<%@ page contentType= "text/html;charset=gb2312" %> |
<html> |
<head> |
<title>计数器</title> |
</head> |
<body bgcolor= "#ffffff" > |
<h1> 一个简单的计数器 </h1> |
<% |
try { |
//使用io操作实现文件的读写,counter.txt是用来存放计数的,如果不存在,就在本目录下创建 |
java.io.FileReader fr= new java.io.FileReader(request.getRealPath( "/" )+ "\\counter.txt" ); |
java.io.BufferedReader br = new java.io.BufferedReader(fr); |
String count = br.readLine(); |
if (count == null ) { |
//counter.txt里的计数为空的话,就向里写入一个初值1 |
java.io.FileWriter fw= new java.io.FileWriter(request.getRealPath( "/" )+ "\\counter.txt" ); |
java.io.PrintWriter pw= new java.io.PrintWriter(fw); |
pw.print( "1" ); |
pw.close(); |
fw.close(); |
} |
else { |
//不为空的话,在原来计数上加1 |
out.println( "本页面是第" +count+ "次被访问!!" ); |
java.io.FileWriter fw= new java.io.FileWriter(request.getRealPath( "/" )+ "\\counter.txt" ); |
java.io.PrintWriter pw= new java.io.PrintWriter(fw); |
pw.print(String.valueOf(Integer.parseInt(count)+ 1 ) ); |
pw.close(); |
fw.close(); |
}} |
catch (Exception e){ |
java.io.FileWriter fw= new java.io.FileWriter(request.getRealPath( "/" )+ "\\counter.txt" ); |
java.io.PrintWriter pw= new java.io.PrintWriter(fw); |
pw.print( "1" ); |
out.println( "本页面是第" + 1 + "次被访问!!" ); |
pw.close(); |
fw.close(); |
} |
%> |
</body> |
</html> |