Is there a restriction on loading "javax" classes from WEB-INF/lib?

Question

I'm having trouble with a webapp in WL 10MP1 that is having trouble loading classes from the "jsr311-api-1.0.jar" in my WEB-INF/lib. Even though I have no trouble with it in Eclipse (no compile errors), classes from that jar fail with "NoClassDefFound" exceptions. I have a feeling it might be the fact that the packages in that jar start with "javax". Assuming that's the case, is there anything I can do to fix this?
What's even stranger is that the errors I get are when I try to load them directly from the Spring context. However, if I remove the test references to those classes, there's other code that loads those classes later in the application startup (after the Spring context finishes loading), and they load perfectly fine (I turned on verbose class loading to verify this).

Answer 1

Note that I've tried two other strategies that both result in the same failed state.
I tried putting the "jsr311-api-1.0.jar" in $JDK_HOME/jre/lib/ext, but that causes a failure to find Spring classes. I then copied the "spring.jar" into $DOMAIN_HOME/lib, and then it fails to find CXF classes. After doing the same with "cxf-2.2.3.jar", it then fails to find "javax.servlet.ServletContextListener", which clearly tells me there's no benefit to this approach.
Similarly, I tried copying the jars into $DOMAIN_HOME/lib, and that fails to find "org.apache.commons.logging.LogFactory". I could continue down this path, but it doesn't seem likely to succeed. Eventually, I'll get to a point where it just can't find the classes specific to my application, which I certainly can't copy into $DOMAIN_HOME/lib.
The first basic problem is that I can't put anything into a higher-level classloader that will eventually reference classes in a lower-level classloader, because references can only go up the chain, and the second problem is that WebLogic appears to ignore classes in WEB-INF/lib in the "javax.*" packages. I think there might be an exception for "javax.xml.*", but not for other subpackages. I tried adding a "prefer-application-packages" clause to my weblogic-application.xml file, but that had no effect.