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Re: Singleton Pattern

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From	Lew <lewbloch@gmail.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Singleton Pattern
Date	Mon, 15 Aug 2011 07:56:15 -0700 (PDT)
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Ian wrote:
> Peter Duniho wrote:
>> I'd never even heard of the "single-element enum type" variation of
>> singleton initialization. That one in particular sounds like a
>> completely over-engineered approach.
>>
> I wouldn't say over-engineered - it's about as verbose as a final field 
> declaration.  ISTR one of the actual advantages is safety in the 
> presence of serialization, although Bloch mentions others . . .
> I'd say it's the right tool for the job of creating instance-controlled 
> data safely.
> [FX: Ducks!]

Actually, pretty much any attempt to lazy initialize is over-engineering.  Just declare a final member in most cases - why be lazy?  It's a false optimization.

Final fields, especially immutable ones, make a lot of useful guarantees, and you don't have the field in the first place unless it's going to be used at some point anyway.  Just freaking initialize it!

(I know, the enum pattern for final fields is not about lazy instantiation, although you do get that for free from it.  I have no issue with that pattern and use it myself.)

-- 
Lew

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Singleton Pattern "vbhavsar@gmail.com" <vbhavsar@gmail.com> - 2011-08-13 13:56 -0700
  Re: Singleton Pattern markspace <-@.> - 2011-08-13 14:41 -0700
  Re: Singleton Pattern Patricia Shanahan <pats@acm.org> - 2011-08-13 14:48 -0700
  Re: Singleton Pattern Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-08-13 16:43 -0700
    Re: Singleton Pattern Ian <m4r35n357@gmail.com> - 2011-08-15 15:00 +0100
      Re: Singleton Pattern Lew <lewbloch@gmail.com> - 2011-08-15 07:56 -0700
        Re: Singleton Pattern Patricia Shanahan <pats@acm.org> - 2011-08-15 22:07 -0700
          Re: Singleton Pattern Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-08-16 00:09 -0700
            Re: Singleton Pattern Patricia Shanahan <pats@acm.org> - 2011-08-16 06:15 -0700
              Re: Singleton Pattern Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-08-16 06:57 -0700
                Re: Singleton Pattern Patricia Shanahan <pats@acm.org> - 2011-08-16 09:25 -0700
                Re: Singleton Pattern Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-08-16 18:10 -0700
  Re: Singleton Pattern Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-13 20:56 -0400
    Re: Singleton Pattern Lew <lewbloch@gmail.com> - 2011-08-13 21:12 -0700
  Re: Singleton Pattern Rajeev <rajeev.nospam@gmail.com> - 2011-08-14 06:37 -0700

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