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Re: Abstract Class versus an Interface, when no Members in Common

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From	Lew <lewbloch@gmail.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Abstract Class versus an Interface, when no Members in Common
Date	Thu, 3 Nov 2011 18:10:08 -0700 (PDT)
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markspace wrote:
> KevinSimonson wrote:
> > So I created an abstract class called<SearchResult>  that has no
> 
> In the real world, when there's a class like this, there's usually some 
> meta data that can decode which type is being returned.  As Arne points 
> out, there's usually also a "getAsType" method.  For example, the JDBC 
> object has various "getBoolean()" and "getBlob()" methods for accessing 
> database columns, as well as metadata describing the object.
> 
> While not the best over all (JPA is better, generally, than JDBC), it's 
> more structured that just an abstract class with no methods.
> 
> I might say that no methods = interface (called a mixin), but I think 
> the potential to add common methods here is high.  So, use a base class 
> so that you don't get tripped up by Java's single inheritance.  It's the 
> most conservative approach in this case.

The OP's approach seems somewhat hackish, based on the paucity of information provided so maybe it isn't.  Would it work to make the varying type a generic parameter?

-- 
Lew

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Abstract Class versus an Interface, when no Members in Common KevinSimonson <kvnsmnsn@hotmail.com> - 2011-11-03 16:09 -0700
  Re: Abstract Class versus an Interface, when no Members in Common Arne Vajhøj <arne@vajhoej.dk> - 2011-11-03 19:32 -0400
  Re: Abstract Class versus an Interface, when no Members in Common markspace <-@.> - 2011-11-03 17:37 -0700
    Re: Abstract Class versus an Interface, when no Members in Common Lew <lewbloch@gmail.com> - 2011-11-03 18:10 -0700
      Re: Abstract Class versus an Interface, when no Members in Common markspace <-@.> - 2011-11-03 18:46 -0700
  Re: Abstract Class versus an Interface, when no Members in Common Roedy Green <see_website@mindprod.com.invalid> - 2011-11-03 22:06 -0700
  Re: Abstract Class versus an Interface, when no Members in Common Ian Pilcher <arequipeno@gmail.com> - 2011-11-04 00:06 -0500
  Re: Abstract Class versus an Interface, when no Members in Common Robert Klemme <shortcutter@googlemail.com> - 2011-11-04 17:57 +0100
  Re: Abstract Class versus an Interface, when no Members in Common Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-11-04 13:54 -0700
    Re: Abstract Class versus an Interface, when no Members in Common Wanja Gayk <brixomatic@yahoo.com> - 2011-11-08 23:15 +0100
      Re: Abstract Class versus an Interface, when no Members in Common Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-11-08 20:58 -0800
  Re: Abstract Class versus an Interface, when no Members in Common Roedy Green <see_website@mindprod.com.invalid> - 2011-11-04 15:17 -0700
  Re: Abstract Class versus an Interface, when no Members in Common Wanja Gayk <brixomatic@yahoo.com> - 2011-11-08 23:13 +0100

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