public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}
}
**2. 创建login.jsp页面以post提交传值到LoginServlet类**```html<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head><title>$Title$</title><style>*{text-align: center;}</style><body><h1>登录</h1><form action="LoginServlet" method="post"><h2>userName：<input type="text" name="username" placeholder="用户名"> <br/></h2><h2>passWord：<input type="password" name="password" placeholder="密码"> <br/></h2><h2>AutoLogin：<input type="checkbox" name="autologin" value="autologin" style="width: 20px;height: 20px"><br/></h2><input type="submit" value="登录" style="width: 100px;height: 50px"/></form></body></body></html>
3. 创建过滤器filter过滤login.jsp传过来的值
package filter;import entity.User;import javax.servlet.*;import javax.servlet.annotation.WebFilter;import javax.servlet.annotation.WebInitParam;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@WebFilter(filterName = "LoginSerlvet",urlPatterns = "/login1.jsp")public class LoginFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {HttpServletRequest request=(HttpServletRequest)servletRequest;HttpServletResponse response=(HttpServletResponse)servletResponse;//获得一个名为autologin的cookieCookie[]cookies=request.getCookies();String autologin=null;for(int i=0;cookies!=null&&i<cookies.length;i++){if("autologin".equals(cookies[i].getName())){autologin=cookies[i].getValue();break;}}if(autologin!=null){String[] parts=autologin.split("-");String username=parts[0];String password=parts[1];if("admin".equals(username)&&"123456".equals(password)){//验证成功//该用户状态user对象存入session域User user=new User();user.setUsername(username);user.setPassword(password);request.getSession().setAttribute("user",user);}}filterChain.doFilter(request,response);}@Overridepublic void destroy() {System.out.println("销毁");}}
4. 创建servlet包新建LoginServlet类接受login.jsp传过来的值
package servlet;import entity.User;import javax.print.DocFlavor;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;@WebServlet("/LoginServlet")public class LoginServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//获取用户名和密码String username = req.getParameter("username");String password = req.getParameter("password");System.out.println(username+password);//验证用户名和密码if ("admin".equals(username) && "123456".equals(password)){//验证成功//将用户状态存入session域User user = new User();user.setUsername(username);user.setPassword(password);req.getSession().setAttribute("user", user);//发送自动的cookieString autologin = req.getParameter("autologin");System.out.println("autologin=" + autologin);if (autologin != null) {Cookie cookie = new Cookie(autologin, username + "-" + password);cookie.setMaxAge(100);System.out.println("hello");cookie.setPath(req.getContextPath());resp.addCookie(cookie);resp.sendRedirect(req.getContextPath()+"/login1.jsp");}//跳转到首页}else{req.setAttribute("errerMsg", "用户名密码错误");req.getRequestDispatcher("/login.jsp").forward(req, resp);}}}
登录成功跳转到login1.jsp首页，登录失败跳回ligin.jsp原页面
首页logion1.jsp
<%--Created by IntelliJ IDEA.User: 小佳Date: /10/7Time: 16:03To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%@taglib prefix="c" uri="/jsp/jstl/core" %><html><head><title>首页</title></head><body>首页<c:if test="${empty user}"><a href="login.jsp">请登录</a></c:if><c:if test="${not empty user}">欢迎：${user.username }</c:if></body></html>
