java|java web实现自动登录 javaweb实现自动登录

本文实例为大家分享了java web实现自动登录的具体代码，供大家参考，具体内容如下
实现思路
1、在登录的 api 或 servlet中验证用户名密码
2、如果验证成功，则把该用户信息存在服务器的 session 缓存中，并把可以表示该用户的信息存在 cookie中返回。例如：

//存储 session request.getSession().setAttribute("userBean", queryUser); Cookie cookie = new Cookie("auto_login", username + "#" + password); // 创建 cookiecookie.setMaxAge(60*60*24*7); //设置时间为一周cookie.setPath(request.getContextPath()); response.addCookie(cookie);

3、创建一个过滤器，拦截所有的用户请求
4、在该过滤器中做相应的逻辑处理，如下：

获取服务器 session 缓存中同名的session。例如： UserBean userBean = (UserBean) request.getSession().getAttribute("userBean");
验证是否为空，不为空说明用户登陆之后没有关闭浏览器，直接让请求通过过滤器，并定位到相应界面
如果session为空，说明用户从上一次登陆后关闭过浏览器，则获取用户请求中的cookie，验证是否有我们定义的可以标识用户的特殊cookie。
如果没有改cookie ，则直接返回登陆界面。
如果有该cookie，则通过cookie中的信息查新到用户的信息，并跳转到用户想跳转的界面

核心代码示例
servlet 登陆逻辑代码

package com.wl.servlet; import com.wl.dao.UserDao; import com.wl.dao.daoImpl.UserDaoImpl; import com.wl.domain.UserBean; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.sql.SQLException; @WebServlet(name = "LoginServlet")public class LoginServlet extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response); }protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {try {String username = request.getParameter("username"); String password = request.getParameter("password"); String autoLogin = request.getParameter("auto_login"); System.out.println(username + " = " + password + "" + autoLogin); UserBean userBean = new UserBean(); userBean.setPassword(password); userBean.setUsername(username); UserDao userDao = new UserDaoImpl(); UserBean queryUser = userDao.login(userBean); if(queryUser != null){if("on".equals(autoLogin)){Cookie cookie = new Cookie("auto_login", username + "#" + password); cookie.setMaxAge(60*60*24*7); cookie.setPath(request.getContextPath()); response.addCookie(cookie); }request.getSession().setAttribute("userBean", queryUser); response.sendRedirect("index.jsp"); }else {request.getSession().setAttribute("errorInfo", "用户名密码不正确"); request.getRequestDispatcher("login.jsp").forward(request,response); }} catch (SQLException e) {e.printStackTrace(); }}}

filter 过滤器核心代码

package com.wl.filter; import com.wl.dao.UserDao; import com.wl.dao.daoImpl.UserDaoImpl; import com.wl.domain.UserBean; import util.CookieUtil; import javax.servlet.*; import javax.servlet.annotation.WebFilter; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import java.io.IOException; import java.sql.SQLException; @WebFilter(filterName = "AutoLoginFilter")public class AutoLoginFilter implements Filter {public void destroy() {}public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {HttpServletRequest request = (HttpServletRequest) req; UserBean userBean = (UserBean) request.getSession().getAttribute("userBean"); if(userBean != null){chain.doFilter(req, resp); } else {Cookie[] cookies = request.getCookies(); Cookie auto_login = CookieUtil.findCookie(cookies, "auto_login"); if(auto_login == null) {chain.doFilter(req,resp); } else {String value = https://www.it610.com/article/auto_login.getValue(); String username = value.split("#")[0]; String password = value.split("#")[1]; UserBean user = new UserBean(); user.setUsername(username); user.setPassword(password); UserDao dao = new UserDaoImpl(); try {UserBean login = dao.login(user); request.getSession().setAttribute("userBean", login); } catch (SQLException e) {e.printStackTrace(); }chain.doFilter(req, resp); }}chain.doFilter(req, resp); }public void init(FilterConfig config) throws ServletException {}}

【java|java web实现自动登录】以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。