springframework-developer

RE: [Springframework-developer] Comparator singletons MIA?

[Oliver H. <Ol...@ou...>]

Actually I see this is only the case for ComparableComparator (I've got
to many versions of the code open at the moment) the NullSafeComparator
and BooleanComparator singletons are still there.=20

My question still stands through.=20

Oliver

> -----Original Message-----
> From: spr...@li...=20
> [mailto:spr...@li...]
>  On Behalf Of Oliver Hutchison
> Sent: Friday, 22 July 2005 10:32 AM
> To: spr...@li...
> Subject: [Springframework-developer] Comparator singletons MIA?
>=20
> Jurgen,=20
>=20
> I've just started upgrading Spring Rich to the latest spring=20
> code base and noticed that all of the Comparator singletons=20
> (which Spring Rich uses a lot) in the o.s.util.comparator=20
> package have been removed.=20
>=20
> These classes are IMHO perfect examples of where you should=20
> be using a singleton. Given that every instance will exhibit=20
> exactly the same behaviour, why would you ever want to have=20
> more that one instance of a class like ComparableComparator?=20
> Also how much cleaner is this:
>=20
> ComparableComparator.nullSafeInstance().compare(argument1, argument2)
>=20
> to this?
>=20
> new NullSafeComparator(new ComparableComparator(),=20
> true).compare(argument1, argument2)
>=20
> and more performant to boot.
>=20
> Anyway, obviously I can live without them, but I'm curious=20
> about the rational behind the removal?=20
>=20
> Thanks,
>=20
> Oliver
>=20
>=20
>=20
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration=20
> Strategies from IBM. Find simple to follow Roadmaps,=20
> straightforward articles, informative Webcasts and more! Get=20
> everything you need to get up to speed, fast.=20
> http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>=20

RE: [Springframework-developer] Comparator singletons MIA?

[Oliver H. <Ol...@ou...>]

Ahhh....

Don't these really belong in ComparableComparator? Given that they would
mostly compare Comparables? To be honest I wouldn't even think to look
in NullSafeComparator for a ComparableComparator.

But I can live with it ;-)

Thanks,

Ollie

> -----Original Message-----
> From: spr...@li...=20
> [mailto:spr...@li...]
>  On Behalf Of Juergen Hoeller
> Sent: Friday, 22 July 2005 6:12 PM
> To: spr...@li...
> Subject: Re: [Springframework-developer] Comparator singletons MIA?
>=20
> NullSafeComparator has two such singletons: NULLS_LOW and=20
> NULLS_HIGH, each using a ComparableComparator underneath. I=20
> guess you could simply use those singletons rather than one=20
> on ComparableComparator itself.
>=20
> Juergen
> =20
>=20
> -----Original Message-----
> From: spr...@li...
> [mailto:spr...@li...]
>  On Behalf Of Oliver Hutchison
> Sent: Friday, July 22, 2005 4:22 AM
> To: spr...@li...
> Subject: RE: [Springframework-developer] Comparator singletons MIA?
>=20
> Actually I see this is only the case for ComparableComparator=20
> (I've got to many versions of the code open at the moment)=20
> the NullSafeComparator and BooleanComparator singletons are=20
> still there.=20
>=20
> My question still stands through.=20
>=20
> Oliver
>=20
> > -----Original Message-----
> > From: spr...@li...
> > [mailto:spr...@li...]
> >  On Behalf Of Oliver Hutchison
> > Sent: Friday, 22 July 2005 10:32 AM
> > To: spr...@li...
> > Subject: [Springframework-developer] Comparator singletons MIA?
> >=20
> > Jurgen,
> >=20
> > I've just started upgrading Spring Rich to the latest=20
> spring code base=20
> > and noticed that all of the Comparator singletons (which=20
> Spring Rich=20
> > uses a lot) in the o.s.util.comparator package have been removed.
> >=20
> > These classes are IMHO perfect examples of where you should=20
> be using a=20
> > singleton. Given that every instance will exhibit exactly the same=20
> > behaviour, why would you ever want to have more that one=20
> instance of a=20
> > class like ComparableComparator?
> > Also how much cleaner is this:
> >=20
> > ComparableComparator.nullSafeInstance().compare(argument1,=20
> argument2)
> >=20
> > to this?
> >=20
> > new NullSafeComparator(new ComparableComparator(),=20
> > true).compare(argument1, argument2)
> >=20
> > and more performant to boot.
> >=20
> > Anyway, obviously I can live without them, but I'm curious=20
> about the=20
> > rational behind the removal?
> >=20
> > Thanks,
> >=20
> > Oliver
> >=20
> >=20
> >=20
> > -------------------------------------------------------
> > SF.Net email is sponsored by: Discover Easy Linux Migration=20
> Strategies=20
> > from IBM. Find simple to follow Roadmaps, straightforward articles,=20
> > informative Webcasts and more! Get everything you need to get up to=20
> > speed, fast.
> > http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> > _______________________________________________
> > Springframework-developer mailing list=20
> > Spr...@li...
> >=20
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
> >=20
>=20
>=20
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration=20
> Strategies from IBM. Find simple to follow Roadmaps,=20
> straightforward articles, informative Webcasts and more! Get=20
> everything you need to get up to speed, fast.
> http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>=20
>=20
>=20
>=20
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration=20
> Strategies from IBM. Find simple to follow Roadmaps,=20
> straightforward articles, informative Webcasts and more! Get=20
> everything you need to get up to speed, fast.=20
> http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>=20

Re: [Springframework-developer] Comparator singletons MIA?

[Juergen H. <ju...@in...>]

Well, depends on whether one consider NullSafeComparator as a plain
decorator. Arguably NullSafeComparator is most useful for Comparables. =
The
primary point of the class is to compare Comparables in a null-safe =
fashion.

ComparableComparator on the other hand is really just a plain adapter
between Comparator and Comparable, without any value-add. It's mainly =
useful
as internal adapter, not so much for plain direct usage.

You would hardly ever use ComparableComparator directly for sorting or =
the
like. You would rather simply rely on "natural" sort order, i.e. =
Comparable
directly. E.g. "Collections.sort(List, Comparator)" vs
"Collections.sort(List)".

Juergen
=20

-----Original Message-----
From: spr...@li...
[mailto:spr...@li...] On Behalf =
Of
Oliver Hutchison
Sent: Friday, July 22, 2005 10:49 AM
To: spr...@li...
Subject: RE: [Springframework-developer] Comparator singletons MIA?

Ahhh....

Don't these really belong in ComparableComparator? Given that they would
mostly compare Comparables? To be honest I wouldn't even think to look =
in
NullSafeComparator for a ComparableComparator.

But I can live with it ;-)

Thanks,

Ollie

> -----Original Message-----
> From: spr...@li...
> [mailto:spr...@li...]
>  On Behalf Of Juergen Hoeller
> Sent: Friday, 22 July 2005 6:12 PM
> To: spr...@li...
> Subject: Re: [Springframework-developer] Comparator singletons MIA?
>=20
> NullSafeComparator has two such singletons: NULLS_LOW and NULLS_HIGH,=20
> each using a ComparableComparator underneath. I guess you could simply =

> use those singletons rather than one on ComparableComparator itself.
>=20
> Juergen
> =20
>=20
> -----Original Message-----
> From: spr...@li...
> [mailto:spr...@li...]
>  On Behalf Of Oliver Hutchison
> Sent: Friday, July 22, 2005 4:22 AM
> To: spr...@li...
> Subject: RE: [Springframework-developer] Comparator singletons MIA?
>=20
> Actually I see this is only the case for ComparableComparator (I've=20
> got to many versions of the code open at the moment) the=20
> NullSafeComparator and BooleanComparator singletons are still there.
>=20
> My question still stands through.=20
>=20
> Oliver
>=20
> > -----Original Message-----
> > From: spr...@li...
> > [mailto:spr...@li...]
> >  On Behalf Of Oliver Hutchison
> > Sent: Friday, 22 July 2005 10:32 AM
> > To: spr...@li...
> > Subject: [Springframework-developer] Comparator singletons MIA?
> >=20
> > Jurgen,
> >=20
> > I've just started upgrading Spring Rich to the latest
> spring code base
> > and noticed that all of the Comparator singletons (which
> Spring Rich
> > uses a lot) in the o.s.util.comparator package have been removed.
> >=20
> > These classes are IMHO perfect examples of where you should
> be using a
> > singleton. Given that every instance will exhibit exactly the same=20
> > behaviour, why would you ever want to have more that one
> instance of a
> > class like ComparableComparator?
> > Also how much cleaner is this:
> >=20
> > ComparableComparator.nullSafeInstance().compare(argument1,
> argument2)
> >=20
> > to this?
> >=20
> > new NullSafeComparator(new ComparableComparator(),=20
> > true).compare(argument1, argument2)
> >=20
> > and more performant to boot.
> >=20
> > Anyway, obviously I can live without them, but I'm curious
> about the
> > rational behind the removal?
> >=20
> > Thanks,
> >=20
> > Oliver
> >=20
> >=20
> >=20
> > -------------------------------------------------------
> > SF.Net email is sponsored by: Discover Easy Linux Migration
> Strategies
> > from IBM. Find simple to follow Roadmaps, straightforward articles,=20
> > informative Webcasts and more! Get everything you need to get up to=20
> > speed, fast.
> > http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> > _______________________________________________
> > Springframework-developer mailing list=20
> > Spr...@li...
> >=20
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
> >=20
>=20
>=20
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration Strategies =

> from IBM. Find simple to follow Roadmaps, straightforward articles,=20
> informative Webcasts and more! Get everything you need to get up to=20
> speed, fast.
> http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> _______________________________________________
> Springframework-developer mailing list=20
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>=20
>=20
>=20
>=20
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration Strategies =

> from IBM. Find simple to follow Roadmaps, straightforward articles,=20
> informative Webcasts and more! Get everything you need to get up to=20
> speed, fast.
> http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> _______________________________________________
> Springframework-developer mailing list=20
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>=20


-------------------------------------------------------
SF.Net email is sponsored by: Discover Easy Linux Migration Strategies =
from
IBM. Find simple to follow Roadmaps, straightforward articles, =
informative
Webcasts and more! Get everything you need to get up to speed, fast.
http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
_______________________________________________
Springframework-developer mailing list
Spr...@li...
https://lists.sourceforge.net/lists/listinfo/springframework-developer

RE: [Springframework-developer] Comparator singletons MIA?

[Oliver H. <Ol...@ou...>]

> You would hardly ever use ComparableComparator directly for=20
> sorting or the like. You would rather simply rely on=20
> "natural" sort order, i.e. Comparable directly. E.g.=20
> "Collections.sort(List, Comparator)" vs "Collections.sort(List)".

True. But most of the code (in SpringRich) that I'm dealing with does
not take the "natural" sort order into consideration i.e. you must
always supply a Comparator. So for me I keep looking to
ComparableComparator for this "natural" case and naturally I also want
everything to be null safe but this is a secondary consideration.

Regardless, I'm happy to use the NullSafeComparator singletons.=20

Thanks,

Ollie

Re: [Springframework-developer] Comparator singletons MIA?

[Juergen H. <ju...@in...>]

NullSafeComparator has two such singletons: NULLS_LOW and NULLS_HIGH, =
each
using a ComparableComparator underneath. I guess you could simply use =
those
singletons rather than one on ComparableComparator itself.

Juergen
=20

-----Original Message-----
From: spr...@li...
[mailto:spr...@li...] On Behalf =
Of
Oliver Hutchison
Sent: Friday, July 22, 2005 4:22 AM
To: spr...@li...
Subject: RE: [Springframework-developer] Comparator singletons MIA?

Actually I see this is only the case for ComparableComparator (I've got =
to
many versions of the code open at the moment) the NullSafeComparator and
BooleanComparator singletons are still there.=20

My question still stands through.=20

Oliver

> -----Original Message-----
> From: spr...@li...
> [mailto:spr...@li...]
>  On Behalf Of Oliver Hutchison
> Sent: Friday, 22 July 2005 10:32 AM
> To: spr...@li...
> Subject: [Springframework-developer] Comparator singletons MIA?
>=20
> Jurgen,
>=20
> I've just started upgrading Spring Rich to the latest spring code base =

> and noticed that all of the Comparator singletons (which Spring Rich=20
> uses a lot) in the o.s.util.comparator package have been removed.
>=20
> These classes are IMHO perfect examples of where you should be using a =

> singleton. Given that every instance will exhibit exactly the same=20
> behaviour, why would you ever want to have more that one instance of a =

> class like ComparableComparator?
> Also how much cleaner is this:
>=20
> ComparableComparator.nullSafeInstance().compare(argument1, argument2)
>=20
> to this?
>=20
> new NullSafeComparator(new ComparableComparator(),=20
> true).compare(argument1, argument2)
>=20
> and more performant to boot.
>=20
> Anyway, obviously I can live without them, but I'm curious about the=20
> rational behind the removal?
>=20
> Thanks,
>=20
> Oliver
>=20
>=20
>=20
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration Strategies =

> from IBM. Find simple to follow Roadmaps, straightforward articles,=20
> informative Webcasts and more! Get everything you need to get up to=20
> speed, fast.
> http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
> _______________________________________________
> Springframework-developer mailing list=20
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>=20


-------------------------------------------------------
SF.Net email is sponsored by: Discover Easy Linux Migration Strategies =
from
IBM. Find simple to follow Roadmaps, straightforward articles, =
informative
Webcasts and more! Get everything you need to get up to speed, fast.
http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=3Dick
_______________________________________________
Springframework-developer mailing list
Spr...@li...
https://lists.sourceforge.net/lists/listinfo/springframework-developer