package com.test;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class Test {

    public static void main(String[] args) {
        FileReader fr = null;
        FileWriter fw = null;
        char[] ch = new char[1024];
        int n = 0;
        List<File> files = getFiles("d:\\java");
        for(File file : files){
            try {
                File f = new File("D:\\java1\\" + file.getName());
                fr = new FileReader(file);
                fw = new FileWriter(f);
                while ((n = fr.read(ch)) != -1)
                    fw.write(ch, 0, n);
                fw.flush();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (fw != null) {
                    try {
                        fw.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
    
                }
                if (fr != null) {
                    try {
                        fr.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            String fileName = file.getAbsolutePath();
            File fl = new File(fileName.substring(0, fileName.indexOf(".")) + ".jad");
            file.renameTo(fl);
        }
    }
    private static List<File> getFiles(String path) {
        List<File> files = new ArrayList<File>();
        File file = new File(path);
        getAllFiles(file, files);
        return files;
    }

    private static void getAllFiles(File file, List<File> files) {
        if (file.isFile()) {
            files.add(file);
        } else {
            File[] fs = file.listFiles();
            for (File f : fs) {
                getAllFiles(f, files);
            }
        }
    }
}