From: rhww at erols.com (R Wentworth)
Date: Mon, 19 Apr 1999 19:21:22 -0400
Subject: Using JPython in servlets?
Message-ID: <371BBA72.5D24945F@erols.com>
Content-Length: 1853
X-UID: 1688                                                  

I don't know if this newsgroup is intended to deal with
issues regarding JPython (implementation of Python
that is tightly coupled to Java and runs under the JVM),
but if this is an appropriate forum...

Can anyone tell me the secret(s) to getting JPython servlets
to run, or even allowing JPython classes to successfully be
accessed from a Java servlet?  (This is under JRun, latest version,
and Java 1.1.7, running under Solaris.)  I'm running into
a seemingly bizarre problem.

Here is a simple example of what I'm seeing:

-- J.java --

  public abstract interface J {}

-- X.py --

  import J
  class X(J):
        pass

-- Test.java --

  ...working servlet code...
  new X();
  ...working servlet code continued...

----------------

Symptom.  Access the servlet GET method via the web, and see
a page titled "JRun Servlet Error":

 Test:

 Traceback (innermost last):  
   (no code object) at line 0
 AttributeError: class 'X' has no attribute 'X'

----------------

I *have* managed to discover one other circumstance
that produces this same type of error.  Suppose I
have a Java application (as opposed to a servlet)
which tries to do "new X()".  This works just fine
if CLASSPATH is set to the value seen by servlets,
i.e., a CLASSPATH including "jpython.jar"; however,
if I alter the CLASSPATH so that it points to either
no jpython libraries, or to an unzipped version of
jpython.jar, then I get a "class 'X' has no attribute 'X'"
error.  So it seems like the error may have something
to do with not being able to get at appropriate JPython
library code.  But the servlet CLASSPATH *does* include
"jpython.jar", so this wouldn't seem to explain the
problem.

Anyone have any clue whatsoever about what might be
wrong with the configuration, or how I might go
about debugging this??

Thanks in advance,
Robert Wentworth
rhww at erols.com




