Hi,
I am using Felix (embedded-style) to create a small plug-in system to our
application. I have built a bundle using Apache Axis to connect to a
webservice. The bundle registers with the main application (which of course
has started up Felix) and upon request from the main app calls the
webservice and returns the results to the main app. (Basically.) The
manifest of the bundle looks like this:
Bundle-Name: A name
Bundle-Description: A description
Bundle-Vendor: 2c8
Bundle-Version: 1.0.0
Bundle-Activator: se.xxx.model.DocumentServiceImpl
Import-Package: org.w3c.dom, javax.naming, javax.xml.parsers, org.xml.sax,
se.conciliate.extensions.documentservice, org.osgi.framework
Bundle-Classpath: ., jaxrpc.jar, axis.jar, commons-logging-1.0.4.jar,
commons-discovery-0.2.jar
Now, when the call from the main app tracks its way down to
DocumentServiceImpl .someMethod(), an exception is thrown from Axis:
java.lang.ExceptionInInitializerError
at org.apache.axis.client.Service.getAxisClient(Service.java:104)
at org.apache.axis.client.Service.<init>(Service.java:113)
a couple of "at se.ourclasses." followed by
Caused by: org.apache.commons.logging.LogConfigurationException:
org.apache.commons.logging.LogConfigurationException:
org.apache.commons.logging.LogConfigurationException: Invalid class loader
hierarchy. You have more than one version of
'org.apache.commons.logging.Log' visible, which is not allowed. (Caused by
<same exception again*2>)
This is the interesting parts of the stack trace (I think?). Apparently
commons-logging does not like to have more than one instance of
org.apache.commons.logging.Log visible on the class path. Problem is, I'm
not using it - Axis is. I've read about PaxLogging but I'm not sure how to
make Axis use another logging facility. If anyone could help me to set up my
(relatively small) bundle so that it can make the webservice calls it needs
to, I'd be very grateful! Or rather, if anyone could guide me through how to
set up a bundle, that uses libraries, that need commons-logging.
I should maybe mention also, that we use Axis for other purposes in our main
app. This must be where the other instance of org.apache.commons.logging.Log
is made visible?? (I don't export this from the system bundle however so I
don't get how this can interfere. Isn't the osgi framework supposed to
guarantee that a bundle only get exposed to one instance of each class, no
matter how badly I as a developer screw things up?)
Since commons-logging is used by many other Apache distributions this must
be a somewhat frequent problem. I have not managed to find a solution though
so I hope that this isn't already answered in a thousand other places. All
I've managed to find is that commons-logging is not suited to "bundleize".
Please be kind if I've misunderstood something badly. I'm new to both Felix
and Axis (and don't know much about logging either). ;-)
Regards,
Per-Erik Svensson
