Is ImageIO.write buffered?

Question

Hello!

Should I write

BufferedOutputStream os = new BufferedOutputStream(new FileOutputStream(file));
ImageIO.write(im, "JPEG", os);

instead of

ImageIO.write(im, "JPEG", file);

I.e. are ImageIO file operations buffered by default or not?

Thanks!

Answer 1

I believe it depends on the specific implementation of the IIORegistry which I suppose is system dependent.

I would expect it to be buffered, but I suppose you could go with the first option to be completely sure.

Answer 2

If you pass in a File, the underlying implementation will write directly to a RandomAccessFile (created in "rw" mode), so no buffering. Specifically, a FileImageOutputStream will be used as the ImageOutputStream.

Answer 3

You will need to use BufferedOutputStream (As in ex. 1 mentioned in question).

ImageIo.write is not buffered by default. It depends upon what you pass to it in arguments. In case of File object being passed it won't be buffered write.