java拷贝文件

public class CopyFile{   /**    * 拷贝文件（把D盘java1中的java文件拷贝到jad文件夹改成txt文件后缀名）    * @param args    * @throws Exception    */public static void main(String args[])throws Exception{long lasting = System.currentTimeMillis();File f = new File("D:\\java1");File md = new File("D:\\jad");if (!md.exists())md.mkdir();if (f.exists() && f.isDirectory()){File file[] = f.listFiles(new FilenameFilter() {public boolean accept(File dir, String name){return name.endsWith(".java");}});for (int i = 0; i < file.length; i++){BufferedReader bf = null;BufferedWriter bw = null;bf = new BufferedReader(new InputStreamReader(new FileInputStream(file[i])));String fname = file[i].getName().replaceAll("\\.java$", ".txt");bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(md, fname))));char ch[] = new char[1024];for (int len = 0; (len = bf.read(ch)) != -1;){bw.write(ch, 0, len);bw.newLine();bw.flush();}bf.close();bw.close();}} else{System.out.println("无此文件夹");}System.out.println(System.currentTimeMillis() - lasting);}}