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Subject: Re: Hierarchy of singletons howto?
From: OC <ocs@ocs.cz>
In-Reply-To: <56FFFF14.3080707@gmx.org>
Date: Sat, 2 Apr 2016 20:01:55 +0200
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Message-Id: <E536D082-C559-488F-9689-B60B393E4EA0@ocs.cz>
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To: users@groovy.apache.org

Jochen,

thanks a lot, nice trick!

If you can spare a moment, might you perhaps check my =93static =
propertyMissing in an interface=94 message of yesterday? The question is =
whether the approach one can rely on to remain in future Groovy =
versions; that it works all right in current ones I have tested :)

Thanks and all the best,
OC

On 2. 4. 2016, at 19:19, Jochen Theodorou <blackdrag@gmx.org> wrote:

> On 01.04.2016 21:38, OC wrote:
> [...]
>> =3D=3D=3D
>> class Foo {
>>   static instance=3DnewInstance()
>> }
>> class Bar extends Foo {
>>   static instance=3DnewInstance()
>> }
>> =3D=3D=3D
>>=20
>> it works like a charm, only -- unlike @Singleton -- it is not lazy =
(and if turned to lazy, it would not be threadsafe).
>=20
> there is an easy Java trick for lazy:
>=20
> class Foo {
>  static getInstance() {
>    return Inner.instance
>  }
>  private Foo(){}
>  private static class Inner {
>     final static instance =3D new Foo()
>  }
> }
>=20
> The trick is that the inner class is only loaded if getInstance is =
called, thus you get lazy behaviour, that is even thread safe.
>=20
> bye Jochen
>=20