Re: Downloading a file in Linux

From:

Daniel Pitts <googlegroupie@coloraura.com>

Newsgroups:

comp.lang.java.programmer

Date:

Mon, 20 Aug 2007 14:43:38 -0000

Message-ID:

<1187621018.382522.166940@x40g2000prg.googlegroups.com>

On Aug 19, 2:55 pm, Grzesiek <grzesiek.wilanow...@gmail.com> wrote:

On 19 Sie, 23:14, Arne Vajh=F8j <a...@vajhoej.dk> wrote:

Grzesiek wrote:

I read one byte at a time because i download a JAR FILE not an image.
No corrupted bytes are allowed here. In fact i tried reading into
byte[1024] and byte[4096] but then downloaded file is 140kB and 160kB
instead of 116kB- which is the size of the file i want to downlaod. To
large file is corrupted and cannot be run.

You can get any file by reading with large buffers - it only
affects performance not functionality.

Code snippet:

             URL url = new URL(urlstr);
             HttpURLConnection con =
(HttpURLConnection)url.openConnection();
             con.connect();
             if(con.getResponseCode() == HttpURLConnection.HTTP_OK)=

{

                InputStream is = con.getInputStream();
                OutputStream os = new FileOutputStream(fnm);
                byte[] b = new byte[100000];
                int n;
                while((n = is.read(b)) >= 0) {
                   os.write(b,0,n);
                }
                os.close();
                is.close();
             }
             con.disconnect();

Arne

Thanx Arne,

i used your snippet and now my function works fine :-) There is no
diffrence between Linux and Windows Xp now. So reading one byte at a
time was the problem.

Thanx all :-)

Glad that worked for you. Something else I forgot to mention was that
reading one Character at a time is VERY different from reading one
Byte at a time. There are some conversions that Java does, which
would explain your corrupt data. Unlike C/C++, Char are 2 bytes, and
they are usually encoded/decoded when written to/read from streams, so
you end up with unexpected values if you're trying to read non-
character data.