上，下线问题！！ - 编程论坛

呵呵，最近好象问了好多的问题哦，那我就再问问哈，别嫌我麻烦哈，呵呵

我就是想在网页上设个session监听器，当用户登陆时，就把该用户信息表中的一个字段"userStatus"设为＂在线＂
当session过期时就把userStatus"设为＂离线＂，不知道我这样做可不可以，我的代码如下：
登陆的代码：
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<html>
<head>
<base href="<%=basePath%>">

<title>登陆页面</title>

</head>

<body>

<div style="z-index:0;position:absolute;left:420px;top:200px";>
<form action="UserLog_Servlet" method=post name=form id=form onsubmit="return check()">
<table border=1 height="35" width="320" align="center" style="size:12">
<tr>
<td colspan="2" align=center><font color=red>
用户登陆
</font></td>
</tr>
<tr>
<td align=right>
名称：
</td>
<td align=center>
<input type=text name=loginName size=20>
</td>
</tr>
<tr>
<td align=right>密码：</td>
<td align=center><input type=password name=passWord size=20> </td>
</tr>
<tr>
<td colspan="2" align=center>  <input type=submit value="登陆">  <input type=reset value="重置"></td>
</tr>
</table>
</form>
</div>
</body>
</html>

Servlet如下：
package myServlet;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import myJavaBean.UserInfo_Bean;
import myListener.onLine_Listener;
public class UserLog_Servlet extends HttpServlet {／／主要对登陆做处理

/**
*
*/
private static final long serialVersionUID = 4842855968990446843L;

public UserLog_Servlet(){
super();
}

public void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException{
response.setContentType("text/html;charset=gb2312");
MD5_Encoding md5=new MD5_Encoding();
String LoginName=request.getParameter("loginName");
String PassWord= request.getParameter("passWord");
UserInfo_Bean userBean=new UserInfo_Bean();
UserReg_Form user=userBean.getuser(LoginName,PassWord);//要定义
if (user!=null){
request.getSession(true).setAttribute("loginName", LoginName);
onLine_Listener listener=new onLine_Listener();
listener.setUser(LoginName);
request.getSession(true).setAttribute("list",listener);
request.getSession().setMaxInactiveInterval(10);
try{
request.getRequestDispatcher("index.jsp").forward(request, response);
}catch(Throwable T){
//要写日记
}

}else{
request.setAttribute("errorMsg","名称或是密码错了，请重新输入！");
request.getRequestDispatcher("user/Login.jsp").forward(request, response);
}
}
public void doPost(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException{
doGet( request, response);
}
}

我的UserInfo_Bean 如下：／／／／里面定义了一些数据库操作方法，
package myJavaBean;

import DBHandle.DBConn;

import java.io.UnsupportedEncodingException;
import java.sql.*;
import java.util.*;
import myForm.UserReg_Form;
public class UserInfo_Bean {

Connection conn;
Statement stmt;
ResultSet rs;
String sql=null;

public void statusOnline(String loginName){
try{
conn=DBConn.getconn();／／连接数据库的，
stmt=conn.createStatement();
sql="update UserInfo_table set userStatus='在线' where loginName='"+loginName+"'";
stmt.executeUpdate(sql);
}catch(SQLException e){
e.printStackTrace();
}
}
public void statusLeave(String loginName){
try{
conn=DBConn.getconn();
stmt=conn.createStatement();
sql="update UserInfo_table set userStatus='离线' where loginName='"+loginName+"'";
stmt.executeUpdate(sql);
}catch(SQLException e){
e.printStackTrace();
}
}
}

我的Listener如下：／／／／监听器
package myListener;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import DBHandle.DBConn;
import myJavaBean.UserInfo_Bean;
public class onLine_Listener implements HttpSessionListener {

private String user;
private HttpServletRequest request;
UserInfo_Bean userbean=new UserInfo_Bean();
public onLine_Listener(){
user="";
}
public String getUser() {
return user;
}

public void setUser(String user) {
this.user = user;
}

public void sessionCreated(HttpSessionEvent arg0) {
// TODO 自动生成方法存根
user=request.getParameter("loginName");
userbean.statusOnline(user);
System.out.print(user+"上线");
}

public void sessionDestroyed(HttpSessionEvent arg0) {
// TODO 自动生成方法存根
userbean.statusLeave(user);
System.out.print(user+"离线");
}

}

不知道我的这个方法能不能行哦，
哪为大哥我改改啊，先谢谢了，