我在 JSP 中制作了一个登录脚本。它工作正常但问题是我使用
<%=session.getAttribute("first_name")%>它显示Null .你能告诉我这里出了什么问题吗？
Main.jsp :
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%
if ((session.getAttribute("user_email") == null) || (session.getAttribute("user_email") == "")) {
response.sendRedirect("login.jsp");
%>
<%} else
%>
<!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>Welcome to the job seeker forum.</title>
<link rel="stylesheet" type="text/css" href="CSS_styles/forum_style.css"/>
<link rel='stylesheet' id='open-sans-css' href='//fonts.googleapis.com/css?family=Open+Sans%3A300italic%2C400italic%2C600italic%2C300%2C400%2C600&subset=latin%2Clatin-ext&ver=4.1-alpha-20141011' type='text/css' media='all' />
<link href='http://fonts.googleapis.com/css?family=Londrina+Solid|Exo:800|Open+Sans:300italic,400,300,600|Roboto:400,100,300,500,700' rel='stylesheet' type='text/css' />
</head>
<body>
<div id="forum">
<h1><b>Welcome <%=session.getAttribute("first_name")%></b>,<br>to Job seeker forum, there are many openings that you can get through here. <a href='logout.jsp'>logout</a></h1>
<form id="forum_form" method="post">
</form>
</div><br><br><br>
<div id="forum2">
<h1 style="text-align: center;">Want to post on going walking,<br>Post your job description here.</h1>
<form id="forum2_form" method="post">
<p>
<label>Job title:</label>
<input type="text" class="" placeholder="e.g XXX Referral program for freshers."/>
</p>
<p>
<label>Your Question:</label>
<textarea class="question_ask_style" rows="3" cols="40" placeholder="Type description here.."></textarea>
</p>
<div id="submit_btn">
<input type="submit" value="Submit Question" />
</div>
</form>
</div>
</body>
</html>
这里是 login_process.jsp
<%@ page import="java.sql.*" %>
<%
String user_email=request.getParameter("user_email");
String user_password=request.getParameter("user_password");
Class.forName("com.mysql.jdbc.Driver");
Connection con=DriverManager.getConnection("jdbc:mysql://localhost:8888/login", "root", "1234");
Statement st=con.createStatement();
ResultSet rs;
rs=st.executeQuery("select * from members where email='"+user_email+"' and password='"+user_password+"'");
if(rs.next()){
session.setAttribute("user_email", user_email);
response.sendRedirect("main.jsp");
}else{
out.println("Invalid Password... Try again.. <a href='login.jsp'>login</a>");
}
%>
这是我创建的 database table :
create table `members`(
`id` int(10) unsigned NOT NULL auto_increment,
`email` varchar(100) NOT NULL,
`password` varchar(100) NOT NULL,
`first_name` varchar(50) NOT NULL,
`last_name` varchar(50) NOT NULL,
PRIMARY KEY(`id`)
)ENGINE= InnoDB default charset=latin1;
这就是我遇到的错误...
最佳答案
<%=session.getAttribute("first_name")%>显示null因为你没有设置 first_name在 session 中。
您设置了唯一的 user_email .
if(rs.next()){
String user_email=rs.getString("first_name");
session.setAttribute("user_email", user_email);
response.sendRedirect("main.jsp");
可以像上面那样设置
附言
几十年来不鼓励使用 Scriptlet，因此建议使用 EL 而不是它们。您可以简单地使用 , ${sessionScope.user_email}在jsp页面打印出来
关于java - 数据库中的用户名未显示在网页中？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26751307/