Salut,
John C. Turnbull wrote:
> OK, I have a little bit more info. If I work with text and a vanilla
> OutputStream then I don’t need to close the stream using Comet for the
> applet to read it but as soon as I change the otherwise identical code
> to use either GZIPOutputStream or ImageIO then I have to close the
> stream for the applet to be able to read anything through that stream.
> Flushing just seems to do nothing. Can anyone suggest why this would be
> so and why it only happens if I use Comet? Without Comet the exact same
> code (without the call to close()) works fine.
That's probably because the Applet client is waiting for the last bytes,
most probably \r\n\r\n...seems a bug on the client side IMO. When a
connection gets suspended (Comet), the response is never committed and
the last bytes not written...until you resume the connection. This is
exactly what's happenning right now.
Can you share a test case?
A+
-- Jeanfrancois
>
>
>
> *From:* John C. Turnbull [mailto:ozemale_at_ozemail.com.au]
> *Sent:* Thursday, 2 July 2009 19:37
> *To:* users_at_grizzly.dev.java.net
> *Subject:* RE: Comet issue with requirement to close output streams
>
>
>
> Oops, the line “/If I uncomment the call to os.close() the applet blocks
> on trying to read the image/” should have read “/If I DON’T uncomment
> the call to os.close() the applet blocks on trying to read the image/”.
>
>
>
> *From:* John C. Turnbull [mailto:ozemale_at_ozemail.com.au]
> *Sent:* Thursday, 2 July 2009 16:29
> *To:* users_at_grizzly.dev.java.net
> *Subject:* Comet issue with requirement to close output streams
>
>
>
> I am trying to get Comet to work between an applet and a servlet with
> GlassFish v2 UR2 for loading images but I have hit a bit of a road
> block. I can get it to work without using Comet no problem but when I
> put the exact same code into my Comet handler I find that I have to
> explicitly close the output stream after sending each image (which
> completely defeats the purpose of using Comet) for the applet to be able
> to read it whereas when the same code is just used in the servlet I can
> get by just doing a flush.
>
>
>
> In my Comet handler I have this code:
>
>
>
> public class ImageCometHandler implements
> CometHandler<ServletOutputStream> {
>
>
>
> private ServletOutputStream os;
>
>
>
> public void attach(ServletOutputStream os){
>
> this.os = os;
>
> }
>
>
>
> public void onEvent(final CometEvent event) throws IOException{
>
> BufferedImage image =
> (BufferedImage)event.attachment();
>
>
> JPEGCodec.createJPEGEncoder(os).encode(image);
>
> os.flush();
>
> // os.close();
>
> }
>
>
>
> ...
>
>
>
> }
>
>
>
> If I uncomment the call to os.close() the applet blocks on trying to
> read the image. The code to read the image in the applet is:
>
>
>
> BufferedImage bi = null;
>
> try {
>
> bi = ImageIO.*read*(this.stream);
>
> } catch (final IOException ioe) {
>
> System.*err*.println("Exception loading image: " + ioe);
>
> }
>
>
>
> Why does putting the code to send the image into the Comet handler
> require that I close the output stream whereas the same code gets by
> with just a flush when Comet is not used? Is there any way around this?
>
>
>
> Thanks,
>
>
>
> John
>