid #FF0000 ; left : 240px ; top : 120px ;
        position : relative ;background-color: purple; text-align: center ;}
</style>
<body>

<hr>
<font style="text-shadow: 3px 3px 3px #FF0000">
不会连接数据库，所以先默认账号123，默认密码000，做练习
</font>
<hr>
<div class="a">
<h1>银行自助终端系统</h1>

<form action="NewFile1.jsp" method="get">
卡号<input type="text"  name="name"><br>
<br><br>
密码<input type="password"  name="password"><br>
<br><br>
<input type="reset" value="重置" >  
<input type="submit" value="登陆">
</form>

</div>
</body>
</html>
<%@page import="java.sql.SQLException"%>
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.DriverManager"%>
<%@page import="java.sql.Connection"%>
<%@ 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 name = request.getParameter("name") ;

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

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

out.write("<br>收到的参数<br>用户名："+name+"<br> 密码："+password+"<br>") ;

if(name.equals("123"))
{
    if(password.equals("000"))
    {
%>
        <!-- 账号密码正确跳转登陆页面-->
        <jsp:forward page="success.jsp"></jsp:forward>
<% 
    }
    else
    {
%>
        <!-- 账号正确密码错误跳转密码错误提示页面 -->
        <jsp:forward page="failpassword.jsp"></jsp:forward>
<% 
    }
}
else
{
%>
    <!-- 账号错误跳转账号错误提示页面 -->
    <jsp:forward page="failkahao.jsp"></jsp:forward>
<% 
}

%>
<!-- 
try {
    Class.forName("oracle.jdbc.driver.OracleDriver") ;
    
    String url ="jdbc:oracle:thin:@localhost:1521:orcl" ;
    
    Connection conn = DriverManager.getConnection(url,"test0816","934617699") ;
    
    String sql = "select * from account_bank where kahao= ? " ;
    
    PreparedStatement ps = conn.prepareStatement(sql) ;
    
    ps.setString(1, name);
    
    ResultSet rs = ps.executeQuery() ;
    
    if(rs.next())
    {
        if(password.equals(rs.getString("passqord")))
        {
            //out.write("登陆成功") ;
        }
        else
        {
            //out.write("密码错误") ;
        }
    }
    else
    {
        out.write(22) ;
        //out.write("账号错误") ;
    }
} catch (Exception e) {
    // TODO 自动生成的 catch 块
    e.printStackTrace();
}
 -->
</body>
</html>
<%@ 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>

<h2>当输入账号错误的时候跳转该到页面</h2>
<br>
<h1>卡号不存在！！！！！！</h1>
</body>
</html>
<%@ 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>
<h2>当输入密码错误的时候跳转到该页面</h2>
<br>
<h1>密码错误！！！！！！</h1>
</body>
</html>
<%@ 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>
<h1>当都输入正确的时候进入该页面</h1>
<br>
<h1>登陆成功！</h1>

</body>
</html>

账号不对时

卡号正确，密码错误的时候

当密码卡号都正确时

 ==================================连接数据库版======================================

<%@page import="java.sql.SQLException"%>
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.DriverManager"%>
<%@page import="java.sql.Connection"%>
<%@ 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 name = request.getParameter("name") ;

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

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

out.write("<br>收到的参数<br>用户名："+name+"<br> 密码："+password+"<br>") ;


try {
    Class.forName("oracle.jdbc.driver.OracleDriver") ;
    
    String url ="jdbc:oracle:thin:@localhost:1521:orcl" ;
    
    Connection conn = DriverManager.getConnection(url,"test0816","934617699") ;
    
    String sql = "select * from account_bank where kahao= ? " ;
    
    PreparedStatement ps = conn.prepareStatement(sql) ;
    
    ps.setString(1, name);
    
    ResultSet rs = ps.executeQuery() ;
    
    if(rs.next())
    {
        if(password.equals(rs.getString("password")))
        {
    %>
            <!-- 账号密码正确跳转登陆页面-->
            <jsp:forward page="success.jsp"></jsp:forward>
    <% 
        }
        else
        {
            %>
            <!-- 账号正确密码错误跳转密码错误提示页面 -->
            <jsp:forward page="failpassword.jsp"></jsp:forward>
    <%
        }
    }
    else
    {
        %>
        <!-- 账号错误跳转账号错误提示页面 -->
        <jsp:forward page="failkahao.jsp"></jsp:forward>
    <% 
    }
} catch (Exception e) {
    // TODO 自动生成的 catch 块
    e.printStackTrace();
}
%>
</body>
</html>

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原文地址：https://www.cnblogs.com/20gg-com/p/6009240.html