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From: Mário on 9 Feb 2010 12:17
Hello,

I am trying to post an object to a servlet via HTTP using the
following code,
but unfortunately, nothing is sent to the server:

private static void doJavaPost() throws IOException {
URL url = new URL("http://localhost:9999/myservlet");
URLConnection connection = url.openConnection();
connection.setDoOutput(true);
ByteArrayOutputStream data = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(data);
out.writeObject(new Date());
out.close();
OutputStream os = connection.getOutputStream();
data.writeTo(os);
os.flush();
os.close();
}

Does someone know why this does not generate a POST request?

Regards,
Mário
From: Lothar Kimmeringer on 9 Feb 2010 12:30
M�rio wrote:

> I am trying to post an object to a servlet via HTTP using the
> following code,
> but unfortunately, nothing is sent to the server:
>
> private static void doJavaPost() throws IOException {
> URL url = new URL("http://localhost:9999/myservlet");
> URLConnection connection = url.openConnection();
> connection.setDoOutput(true);
> ByteArrayOutputStream data = new ByteArrayOutputStream();
> ObjectOutputStream out = new ObjectOutputStream(data);
> out.writeObject(new Date());
> out.close();
> OutputStream os = connection.getOutputStream();
> data.writeTo(os);
> os.flush();
> os.close();
> }
>
> Does someone know why this does not generate a POST request?

Because you don't ask the connection to do that. Call
connection.getInputStream() and the request will be sent.
BTW: You can skip the writing to the ByteArrayOutputStream
and initialized the ObjectOutputStream with
connection.getOutputStream()
Calling of os.close() isn't needed, either.


Regards, Lothar
--
Lothar Kimmeringer E-Mail: spamfang(a)kimmeringer.de
PGP-encrypted mails preferred (Key-ID: 0x8BC3CD81)

Always remember: The answer is forty-two, there can only be wrong
questions!
From: markspace on 9 Feb 2010 12:39
M�rio wrote:
> ByteArrayOutputStream data = new ByteArrayOutputStream();
....
> Does someone know why this does not generate a POST request?

Even after correcting the calls as Lothar suggested, I don't see how
this is going to generate a POST request, or that sending binary data to
an HTTP socket is going to be a good idea.

Are you sure this is really what you want to do? Could you explain a
bit more what you are trying to accomplish?
From: Mário on 9 Feb 2010 13:26
On Feb 9, 5:30 pm, Lothar Kimmeringer <news200...(a)kimmeringer.de>
wrote:
> Mário wrote:
> > I am trying to post an object to a servlet via HTTP using the
> > following code,
> > but unfortunately, nothing is sent to the server:
>
> >    private static void doJavaPost() throws IOException {
> >            URL url = new URL("http://localhost:9999/myservlet");
> >            URLConnection connection = url.openConnection();
> >            connection.setDoOutput(true);
> >            ByteArrayOutputStream data = new ByteArrayOutputStream();
> >            ObjectOutputStream out = new ObjectOutputStream(data);
> >            out.writeObject(new Date());
> >            out.close();
> >            OutputStream os = connection.getOutputStream();
> >            data.writeTo(os);
> >            os.flush();
> >            os.close();
> >         }
>
> > Does someone know why this does not generate a POST request?
>
> Because you don't ask the connection to do that. Call
> connection.getInputStream() and the request will be sent.
> BTW: You can skip the writing to the ByteArrayOutputStream
> and initialized the ObjectOutputStream with
> connection.getOutputStream()
> Calling of os.close() isn't needed, either.
>
> Regards, Lothar
> --
> Lothar Kimmeringer                E-Mail: spamf...(a)kimmeringer.de
>                PGP-encrypted mails preferred (Key-ID: 0x8BC3CD81)
>
> Always remember: The answer is forty-two, there can only be wrong
>                  questions!

Nice!
I've added the lines

InputStream in = connection.getInputStream();
in.close();

and it now works: the Date object is sent to the servlet.

But, why is the binary data sent in a subsequent packet? What can be
done to send a single packet for the POST request?

Regards,
Mário
From: Roedy Green on 9 Feb 2010 13:30
On Tue, 9 Feb 2010 09:17:34 -0800 (PST), M�rio <mljrg2(a)gmail.com>
wrote, quoted or indirectly quoted someone who said :

>
>I am trying to post an object to a servlet via HTTP using the
>following code,
>but unfortunately, nothing is sent to the server:

see http://mindprod.com/products1.html#HTTP

for POST code that works.
for an example of use see

https://wush.net/websvn/mindprod/filedetails.php?repname=mindprod&path=%2Fcom%2Fmindprod%2Fposter%2FAllPostersSOAP.java
--
Roedy Green Canadian Mind Products
http://mindprod.com

Every compilable program in a sense works. The problem is with your unrealistic expections on what it will do.
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