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Groups > comp.lang.java.programmer > #24742

Re: Interface with implied Constructor

From Robert Klemme <shortcutter@googlemail.com>
Newsgroups comp.lang.java.programmer
Subject Re: Interface with implied Constructor
Date 2013-07-15 20:45 +0200
Message-ID <b4iuafFmlhqU1@mid.individual.net> (permalink)
References (1 earlier) <925adeb1-65b5-4a50-86a8-4f04784f8da0@googlegroups.com> <kri3sj$lnl$1@speranza.aioe.org> <51df65bd$0$52780$742ec2ed@news.sonic.net> <b4fvsjF33d6U1@mid.individual.net> <51e41c16$0$52743$742ec2ed@news.sonic.net>

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On 15.07.2013 17:58, Kevin McMurtrie wrote:
> In article <b4fvsjF33d6U1@mid.individual.net>,
>   Robert Klemme <shortcutter@googlemail.com> wrote:
>
>> On 12.07.2013 04:11, Kevin McMurtrie wrote:
>>
>>> There's a builder pattern than works.  It's a little ugly but it's what
>>> you have when you can't use abstract classes for some reason.  Move
>>> around the interfaces as you see fit.
>>
>> <snip/>
>>
>> I'd call that "factory pattern".  Why did you pick "builder"?

> They're similar.  I've seen the term "builder" used more often when the
> construction is done by the implementor and "factory" more often when
> the construction is performed by a single system.  Builder also has a
> pattern of SomeThing a= new
> Builder().with(Options.B).add(x).add(y).addAll(Z).makeImmutable();  It's
> a way to specify arguments after construction without allowing access to
> a partially built object.

But you do not use that feature of chaining in your sample code.  To me 
that's a plain factory.  If you had taken advantage of Builder you would 
have had an interface like this, I believe:

interface MyThing {
   ...
}

public interface MyThingBuilder {
   MyThingBuilder addArg1(int arg1);
   MyThingBuilder addArg2(int arg1);
   MyThing finish();
}

The consistency checking ("Do we have all the arguments?") is put into 
the MyThingBuilder implementation and the client can rely on the 
returned MyThing to be complete so not all methods of MyThing have to 
check state (a concern that has been voiced).

It's a bit like Command pattern applied to object construction: the 
command object's configuration methods (addArg1 and addArg2 above) 
replace constructor arguments and the construction is eventually done by 
a no argument method.

Kind regards

	robert


-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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Thread

Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-09 18:41 +0800
  Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-09 04:08 -0700
    Re: Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-10 06:46 +0800
      Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-09 21:08 -0400
      Re: Interface with implied Constructor Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-07-11 19:11 -0700
        Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-14 17:53 +0200
          Re: Interface with implied Constructor Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-07-15 08:58 -0700
            Re: Interface with implied Constructor Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-07-15 10:57 -0700
              [OT] Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-15 14:13 -0400
                Re: [OT] Re: Interface with implied Constructor Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-07-15 12:58 -0700
            Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-15 20:45 +0200
      Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-14 18:03 +0200
        Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-18 23:21 -0300
          Re: Interface with implied Constructor Gene Wirchenko <genew@telus.net> - 2013-07-19 12:38 -0700
            Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-19 17:56 -0300
              Re: Interface with implied Constructor Gene Wirchenko <genew@telus.net> - 2013-07-22 12:39 -0700
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-22 16:02 -0400
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-22 18:08 -0300
                Re: Interface with implied Constructor Gene Wirchenko <genew@telus.net> - 2013-07-23 14:32 -0700
                Re: Interface with implied Constructor Jim Gibson <jimsgibson@gmail.com> - 2013-07-23 14:43 -0700
                Re: Interface with implied Constructor Gene Wirchenko <genew@telus.net> - 2013-07-24 13:27 -0700
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-24 18:20 -0300
                Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-26 00:03 +0200
                Re: Interface with implied Constructor Martin Gregorie <martin@address-in-sig.invalid> - 2013-07-24 21:18 +0000
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-24 17:42 -0400
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-23 18:19 -0400
                Re: Interface with implied Constructor Gene Wirchenko <genew@telus.net> - 2013-07-24 13:31 -0700
                Re: Interface with implied Constructor Steven Simpson <ss@domain.invalid> - 2013-07-27 04:06 +0100
            Re: Interface with implied Constructor Martin Gregorie <martin@address-in-sig.invalid> - 2013-07-19 21:21 +0000
              Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-19 18:56 -0300
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-19 18:10 -0400
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-19 20:46 -0300
                Re: Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-20 12:42 +0800
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-20 09:08 -0300
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-20 09:08 -0400
              Re: Interface with implied Constructor Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-07-19 19:20 -0700
                Re: Interface with implied Constructor markspace <markspace@nospam.nospam> - 2013-07-19 20:11 -0700
                Re: Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-20 12:26 +0800
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-20 09:38 -0300
              Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-20 19:46 +0200
                Re: Interface with implied Constructor Martin Gregorie <martin@address-in-sig.invalid> - 2013-07-20 19:12 +0000
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-20 17:12 -0400
                Re: Interface with implied Constructor Martin Gregorie <martin@address-in-sig.invalid> - 2013-07-20 21:18 +0000
                Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-21 12:13 +0200
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-21 16:18 -0300
                Re: Interface with implied Constructor markspace <markspace@nospam.nospam> - 2013-07-21 13:45 -0700
                Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-21 16:58 -0400
                Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-21 21:19 -0300
          Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-20 20:09 +0200
            Re: Interface with implied Constructor Robert Klemme <shortcutter@googlemail.com> - 2013-07-20 20:21 +0200
            Re: Interface with implied Constructor Joerg Meier <joergmmeier@arcor.de> - 2013-07-20 23:17 +0200
              Re: Interface with implied Constructor Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-07-20 17:32 -0400
                Re: Interface with implied Constructor Joerg Meier <joergmmeier@arcor.de> - 2013-07-21 00:10 +0200
            Re: Interface with implied Constructor Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-07-21 17:53 -0300
  Re: Interface with implied Constructor markspace <markspace@nospam.nospam> - 2013-07-09 18:13 -0700
    Re: Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-10 18:03 +0800
      Re: Interface with implied Constructor markspace <markspace@nospam.nospam> - 2013-07-10 08:41 -0700
        Re: Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-11 06:53 +0800
  Re: Interface with implied Constructor Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-07-09 21:41 -0700
    Re: Interface with implied Constructor Richard Maher <maher_rjSPAMLESS@hotmail.com> - 2013-07-10 17:55 +0800
    Re: Interface with implied Constructor Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-07-10 14:52 -0700
  Re: Interface with implied Constructor Roedy Green <see_website@mindprod.com.invalid> - 2013-07-10 16:02 -0700

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