检测在写入文件后何时可以强制卸载USB-OTG闪存驱动器

Question

I write file to flash drive:

out.write(bytes);
out.flush();
out.close();

Then I need faster remove usb-org flash drive. And now file not fully written down to flash drive. How to detect when file fully written down?

Answer 1

Rather than the code you have, assuming out is a FileOutputStream , do this:

out.write(bytes);
out.flush();
out.getFD().sync();
out.close();

After sync() , the bytes will have been written completely to disk. This puts added emphasis on doing all of this I/O on a background thread, off of the main application thread.