Like Gareth said, you can change your jython.bat to add new jar files to the classpath.
Alternatively, you can load your jar file dynamically by appending to the sys path:
from mypackage import *
Message: 2
Date: Wed, 12 Mar 2008 14:17:38 +0100
From: "Sebastian Rhode" <>
Subject: [Jython-users] Import external JAR into Jython
Message-ID: <>
Content-Type: text/plain; charset="iso-8859-1"


I am quite new to jython and face the following problem. I need to import an external jar into jython, but I can not get to work.

JAR-File: jmathplot.jar

The jar works fine in Java. It is on the enviromental variable "CLASSPATH":


Thanks for your help!