jboss library loading sequence

[jbossfann]

Hi guys,

I am new to JBoss 4.0.2, and I am trying to find some info on how JBoss loads library jars.

Let's say I have 2 web applications in 2 WAR files that both need to use struts.jar library. It seems if I put it into .../server/default/lib directory it does not work and it only works when I put it inside .WAR archives in WEB-INF/lib directory.

So, how does JBoss handle Class loading and in what sequence from WEB-INF/lib, .../server/default/lib and other applciation lib directories?

Is there any way to see through web-console what libs are currently loaded

Thanks a lot

[ankurkkapadia]

your answer lies in the post below,

however its a bit of a mess

http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassLoadingConfiguration

[jbossfann]

I went trrough this before but I still have a question that I can't answer.

If I only put libraries into .../server/default/lib shouldn't an application always be able to see it.

Somehow I have to put struts.jar into both .../server/default/lib and WEB-INF/lib (part of war archive) otherwise I am getting different exceptions... (tld or classes not found...)

I will really appreciate a fe tips.

Thanks!

[weston.price]

Typicall you don't have to do this. WARS use an isolated classloader by default which should allow you to simply wrap things up in your WEB-INF/lib directory and you should be all set. But I think the struts.jar has some weirdness associated with the deployment. Again, the Web forum is probably a better place to get better coverage simply because users in the forum have probably gone through this a few times.

[weston.price]

Note, I apologize for posting things you probably have already read. It took me a while to remember that Struts may have different dependencies that a typical utility jar.

[jbossfann]

Thanks for your help. I will try the web forum as well.

I still have a question you may be able to help me answer, though.

If I do drop some libraries into .../server/default/lib would I need to put something in Class_Path attribute into a manifest file of my war or ear application to be able to see them from within ear or war application classes?

I just thought that an application, ear or war should be able to see the libs in the server directory, .../server/default/lib, by default.

[weston.price]

Right, server/lib takes precendence in the CL order. Typically most Classloading errors in JBoss occur when classes from multiple classloading domains conflict. A good example of this is having classes in server/lib and having them packaged in your archive as well.

[jbossfann]

Thanks a lot for your help!!