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From Sébastien Lorber <lorber.sebast...@gmail.com>
Subject Re: [collections] Iterate over sublists of an original list
Date Thu, 18 Aug 2011 12:48:22 GMT
Hello

Actually if you look at my implementation, i use that List.sublist() method.

It's a little pain to use it to split because you must always take care of
an out of bound...
IMHO, people do not really like to play with array/list indexes... If they
just want to split a big list of a couple of small sublists,
they probably do not like to have to deal with calculating the good index
positions, they just want the list to be splitted :)

I've looked at some guava classes but wasn't able to find anything to do
this: a convenient way to split a list



2011/8/18 David Karlsen <davidkarlsen@gmail.com>

> Guava also has a lot of handy classes for working on collections.
>
> 2011/8/18 Simone Tripodi <simonetripodi@apache.org>
>
> > Salut Sébastien,
> > wouldn't the List#subList(int, int)[1] method be helpful for your
> purposes?
> > HTH,
> > Simo
> >
> > [1]
> >
> http://download.oracle.com/javase/1.5.0/docs/api/java/util/List.html#subList(int
> > ,
> > int)
> >
> >
> > http://people.apache.org/~simonetripodi/
> > http://www.99soft.org/
> >
> >
> >
> > On Thu, Aug 18, 2011 at 2:26 PM, Sébastien Lorber
> > <lorber.sebastien@gmail.com> wrote:
> > > Hello,
> > >
> > >
> > > It's not the first time i have to split a big list of hibernate
> entities
> > > ID's to sublists of 100 items for exemple so that i could load all
> these
> > > entities 100 in a single request (with a "where id in (<id sublist>")
> > >
> > > Thus I want to iterate easily on sublists of a list, with the
> possibility
> > to
> > > give the sublist a size...
> > > I though i would find the tool in apache collections but i didn't find
> > it.
> > > Perhaps i've missed the class...
> > >
> > >
> > >
> > > If there's no tool to do that yet, i think it would be great to make
> one
> > in
> > > apache collections.
> > >
> > > The kinda simple implementation i use at work is the following:
> > > http://pastebin.com/CRitkWTG
> > >
> > >
> > > And you use it like that:
> > >
> > >        // We load vehicles 100 by 100
> > >         for ( List<String> idSublist : new
> > > SublistIterable<String>(allIds,100) ) {
> > >            List<Vehicle> vehiclesSublist =
> > vehicleDAO.findByIds(idSublist);
> > >            // blablabla
> > >        }
> > >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
> > For additional commands, e-mail: dev-help@commons.apache.org
> >
> >
>
>
> --
> --
> David J. M. Karlsen - http://www.linkedin.com/in/davidkarlsen
>

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