用Session完成登录验证

最新推荐文章于 2025-05-29 17:48:18 发布

原创最新推荐文章于 2025-05-29 17:48:18 发布 · 2.7k 阅读

17 ·

CC 4.0 BY-SA版权

java 同时被 3 个专栏收录

120 篇文章

订阅专栏

Servlet

23 篇文章

订阅专栏

jsp

11 篇文章

订阅专栏

本文介绍了如何通过Session进行登录验证。主要涉及了jsp、Servlet、JavaBean及DAO、Service层的交互，包括User类、IUserDao接口、UserDaoImpl实现类、IUserService接口、UserServiceImpl实现类、LogonServlet登录处理以及ProductServlet中检查用户Session状态来实现权限控制。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

效果图：
在这里插入图片描述

代码：
index3.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>

<body>
	${msg}
	<form action="/logon2" method="post">
		姓名：<input type="text" name="username"/><br/>
		密码：<input type="text" name="password"/><br/>
		<input type="submit" value="登录"/>
	</form>
</body>
</html>

<%session.invalidate(); %>

main.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<h1>欢迎${USER_IN_SESSION.username}登录本系统，<a href="/index3.jsp">退出</a></h1>
	<hr>
	<center><h2>商品列表</h2></center>
</body>
</html>

User.java：

package text.session.bean;

public class User {
	
	private String username;
	private String password;
	
	
	
	
	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public User(String username, String password) {
		super();
		this.username = username;
		this.password = password;
	}

	public User() {
	}
	
	
	
	

}

IUserDao.java（接口）：

package text.session.dao;

import text.session.bean.User;

public interface IUserDao {
	
	User selectByUsernameAndPassword(String username,String password);

}

UserDaoImpl.java：

package text.session.dao.impl;

import text.session.bean.User;
import text.session.dao.IUserDao;

public class UserDaoImpl implements IUserDao {

	public User selectByUsernameAndPassword(String username, String password) {
		
		//查询数据库
		if("rose".equals(username) && "123".equals(password)){
			User user = new User("rose","123");
			return user;
		}
		return null;
	}

}

IUserService.java（接口）：

package text.session.service;


import text.session.bean.User;

public interface IUserService {

	User Login(String username,String password);
}

UserServiceImpl.java：

package text.session.service.impl;

import text.session.bean.User;
import text.session.dao.IUserDao;
import text.session.dao.impl.UserDaoImpl;
import text.session.service.IUserService;

public class UserServiceImpl implements IUserService {

	private IUserDao dao = new UserDaoImpl();
	
	public User Login(String username, String password) {
		return dao.selectByUsernameAndPassword(username, password);
	}

}

LogonServlet.java：

package text.session.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import text.session.bean.User;
import text.session.service.IUserService;
import text.session.service.impl.UserServiceImpl;

@WebServlet("/logon2")
public class LogonServlet extends HttpServlet{
	
	private IUserService service = new UserServiceImpl();

	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		
		//获取请求的参数
		String username = req.getParameter("username");
		String password = req.getParameter("password");

		//调用业务的方法
		User user = service.Login(username, password);
		
		
		//控制页面的跳转
		if(user!=null) {
			
			//把用户逇信息，存入session的作用域
			HttpSession session = req.getSession();
			session.setAttribute("USER_IN_SESSION", user);

			resp.sendRedirect("/main");
		}else {
			req.setAttribute("msg", "用户名或者密码错误！！");
			req.getRequestDispatcher("/index3.jsp").forward(req, resp);
		}
		
	}
	
	
}

ProductServlet.java：

package text.session.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@WebServlet("/main")
public class ProductServlet extends HttpServlet{

	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		
		//判断用户是否登录
		//判断Session的作用域中是否有“USER_IN_SESSION” 的值
		HttpSession session = req.getSession();
		Object object = session.getAttribute("USER_IN_SESSION");
		
		if(object == null) {
			resp.sendRedirect("/index3.jsp");
			return;
		}

		req.getRequestDispatcher("/main.jsp").forward(req, resp);
		
	}

	
}