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://forums.alfresco.com/viewtopic.php?t=3630).
I have further tried it out making a simple example, but I experience some class loading issues. I assume this might be due to the fact that the spring.jar is loaded from common/lib of the virtualization server, so by a classloader that does not have access to my deployed web application classes directly if I'm not mistaken. I don't find a good way to solve these issues I am experiencing anyway.
Has anyone tried this, or can anyone provide some further insight to the topic?
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
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).
