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Groups > comp.lang.java.programmer > #21758

Re: The first 10 files

From Jim Janney <jjanney@shell.xmission.com>
Newsgroups comp.lang.java.programmer
Subject Re: The first 10 files
Date 2013-01-26 16:00 -0700
Organization by the dead and drowsy fire
Message-ID <ydnbocb1rdx.fsf@shell.xmission.com> (permalink)
References <mn.d04a7dd156c148ef.70216@a.com>

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Wojtek <nowhere@a.com> writes:

> Using:
>
> int max = 10;
> int count = 0;
>
> for (File thisFile : aDir.listFiles())
> {
>  doSomething(thisFile);
>
>  if ( ++count >= max )
>    break;
> }
>
> gives me the first ten files in aDir. But if aDir contains 30K files,
> then the listFiles() will run for a long time as it builds an array
> for the 30K files.
>
> Is there a way to have Java only get the first "max" files?

As Roedy says, in pure Java there's no way to avoid reading the entire
directory, whether it builds the entire array or not.  And if you want
them in any particular order it's necessary to read them all and sort
them anyway.

-- 
Jim Janney

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Thread

The first 10 files Wojtek <nowhere@a.com> - 2013-01-26 01:14 -0800
  Re: The first 10 files Roedy Green <see_website@mindprod.com.invalid> - 2013-01-26 02:44 -0800
    Re: The first 10 files Lew <lewbloch@gmail.com> - 2013-01-26 10:20 -0800
  Re: The first 10 files "John B. Matthews" <nospam@nospam.invalid> - 2013-01-26 06:31 -0500
    Re: The first 10 files Wojtek <nowhere@a.com> - 2013-01-26 15:42 -0800
      Re: The first 10 files Jim Janney <jjanney@shell.xmission.com> - 2013-01-26 17:13 -0700
      Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 21:21 -0500
      Re: The first 10 files "John B. Matthews" <nospam@nospam.invalid> - 2013-01-26 22:05 -0500
  Re: The first 10 files Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-26 08:24 -0400
    Re: The first 10 files Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-26 08:25 -0400
    Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 13:26 -0500
      Re: The first 10 files Robert Klemme <shortcutter@googlemail.com> - 2013-01-26 22:15 +0100
        Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 16:25 -0500
        Re: The first 10 files Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-01-26 17:06 -0500
          Re: The first 10 files Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-26 15:21 -0800
            Re: The first 10 files Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-01-26 20:42 -0500
              Re: The first 10 files Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-26 17:56 -0800
                Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 21:29 -0500
                Re: The first 10 files Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-01-26 21:56 -0500
                Re: The first 10 files Jim Janney <jjanney@shell.xmission.com> - 2013-01-26 20:51 -0700
                Re: The first 10 files Jim Janney <jjanney@shell.xmission.com> - 2013-01-26 20:47 -0700
              Re: The first 10 files Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-26 22:02 -0400
                Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 21:35 -0500
                Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 21:43 -0500
                Re: The first 10 files Robert Klemme <shortcutter@googlemail.com> - 2013-01-27 13:55 +0100
                Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-02-24 17:50 -0500
                Re: The first 10 files Robert Klemme <shortcutter@googlemail.com> - 2013-02-25 21:53 +0100
                Re: The first 10 files Jim Janney <jjanney@shell.xmission.com> - 2013-01-26 20:57 -0700
                Re: The first 10 files Wojtek <nowhere@a.com> - 2013-01-26 21:20 -0800
                Re: The first 10 files Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-27 07:23 -0400
                Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-27 20:36 -0500
                Re: The first 10 files Wojtek <nowhere@a.com> - 2013-01-28 16:28 -0800
            Re: The first 10 files Arne Vajhøj <arne@vajhoej.dk> - 2013-01-26 21:23 -0500
            Re: The first 10 files Roedy Green <see_website@mindprod.com.invalid> - 2013-01-26 19:09 -0800
  Re: The first 10 files Jim Janney <jjanney@shell.xmission.com> - 2013-01-26 16:00 -0700
  Re: The first 10 files Knute Johnson <nospam@knutejohnson.com> - 2013-01-26 18:37 -0800
    Re: The first 10 files Wojtek <nowhere@a.com> - 2013-03-14 03:07 -0700
      Re: The first 10 files lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-03-14 12:49 +0000
      Re: The first 10 files Robert Klemme <shortcutter@googlemail.com> - 2013-03-15 11:38 +0100
        Re: The first 10 files Wojtek <nowhere@a.com> - 2013-03-15 10:31 -0700

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