LogOutServlet
用于用户的安全退出！
package cn.hncu.servlet; 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; public class LogOutServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //用户安全退出很简单，我们在服务器端移除用户的session就可以了 request.getSession().invalidate(); response.sendRedirect(request.getContextPath()+"/index.jsp"); } }
ShowServlet
显示所有用户信息时的servlet，需要把信息全部封装到request这个容器中，再转发到前台jsp显示的页面。
package cn.hncu.servlet; import java.io.IOException; import java.io.PrintWriter; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Map.Entry; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class ShowServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Map<String, HttpSession> onLines = (Map<String, HttpSession>) getServletContext().getAttribute("onLines"); List<Map<String, Object>> lists = new ArrayList<Map<String,Object>>(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //遍历onlines，针对每个session对象封装一个map(信息包含:name,createTime,lastAccessTime,ip)，把该map添加到list当中 Iterator<Entry<String, HttpSession>> it = onLines.entrySet().iterator(); while(it.hasNext()){ Entry<String, HttpSession> en = it.next(); Map<String, Object> m = new HashMap<String, Object>(); m.put("id", en.getValue().getId() ); m.put("user", en.getValue().getAttribute("user")); String creationTime = sdf.format(new Date(en.getValue().getCreationTime())); m.put("creationTime", creationTime); String lastAccessTime = sdf.format( new Date(en.getValue().getLastAccessedTime()) ); m.put("lastAccessTime", lastAccessTime); //注意,该ip数据是在CharsetFilter中封装的 m.put("ip", en.getValue().getAttribute("ip")); lists.add(m); } request.setAttribute("onLines", lists); request.getRequestDispatcher("/jsps/show.jsp").forward(request, response); } }
show.jsp
前台在线用户的显示页面，会员和管理员看到的页面是不同的，管理员可以踢人。
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>在线人信息管理</title> <style type="text/css"> table{ border: 1px solid red; border-collapse: collapse;/*设置单线-线合并*/ width: 80%; } td{ border: 1px solid red; padding:3px; } .header{ background: gray; } </style> </head> <body> <h2>以下是所有在线用户信息</h2> <table> <tr class="header" > <td>姓名</td> <td>上线时间</td> <td>最后访问时间</td> <td>IP</td> <td>操作</td> </tr> <c:forEach items="${requestScope.onLines}" var="map"> <tr> <td> <c:if test="${empty map.user}" var="boo"> 游客 </c:if> <c:if test="${!boo}"> ${map.user.name} </c:if> </td> <td>${map.creationTime} </td> <td>${map.lastAccessTime}</td> <td>${map.ip } </td> <td> <c:if test="${!boo&&user.admin}"> <a href="<c:url value='/servlet/KickOutServlet?id=${map.id}'/> " >踢出${map.user.name}</a> </c:if> </td> </tr> </c:forEach> </table> <br/>网站访问量:${count} </body> </html>
KickOutServlet
管理踢人时请求的servlet，在这里我们把被踢的人的session从服务器端移除就可以了。但是注意防范一下，那个被踢者是否已经被踢走了、
package cn.hncu.servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.Map; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class KickOutServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); String id = request.getParameter("id"); Map<String, HttpSession> onLines = (Map<String, HttpSession>) getServletContext().getAttribute("onLines"); if(onLines.containsKey(id)){ HttpSession session = onLines.get(id);//得到该session session.invalidate();//移除该session out.println("该用户已被踢出!"); }else{ out.println("该用户已经不存在!"); } } }
user
JavaBean,在这里，我就是简单的封装了一个JavaBean使用了。我们的知识点并不是这里。
package cn.hncu.servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.Map; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class KickOutServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); String id = request.getParameter("id"); Map<String, HttpSession> onLines = (Map<String, HttpSession>) getServletContext().getAttribute("onLines"); if(onLines.containsKey(id)){ HttpSession session = onLines.get(id);//得到该session session.invalidate();//移除该session out.println("该用户已被踢出!"); }else{ out.println("该用户已经不存在!"); } } }
web.xml
注意啊！无论是servlet还是监听器，过滤器！一定要记得配置web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <display-name></display-name> <listener> <listener-class>cn.hncu.listeners.MyServletContextListener</listener-class> </listener> <listener> <listener-class>cn.hncu.listeners.MySessionListener</listener-class> </listener> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>cn.hncu.servlet.LoginServlet</servlet-class> </servlet> <servlet> <servlet-name>LogOutServlet</servlet-name> <servlet-class>cn.hncu.servlet.LogOutServlet</servlet-class> </servlet> <servlet> <servlet-name>ShowServlet</servlet-name> <servlet-class>cn.hncu.servlet.ShowServlet</servlet-class> </servlet> <servlet> <servlet-name>KickOutServlet</servlet-name> <servlet-class>cn.hncu.servlet.KickOutServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/LoginServlet</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>LogOutServlet</servlet-name> <url-pattern>/servlet/LogOutServlet</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>ShowServlet</servlet-name> <url-pattern>/servlet/ShowServlet</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>KickOutServlet</servlet-name> <url-pattern>/servlet/KickOutServlet</url-pattern> </servlet-mapping> <filter> <filter-name>charset</filter-name> <filter-class>cn.hncu.filter.CharsetFilter</filter-class> </filter> <filter> <filter-name>login</filter-name> <filter-class>cn.hncu.filter.LoginFilter</filter-class> </filter> <filter-mapping> <filter-name>login</filter-name> <url-pattern>/servlet/*</url-pattern> <url-pattern>/jsps/*</url-pattern> </filter-mapping> <filter-mapping> <filter-name>charset</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
演示结果：
登录之前显示的主页:
未登录的时候，是无法进入显示所有在线用户的，用过滤器拦截了。
登录之后显示的主页:
管理员登录后显示的在线人信息
如果不是管理员登录后，最后的操作时不会显示的。
完整的项目链接：
https://github.com/chenhaoxiang/Java/tree/master/myOnlinesWeb2
希望本篇博客对大家有一点用(^-^)
