jython-users

[Jython-users] Problems with Java/Jython subclassing

[Steinar R. E. <ste...@fi...>]

Hi

Can anyone please give me some guidance on this. I try to create a =
system where I use Java classes that are subclassed for prototyping in =
Jython. Within the rest of the Java code (after initialization) I would =
like to refer to standard Java classes rather than PyObject. Hence, I =
try to subclass a Java class in Python and later just use the Java class =
itself when calling methods.

Am I trying to do something that is not possible within the Jython =
framework, or is there away around it.

Java :
class MyClass
{
    void Method()

}

Jython :

def PyMyClass (MyClass):
    def Method()


Java (Factory class)
class MyClassFactory

    public MyClass createMyClass()
    {
        /*
            use PythonInterpreter to create
            PyObject instance of PyMyClass()
           =20
            This works fine. I can call methods here (with invoke)
        */=20
        MyClass p=3D(MyClass) myPyObject;=20
        // Why does this typecase fail (error on PyInstance) ?
        // I thought this cast would work since the PyMyClass object =
subclasses MyClass... ??
   =20
    }
   =20

Re: [Jython-users] Problems with Java/Jython subclassing

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

Hi Steinar,

On Mon, 30 Apr 2001, Steinar Rune Eriksen wrote:
> Hi
>
> Can anyone please give me some guidance on this. I try to create a system where I use Java classes that are subclassed for prototyping in Jython. Within the rest of the Java code (after initialization) I would like to refer to standard Java classes rather than PyObject. Hence, I try to subclass a Java class in Python and later just use the Java class itself when calling methods.
>
> Am I trying to do something that is not possible within the Jython framework, or is there away around it.
>
> Java :
> class MyClass
> {
>     void Method()
>
> }
>
> Jython :
>
> def PyMyClass (MyClass):
>     def Method()
>
>
> Java (Factory class)
> class MyClassFactory
>
>     public MyClass createMyClass()
>     {
>         /*
>             use PythonInterpreter to create
>             PyObject instance of PyMyClass()
>
>             This works fine. I can call methods here (with invoke)
>         */
>         MyClass p=(MyClass) myPyObject;
>         // Why does this typecase fail (error on PyInstance) ?
>         // I thought this cast would work since the PyMyClass object subclasses MyClass... ??
>
>     }

Try:

    MyClass p = PyObject.__tojava__(MyClass.class);


-rb