本文实例为大家分享了JavaWeb实现自动登录功能的具体代码，供大家参考，具体内容如下
自动登录是通过存储cookie值来实现的。
工程目录如下：
login.jsp:
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<%@ 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>登录</title></head><body> <form action="login" method="post"> 用户名：<input name="username" type="text"><br> 密码：<input name="password" type="password"> <input type="checkbox" name="autoLogin" value="autoLogin">自动登录 <input type="submit" value="提交"> </form></body></html> |
success.jsp(主要用于测试是否储存成功):
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<%@ 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> ${sessionScope.username }<br> ${sessionScope.password }</body></html> |
LoginServlet(用于登录逻辑处理):
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package servletLogin; import java.io.IOException;import java.net.URLEncoder; import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession; public class LoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); String username = request.getParameter("username"); String password = request.getParameter("password"); HttpSession session = request.getSession(); //登录成功，（在这应该是和数据库的值对比） if(username.equals("alan呵呵") && password.equals("123")){ String autoLogin = request.getParameter("autoLogin"); if(autoLogin!=null){ //编码是为了在cookie中存储汉字 String usernameCode = URLEncoder.encode(username, "utf-8"); Cookie usernameCookie = new Cookie("username",usernameCode); Cookie passwordCookie = new Cookie("password",password); //设置持久化时间 usernameCookie.setMaxAge(60*60); passwordCookie.setMaxAge(60*60); //设置cookie携带路径 usernameCookie.setPath(request.getContextPath()); passwordCookie.setPath(request.getContextPath()); //发送cookie response.addCookie(usernameCookie); response.addCookie(passwordCookie); } session.setAttribute("username", username); session.setAttribute("password", password); response.sendRedirect("success.jsp"); }else{ request.getRequestDispatcher("login.jsp").forward(request, response); } }} |
LoginFilter(用于自动登录的拦截器):
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package filter; import java.io.IOException;import java.net.URLDecoder; 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.HttpSession; public class LoginFilter implements Filter { public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request; HttpSession session = req.getSession(); // 获得cookie中用户名和密码 进行登录的操作 // 定义cookie_username String cookie_username = null; // 定义cookie_password String cookie_password = null; // 获得cookie Cookie[] cookies = req.getCookies(); if (cookies != null) { for (Cookie cookie : cookies) { // 获得名字是cookie_username和cookie_password if ("username".equals(cookie.getName())) { cookie_username = cookie.getValue(); // 对cookie中的值解码 cookie_username = URLDecoder.decode(cookie_username, "UTF-8"); } if ("password".equals(cookie.getName())) { cookie_password = cookie.getValue(); } } } if(cookie_username != null && cookie_password != null){ if(cookie_username.equals("alan呵呵") && cookie_password.equals("123")){ session.setAttribute("username", cookie_username); session.setAttribute("password", cookie_password); } } chain.doFilter(request, response); } public void destroy() { } public void init(FilterConfig fConfig) throws ServletException { }} |
web.xml配置文件：
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<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID"version="2.5"> <display-name>WEB24</display-name> <!-- 自动登录的filter --> <filter> <filter-name>AutoLoginFilter</filter-name> <filter-class>filter.LoginFilter</filter-class> </filter> <filter-mapping> <filter-name>AutoLoginFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>servletLogin.LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping> </web-app> |
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服务器之家。
原文链接：https://blog.csdn.net/Alan_TW/article/details/80535844
