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

[<sp...@is...>]

> So when the "import net.sourceforge.spedit.app" works it means that
> jython have found the SPEdit.jar file and scanned it.
>
> You can verify that the SPEdit classes can be found by the JVM with =
this
> code:
>
>>>> import java
>>>> java.lang.Class.forName("net.sourceforge.spedit.app.Application")
>
> That should take jython out of the equation and if it doesn't work it
> means you have not added SPEdit.jar to your OSX classpath correctly.

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

*sys-package-mgr*: processing modified jar,=20
=
'/Users/spierre/Projects/SPEdit/prototype/build/SPEdit.app/Contents/Resour=
ces/
Java/SPEdit.jar'
*sys-package-mgr*: rewriting cachefile for=20
=
'/Users/spierre/Projects/SPEdit/prototype/build/SPEdit.app/Contents/Resour=
ces/
Java/SPEdit.jar'
*sys-package-mgr*: writing modified index file

So here the jar that contains the classes I want is loaded.
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)
         at java.security.AccessController.doPrivileged(Native Method)
         at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:297)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:253)
         at java.lang.Class.forName0(Native Method)
         at java.lang.Class.forName(Class.java:120)
         at java.lang.reflect.Method.invoke(Native Method)
         at=20
=
org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:158)=

         at=20
=
org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:166)=

         at org.python.core.PyObject.__call__(PyObject.java:272)
         at org.python.core.PyObject.invoke(PyObject.java:2105)
         at org.python.pycode._pyx2.f$0(<console>)
         at org.python.pycode._pyx2.call_function(<console>)
         at org.python.core.PyTableCode.call(PyTableCode.java:155)
         at org.python.core.Py.runCode(Py.java:1055)
         at org.python.core.Py.exec(Py.java:1076)
         at=20
org.python.util.PythonInterpreter.exec(PythonInterpreter.java:145)
         at=20
=
org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter.java=
:
87)
         at=20
=
org.python.util.InteractiveInterpreter.runsource(InteractiveInterpreter.ja=
va:
68)
         at=20
=
org.python.util.InteractiveInterpreter.runsource(InteractiveInterpreter.ja=
va:
42)
         at=20
org.python.util.InteractiveConsole.push(InteractiveConsole.java:83)
         at=20
org.python.util.InteractiveConsole.interact(InteractiveConsole.java:62)
         at org.python.util.jython.main(jython.java:178)

java.lang.ClassNotFoundException: java.lang.ClassNotFoundException:=20
net.sourceforge.spedit.app.Application

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.

I have written the equivalent in Java:

class Test
{

         public static void main (String[] args)
         {
                 try
                 {
                        =20
=
System.out.println(Class.forName("net.sourceforge.spedit.app.Application")=

);
                 }
                 catch ( Exception e )
                 {
                         System.out.println("Class not=20
found.\n\t"+e.toString());
                         e.printStackTrace();
                 }
         }
}

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'
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.

Cheers,
   -- S=E9bastien.