jsp利用application统计在线人数的方法

%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
html>
  head>
  title>application/title>
  /head>
  
  body>
  %!
Integer number;//
synchronized void numberVisiter()
{
ServletContext application = getServletContext();
Integer num = (Integer)application.getAttribute("count");
if(num == null)//如果是第一个访问者
{
num = new Integer(1);
application.setAttribute("count",num);
}
else
{
num = new Integer(num.intValue() + 1);
application.setAttribute("count",num);
}
}
  %>
  %
  if(session.isNew())
  {
  numberVisiter();
  Integer number = (Integer)application.getAttribute("count");
  }
  %>
  p>
  font size="2" color="blue">简单的页面访问计数器/font>
  /p>
  p>
  font size="2" color="#000000">
  欢迎访问此页面，您是%=number%>个访问用户
  /font>
  /p>
  /body>
/html>