Groups > comp.lang.java.programmer > #7132

Re: Singleton Pattern

Date	2011-08-16 00:09 -0700
From	Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Singleton Pattern
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On 8/15/11 10:07 PM, Patricia Shanahan wrote:
> On 8/15/2011 7:56 AM, Lew wrote:
> ....
>> 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!
>
> Different program runs do different things, so there can be fields that
> are used some runs but not others. That is especially the case for
> library classes that may be used in many different programs.
>
> However, the initializer for a static field executes during class
> initialization. How often does a singleton class get initialized without
> its getInstance method ever being called?

What does the Java specification say?

In C#, the run-time is permitted to, and in fact does, delay class 
initialization until the class is actually accessed.  I'd just always 
assumed Java took advantage of the same optimizations.

If so, there is almost never any problem initializing singletons in a 
field initializer, because the classes are inherently not accessed 
unless you need the singleton.

Pete

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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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