[RFC][plugin]: make PluginObjectStore a singleton.

[Denis Lila]

> Being at home, I do have my copy with me and it says (in bold type):
> 
> 'a single-element enum type is the best way to implement a singleton'.
> 
> What Deepak says is true, and there are also benefits for
> serialization too.

Less importantly, enums also prevent any cloneable business.

> It initially seemed odd to me too, but I'm fine with it. I would cite
> the reference, which is:
> 
> Bloch, Joshua. Effective Java, 2nd Edition. Item 3, Chapter 2. ISBN:
> 0-321-35668-3.

Good idea. Done.

Regards,
Denis.

----- Original Message -----
> On 15:32 Thu 31 Mar , Deepak Bhole wrote:
> > * Denis Lila <dlila at redhat.com> [2011-03-31 15:29]:
> > >
> > > > I particularly like this comment ;) Do you have a source for
> > > > this? I
> > > > would prefer it if this was an actual class. It's not
> > > > behaviourally an
> > > > enum, so it should not be marked as such.
> > >
> > > Effective Java, second edition.
> > > I don't have the book with me, and I forget what Joshua Bloch's
> > > arguments for enum singletons were (except for how much easier
> > > the singleton property is to enfoce (which is more than enough
> > > of a reason by itself, but there were others)), but they were
> > > very good ones.
> > >
> >
> > I've read this before too. The top things if I recall correctly are
> > that
> > an enum cannot be constructed, not even via reflection and it is
> > implicitly final.
> >
> 

> 
> > Cheers,
> > Deepak
> >
> 
> --
> Andrew :)
> 
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