XPath class resolution in JBoss5

Question

I\'m having a hard time figuring out where the problem is coming from, so I\'m posting this in the hopes that others might have found something similar to this elsewhere and

Answer 1

It seems that the problem was solved by removing the javax.xml.namespace.* package and respective classes from the deployed Axis2 JAR files. Namely, using Axis2 1.4.1 (instead of 1.4), I repackaged these JAR files:

• axis2-saaj-api-1.4.1.jar, by removing javax.xml.namespace
• woden-impl-dom-1.0M8.jar, by removing javax

Also, Eclipse is extremely picky at the project configuration. So far, I've found that the Project Facet for the Dynamic Web Project has to be created with a Dynamic Web Module of version 2.4 (and not 2.5 as it suggests by default), but with a Java version 6 (same as the branch of the used JDK). I don't know why this happens, I suppose the Dynamic Web Module version 2.4 tying up by default with Java 1.4 in Eclipse is where all the confusion comes from. Some googling led me to believe that package javax.xml didn't become incorporated into the JDK until Java 5 or Java 6 -- hence the possible mixup! However, I'm not knowledgeable enough to investigate if the problem comes from how Eclipse packages the archive files for deployment so this is just a suspicion I have so far.

Answer 2

JBoss will throw a LinkageError when the application's classpath contains classes which JBoss considers "protected", i.e. it does not permit the application to contain its own copies of certain key APIs.

In this case, it looks like your appcontains its own copies of the javax.xml.xpath API, and possibly some others as well, as you mentioned.

You need to remove anything from your EAR/WAR's lib directories that clashes with JBoss's own libraries (e.g. axis2-saaj-api-1.4.jar).