[Jython-users] Problems extending an abstract Java class.

[<ge...@ya...>]

I'm having some problems extending an abstract Java
class.  Everything is fine, except when the extended
class is called from within the constructor.

First of all is my Abstract Java class.

-----------------------------------------------------------
01 public abstract class Abstract {
02	
03    public Abstract() {
04       System.out.println("Java Class Abstract
Constructing");
05       // showInt(5);
06       System.out.println("Java Class Abstract
Constructed");
07    }
08	
09    public abstract void showInt(int i);
10		
11    public void showSix() {
12       showInt(6);
13    }
10 }
---------------------------------------------
Abstract.java

My Jython script looks like this.
-----------------------------------------------------------
01 import Abstract
02
03 class extends(Abstract):
04
05    def __init__(self):
06       print "Jython class 'extends' initialised"
07
08    def showInt(self, i):
09       print "showInt called with : ", i
10
11		
12 x = extends()
13 x.showInt(6)
14 x.showSix()
------------------------------------------------
Extends.jy

The output is as expected:

Jython class 'extends' initialised
Java Class Abstract Constructing
Java Class Abstract Constructed
showInt called with :  6
showInt called with :  6



However, if I decomment line 5 in Abstract.java, so
that the system
attempts to call the abstract method in the
constructor the output is
an error:

Jython class 'extends' initialised
Java Class Abstract Constructing
Traceback (innermost last):
  File "D:\gedbs\Java\lib\uk\co\RushCoding\extend.jy",
line 12, in ?
AttributeError: abstract method "showInt" not
implemented



Obviously this can be solved by using an explicitly
called init()
function rather than the constructor, but since I'm
actually extended
a public api I'd prefer to avoid this.

Is there any way of calling an extended abstract
method in the
constructor, or preventing the abstract classes
default constructor
from being called?

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