int read = 0;
byte[] bytes = new byte[1024];
while ((read = inputStream.read(bytes)) != -1) {
out.write(bytes, 0, read);
}Seriously, guys, don't you think there is something wrong here? Even in C++ people do not copy streams by operating bytes anymore! There should be a lot better way :) (I am not considering now usage of any additional libraries that require some additional jar files).
import sun.misc.IOUtils;
new FileOutputStream("tmp.txt").write(IOUtils.readFully(inputStream, -1, false));
While I agree that intermediate temporary byte arrays look wonky at best, I have to point out that this approach has reasons. First, when reading into a buffer you get the chance to modify data if you need. Unless you're willing to supply a custom output stream, of course. But more importantly, second - passing "-1" to IOUtils.readFully has one major flaw. What would happen if I was to feed it a 10Gb file? So I'm afraid readFully has to be called in a loop with a more sane "length" parameter as well. :]
ReplyDeleteOf course you are right. Here I estimate that we know, where from and what file we are downloading, so we expect it to be of a reasonable size to read it fully. :)
ReplyDeleteShould use channels actually, something like this:
ReplyDeleteval out = new FileOutputStream(theFile).getChannel
val in: InputStream = ...
val ch = Channels.newChannel(in)
try { out.transferFrom(ch, 0, in.available) } finally { out.close() }
(that's scala, but who cares)