最近看了一些在线统计人数的案例，下面说一下最简单的实现方式是通过jsp利用application统计在线人数。代码如下：
<%@ 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){
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="3" color="blue">简单的页面访问计数器</font>
</p>
<p>
<font size="3" color="#000000">
欢迎访问此页面，您是<%=number%>个访问用户
</font>
</p>
</body>
</html>本文对于初学者应该有些帮助。
