Re: [Jython-users] casting a java object created in jython to its true class

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

[brian zimmer]

>If you have a PyObject and want to get the underlying Java instance, use:
>
>  po.__tojava__(<the Java class you want>)
>
>For instance, say arg is a PyInteger instance, the following would get the
>long value:
>
>  long ticks = ((Number) arg.__tojava__(Number.class)).longValue();

Just the smallest little nit about style: If arg isn't a number, the
line above will throw an ugly classcast exception. Normally it is better
to do:

   Object tmp = arg.__tojava__(Number.class):
   if (tmp != Py.NoConversion) {
       long ticks = ((Number) tmp).longValue();
   }

>Most subclasses (maybe all) ...

All subclasses that we want to use as arguments to java methods must
implement __tojava__().

regards,
finn