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Groups > comp.lang.java.programmer > #7667

Re: Avoid derived class to override a method yet should allow callers to invoke the method

From Ethan <sam_cit@yahoo.co.in>
Newsgroups comp.lang.java.programmer
Subject Re: Avoid derived class to override a method yet should allow callers to invoke the method
Date 2011-09-06 22:40 -0700
Organization http://groups.google.com
Message-ID <1e0a57fd-cd79-45d8-ab37-252b981e3dfe@s2g2000vby.googlegroups.com> (permalink)
References <79cc1af8-1f3c-41c7-bbe2-8c5085b25e7c@t9g2000yqi.googlegroups.com> <38560bc6-af42-471f-b750-d2966452b1c3@glegroupsg2000goo.googlegroups.com>

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On Sep 6, 9:40 pm, Lew <lewbl...@gmail.com> wrote:
> Ethan wrote:
> >    I have a requirement where base class has method (implemented) and
> > derived class shouldn't be able to override it.
> > However, the method needs to be invoked by a caller who creates an
> > instance of the derived class.
>
> >   Is this possible?
>
> Absolutely.
>
> You prevent an override by 'final' in the method signature, and this is very frequently The Right Thing To Do.  
>
> You make the method callable by client code through 'public' in the method signature, which is the standard thing to do.
>
> public class BaseOfOperations
> {
>   public final void DoSomething()
>   {
>     // implementation here
>   }
>
> }
>
> public class SpecificOperations extends BaseOfOperations
> {
>   // cannot override DoSomething()
>
> }
>
> public class Client
> {
>   public void Whatever()
>   {
>     BaseOfOperations boo = new SpecificOperations();
>     boo.DoSomething();
>   }
>
> }
>
> I suggest that you read the Java tutorials and a good basic book on Java programming.http://download.oracle.com/javase/tutorial/
>
> --
> Lew

Thanks Lew and Peter. Its been a while that i have coded in java and
didn't knew much about final.

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Thread

Avoid derived class to override a method yet should allow callers to invoke the method Ethan <sam_cit@yahoo.co.in> - 2011-09-06 21:05 -0700
  Re: Avoid derived class to override a method yet should allow callers to invoke the method Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-09-06 21:38 -0700
  Re: Avoid derived class to override a method yet should allow callers to invoke the method Lew <lewbloch@gmail.com> - 2011-09-06 21:40 -0700
    Re: Avoid derived class to override a method yet should allow callers to invoke the method Ethan <sam_cit@yahoo.co.in> - 2011-09-06 22:40 -0700
    Re: Avoid derived class to override a method yet should allow callers to invoke the method Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-09-07 10:35 +0000
      Re: Avoid derived class to override a method yet should allow callers to invoke the method Lew <lewbloch@gmail.com> - 2011-09-07 08:14 -0700

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