[010]Java实现文件夹复制

       文件夹的读写是很好的一个Java I/O操作的典型案例，涉及到I/O流的操作、递归调用、循环。用程序修改文件名、复制拷贝文件本文都有可参考价值。通过编写此程序也将对递归思想有更好的理解。

本程序也加了一个定时器，可1秒执行一次复制操作，写定时任务也是经常会用到的。定时对文件夹的备份，就不用我们自己再去执行备份工作了。重复的工作都可交给机器来做。

import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.util.Calendar;import java.util.Timer;import java.util.TimerTask;public class Copy{public static void copyFile(String oldPath, String newPath)throws Exception{File createFile = new File(newPath);if (!createFile.exists()){createFile.createNewFile();}FileInputStream is = new FileInputStream(oldPath);BufferedInputStream bs = new BufferedInputStream(is);FileOutputStream os = new FileOutputStream(newPath);BufferedOutputStream bos = new BufferedOutputStream(os);byte[] buffer = new byte[1024];int length = 0;while (-1 != (length = bs.read(buffer, 0, 1024))){//String str = new String(buffer, 0, length);//bos.write(str.getBytes());bos.write(buffer, 0 , length);}bos.flush();bos.close();bs.close();}public static void copyDirectory2(String oldPath, String newPath)throws Exception{File createFile = new File(newPath);createFile.mkdirs();File file = new File(oldPath);File[] f = file.listFiles();for (int i = 0; i < f.length; i++){if (f[i].isDirectory()){String dir1 = oldPath + "/" + f[i].getName();String dir2 = newPath + "/" + f[i].getName();copyDirectory2(dir1, dir2);}if (f[i].isFile()){copyFile(oldPath + "/" + f[i].getName(), newPath + "/" + f[i].getName());}}}public static void main(String[] args){Calendar second = Calendar.getInstance();second.setTimeInMillis(1000);Timer t = new Timer();t.schedule(new TimerTask(){@Overridepublic void run(){String oldPath = "e:/书";String newPath = "e:/书2";try{File file = new File(oldPath);if (file.isDirectory()){copyDirectory2(oldPath, newPath);}elsecopyFile(oldPath, newPath);}catch (Exception e){e.printStackTrace();}}}, 0,second.getTimeInMillis());}}