| <%@ page contentType="text/html;charset=gb2312" %> <!--jsp计数器--> <%-- 以前学ASP时,用ASP做防止刷新的计数器很简单,以下是一个用JSP做的计数器--%> <html> <head> <title>jsp计数器</title> </head> <body> <%@ page import="java.io.*" %> <% //out.println(request.getHeader("Cookie")); String currentRecord = null;//保存文本的变量 BufferedReader file; //BufferedReader对象，用于读取文件数据 String nameOfTextFile = "count.txt"; //读取 file = new BufferedReader(new FileReader(nameOfTextFile)); String readStr =null; int writeStr =0; //如果计数文本中的计数值为空则让它显示时变成1并写入 try { readStr = file.readLine(); } catch (IOException e) { System.out.println("读取数据错误."); } if (readStr == null) readStr = "没有任何记录"; //判断cookie,第一次登陆时加1,刷新时不累计计数 else if (request.getHeader("Cookie")==null) { writeStr = Integer.parseInt(readStr)+1;} else { writeStr = Integer.parseInt(readStr);} //写入时控制因为刷新引起的重复计数 if (request.getHeader("Cookie")==null) { try { PrintWriter pw = new PrintWriter(new FileOutputStream(nameOfTextFile)); pw.println(writeStr); pw.close();} catch(IOException e) { out.println(e.getMessage());} } %> <p align="center">您是CNJSP的第<b><font color="red"><%=writeStr%></font></b>位客人。</p> </body> </html> |
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