Session实现用户登录(九)

来源：互联网发布：飞飞cms官网编辑：程序博客网时间：2024/06/13 03:13

(一)创建登录页面

<!DOCTYPE html><html><head><meta charset="UTF-8"><title>Insert title here</title></head><body><form action="/Project01/LoginServlet"  method="post">  用户名：<input  name="username" type="text"><br/><br/>  密      码：<input  name="password" type="password"><br/><br/> <input  type="submit"  value="提交"></form></body></html>

(二)使用HttpServletRequest对象处理登陆数据

package com.Test;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;//此类处理login.html表单提交public class LoginServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        response.setContentType("text/html;charset=utf-8");        String username=request.getParameter("username");        String password=request.getParameter("password");        PrintWriter out=response.getWriter();        //1.把账号、密码分别设置为root、123        if(username.equals("root")&&password.equals("123")){            //2.创建User对象保存账号、密码            User user=new User();            user.setUsername(username);            user.setPassword(password);            //3.创建Session对象保存User对象            request.getSession().setAttribute("user", user);            //4.登陆成功跳转指定页面            response.sendRedirect("/Project01/IndexServlet");        }        else{            out.println("账号或密码错误，请从新输入....");        }    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}

(三)验证登录成功跳转到IndexServlet类

package com.Test;import java.io.IOException;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;//1.创建IndexServlet显示网站的首界面 public class IndexServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        //2.response解决乱码问题        response.setContentType("text/html;charset=utf-8");        //3.创建Session对象保存用户信息        HttpSession session=request.getSession();        //4.方法体中的参数要与setAttribute()键一致        User user=(User) session.getAttribute("user");        if(user==null){            response.getWriter().print("您还未登陆，请<a href='/Project01/login.html'>登陆</a>");        }else{            response.getWriter().print("您已登陆，欢迎您 "+user.getUsername());            response.getWriter().print("<a href='/Project01/LogoutServlet'>退出</a>");            //5.创建Cookie对象用来保存Session的id            Cookie cookie=new Cookie("JSESSIONID",session.getId());            cookie.setMaxAge(30*60);            cookie.setPath("/Project01");            response.addCookie(cookie);        }    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}

(四)LogoutServlet 类用于完成用户注销

package com.Test;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;//此类用于处理用户注销public class LogoutServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        //1.Session对象删除保存User对象        request.getSession().removeAttribute("user");        response.sendRedirect("/Project01/IndexServlet");    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}

(五)配置各个Servlet类

<?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>Project01</display-name>  <welcome-file-list>    <welcome-file>index.html</welcome-file>  </welcome-file-list>  <servlet>    <description></description>    <display-name>IndexServlet</display-name>    <servlet-name>IndexServlet</servlet-name>    <servlet-class>com.Test.IndexServlet</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>IndexServlet</servlet-name>    <url-pattern>/IndexServlet</url-pattern>  </servlet-mapping>  <servlet>    <description></description>    <display-name>LoginServlet</display-name>    <servlet-name>LoginServlet</servlet-name>    <servlet-class>com.Test.LoginServlet</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>LoginServlet</servlet-name>    <url-pattern>/LoginServlet</url-pattern>  </servlet-mapping>  <servlet>    <description></description>    <display-name>LogoutServlet</display-name>    <servlet-name>LogoutServlet</servlet-name>    <servlet-class>com.Test.LogoutServlet</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>LogoutServlet</servlet-name>    <url-pattern>/LogoutServlet</url-pattern>  </servlet-mapping></web-app>

结果演示：

这里写图片描述

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