1：配置应用的web.xml中

如下配置web.xml

<servlet>
     <servlet-name>startup</servlet-name>
     <servlet-class>com.usease.Startup</servlet-class>
     <load-on-startup>1</load-on-startup>
   </servlet>

2：实现这个Startup类，这个类实际上是一个serverlet

package com.usease;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class Startup extends HttpServlet {
     private static final String CONTENT_TYPE = "text/html; charset=GBK";

//Initialize global variables
     public void init() throws ServletException {
         try {
             File file = new File("d:/test.txt");
             int count = 0;
             if (file.exists()) {
                 BufferedReader in = new BufferedReader(new FileReader(file));
                 String inString = in.readLine();
                 count = Integer.parseInt(inString);
                 in.close();
             }
             count++;
             PrintWriter out = new PrintWriter(new FileOutputStream("d:/test.txt"));
             out.print(count);
             out.close();
         }
catch (IOException e) {}
         System.out.println("Count completed!");
     }

//Process the HTTP Get request
     public void doGet(HttpServletRequest request, HttpServletResponse response) throws
             ServletException, IOException {
     }

//Clean up resources
     public void destroy() {
     }
}