6 Replies Latest reply on Jan 26, 2009 10:00 AM by Ales Justin

    Mapping web resources over VDF

    Ales Justin Master

      WRT:
      - http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4203370#4203370
      - http://www.jboss.com/index.html?module=bb&op=viewtopic&t=149197

      How hard would it be to 'move'/impl JBossWeb's TLD lookup based on MC's VDF?

      My use case for JBossPortal (JBP) would be:
      1) recognize that deployment is JBP app
      2) add JBP's custom TLD to VFSDeploymentUnit's metadata locations

      e.g.

      VirtualFile customJbpTLDs = VFS.getRoot(".../jboss-portal/config/tlds");
      unit.appendMetaDataLocation(customJbpTLDs);
      


      3) JBossWeb would understand VDF (VFSDeploymentUnit - VDU)
      and do a tld lookup based on VDU's metadata locations

      This would mean if we run in an environment that uses VDF
      we should first try to look for metadata via VDF
      only then fall back to plain resources lookup.

      This way the services that use VDF won't have to introduce
      hacks to add custom metadata - like JBP does it currently.

      btw: where exactly does .tld file lookup happen?

        • 1. Re: Mapping web resources over VDF
          Ales Justin Master

           

          "remy.maucherat@jboss.com" wrote:

          Normally, the web tier embedded in AS uses VFS for almost everything
          already (it has a DirContext-over-VFS implementation), but indeed TLD
          may use some work. It should be pluggable for Catalina (it only uses it
          to lookup for listeners), but for Jasper it's harder. I sort of hoped
          nobody would notice ... So I suppose some review is needed.


          • 2. Re: Mapping web resources over VDF
            Ales Justin Master

             

            "remy.maucherat@jboss.com" wrote:

            Normally, the web tier embedded in AS uses VFS for almost everything
            already (it has a DirContext-over-VFS implementation),

            As it seems, direct VFS is not enough,
            we need whole VDF, with its mutable VFSDeploymentUnit (VDU).

            Like my code suggests, one would add an 'external' metadata location,
            containing custom resources (in JBP's case their custom .tld),
            and once web tier would do a lookup for those resources,
            it would go over VDU's metadata locations, not really caring where they come from.



            • 3. Re: Mapping web resources over VDF
              Ales Justin Master

               

              "remy.maucherat@jboss.com" wrote:

              it has a DirContext-over-VFS implementation

              I'm having problems locating the usage of VFSDirContext.
              It used to be in TomcatDeployment, but it's not there anymore.

              • 4. Re: Mapping web resources over VDF
                Ales Justin Master

                 

                "remy.maucherat@jboss.com" wrote:

                Ok, I've had a look and I remember the story a bit better now. The
                bottom line is that it's not going to happen (running on VFS works fine,
                but makes certain legacy Servlet API features not work - like the
                getRealPath stuff).

                So the solution is to (eventually) provide some configuration in Jasper
                to allow plugging in the component that handles TLDs.

                And that is really the best I can offer.


                • 5. Re: Mapping web resources over VDF
                  Ales Justin Master

                   

                  "remy.maucherat@jboss.com" wrote:

                  "alesj" wrote:

                  At least I wouldn't limit myself to TLDs ... if that's possible.

                  All "standard" descriptors and annotations are already given by AS.
                  context.xml files are then read through the VFS in JBossContextConfig.
                  The only thing missing is really TLDs, parsed using TldLocationsCache
                  and TagLibraryInfoImpl in Jasper, which is not pluggable right now.

                  It is a two step process:
                  1) scan to associate the requested taglib uri with the location of its
                  TLD
                  2) parse the actual TLD file


                  "remy.maucherat@jboss.com" wrote:

                  "alesj" wrote:

                  afaik they are eager to get things working cleanly/nicely on the new VDF.

                  Hence the mutable VFSDeploymentUnit.

                  That's what is used: WebApplication.getDeploymentUnit.getFile

                  But redoing TLD processing is not trivial. I think in theory since they
                  are standard EE metadata, then the parsing should be in
                  JBossWebMetaData, and Jasper should not have to do any TLD scanning and
                  parsing like it does right now.



                  • 6. Re: Mapping web resources over VDF
                    Ales Justin Master

                     

                    "remy.maucherat@jboss.com" wrote:

                    "alesj" wrote:

                    "remy.maucherat@jboss.com" wrote:

                    then the parsing should be in
                    JBossWebMetaData, and Jasper should not have to do any TLD scanning and parsing like it does right now.

                    Exactly!
                    Couldn't agree more.

                    How fast can we change this? :-)

                    Not very fast.

                    For starters, TLDs are located in a variety of funny locations, which
                    usually needs caching since usually people also want to be able to put
                    some in shared JARs, etc :(
                    Then Jasper components need to be pluggable and have a new impl.
                    And then test and fix problems.

                    To be honest, if you are in a hurry, there is no way you can rely on
                    this.