Thread Subject: urlread timeout

urlread has a serious problem, at least in R13, in that if
the url you're trying to read doesn't answer, urlread just
hangs without returning an error. In fact the only way to
regain control is to open the process manager and kill Matlab.

I tried Fu-Sung Wang's urlread2 which claims to fix this but
it generates the following error:

img = urlread2('http://192.168.0.107/image.jpg', [], [], 5);
??? Undefined variable 'com' or class
'com.mathworks.mlwidgets.html.HTMLPrefs.setProxySettings'.

Error in ==> C:\matlab\toolbox\matlab\iofun\urlread2.m
On line 41 ==>
com.mathworks.mlwidgets.html.HTMLPrefs.setProxySettings

I tried saying

com.mathworks.services.Prefs.setStringPref('HelpSelectedProducts','MATLAB');

and then restarting Matlab as suggested in another post, but
that had no effect.

The author isn't answering his email and I'm really stuck.
Does anyone have a way to read web pages without hanging if
the url is down? Any help would be greatly appreciated.
Thanks.

Nothing? No one else has this problem? Anyone? I could
still use some help with this one. Thanks.

"Michele " <denber.nospam@mindspringNOSPAM.com> writes:

> Nothing? No one else has this problem? Anyone? I could
> still use some help with this one. Thanks.

On USENET, your previous post isn't here, so we don't have access to
it. But I gather you want urlread to timeout gracefully.


urlread uses a Java class to do the connection. "edit urlread" and
"edit urlreadwrite" for the code. Without knowing much about it, the
urlConnection object which is returned by urlreadwrite and used at the
end of urlread has a method "getReadTimeout", "getConnectTimeout", and
corresponding "set" methods. I bet if you modify urlread.m (I would
make yourself a local copy of it, on your MATLAB path, to avoid toolbox
and hashing issues) to set appropriate timeouts for these, things would
work nicely. You might call your copy urlread_with_timeout.m

-Peter

In article <muyfxps1swc.fsf@G99-Boettcher.llan.ll.mit.edu>,
Peter Boettcher <boettcher@ll.mit.edu> wrote:
>"Michele " <denber.nospam@mindspringNOSPAM.com> writes:
>
>> Nothing? No one else has this problem? Anyone? I could
>> still use some help with this one. Thanks.

>On USENET, your previous post isn't here, so we don't have access to
>it.

Amendment: the post had expired at your location, since it was
from the beginning of March.
--
  "The beauties of conception are always superior to those of
   expression." -- Walter J. Phillips

Peter Boettcher <boettcher@ll.mit.edu> wrote in message <muyfxps1swc.fsf@G99-Boettcher.llan.ll.mit.edu>...

> Without knowing much about it, the
> urlConnection object which is returned by urlreadwrite and used at the
> end of urlread has a method "getReadTimeout", "getConnectTimeout", and
> corresponding "set" methods.

Thanks for the reply. Uunfortunately I can't get mine to do that. I get this:

>> urlConnection.getReadTimeout
??? No appropriate method or public field getReadTimeout for class sun.net.www.protocol.http.HttpURLConnection.

I get the same error when trying setReadTimeout.

The Sun website Java documentation for urlConnection also does not list these Timeouts. Is this just not in V6R13 or am I missing something here? Anyway, this doesn't work for me.

Any other ideas for preventing an unresponsive server from hanging your Matlab session? Thanks.

I struggled with this for a while, until I realized that the timeout time is in milliseconds:
urlConnection.setReadTimeout(5000); % timeout in 5 seconds

I added this on line 96 or urlread.m (R2006b) and it works.
dave