Re: [Jython-users] How to call super class attributes inPython-derived Java classes

[Robert W. B. <rb...@di...>]

On Thu, 25 Oct 2001, Andres Corrada-Emmanuel wrote:
> On Thu, 25 Oct 2001, Kevin Butler wrote:
> > [CC's removed]
> > Andres,
> > You need to explicitly declare the 'outputTags' attribute as public:
> >
> >     public String outputTags;
> >
> > Your existing declaration:
> >
> > >     String outputTags;
> >
> > leaves it 'package-protected' ("friendly"), and subclasses could normally use it just fine, but because Jython attempts to access the attribute from its own package, the field is not visible.
> >
> > kb
>
> Okay. I got that working. But this brings me back to my original problem:
> I have a Python class that subclasses a Java class in a package. How do I
> tell Python that it can access that package's attributes?

I was mistaken earlier about saying there's a difference between package
private fields and methods.  I confused myself into thinking protected
attributes.

Yes, package private attributes are inaccessible. I do not know of a way
to "tell" jython that it can access them other than setting
respectJavaAccessibility to false.

> When I compile the Python class with jythonc I use the --package option
> and can see that the .java file created does have the correct package
> statement but I still cannot see the super's attributes.

You mean just package private attributes and protected fields, right? You
do have access to protected methods and everything public in the
superclass.

> Isn't that problematic?

<opinion>
Not really.  If you are writing the package, you have the power to use
jython-friendly permissions. If someone else wrote the package, chastise
them for making users develop in the same package <g>
You also have the choice to set respectJavaAccessibility to false.
</opinion>

-robert

> Andres Corrada-Emmanuel
> Senior Research Fellow
> Center for Intelligent Information Retrieval
> University of Massachusetts, Amherst