实验小组成员:
(1)庞斌(负责环境配置、登录验证、cookie) 博客地址:https://www.cnblogs.com/XiaoPB/
(2)郭昭杰(负责session、博客编写) 博客地址:https://www.cnblogs.com/ashes-g/
(3)唐任峻杰 (负责过滤器) 博客地址:https://www.cnblogs.com/trjjcool/
项目码云地址:https://gitee.com/ashes-g/j2ee
一、配置MySQL
主要参考博文https://www.cnblogs.com/winton-nfs/p/11524007.html进行MySQL安装与配置
首先进入官网https://www.mysql.com/,找到DOWNLOAD标签,下载安装包
也可以通过百度网盘下载:https://pan.baidu.com/s/1oz0TZZWkaFwoC9r2XwYGXA 提取码:2b25
下载完成后双击开始安装并设置初始账户的密码,安装选项都选择默认选项即可
安装完成后,在任务栏左下角搜索框内输入cmd,以管理员身份运行
进入MySQL安装目录的bin文件夹内,输入mysqld --install安装MySQL服务
随后输入mysqld --initialize --console命令进行初始化
输入net start mysql开启MySQL的服务
注:后续可按照上述参考博文进一步进行修改密码等操作,但我们小组使用的是可视化界面进行数据库操作,跳过了这一步
为防止IDEA中连接数据库失败,还需要在命令行中设置时区
参考博文:https://blog.csdn.net/liuqiker/article/details/102455077
在命令行中依次输入命令并执行即可完成设置时区:mysql -hlocalhost -uroot -p;show variables like'%time_zone';set global time_zone = '+8:00'
右击此电脑→高级系统设置→环境变量,在系统变量中找到Path,点击编辑并加入MySQL的安装目录
在开始菜单找到MySQL Workbench 8.0 CE,运行MySQL的可视化操作界面
找到红框处的加号,输入安装时设置的用户名和密码新建数据库连接
完成后点击连接,在界面内找到左下角的SCHEMAS,右键选择Create Schema创建数据库
在建立的数据库下以类似操作创建表,并录入网页登录要校验的用户名和密码数据
MySQL相关配置完成
二、在IDEA中的相关配置
在IDEA中建立一个web项目,点击右上角运行的左边,选择Edit Configurations
配置Tomcat服务器
进入Moudles配置,在下图红框位置创建两个文件夹lib和classes
在path选项中更改为刚才Classes文件夹的路径
在dependencies选项中添加lib文件夹依赖
在C:Program Files (x86)MySQLConnector J 8.0文件夹中找到驱动JAR文件,将其放入lib文件夹下
IDEA相关配置完成
三、用户名和密码校验
相关代码:
1 import javax.servlet.ServletContext; 2 import javax.servlet.ServletException; 3 import javax.servlet.annotation.WebServlet; 4 import javax.servlet.http.*; 5 import java.io.IOException; 6 import java.io.PrintWriter; 7 import java.sql.Connection; 8 import java.sql.DriverManager; 9 import java.sql.ResultSet; 10 import java.sql.Statement; 11 12 13 @WebServlet(name = "LoginServlet") 14 public class LoginServlet extends HttpServlet { 15 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 16 response.setContentType("text/html; charset=UTF-8"); 17 request.setCharacterEncoding("UTF-8"); 18 19 PrintWriter output=response.getWriter(); 20 String username = request.getParameter("username"); 21 String pwd = request.getParameter("pwd"); 22 //output.println("账号: "+username+" 密码: "+pwd+"<br>"); 23 ResultSet rs ; 24 Statement statement = null; 25 Connection conn =null; 26 27 try { 28 Class.forName("com.mysql.jdbc.Driver"); 29 conn = DriverManager.getConnection("jdbc:mysql://localhost:3306","root","Guozhaojie610"); 30 String sql="select * from test_db.login_chitestlist where username='"+username+"' and password='"+pwd+"'"; 31 statement =conn.createStatement(); 32 rs = statement.executeQuery(sql); 33 34 35 36 if(rs.next()){ 37 output.println("登录成功!<br>"); 38 output.println("当前用户: "+username+" "+" 密码: "+pwd+"<br>"); 39 40 Cookie uname = new Cookie("usname",username); 41 uname.setMaxAge(60*60*24*30); 42 response.addCookie(uname); 43 44 Cookie upwd = new Cookie("password",pwd); 45 upwd.setMaxAge(60*60*24*30); 46 response.addCookie(upwd); 47 48 //创建session 49 HttpSession session=request.getSession(); 50 //获取session内的计数 51 Object count; 52 ServletContext servletContext=getServletContext(); 53 count=servletContext.getAttribute("count"); 54 //显示当前在线人数 55 output.println("当前在线人数:"+count); 56 57 }else { 58 output.println("账号或密码错误"); 59 } 60 61 62 } catch (Exception e) { 63 e.printStackTrace(); 64 } 65 } 66 67 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 68 69 } 70 }
四、使用cookie保存登录信息
相关代码:
1 import javax.servlet.ServletException; 2 import javax.servlet.annotation.WebServlet; 3 import javax.servlet.http.Cookie; 4 import javax.servlet.http.HttpServlet; 5 import javax.servlet.http.HttpServletRequest; 6 import javax.servlet.http.HttpServletResponse; 7 import java.io.IOException; 8 9 @WebServlet(name = "GetCookie") 10 public class GetCookie extends HttpServlet { 11 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 12 13 } 14 15 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 16 Cookie coo[] = request.getCookies();//获取request中cookie集合 17 18 //循环遍历 19 for (Cookie co : coo) { 20 System.out.println(co.getName() + ":" + co.getValue()); 21 response.getWriter().println(co.getValue()); 22 } 23 } 24 }
五、使用session显示当前在线人数
相关代码:
1 import javax.servlet.ServletContext; 2 import javax.servlet.annotation.WebListener; 3 import javax.servlet.http.HttpSession; 4 import javax.servlet.http.HttpSessionEvent; 5 import javax.servlet.http.HttpSessionListener; 6 7 @WebListener 8 public class SessionListener implements HttpSessionListener { 9 public static int count=0; 10 11 //session创建时计数+1 12 @Override 13 public void sessionCreated(HttpSessionEvent hse){ 14 HttpSession httpSession=hse.getSession(); 15 ServletContext servletContext=httpSession.getServletContext(); 16 count++; 17 servletContext.setAttribute("count",count); 18 } 19 20 //session销毁时计数-1 21 @Override 22 public void sessionDestroyed(HttpSessionEvent hse){ 23 HttpSession httpSession=hse.getSession(); 24 ServletContext servletContext=httpSession.getServletContext(); 25 count--; 26 servletContext.setAttribute("count",count); 27 } 28 29 }
六、使用过滤器解决中文乱码问题
相关代码:
1 import javax.servlet.*; 2 import javax.servlet.annotation.WebFilter; 3 import java.io.IOException; 4 5 @WebFilter(filterName = "Filter") 6 public class Filter implements javax.servlet.Filter { 7 public void destroy() { 8 } 9 10 public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException { 11 String encoding=req.getCharacterEncoding(); 12 System.out.println("before encoding"+encoding+"filter"); 13 encoding="utf-8"; 14 req.setCharacterEncoding(encoding); 15 resp.setContentType("text/html;charset="+encoding); 16 System.out.println("after encoding"+encoding+"filter"); 17 System.err.println("-----"); 18 chain.doFilter(req, resp); 19 } 20 21 public void init(FilterConfig config) throws ServletException { 22 23 } 24 25 }
七、web.xml中相关的配置信息
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" 5 version="4.0"> 6 <servlet> 7 <servlet-name>TestServlet</servlet-name> 8 <servlet-class>TestServlet</servlet-class> 9 </servlet> 10 <servlet-mapping> 11 <servlet-name>TestServlet</servlet-name> 12 <url-pattern>/swpu</url-pattern> 13 </servlet-mapping> 14 <servlet> 15 <servlet-name>LoginServlet</servlet-name> 16 <servlet-class>LoginServlet</servlet-class> 17 </servlet> 18 <servlet-mapping> 19 <servlet-name>LoginServlet</servlet-name> 20 <url-pattern>/TEST</url-pattern> 21 </servlet-mapping> 22 <servlet> 23 <servlet-name>GetCookie</servlet-name> 24 <servlet-class>GetCookie</servlet-class> 25 </servlet> 26 <servlet-mapping> 27 <servlet-name>GetCookie</servlet-name> 28 <url-pattern>/GetCookie</url-pattern> 29 </servlet-mapping> 30 <listener> 31 <listener-class>SessionListener</listener-class> 32 </listener> 33 <session-config> 34 <session-timeout>3</session-timeout> 35 </session-config> 36 <filter> 37 <filter-name>Filter</filter-name> 38 <filter-class>Filter</filter-class> 39 </filter> 40 <filter-mapping> 41 <filter-name>Filter</filter-name> 42 <url-pattern>/*</url-pattern> 43 <dispatcher>REQUEST</dispatcher> 44 <dispatcher>FORWARD</dispatcher> 45 </filter-mapping> 46 47 </web-app>
八、最终运行效果
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