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Groups > comp.lang.java.programmer > #25089

Re: Autoboxing and Performance ?

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A little up in the source code one finds also:

     /**
      * Cache to support the object identity semantics of
      * autoboxing for values between -128 and 127 (inclusive)
      * as required by JLS.
      *
      * The cache is initialized on first usage.  The size of the cache
      * may be controlled by the -XX:AutoBoxCacheMax=<size> option.


> P.S.: Here is the JDK 1.7.25 source code of Integer.valueOf:
>
>     /**
>       * Returns an {@code Integer} instance representing the specified
>       * {@code int} value.  If a new {@code Integer} instance is not
>       * required, this method should generally be used in preference to
>       * the constructor {@link #Integer(int)}, as this method is likely
>       * to yield significantly better space and time performance by
>       * caching frequently requested values.
>       *
>       * This method will always cache values in the range -128 to 127,
>       * inclusive, and may cache other values outside of this range.
>       *
>       * @param  i an {@code int} value.
>       * @return an {@code Integer} instance representing {@code i}.
>       * @since  1.5
>       */
>      public static Integer valueOf(int i) {
>          assert IntegerCache.high >= 127;
>          if (i >= IntegerCache.low && i <= IntegerCache.high)
>              return IntegerCache.cache[i + (-IntegerCache.low)];
>          return new Integer(i);
>      }
>
>

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Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 05:15 -0500
  Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-20 12:20 +0200
    Re: Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 05:33 -0500
      Re: Autoboxing and Performance ? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2013-08-20 10:43 +0000
        Re: Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 06:04 -0500
          Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-20 08:08 -0400
          Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:15 -0400
      Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:12 -0400
      Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-21 03:52 +0300
        Re: Autoboxing and Performance ? Sebastian <news@seyweiler.dyndns.org> - 2013-08-21 07:27 +0200
          Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 18:43 -0400
            Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-22 08:08 +0300
          Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-22 07:56 +0300
            Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 10:51 -0700
              Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-22 19:36 +0000
                Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 13:01 -0700
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-22 21:19 +0000
                Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 14:39 -0700
                Re: Autoboxing and Performance ? markspace <markspace@nospam.nospam> - 2013-08-22 19:50 -0700
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-23 23:16 +0000
                Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-24 17:20 +0300
                Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-23 11:08 -0700
                Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-23 22:52 +0200
                Re: Autoboxing and Performance ? Jim Gibson <jimsgibson@gmail.com> - 2013-08-23 16:38 -0700
                Re: Autoboxing and Performance ? "John B. Matthews" <nospam@nospam.invalid> - 2013-08-23 06:17 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-23 17:25 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-25 18:34 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-28 10:52 -0400
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-23 23:37 +0000
        Re: Autoboxing and Performance ? Robert Klemme <shortcutter@googlemail.com> - 2013-08-26 19:33 +0200
          Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-29 10:09 +0300
            Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-29 14:14 +0200
      Re: Autoboxing and Performance ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-29 21:28 -0300
  Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-20 20:03 +0200
    Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-20 16:23 -0700
      Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-21 11:51 +0200
        Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-21 08:39 -0700
          Re: Autoboxing and Performance ? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-21 16:51 +0100
        Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 19:19 -0400
          Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-22 09:49 +0200
    Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-21 11:54 +0200
  Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:06 -0400
    Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-20 21:19 -0400
      Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-21 10:05 +0200
        Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-21 07:19 -0400
          Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-22 00:18 +0200
            Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-21 19:58 -0400
        Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-21 08:36 -0700
      Re: Autoboxing and Performance ? taqmcg@gmail.com - 2013-08-21 09:37 -0700
  Re: Autoboxing and Performance ? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-08-20 23:28 -0500
  Re: Autoboxing and Performance ? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-21 10:09 +0100
    Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 19:04 -0400
      Re: Autoboxing and Performance ? Arivald <NOSPAMarivald@interia.pl> - 2013-08-22 07:39 +0200
  Re: Autoboxing and Performance ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-29 01:42 -0300

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