topic Re: Hosting Spring-based dynamic webapps with Alfresco WCM in Alfresco Archive

Hosting Spring-based dynamic webapps with Alfresco WCM

bjornl — Sun, 20 May 2007 16:30:30 GMT

Is it possible in an easy way to host spring-based web applications with Alfresco WCM? As was pointed out in another post regarding using java technologies other than plain jsp/servlets, it should theoretically work but for frameworks accessing for example configuration files, it might not (see http

Re: Hosting Spring-based dynamic webapps with Alfresco WCM

alexander — Mon, 21 May 2007 07:12:23 GMT

You might need to mount you alfresco AVM share as V: drive (on windows) or /media/alfresco/cifs/v on Linux.

Re: Hosting Spring-based dynamic webapps with Alfresco WCM

jcox — Wed, 23 May 2007 14:46:30 GMT

For now, try removing the Spring jar file from your
webapp, and rely upon the one pre-loaded by the
virtualization server. In the near future, I hope to
make this unnecessary, but for now that's what
you've got to do.

Tomcat's classloader hiararchy looks like this:

                    
                              Bootstrap
                                  |
                               System
                                  |
                               Common
                              /      \
                         Catalina   Shared
                                     /   \
                                Webapp1  Webapp2

‍‍‍‍‍‍‍‍‍‍‍‍

Classloader rules:

Classloaders will only load the "same" class once.

Two classes are only the "same" if they have the same name, and were loaded by the same classloader.

When your webapp references a class, if it's not already loaded, the search order goes:

yourWebapp –> Shared –> Common –> System –> Bootstrap

Currently, the virtualization server needs the Spring jar file within
$VIRTUAL_TOMCAT_HOME/common/lib/ (i.e.: Common in the diagram above).

Thus, your webapp does have access to the pre-loaded Spring libs in Common.
It also has access to the Spring jar you've got in your webapp…
and that's the problem.

What I'm planning on doing is restructuring things a bit so that
the virt server's use of Spring is completely invisible to the webapps
it hosts. I've just filed a bug so you can see when this issue is resolved:
http://issues.alfresco.com/browse/WCM-494

Re: Hosting Spring-based dynamic webapps with Alfresco WCM

jcox — Mon, 28 May 2007 20:17:19 GMT

I've just fixed WCM-494.

Therefore, given your build is new enough, you should now be able to
virtualize webapps that contain Spring without doing anything special
(i.e: you don't need to remove spring.jar from your webapp).

Cheers,
-Jon