Java 实现自动登陆

来源：互联网发布：淘宝店长和客服编辑：程序博客网时间：2024/05/16 11:15

<%@ page contentType="text/html;charset=UTF-8" language="java" %><%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><html><head>    <title>Login</title></head><body>    <%--用户信息验证失败，显示错误信息--%>    <c:if test="${not empty requestScope.msg}">        <div class="form-group">            <label for="username" class="col-sm-2 control-label"></label>            <div class="col-sm-10">                <font style="color: #f00; font-weight: bold;">${msg}</font>            </div>        </div>    </c:if>    <form action="${pageContext.request.contextPath}/autoLogin" method="post">        <input type="text" name="username" placeholder="请输入用户名">        <input type="password" name="password" placeholder="请输入密码">        <input type="checkbox" name="autoLogin">        <input type="submit" width="100" value="登录">    </form></body></html>

登陆表单页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %><%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><html>  <head>    <title>$Title$</title>  </head>  <body>    <%--用户信息验证成功，显示用户名--%>    <c:if test="${not empty loginUser}">      ${loginUser.username}    </c:if>  </body></html>

登陆成功跳转页

package com.zjl.main;import com.zjl.main.domain.User;import com.zjl.main.service.UserService;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 = "Test04Servlet")public class Test04Servlet extends HttpServlet {    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        request.setCharacterEncoding("UTF-8");        // 获取 request 参数        String username = request.getParameter("username");        String password = request.getParameter("password");        String autoLogin = request.getParameter("autoLogin");        // 用户登陆信息验证        User user = new User();        user.setUsername(username);        user.setPassword(password);        UserService service = new UserService();        User loginUser = null;        try {            loginUser = service.login(user);        } catch (SQLException e) {            e.printStackTrace();        }        if (loginUser != null) {            // 如果确认自动登陆，则将用户名密码封装成一个字符串，添加在cookie中返回给客户端            if (autoLogin != null) {                Cookie cookie = new Cookie("autoLoginCookie", username + "@" + password);                cookie.setPath("/");                cookie.setMaxAge(60*60);                response.addCookie(cookie);            }            // 验证成功，将用户信息设置在session对象中            request.getSession().setAttribute("loginUser", loginUser);            // 重定向至index.jsp            response.sendRedirect(request.getContextPath() + "/index.jsp");        } else {            // 验证失败，将错误信息设置在 request 中，转发到login.jsp中            request.setAttribute("msg", "用户名与密码不匹配");            request.getRequestDispatcher("/login.jsp").forward(request, response);        }    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {       this.doPost(request, response);    }}

package com.zjl.main.filter;import com.zjl.main.domain.User;import com.zjl.main.service.UserService;import javax.servlet.*;import javax.servlet.annotation.WebFilter;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;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 {        // 强转        HttpServletRequest request = (HttpServletRequest) req;        HttpServletResponse response = (HttpServletResponse) resp;        // 验证 session 中是否存在此用户        User loginUser = (User) request.getSession().getAttribute("loginUser");        if (loginUser != null) {            chain.doFilter(request, response);            return;        }        // 验证是否包含自动登陆的cookie        Cookie[] allCookie = request.getCookies();        Cookie userCookie = null;        if (allCookie != null) {            for (Cookie c : allCookie) {                if ("autoLoginCookie".equals(c.getName())) {                    userCookie = c;                    break;                }            }        }        if (userCookie == null) {            chain.doFilter(request, response);            return;        }        // 验证cookie中信息是否正确        String[] u = userCookie.getValue().split("@");        String username = u[0];        String password = u[1];        User user = new User();        user.setUsername(username);        user.setPassword(password);        UserService service = new UserService();        try {            loginUser = service.login(user);        } catch (SQLException e) {            e.printStackTrace();        }        if (loginUser == null) {            chain.doFilter(request, response);            return;        }        request.getSession().setAttribute("loginUser", loginUser);        chain.doFilter(request, response);    }    public void init(FilterConfig config) throws ServletException {    }}

过滤器

 <filter>        <filter-name>AutoLoginFilter</filter-name>        <filter-class>com.zjl.main.filter.AutoLoginFilter</filter-class>    </filter>    <filter-mapping>        <filter-name>AutoLoginFilter</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>

在web.xml中注册过滤器

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