用时29ms
BufferedInputStream in = new BufferedInputStream(new FileInputStream(srcFile));
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(destFile));
int bytes;
byte[] buf = new byte[1024 * 8];
while ((bytes = in.read(buf)) > -1) {
out.write(buf, 0, bytes);
}
out.flush();
in.close();
out.close();
