[undertow-dev] response-code handler bypasses configured error pages

[Brad Wood]

Before I give that workaround a try, a couple existential questions...

   - Should the *response-code* handler also set the *errorCode* as well in
   the servlet request context so it triggers the doErrorDispatch() action?
   - Or should there be another built-in handler called "send-error" or
   similar that does this.

Ex:
path( /secret.json ) -> send-error ( 404 )
path( /admin/ ) -> send-error( 503 )

I'm sort of questioning what the usefulness is of the *response-code*
handler however (at least in the context of the predicate language) if it's
default behavior is NOT to trigger the error code and therefore the error
page.

Thanks!

~Brad

*Developer Advocate*
*Ortus Solutions, Corp *

E-mail: brad at coldbox.org
ColdBox Platform: http://www.coldbox.org
Blog: http://www.codersrevolution.com



On Thu, Jul 2, 2020 at 7:01 PM Stuart Douglas <sdouglas at redhat.com> wrote:

> Hmm, this is because the servlet status code is only triggered by a
> sendError method, not by just setting the code.
>
> You probably need to write a custom one that looks like this (plus the
> relevant predicate languge bits):
>
> public class SendErrorHandler implements HttpHandler {
>
>     private final int code;
>
>     public SendErrorHandler(int code) {
>         this.code = code;
>     }
>
>     @Override
>     public void handleRequest(HttpServerExchange exchange) throws
> Exception {
>         ServletRequestContext src =
> exchange.getAttachment(ServletRequestContext.ATTACHMENT_KEY);
>         ((HttpServletResponse)src.getServletResponse()).sendError(code);
>     }
> }
>
> Stuart
>
>
>
> On Fri, 3 Jul 2020 at 09:40, Brad Wood <bdw429s at gmail.com> wrote:
>
>> Thanks for the reply Stuart.  I've tried this with no success, but
>> perhaps I'm doing it wrong.
>>
>> List<PredicatedHandler> ph =
>> PredicatedHandlersParser.parse(predicatesLines, _classLoader);
>> servletBuilder.addOuterHandlerChainWrapper(next ->
>> Handlers.predicates(ph,next));
>>
>> When the response-code handler fires, I still get no response body.
>>
>> On a related note, when I move the predicates into an outer handler chain
>> wrapper, my default response listener also doesn't fire at all.
>>
>> On an unrelated train of thought, I've been trying to see if I can get
>> the default response listener to automatically dispatch the correct error
>> page, but that hasn't been going well either.  If I don't use the outer
>> handler chain idea, but try to capture the empty response in a default
>> response listener, I can return a static message using the Sender class
>>
>> Sender sender = exchange.getResponseSender();
>> sender.send(errorHTMLString);
>>
>> But if I try to run something this in my default response listener to
>> invoke my error pages
>>
>> ServletRequestContext src =
>> exchange.getAttachment(ServletRequestContext.ATTACHMENT_KEY);
>> HttpServletResponseImpl response = src.getOriginalResponse();
>> response.doErrorDispatch( exchange.getStatusCode(),
>> exchange.getReasonPhrase() );
>>
>> Then it's as though nothing happens and I still get an empty response.
>>
>> Thanks!
>>
>> ~Brad
>>
>> *Developer Advocate*
>> *Ortus Solutions, Corp *
>>
>> E-mail: brad at coldbox.org
>> ColdBox Platform: http://www.coldbox.org
>> Blog: http://www.codersrevolution.com
>>
>>
>>
>> On Thu, Jul 2, 2020 at 6:17 PM Stuart Douglas <sdouglas at redhat.com>
>> wrote:
>>
>>> The predicate languages are executed before the Servler handlers, so
>>> they won't be handled by Servlet error pages.
>>>
>>> If you are setting this all up programmatically you could use
>>> io.undertow.servlet.api.DeploymentInfo#addOuterHandlerChainWrapper to setup
>>> the predicate handler after the initial servlet one, which should mean that
>>> the servlet error handling will handle the response code.
>>>
>>> Stuart
>>>
>>> On Fri, 3 Jul 2020 at 08:25, Brad Wood <bdw429s at gmail.com> wrote:
>>>
>>>> When I configure an error page similar to this:
>>>>
>>>> servletBuilder.addErrorPage( new ErrorPage( "404.html", 404));
>>>>
>>>> This works great when I hit a path in my browser that doesn't exist.
>>>> The contents of the *404.html* file is served with a response code of
>>>> *404*.
>>>>
>>>> However, if I also use the predicate language to define something like:
>>>>
>>>> path(/box.json)->response-code(404)
>>>>
>>>> and then I hit *localhost/box.json* in my browser, I get a *404*
>>>> status code but with no response body.
>>>>
>>>>    - The docs say the response-code handler ends the exchange, but
>>>>    should it still respect the error pages?
>>>>    - How can I modify my use of Undertow to respect the error pages
>>>>    when using the response-code handler?
>>>>    - I've seen in the docs the ability to have a
>>>>    *addDefaultResponseListener()* but I'm not sure if it is the
>>>>    correct solution for this, nor how I would access the error page
>>>>    configuration dynamically as to not need to duplicate my work.
>>>>
>>>> Thanks!
>>>>
>>>> ~Brad
>>>>
>>>> *Developer Advocate*
>>>> *Ortus Solutions, Corp *
>>>>
>>>> E-mail: brad at coldbox.org
>>>> ColdBox Platform: http://www.coldbox.org
>>>> Blog: http://www.codersrevolution.com
>>>>
>>>> _______________________________________________
>>>> undertow-dev mailing list
>>>> undertow-dev at lists.jboss.org
>>>> https://lists.jboss.org/mailman/listinfo/undertow-dev
>>>
>>>
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