Java文件复制

byte[] buffer = null;
            File file = new File("C:\Users\admin\Desktop\data.txt");
            FileInputStream fis = new FileInputStream(file);
            ByteArrayOutputStream bos = new ByteArrayOutputStream(1000);
            byte[] b = new byte[1000];
            int n;
            while ((n = fis.read(b)) != -1) {
                  bos.write(b, 0, n);
              }
            fis.close();
            bos.close();
            buffer = bos.toByteArray();


            File file2 = new File("C:\Users\admin\Desktop\test.txt");
            FileOutputStream  fos = new FileOutputStream(file2);
            BufferedOutputStream bos2 = new BufferedOutputStream(fos);
            bos2.write(buffer);