Re: java inheritance

From:
Robert Klemme <shortcutter@googlemail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 11 Nov 2013 19:19:17 +0100
Message-ID:
<becldeF7cdaU1@mid.individual.net>
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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