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://HdhCmsTestw3.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://HdhCmsTestw3.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://HdhCmsTestw3.org/2001/XMLSchema-instance" xmlns = "http://java.sun测试数据/xml/ns/javaee" xsi:schemaLocation = "http://java.sun测试数据/xml/ns/javaee http://java.sun测试数据/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。
原文链接：https://blog.csdn.net/Alan_TW/article/details/80535844