That's true. The grouped() method in scala do exactly that.
I agree, these functions are quite useful that's why i sent a mail: to see if we can integrate them in apache libs 2011/8/18 Matthew Pocock <turingatemyhams...@gmail.com> > The scala collections library has the grouped() method. From the scaladoc: > > defgrouped (size: Int < > http://www.scala-lang.org/api/current/scala/Int.html> > ): Iterator< > http://www.scala-lang.org/api/current/scala/collection/Iterator.html> > [List< > http://www.scala-lang.org/api/current/scala/collection/immutable/List.html > > > [A]] > > Partitions elements in fixed size lists. > size > > the number of elements per group > returns > > An iterator producing lists of size size, except the last will be truncated > if the elements don't divide evenly. > > I'm not suggesting you should jump to scala to use its collections library, > or even use scala-library.jar from your Java app, but I do find this method > together with groupBy() one of the more useful bits of functionality. Pity > something like it isn't supported by other 3rd party collections for Java. > > Matthew > > On 18 August 2011 13:48, Sébastien Lorber <lorber.sebast...@gmail.com > >wrote: > > > 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 <davidkarl...@gmail.com> > > > > > Guava also has a lot of handy classes for working on collections. > > > > > > 2011/8/18 Simone Tripodi <simonetrip...@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.sebast...@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-unsubscr...@commons.apache.org > > > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > > > > > > > > > > > > > -- > > > -- > > > David J. M. Karlsen - http://www.linkedin.com/in/davidkarlsen > > > > > > > > > -- > Dr Matthew Pocock > Visitor, School of Computing Science, Newcastle University > mailto: turingatemyhams...@gmail.com > gchat: turingatemyhams...@gmail.com > msn: matthew_poc...@yahoo.co.uk > irc.freenode.net: drdozer > tel: (0191) 2566550 > mob: +447535664143 >
