Hi all,
Can I ask what may be a stupid question here. If QName is now bundled
with 1.5, and JAXB requires 1.5, then why is JAXB shipping QName?
There seems to be no more logic to that than JAXB shipping its own
version of java.lang.StringBuilder. This same argument goes for
IntelliJ shipping with QName in their classpath (given that it also
requires 1.5).
Am I missing something here?
cheers
dim
On 3/22/06, Kirill Grouchnikov <kirillcool_at_yahoo.com> wrote:
> Kohsuke,
>
> With the class loader being
> com.intellij.ide.plugins.cl.PluginClassLoader (not much i
> can do here) and four (!) versions of QName class in the classpath:
> jar:file:/H:/IntelliJ%20IDEA%205.1/jre/lib/rt.jar!/javax/xml/namespace/QName.class
> jar:file:/C:/Documents and
> Settings/Owner/.IntelliJIdea50/sandbox/plugins/jaxbw-plugin/lib/jsr173_1.0_api.jar!/javax/xml/namespace/QName.class
> jar:file:/H:/IntelliJ IDEA
> 5.1/lib/xml-apis.jar!/javax/xml/namespace/QName.class
> jar:file:/H:/IntelliJ IDEA
> 5.1/lib/ant/lib/xml-apis.jar!/javax/xml/namespace/QName.class
>
> it's obviously a complete disaster.
>
> Moreover, the LinkageError is thrown not always. On one computer it's thrown
> on simple schema, on another it's not thrown on the same schema but is
> thrown on FPML / HRXML / VoiceXML. The IDEA version is the same in both
> cases.
>
> I have tried using the user classpath option and point to the rt.jar, but
> the XJC driver fails nonetheless. Any option that comes to your mind?
>
> Kirill
>
>
> Kohsuke Kawaguchi <Kohsuke.Kawaguchi_at_Sun.COM> wrote:
> Kirill Grouchnikov wrote:
> > The jsr173_1.0_api.jar contains the version of QName without
> > serialVersionUID (in package javax.xml.namespace). The rt.jar of JDK
> > 5.0_06 contains QName (in the same package) with serialVersionUID.
>
> When you have a conflict between a class in rt.jar and a class in a jar
> file on your classpath, rt.jar always wins, by the default Java class
> loader delegation rule.
>
> So when you see a loader constraints violated like this, it must be that
> you are setting up a classloader that doesn't follow the parent-first
> delegation rule. Such a classloader usually allows certain classes to be
> loaded from the parent (for example you need to get java.lang.String
> from rt.jar), and if so, you can usually fix them by tweaking that list
> to include javax.xml.namespace.
>
> > As i understand, the JAXB 2.0 compiled classes use the former version,
> > while at runtime the class loader may decide to use the JRE version
> > instead - i think this is what causes the LinkageError.
>
> Compiling classes against one version of QName and using it against
> another version of QName is not an issue, unless we generate code that
> relies on serialVersionUID, which we don't.
>
> Even if this is an issue, you'll get a different error, not "loader
> constraints violated" error.
>
> > Any reason why the QName classes are different and why JAXB 2.0 is not
> > compiled against the JDK version? I know there's little time left until
> > FCS but this seems like a serious issue.
>
> I don't think the compilation vs the runtime difference is the problem,
> for the reason I mentioned. JAXB RI is compilied against JDK 5.0 (in
> fact it's very difficult not to!)
>
> --
> Kohsuke Kawaguchi
> Sun Microsystems kohsuke.kawaguchi_at_sun.com
>
>
>
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