Re: Forcing sub-classes to implement Constructor

On Thursday 09 August 2007 08:14, Jeff Kesselman wrote:
> Brian Maso wrote:
> > No.
> >
> > Constructors are more like static methods than regular methods:
> > they can't be declared abstract and thus force subclasses to have
> > them. You can add tools to your build to recognize certain
> > annotations that trigger verifier rules. For example, you could
> > define an annotation such as:
>
> Hmm. Brian appears to be correct after a quick test.
>
> Whats weird is that I *know* I've seen situations where the
> definition of a super class contrutctir forced the definition of sub
> class one...

I think this would do it:

class Super
{
    private
    Super()
    {
    }

    protected
    Super(...)
    {
        ...
    }
}

class Sub
extends Super
{
    // Implicit default constructor implicitly calls super()
    //  which is private, forcing the definition of a constructor
    //  to call an accessible Super constructor
}


> JK


Randall Schulz

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