[Jpype-users] Problem with JPype (newbie)

[<lc...@cs...>]

Hi,

I am a newbie in python and JPype.  I need to use JPype to communicate =20
a python program with the java program.  I tested a small java program =20
that didn't have any external jar file (it just uses java.lang =20
library) and I called it from a python program using JPype and It =20
works fine.  I am using version JPype-0.5.2.1, wich is the latest that =20
I found for python 2.4 (running on windows).  I am trying to run a =20
program that uses the datamining library, weka, that is written in =20
java (it is in a jar file: weka.jar which is in defined in the =20
classpath, and when I run the java program independently it works =20
fine).  My problem is that I get the following error message when I =20
try to call the program from python using JPype:

D:\Lorena\weka\examples>python Nav1.py
Traceback (most recent call last):
   File "Nav1.py", line 7, in ?
     csvArffClass.convert("bank-data.csv","bank-data.arff")
jpype._jexception.java.lang.LinkageErrorPyRaisable: =20
java.lang.NoClassDefFoundErr
or: weka/core/converters/CSVLoader

Here is the code:

Nav1.py
------------

from jpype import *

startJVM("c:/Program Files/Java/jdk1.6.0_01/jre/bin/server/jvm.dll", "-ea")
csvArffClass =3D JClass("CSV2Arff")
csvArffClass.convert("bank-data.csv","bank-data.arff")
shutdownJVM()

CSV2Arff.java
--------------------

import weka.core.Instances;
import weka.core.converters.ArffSaver;
import weka.core.converters.CSVLoader;

import java.io.File;

public class CSV2Arff {

   public static void convert(String inputfile, String outputfile)
   {
     try
     {
        // load CSV
        CSVLoader loader =3D new CSVLoader();
        loader.setSource(new File(inputfile));
        Instances data =3D loader.getDataSet();

        // save ARFF
        ArffSaver saver =3D new ArffSaver();
        saver.setInstances(data);
        saver.setFile(new File(outputfile));
        saver.setDestination(new File(outputfile));
        saver.writeBatch();
      }
      catch (Exception e) {}
   }
}


Please let me know what am I doing wrong?.

Thanks,

Lorena Carlo