JavaWeb實現自動登入功能
阿新 • • 發佈：2021-08-16
本文例項為大家分享了Web實現自動登入功能的具體程式碼，供大家參考，具體內容如下
自動登入是通過儲存cookie值來實現的。
工程目錄如下：
login.p:
<%@ 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>登入</title>
</head>
<body>
<form action="login" method="post">
使用者名稱：<input name="username" type="text"><br>
密碼：<input name="password" type="password">
<input type="checkbox" name="autoLogin" value="autoLogin">自動登入
<input type="submit" value="提交">
</form>
</body>
</html>success.jsp(主要用於測試是否儲存成功):
<%@ 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(用於登入邏輯處理):
package servletLogin; import java.io.IOException; import java.net.URLEncoder; import javax.servlet.ServletException; import javax.servlet.http.Cookie; http://www.cppcns.comimport 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,IOException { request.setCharacterEncoding("utf-8"); String username = request.getParameter("username"); String password = request.getParameter("password"); HttpSession session = request.getSession(); //登入成功，（在這應該是和的值對比） if(username.equals("alan呵呵") && password.equals("123")){ String autoLogin = request.getParameter("autoLogin"); if(autoLogin!=null){ //編碼是為了在cookie中儲存漢字 http://www.cppcns.comString usernameCode = URLEncoder.encode(username,"utf-8"); Cookie usernameCookie = new Cookie("username",usernameCode); Cookie passwordCookie = new Cookie("password",password); //設定持久化時間 usernameCookie.setMaxAge(60*60); passwordCookie.setMaxAge(60*60); //設定cookie攜帶路徑 usernameCookie.setPath(request.getContextPath()); passwordCookie.setPath(request.getContextPath()); //傳送cookie response.addCookie(usernameCookie); response.addCookie(passwordCookie); http://www.cppcns.com } session.setAttribute("username",username); session.setAttribute("password",password); response.sendRedirect("success.jsp"); }else{ request.getRequestDispatcher("login.jsp").forward(request,response); } } }
LoginFilter(用於自動登入的攔截器):
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();
// 獲得cookie中使用者名稱和密碼 進行登入的操作
// 定義cookie_username
String cookie_username = null;
// 定義cookie_password
String cookie_password = null;
// 獲得cookie
Cookie[] cookies = req.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
// 獲得名字是cookie_username和cookie_password
if ("username".equals(cookie.getName())) {
cookie_username = cookie.getValue();
// 對cookie中的值解碼
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配置檔案：
<?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>
<!-- 自動登入的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>http://www.cppcns.com
</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內容，希望對大家的學習有所幫助，也希望大家多多支援我們。