Update mass of file

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class PortChange {

public static int time=0;

public static void main(String[] args){
   String fileName="E:\\zip";
   String fileType=".xml";
   iteratorFile(fileName,fileType,"","");
   System.out.println("一共更新了"+time+"个文件");
}

public static void iteratorFile(String fileName,String fileType,String from,String to){
   File file=new File(fileName);
   File[] files=file.listFiles();
   for(int i=0;i<files.length;i++){
    if(files[i].isDirectory()){
     iteratorFile(files[i].getAbsolutePath().replace('\\','/'),fileType,from,to);
    }else if(files[i].isFile()){
     String file_name=files[i].getAbsolutePath().replace('\\','/');
     updateFile(new File(file_name),fileType,from,to);
    }
   }
}

public static void updateFile(File file,String fileType,String from,String to){
   if(file.getName().length()>4&&file.getName().substring(file.getName().length()-4).equals(fileType)){
   try {
    int index=file.getAbsolutePath().lastIndexOf('\\')+1;
    String fileName=file.getName();
    File file1=new File(file.getAbsolutePath().substring(0,index)+fileName+"_bakj");
    System.out.println(file.getAbsolutePath());
    BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream(file)));
    BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file1)));
    String line=null;
    while((line=br.readLine())!=null){
    // bw.write(line.replace("charset=gb2312", "charset=gbk").replace("charset=GB2312","charset=gbk")+"\n");
   //  bw.write(line.replace("<Connector port=\"8080\"", "<Connector port=\"8888\""));
     bw.write(line.replace("<Connector port=\""+from+"\"", "<Connector port=\""+to+"\""));
    }
    time++;
    bw.flush();
    bw.close();
    br.close();
    file.delete();
    file1.renameTo(new File(file.getAbsolutePath().substring(0,index)+fileName));
   } catch (FileNotFoundException e) {
    e.printStackTrace();
   } catch (IOException e) {
    e.printStackTrace();
   }
   }
}
}