Using NLTK in Java

hussainsaiger at hussainsaiger at
Tue Sep 2 16:40:59 CEST 2008

On 1 Sep, 16:21, "Diez B. Roggisch" <de... at> wrote:
> hussainsai... at wrote:
> > On 1 Sep, 11:55, "Diez B. Roggisch" <de... at> wrote:
> >> hussainsai... at schrieb:
> >> > I am trying to convert a python module (that contains the use of
> >> > NLTK.Corpus) by jythonc. It is not able to include nltk dependencies
> >> > within the java class it creates. So when i use this class in java, it
> >> > fails to recognize nltk. Can anyone please let me know how should i
> >> > use nltk in python/jython modules so i can use in Java.
> >> If there are any binary dependencies, you are out of luck. It won't
> >> work. You would need to write a RPC-Server then, with technologies such
> >> as XMLRPC or CORBA.
> >> Diez
> > So does that mean that Jython does not support nltk uptil now. I ask
> > this because when I try to import nltk in Jython (which is assumed to
> > replace Python), i get the same error. Its just nltk that I am not
> > able to use. The rest of the jython functions and libraries work fine
> > within Java.
> I don't know for sure - how about you post the error-message? Otherwise we
> can't assess the problem.
> Diez- Hide quoted text -
> - Show quoted text -


What i did was create a python file as:

import nltk
from java.util import Random

class NLPPresentation(Random):
    def nextDouble(self):
        return 1
    def TagByBrown(self,sent):
        "@sig public String[] TagByBrown(String sent)"
        brown_a = nltk.corpus.brown.tagged_sents(categories='a')
        bigram_tagger = nltk.BigramTagger(brown_a, cutoff=0)
        lst = bigram_tagger.tag(sent.split())
        return lst

I processed the following code through jythonc compiler to form a JAR
file. I then imported this jar
file into java ide (Java Builder). I then wrote the following program
in java to access this python class:

import org.python.core.PyException;
import org.python.core.PyInteger;
import org.python.core.PyObject;
import org.python.util.PythonInterpreter;
import java.util.Random;
import org.nltk.*;
import org.nltk.mallet.*;
public class SimpleEmbedded extends NLPPresentation{
	public static void main(String[] args) throws PyException {
        SimpleEmbedded so = new SimpleEmbedded();
		String s = "he is a boy";
	public void Call(String s)
		String[] arr = TagByBrown(s);

When i compile the above java code, i get the following error:

Exception in thread "main" Traceback (innermost last):
  File "C:\jython2.2.1\", line 0, in main
ImportError: no module named nltk

Your comments are highly appreciated.

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