统计网站 在线人数
login.jsp
<%@ page language="java" import="java.util.*,bean.SessionUser" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
<%
//
//获取IP
String ip=request.getRemoteAddr();
SessionUser sessionUser=new SessionUser();
sessionUser.setIp(ip);
System.out.println("JSP页面SessionUser= "+sessionUser);
session.setAttribute("userinfo", sessionUser);
%>
<form action="${pageContext.request.contextPath}/LoginServlet" method="post">
员工信息录入<br/>
用户名：<input type="text" value="" name="username" /> <br/>
密码：<input type="password" name="psw"/> <br/>
<input type="submit" value="保存" onclick="save()"/>
</form>
</body>
</html>
2. onlinenum.jsp
<%@ page language="java" import="java.util.*,bean.SessionUser" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<br/>
显示游客信息：<br/>
<c:forEach items="${applicationScope.onlinemap}" var="sessionUser">
<c:if test="${sessionUser.value.username==null}">
${sessionUser.value.ip}~~~~${sessionUser.value.username}~~~~
</c:if>
</c:forEach>
<br/>
显示注册用户信息：<br/>
<c:forEach items="${applicationScope.onlinemap}" var="sessionUser">
<c:if test="${sessionUser.value.username!=null}">
${sessionUser.value.ip}~~~~${sessionUser.value.username}~~~~
<a href="${pageContext.request.contextPath}/RemoveServlet?sessionid=${sessionUser.key}">转为游客</a>
</c:if>
</c:forEach>
3. web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
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_2_5.xsd">
<listener>
<listener-class>listener.MyServletContextListener</listener-class>
</listener>
<listener>
<listener-class>listener.MyHttpSessionListener</listener-class>
</listener>
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>web.LoginServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>RemoveServlet</servlet-name>
<servlet-class>web.RemoveServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>RemoveServlet</servlet-name>
<url-pattern>/RemoveServlet</url-pattern>
</servlet-mapping>
</web-app>
4.title.jsp
bean:
1 User
package bean;
public class User {
private String username;
private String psw;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPsw() {
return psw;
}
public void setPsw(String psw) {
this.psw = psw;
}
}
2.SessionUser:
package bean;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
public class SessionUser extends User implements HttpSessionBindingListener {
private String ip;//登陆用户和游客的IP
public String getIp() {
return ip;
}
public void setIp(String ip) {
this.ip = ip;
}
public void valueBound(HttpSessionBindingEvent event) {
System.out.println("valueBound~~~~~~~~~~~");
System.out.println("this= "+this);
HttpSession session=event.getSession();
String sessionid=session.getId();
System.out.println("sessionid= "+sessionid);
ServletContext sc=session.getServletContext();
Map<String, SessionUser> onlinemap=(Map<String, SessionUser>)sc.getAttribute("onlinemap");
onlinemap.put(sessionid, this);
}
public void valueUnbound(HttpSessionBindingEvent arg0) {
// TODO Auto-generated method stub
}
}
listener:
1.MyServletContextListener:
package listener;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import bean.SessionUser;
public class MyServletContextListener implements ServletContextListener {
public void contextDestroyed(ServletContextEvent sce) {
}
public void contextInitialized(ServletContextEvent sce) {
Map<String,SessionUser> map=new HashMap<String,SessionUser>(); //获取servletContext
ServletContext sc=sce.getServletContext();
if (sc!=null) {
sc.setAttribute("onlinemap", map);
}}}
2. MyHttpSessionListener:
package listener;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import bean.SessionUser;
public class MyHttpSessionListener implements HttpSessionListener {
public void sessionCreated(HttpSessionEvent arg0) {
// TODO Auto-generated method stub
}
public void sessionDestroyed(HttpSessionEvent se) {
// 当session过期后或销亡才调用
HttpSession session=se.getSession();
String sessionid=session.getId();
ServletContext sc=session.getServletContext();
Map<String, SessionUser> onlinemap=(Map)sc.getAttribute("onlinemap");
onlinemap.remove(sessionid);
session.removeAttribute("userinfo");
}
}
web
1.LoginServlet:
package web;
import java.io.IOException;
import java.io.PrintWriter;
import javax.jms.Session;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import bean.User;
public class LoginServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
HttpSession session=request.getSession(false);
String path="";
String username=request.getParameter("username");
if (session!=null) {
User user=(User)session.getAttribute("userinfo");
user.setUsername(username);
path="/title.jsp";
}
request.getRequestDispatcher(path).forward(request, response);
}
}
2. RemoveServlet
package web;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import bean.SessionUser;
public class RemoveServlet 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 {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
String sessionid=request.getParameter("sessionid");
ServletContext sc=this.getServletContext();
Map<String, SessionUser> onlinemap=(Map)sc.getAttribute("onlinemap");
SessionUser sessionUser=onlinemap.get(sessionid);
sessionUser.setUsername(null);
}
}