public class CopyDir {

     public static void main(String[] args) {

         copyDir(new File("d:\\a"), new File("d:\\b"));

     }

     //file1为被复制目录， file2为目标目录

     public static void copyDir(File file1 ,File file2) {

         //目标目录不存在则创建

         if(!file2.exists()) {

             file2.mkdir();

         }

         //将源目录所有对象取出存入File[]数组中

         File[] fList =file1.listFiles();

         //遍历源目录

         for (File f : fList) {

             //当子对象为目录时在目标目录中创建此目录

             if(f.isDirectory()) {

                 File file =new File(file2,f.getName());

                 file.mkdir();

                 //调用自己

                 copyDir(f, file);

             }else if(f.isFile()) {

                 //当子对象为文件时用字节流读取并写入目标目录中（复制）

                 BufferedInputStream bis = null ;

                 BufferedOutputStream bos = null;

                 try {

                     bis = new BufferedInputStream(new FileInputStream(f));

                     bos = new BufferedOutputStream(new FileOutputStream(new File(file2,f.getName())));

                     int len = 0;

                     byte[] bytes = new byte[1024];

                     while((len = bis.read(bytes)) != -1) {

                         bos.write(bytes, 0, len);

                     }

                 } catch (IOException e) {

                     throw new RuntimeException("操作失败！");

                 }finally {

                     try {

                         bis.close();

                         bos.close();

                     } catch (IOException e) {

                         throw new RuntimeException("关闭失败！");

                     }

                 }

             }

         }

     }

 }