UserDao.java从数据库中查询用户名与密码
//登录public User login(User user) throws SQLException {QueryRunner qr = new QueryRunner(DataSourceUtils.getDataSource());String sql = "select from user where username = ? and password = ?";return qr.query(sql, new BeanHandler<User>(User.class),user.getUsername(),user.getPassword());}UserService.javapublic User login(User user){try {return ud.login(user);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return null;}
UserServlet.java实现登录功能
//登录public void login(HttpServletRequest request,HttpServletResponse response) throws IOException, IllegalAccessException, InvocationTargetException, ServletException{Map<String,String[]> map = request.getParameterMap();User user = new User();BeanUtils.populate(user,map);if (map.get("autoLogin")!=null){Cookie username = new Cookie("username", map.get("username")[0]);username.setMaxAge(6060);Cookie password = new Cookie("password", map.get("password")[0]);password.setMaxAge(60*60);response.addCookie(username);response.addCookie(password);}user = us.login(user);if (user != null){request.getSession().setAttribute("user", user);response.sendRedirect("/ShopStore/default.jsp");}else{request.setAttribute("message", "用户或密码错误！");request.getRequestDispatcher("/login.jsp").forward(request, response);}}
工具类:AutoLoginFilter.java用来实现自动登录
package com.yinhe.web.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.yinhe.bean.User;import com.yinhe.service.UserService;public class AutoLoginFilter implements Filter{br/>@Overridepublic void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {HttpServletRequest req = (HttpServletRequest)request;HttpServletResponse resp = (HttpServletResponse)response;//是否已登录if (req.getSession().getAttribute("user") == null){//如果已登录，则啥都不干//判断cookie中有没有账户密码Cookie[] cookies = req.getCookies();if (cookies != null){String username = "";String userpass = "";for (Cookie cookie : cookies) {if (cookie.getName().equals("username")){//找到感兴趣的cookieusername = cookie.getValue();}if (cookie.getName().equals("password")){//找到感兴趣的cookieuserpass = cookie.getValue();}}UserService us = new UserService();User user = new User();user.setUsername(username);user.setPassword(userpass);if (us.login(user) != null){req.getSession().setAttribute("user", user);}}}chain.doFilter(request, response);br/>}@Overridepublic void init(FilterConfig filterConfig) throws ServletException {// TODO Auto-generated method stubbr/>}@Overridepublic void destroy() {// TODO Auto-generated method stub}}
前台:login.jsp此单选框被选中下次访问即为自动登录
<p class="checkbox"><label> <input type="checkbox" name="autoLogin" > 自动登录</label> <label> <inputtype="checkbox" > 记住用户名</label></p><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head><title>系统首页</title><style>#nav{height: 88px;padding: 5px 200px;background-color: aquamarine;}#logo{float: left;}#userinfo{float: right;height: 50px;line-height: 80px;}#container{background-color: aqua;height: 800px;margin: 2px 200px;font-size: xx-large;text-align: center;}</style></head><body><p id="nav"><p id="logo"><img src="csdn-logo.png" width="180" height="88"></p><p id="userinfo"><%-- 不推荐使用<%String loginUser = (String) request.getAttribute("loginUser");if (loginUser != null){out.println(loginUser);}else {%><a href="login.jsp" rel="external nofollow" rel="external nofollow" rel="external nofollow" >登录</a><a>/注册</a><%}%>--%><%String loginUser = (String) session.getAttribute("loginUser");if (loginUser != null){out.println(loginUser);out.println("<a href='logoutServlet'>退出</a>");}else {%><a href="login.jsp" rel="external nofollow" rel="external nofollow" rel="external nofollow" >登录</a><a>/注册</a><%}%></p></p><p id="container">
主页内容
<a href="info.jsp" rel="external nofollow" >Python——画一棵漂亮的樱花树（不同种樱花+玫瑰+圣诞树喔）</a></p></body></html>login.jsp<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head><title>登录</title><style>tr{height:50px;}td{text-align: center;}</style></head><body><%String msg = (String)request.getAttribute("msg");%><%if(msg != null){out.print(msg);}%><form action="myServlet02" method="get"><h1 align="center">登录</h1><table width="500" border="1" cellspacing="0" cellpadding="0" align="center"><tr><td>账号：</td><td><input type="text" name="username" /></td></tr><tr><td>密码：</td><td><input type="password" name="password" /></td></tr><tr><td colspan="2"><input type="submit" value="登录" /></td></tr></table></form></body></html>
info.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head><title>Title</title><style>#nav{height: 88px;padding: 5px 200px;background-color: aquamarine;}#logo{float: left;}#userinfo{float: right;height: 50px;line-height: 80px;}#container{background-color: aqua;height: 800px;margin: 2px 200px;font-size: xx-large;text-align: center;}</style></head><body><p id="nav"><p id="logo"><img src="csdn-logo.png" width="180" height="88"></p><p id="userinfo"><%String loginUser = (String) session.getAttribute("loginUser");if (loginUser != null){out.println(loginUser);out.println("<a href='logoutServlet'>退出</a>");}else {%><a href="login.jsp" rel="external nofollow" rel="external nofollow" rel="external nofollow" >登录</a><a>/注册</a><%}%></p></p><p id="container">主页内容</p></body></html>
Servlet02.java
import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import java.io.IOException;br/>@WebServlet("/myServlet02")public class Servlet02 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//修改编码request.setCharacterEncoding("utf-8");//请求过来的编码是亨达返佣www.kaifx.cn/broker/hantecglobal.htmlutf-8response.setContentType("text/html;charset=utf-8");//响应出去的内容，为网页编码utf-8//获取表单数据String username = request.getParameter("username");String password = request.getParameter("password");//验证if("aaa".equals(username) && "123".equals(password)){//跳转(请求转发 请求重定向)//重定向：两次请求，不能在request作用域中共享数据。//如果要在两次请求或多次请求之间，进行数据共享，需要用session//使用session步骤//获取sessionHttpSession session = request.getSession();//如果存在已有的session，则直接返回，否则会创建一个新的，返回。//HttpSession session = request.getSession(true);//同上//HttpSession session = request.getSession(false);//如果存在已有的session，则直接返回，否则返回null。//在session的作用域保存数据，供后续请求使用session.setAttribute("loginUser",username);response.sendRedirect("index.jsp");/ 多个页面不推荐使用请求转发request.setAttribute("loginUser",username);request.getRequestDispatcher("index.jsp").forward(request,response);/}else {//转发：一次请求，可以在request作用域中，共享数据request.setAttribute("msg","<script>alert('登录失败！');</script>");// response.sendRedirect("login.jsp");request.getRequestDispatcher("login.jsp").forward(request,response);}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}}
LogoutServlet.java
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 java.io.IOException;br/>@WebServlet("/logoutServlet")public class LogoutServlet extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//退出系统//获取sessionHttpSession session = request.getSession();//删除sessionsession.removeAttribute("loginUser");//跳转到登录页面/首页response.sendRedirect("index.jsp");}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}}
web.xml
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"version="3.1"><welcome-file-list><welcome-file>index.jsp</welcome-file></welcome-file-list></web-app>
总结
以上所述是小编给大家介绍的使用Java servlet实现自动登录退出功能，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！如果你觉得本文对你有帮助，欢迎转载，烦请注明出处，谢谢！
本文标题: 使用Java servlet实现自动登录退出功能
以上就上有关使用Javaservlet实现自动登录退出功能的相关介绍，要了解更多java,自动登录,退出,java,servlet内容请登录学步园。