使用Java servlet實現自動登入退出功能
阿新 • • 發佈:2020-01-07
UserDao.java從資料庫中查詢使用者名稱與密碼
//登入 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.java public User login(User user){ try { return ud.login(user); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; }
UserServlet.java實現登入功能
//登入 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","使用者或密碼錯誤!"); request.getRequestDispatcher("/login.jsp").forward(request,response); } }
工具類:AutoLoginFilter.java用來實現自動登入
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/>@Override public void doFilter(ServletRequest request,ServletResponse response,FilterChain chain) throws IOException,ServletException { HttpServletRequest req = (HttpServletRequest)request; HttpServletResponse resp = (HttpServletResponse)response; //是否已登入 if (req.getSession().getAttribute("user") == null){//如果已登入,則啥都不幹 //判斷cookie中有沒有賬戶密碼 Cookie[] cookies = req.getCookies(); if (cookies != null){ String username = ""; String userpass = ""; for (Cookie cookie : cookies) { if (cookie.getName().equals("username")){//找到感興趣的cookie username = cookie.getValue(); } if (cookie.getName().equals("password")){//找到感興趣的cookie userpass = 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/>} @Override public void init(FilterConfig filterConfig) throws ServletException { // TODO Auto-generated method stubbr/>} @Override public void destroy() { // TODO Auto-generated method stub } }
前臺:login.jsp此單選框被選中下次訪問即為自動登入
<div class="checkbox"> <label> <input type="checkbox" name="autoLogin" > 自動登入 </label> <label> <input type="checkbox" > 記住使用者名稱 </label> </div> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>系統首頁</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> <div id="nav"> <div id="logo"> <img src="csdn-logo.png" width="180" height="88"> </div> <div id="userinfo"> <%-- 不推薦使用 <% 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" >登入</a><a>/註冊</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" >登入</a><a>/註冊</a> <% } %> </div> </div> <div id="container">
主頁內容
<a href="info.jsp" rel="external nofollow" >Python——畫一棵漂亮的櫻花樹(不同種櫻花+玫瑰+聖誕樹喔)</a> </div> </body> </html> login.jsp <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>登入</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">登入</h1> <table width="500" border="1" cellspacing="0" cellpadding="0" align="center"> <tr> <td>賬號:</td> <td><input type="text" name="username" /></td> </tr> <tr> <td>密碼:</td> <td><input type="password" name="password" /></td> </tr> <tr> <td colspan="2"><input type="submit" value="登入" /></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> <div id="nav"> <div id="logo"> <img src="csdn-logo.png" width="180" height="88"> </div> <div 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" >登入</a><a>/註冊</a> <% } %> </div> </div> <div id="container"> 主頁內容 </div> </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 { //修改編碼 request.setCharacterEncoding("utf-8");//請求過來的編碼是亨達返傭www.kaifx.cn/broker/hantecglobal.htmlutf-8 response.setContentType("text/html;charset=utf-8");//響應出去的內容,為網頁編碼utf-8 //獲取表單資料 String username = request.getParameter("username"); String password = request.getParameter("password"); //驗證 if("aaa".equals(username) && "123".equals(password)){ //跳轉(請求轉發 請求重定向) //重定向:兩次請求,不能在request作用域中共享資料。 //如果要在兩次請求或多次請求之間,進行資料共享,需要用session //使用session步驟 //獲取session HttpSession session = request.getSession();//如果存在已有的session,則直接返回,否則會建立一個新的,返回。 //HttpSession session = request.getSession(true);//同上 //HttpSession session = request.getSession(false);//如果存在已有的session,則直接返回,否則返回null。 //在session的作用域儲存資料,供後續請求使用 session.setAttribute("loginUser",username); response.sendRedirect("index.jsp"); / 多個頁面不推薦使用請求轉發 request.setAttribute("loginUser",username); request.getRequestDispatcher("index.jsp").forward(request,response); / }else { //轉發:一次請求,可以在request作用域中,共享資料 request.setAttribute("msg","<script>alert('登入失敗!');</script>"); // response.sendRedirect("login.jsp"); request.getRequestDispatcher("login.jsp").forward(request,response); } } protected void doGet(HttpServletRequest request,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,IOException { //退出系統 //獲取session HttpSession session = request.getSession(); //刪除session session.removeAttribute("loginUser"); //跳轉到登入頁面/首頁 response.sendRedirect("index.jsp"); } protected void doGet(HttpServletRequest 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>
總結
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