Re: [Jython-users] Re: Import strange error

[<bc...@wo...>]

[Sebastien Pierre]

>You pointed interesting things with the Java reflection. Here is what I=20=
>
>do:
> > java -Dpython.home=3D"/sw/share/jython" -cp SPEdit.jar=20
>org.python.util.jython -v

How does java find jython.jar with that command line?

Is jython.jar located in the jre/lib/ext directory? It probably
shouldn't be.

>But when I do:
>
> >>> import java
> >>> java.lang.Class.forName("net.sourceforge.spedit.app.Application")
>
>I get:
>Traceback (innermost last):
>   File "<console>", line 1, in ?
>java.lang.ClassNotFoundException: net.sourceforge.spedit.app.Application
>         at java.net.URLClassLoader$1.run(URLClassLoader.java:200)

Since this doesn't work, there is no way jython can find the Application
class (We are ignoring sys.path loading here).

>Then I do:
> >>> import net
>import: 'net' as java package
> >>> dir(net.sourceforge.spedit.app)
>
>and I get :
>['Application', 'AuthorDisplay', 'DBView', 'NavigationTree', 'Pool',=20
>'__name__']
>
>This is quite strange as I have explicitely specified the SPEdit.jar as=20=
>
>a classpath item...The problem is solved when I put the SPEdit.jar into=20=
>
>the jre/lib/ext MacOS X equivalent.
>
>In this case Jython has managed to index the SPEdit.jar, which is shown=20=
>by the result of the dir function call, but Java itself is then unable=20=
>to locate the SPEdit.jar, as if the classpath has been reset by jython.

Nope, can't blame jython for this.

My guess is that jython.jar exists in jre/lib/ext and that is the reason
that jython can only load other code that also reside on the
boot-classpath.

>I have written the equivalent in Java:

[...]

>When I run it:
>java -cp SPEdit.jar:. Test
>
>I get:
>*sys-package-mgr*: processing new jar,=20
>'/Users/spierre/Projects/SPEdit/prototype/build/SPEdit.app/Contents/Resour=
>ces/Java/SPEdit.jar'

Hmm, that output can't be from your little java program.

>class net.sourceforge.spedit.app.Application
>
>So actually Java find the class. This seems to point that the bug may be=20=
>in Jython overriding in some way the class path, so that URLClassLoader=20=
>is unable to find the classes anymore.

regards,
finn