Hi Cezary,
this sounds great, so I now see my error, but will try it with the
configuration parameter, you mentioned.
Thanks a lot.
Best Regards, Ric
On Sun, Dec 1, 2019 at 10:50 PM Cezary Biernacki <cezary...@gmail.com>
wrote:
> Hi,
> you get empty output because in line
>
> *boolean* handled = handler.service(httpServletRequest,
> httpServletResponse);
> you pass the original "httpServletResponse". This lines pass processing to
> the rest of the filter pipeline where actual generation of the response
> happens, and because the original object is passed, the content of the
> response is sent to the client, not captured by your wrapper class.
>
> You need to create your wrapper before calling "handler.service()", pass
> the wrapper as the second argument, and process captured output after
> "handler.service()". It should fix the problem with getting always an empty
> output.
>
> But I suspect you will have more problems and this way is not really
> optimal. Tapestry has a special pipeline for handling assets like
> JavaScript in the form of StreamableSource decorators,
> ResourceTransformer-s and ResourceMinimisers. Files translated, minified
> and compressed before sending to output - so your code would probably not
> find any recognisable part to process. Tapestry also caches results of this
> processing, so usually it is done only once, not on every requests as in
> your code, which significantly improves performance. More importantly,
> minification of JavaScript files removes comments. Minification is
> controlled by "tapestry.enable-minification"
> (see org.apache.tapestry5.SymbolConstants#MINIFICATION_ENABLED), which
> normally is enabled in the production mode and disabled in the development
> mode. So if your goal is to remove comments from JavaScript files, just run
> your Tapestry application mode.
>
> Best regards,
> Cezary
>
>
> On Sun, Dec 1, 2019 at 5:12 PM Ric 2000 <erich.gorma...@gmail.com> wrote:
>
> > Hi again,
> >
> > here is the code I used:
> >
> > First the way I contributed the HttpServletRequestHandlerin my Tapestry
> > Filter Module:
> >
> > @Contribute(HttpServletRequestHandler.*class*)
> >
> > *public* *void*
> >
> contributeHttpServletRequestHandler(OrderedConfiguration<HttpServletRequestFilter>
> > configuration) {
> >
> >
> >
> > configuration.add("JavascriptCommentFilter", *new**
> > JavascriptCommentFilter(**)*,
> >
> > *after*("StoreIntoGlobals").build());
> >
> > }
> >
> > Here is the code of my HttpServletRequestFilter (the used
> > ServletResponseWrapperCopier I attached to this post):
> >
> > *package* *com.xyz.common.services.requestfilter*;
> >
> >
> >
> > *import* java.io.IOException;
> >
> > *import* java.io.PrintWriter;
> >
> >
> >
> > *import* javax.servlet.http.HttpServletRequest;
> >
> > *import* javax.servlet.http.HttpServletResponse;
> >
> >
> >
> > *import* org.apache.log4j.Logger;
> >
> > *import* org.apache.tapestry5.services.HttpServletRequestFilter;
> >
> > *import* org.apache.tapestry5.services.HttpServletRequestHandler;
> >
> >
> >
> > *import* *com.xyz <http://com.xyz>*.utils.ServletResponseWrapperCopier;
> >
> >
> >
> > *public* *class* JavascriptCommentFilter *implements*
> > HttpServletRequestFilter {
> >
> >
> >
> > *private* *final* *static* Logger *LOG* = Logger.*getLogger*
> > (JavascriptCommentFilter.*class*);
> >
> >
> >
> > @Override
> >
> > *public* *boolean* service(HttpServletRequest httpServletRequest,
> > HttpServletResponse httpServletResponse,
> >
> > HttpServletRequestHandler handler) *throws*
> > IOException {
> >
> >
> >
> > String requestUrl = httpServletRequest
> > .getRequestURL().toString();
> >
> >
> >
> > *boolean* handled = handler.service(httpServletRequest,
> > httpServletResponse);
> >
> >
> >
> > *LOG*.debug(requestUrl + " handled by Tapestry filter: " +
> > handled);
> >
> >
> >
> > *if* (!handled) {
> >
> >
> >
> > }
> >
> >
> >
> > *if* (requestUrl.endsWith(".js")) {
> >
> >
> >
> > // CharResponseWrapper charResponseWrapper = new
> > CharResponseWrapper(httpServletResponse);
> >
> >
> >
> > *ServletResponseWrapperCopier*
> > capturingResponseWrapper = *new* *ServletResponseWrapperCopier*(
> >
> > httpServletResponse);
> >
> >
> >
> > PrintWriter responseWriter = httpServletResponse
> > .getWriter();
> >
> >
> >
> > // String originalContent =
> > charResponseWrapper.toString();
> >
> > String originalContent = capturingResponseWrapper
> > .getCaptureAsString();
> >
> > // String originalContent =
> > capturingResponseWrapper.getCaptureAsString();
> >
> > *LOG*.debug("javascript resource detected with
> > content: " + originalContent);
> >
> > //
> >
> > // int commentEnd = originalContent.indexOf("*/");
> >
> > // if (commentEnd > -1) {
> >
> > //
> >
> > // originalContent =
> > originalContent.substring(commentEnd);
> >
> > // }
> >
> > //
> >
> > // originalContent =
> > originalContent.replaceAll("(?m)^//.*", "");
> >
> > //
> >
> > // responseWriter.write(originalContent);
> >
> > }
> >
> >
> >
> > *return* handled;
> >
> > }
> >
> > }
> >
> > I tried several variations, like writing an own servlet filter and puting
> > it after the Tapestry Filter, but always the same: the content appears to
> > be empty.
> > Thanks in advance for your suggestions!
> >
> > Best Regards, Ric
> >
> > On Sun, Dec 1, 2019 at 3:38 PM Ric 2000 <erich.gorma...@gmail.com>
> wrote:
> >
> >> Hi Cezary,
> >>
> >> first thanks for your reply. Then I was at least not completely wrong.
> >> Let me show my code in the next reply, I will restore the version from
> GIT
> >> first.
> >>
> >> Best Regards, Erich
> >>
> >>
> >> On Sat, Nov 30, 2019 at 8:38 PM Cezary Biernacki <cezary...@gmail.com>
> >> wrote:
> >>
> >>> Hi,
> >>> as you suggested, it is possible to capture output of handling request
> by
> >>> subclassing HttpServletResponseWrapper, providing your own
> >>> ServletOutputStream, and wrapping the original HttpServletResponse
> >>> inside a
> >>> filter on the requested processing pipeline. This way is not specific
> to
> >>> Tapestry, maybe you only need to remember that Tapestry on the request
> >>> processing pipeline is implemented as a filter, not a servlet. Tapestry
> >>> itself uses this approach to implement compressing responses, see class
> >>> org.apache.tapestry5.internal.gzip.GZipFilter. I don't know why it is
> >>> not
> >>> working for you, probably you have a bug, but without seeing your code
> it
> >>> hard to help you.
> >>>
> >>> Best regards,
> >>> Cezary
> >>>
> >>>
> >>>
> >>>
> >>> On Sat, Nov 30, 2019 at 10:38 AM Ric 2000 <erich.gorma...@gmail.com>
> >>> wrote:
> >>>
> >>> > Dear all,
> >>> >
> >>> > I'm struggling on how to filter and modify the response sent to the
> >>> client
> >>> > in a Tapestry web application.
> >>> > I tried first with a RequestFilter contributed to the RequestHandler
> >>> > service.
> >>> > The problem occurred when I tried to read the content of the current
> >>> > response out stream. There are different hints on the internet how to
> >>> do a
> >>> > "capture" of this output stream using a custom
> >>> HttpServletResponseWrapper
> >>> > and overwriting the write method of the ServletOutputStream, to get
> the
> >>> > current content of the outputstream as byte array.
> >>> >
> >>> > But this is always empty, regardless of how I try to do it.
> >>> >
> >>> > Can you tell me, what is the right way in Tapestry to do it? Which
> >>> service
> >>> > do I have to contribute, in which phase of the request processing the
> >>> > response is filled and can be read, BEFORE it is send to the client?
> >>> >
> >>> > Thanks a lot for your suggestions, I really appreciate them!
> >>> >
> >>> > Best Regards, Ric
> >>> >
> >>>
> >>
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>
