Re: [Jython-users] Generated java classes dependency

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

[Pierre Dittgen]

>I'm quite new to jython, i find it very powerful as a script language.
>But at this time, I have a problem to make an independant jar from a jython
>script.
>I use Jython 2.0, with SUN JDK1.3.0 on Win2000 Pro.
>
>My script is called dir.py and contains:
>== begin ======
>import os
>
>for file in os.listdir('.'):
>	print file
>== end ========
>
>It works well as I use the command line:
>jython dir.py
>(it shows me the list of the files of the current directory)
>
>I want to build a jar file from this script.
>I used this command :
>jythonc -a -j dir.jar dir.py
>It created a jar file (called dir.jar) which contains normally all the
>needed jython libraries
>needed to make it run.
>But as I want to run it, using the command
>java -jar dir.jar
>I got an exception :
>== begin ==============
>
>java.lang.ExceptionInInitializerError: java.lang.NullPointerException
>        at org.python.modules.os.<clinit>(os.java:11)

It is a bug in the os.java module when running without an unset
sys.prefix. This normally happens for jythonc compiled applications.

As a workaround, you can set sys.prefix before importing the "os"
module.

  import sys; sys.prefix = "."
  import os
  ...

or you can upgrade to Jython-2.1a1 where the bug is fixed.

>I solved the problem giving the root dir of jython installation as a system
>property:
>java -Dpython.home=c:\dev\jython-2.0 -jar dir.jar
>
>But it annoys me...
>Is the generated jar (dir.jar) still dependant of the jython installation ?

No.

regards,
finn