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From: Robert Klemme <shortcutter@googlemail.com>
Newsgroups: comp.lang.java.programmer
Subject: Re: java inheritance
Date: Mon, 11 Nov 2013 19:19:17 +0100
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On 11.11.2013 14:30, asdf9797 wrote:
> Hi
>
> I did a java test recently and one of the questions was on the subject of
> inheritance/ OO design
>
> The idea was there was a "Storable" abstract class which contained a store() method.
>
> There was a IStorable interface
>
> And then there was
>
> class Book extends Storable implements IStorable {
>     public void save(Book) {
>     }
>
> }
> The question was how to improve the implementation.

Get rid of the argument of method save().  A Book has immediate access 
to all its state.

If at all, you would want to pass something like a Store, a Store 
interface or something which is able to store data.  For that it would 
have to exhibit methods for basic store operations much like DataOutput 
does.

http://docs.oracle.com/javase/7/docs/api/java/io/DataOutput.html

> What is the current thinking on extending abstract classes ?

Extending abstract classes is absolutely necessary.

> Is that the issue?

What?

Kind regards

	robert

-- 
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