[Dev] Unbroken & Heads-up

[Brett Wooldridge]

Those of you running Java6 have probably noticed an exception stacktrace
during server start-up and an inability to access SOAP services from the
client.  This is due to Sun including backlevel versions of libraries in the
JDK that we depend on for the Web Services component.  We use JAXB 2.1, they
ship JAXB 2.0.

This issue should now be resolved through the magic of OSGi.  We¹ve switched
over to using OSGi¹s strict classloading delegation model rather than the
³loose² mode that Equinox runs in by default.  The loose model was causing
Equinox to look in the system libraries before consulting our bundles for
classes in the javax.* package hierarchy ‹ and therefore finding backlevel
versions of some classes that we ship (particularly in
org.ziptie.server.metro).  When we flipped the switch to strict mode all
heck broke loose but not as much as we feared, and within about 30 minutes
had all the classloading issues resolved.

What this means to you is that you can¹t necessarily depend on the fact that
³it¹s in the JDK, therefore it is available to me.²  The strict OSGi
classloading means that all java.* classes are indeed still resolved by the
system bundle in OSGi (as they always were), but anything else ‹ including
classes in org.xml.*, org.w3c.*, javax.*, etc. are no longer implicitly
resolvable.  This may result in you encountering the occasional
ClassNotFound exeception when writing new code.  If you get a ClassNotFound
exception and it¹s in one of these ³core² kinds of packages, you will need
to edit server.sh and server.bat to explicity declare that package into the
system classloader.  We¹ve already declared a bunch of packages into that
system classloader so the likelihood of you encountering a CNF due to this
is small.

As always, let me know if you encounter any issues that seem related to this
change.

-Brett

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