java防刷新网站计数器(BigInteger)

clplain · 发表于 2013-2-7 17:22:18

1:计数器的类;
package com;
import java.io.*;
import java.util.*;
import java.math.*;
/**
* 防刷新的网站计数器;
* 使用BigInteger来存贮;
* @author clplain;
*
*/
public class count {
BigInteger count=null;
public BigInteger load(File file) throws Exception{
  if(file.exists()){
  Scanner scn=new Scanner(new FileInputStream(file));
  if(scn.hasNext()){
   count=new BigInteger(scn.next());
  }
  scn.close();
  }else{
    count=new BigInteger("0");
    save(file,count);
  }
  return count;
}

public void save(File file,BigInteger count)throws Exception{
  PrintStream ps=null;
  ps=new PrintStream(new FileOutputStream(file));
  ps.println(count);
  ps.close();
}
}
2:计数器页面;
<[email=%@page]%@page[/email] contentType="text/html;charset=gb2312"%>
<[email=%@page]%@page[/email] import ="java.math.*"%>
<[email=%@page]%@page[/email] import="java.util.*"%>
<[email=%@page]%@page[/email] import="java.io.*" %>
<[email=%@page]%@page[/email] import="com.count"%>
<html>
<head>
<title>网站计数器</title>
<style type="text/css">

</style></head>
<%!BigInteger count=null; %>
<%String path=this.getServletContext().getRealPath("/")+"count.txt"; %>
<%
count t=new count();
File file=new File(path);
if(session.isNew()){
synchronized(this){
count=t.load(file);
count=count.add(new BigInteger("1"));
t.save(file,count);
}
}
%>
<body topmargin="50">
<table width="401" height="30" border="1" align="right">
<tr>
    <td width="391" height="24" align="center"><strong>您是第<%=count==null?0:count%>位访问本站的用户</strong></td>
</tr>
</table>
</body>
</html>

		自动登录	找回密码
密码			立即注册