jython-users

[Jython-users] Importing and using nested classes

[Michael H. <mh...@al...>]

Hello,

I'm new to Jython and to Java, so I might be trying things that are
just nonsense.  But I am having trouble importing and using
multiply-nested java classes using jython.  The following illustrates
the problem:

In testlib.java:

public class testlib {
    static public class B {
        static public class C {
            public C() {
                System.out.print("This must be working!\n");
            }
        }
    }
}


In test.java:
import testlib.B.C;

public class test {
    static public void main(String[] args) {
    }
}


In test.py:

#! /usr/bin/env jython

import testlib
import testlib.B
import testlib.B.C


Try to run it:

$ JIKESPATH=.:$JIKESPATH jikes testlib.java test.java
$ java test
This must be working!
$ jython test.py
Traceback (innermost last):
  File "test.py", line 5, in ?
ImportError: No module named C
$ 

I thought this should import the C class from jython, but it doesn't
seem to work.  Could the problem be that it is doubly-nested (i.e.,
the .class file has two '$' in it)?

Otherwise I've been astounded how easy it is to use Jython and Java
together, and we will probably start using it on a medium-big project
at work.

Thanks,
Michael

--
Michael Haggerty
mh...@al...

Re: [Jython-users] Importing and using nested classes

[D-Man <ds...@ri...>]

On Wed, Jul 11, 2001 at 01:40:37PM +0200, Michael Haggerty wrote:
| Hello,
| 
| I'm new to Jython and to Java, so I might be trying things that are
| just nonsense.  But I am having trouble importing and using
| multiply-nested java classes using jython.  The following illustrates
| the problem:

| In test.py:
| 
| #! /usr/bin/env jython
| 
| import testlib
| import testlib.B
| import testlib.B.C

import is usually only used with modules or packages.  With Jython,
however, you can import top-level classes.

Instead try this and see if it helps :


#!/usr/bin/env jython
import testlib

print testlib.B
print testlib.B.C

| Otherwise I've been astounded how easy it is to use Jython and Java
| together, and we will probably start using it on a medium-big project
| at work.

Sounds good!  IMO Python (Jython) is much easier to use than Java.

-D

Re: [Jython-users] Importing and using nested classes

[Michael H. <mh...@al...>]

D-Man writes:
> Instead try this and see if it helps :
> 
> #!/usr/bin/env jython
> import testlib
> 
> print testlib.B
> print testlib.B.C

It doesn't help:

$ jython
Jython 2.0 on java1.3.1 (JIT: null)
Type "copyright", "credits" or "license" for more information.
>>> import testlib
>>> print testlib   
testlib
>>> print testlib.B
testlib.B
>>> print testlib.B.C
Traceback (innermost last):
  File "<console>", line 1, in ?
AttributeError: class 'testlib.B' has no attribute 'C'
>>> 

--
Michael Haggerty
mh...@al...