Re: COMPRESSED FILE
max wrote:
I receive a file in an InputStream , and I'd like to know which kind of
file is it, compressed, or not.
How can I do it? Which method can I use on this InputStream
Thanks
There is no existing method that you can use. You can try various
heuristics that will let you guess what type of file it is.
e.g. see Unix "file" command.
Another approach would be to buffer the InputStream. i.e. read it into
an array or ByteArrayOutputStream, and then create a reusable
InputStream from that using ByteArrayInputStream.
Then , in the order of most likely to least likely, or most
deterministic to least deterministic, simply try your various options.
e.g.
byte[] buff = // your entire inputstream read into an array
InputStream is = new ByteArrayInputStream(buff);
// is it a GZipped stream?
try {
GzipInputStream gzis = new GzipInputStream(is);
byte[] buff2 = new byte[2048];
while (gzis.read(buff)>-1);
gzis.close();
// looks like it is a Gzipped stream
} catch (IOException ioe) {
// guess it isn't
}
Hope this helps
Rogan