package com.demo;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ShowLoginTimesServlet extends HttpServlet {
public void init(ServletConfig config)throws ServletException
    {
     super.init(config);
    }
   int count = 0;
public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
     
      File file = new File("D:/count.txt");
      if (!file.exists()) {
         file.createNewFile();
      }
      if (file.length() > 0) {
         DataInputStream dis = new DataInputStream(new FileInputStream(file));
         count = dis.readInt();
         dis.close();
      } else {
         count = 1;
      }    
      DataOutputStream dos = new DataOutputStream(new FileOutputStream(file));
      dos.writeInt(count+1);      dos.close();
}
}
为什么count的值在count.txt文件里没有显示出来呢