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Re: CLI Java Glitch

From Tom Anderson <twic@urchin.earth.li>
Newsgroups comp.lang.java.programmer
Subject Re: CLI Java Glitch
Date 2011-06-22 20:00 +0100
Organization Stack Usenet News Service
Message-ID <alpine.DEB.2.00.1106221950030.10728@urchin.earth.li> (permalink)
References <meevv65a675khs5c9goa9sp6f2hotf1321@4ax.com> <itogee$k8r$1@localhost.localdomain> <4dffe2ea$0$57121$c30e37c6@exi-reader.telstra.net> <alpine.DEB.2.00.1106212245430.6476@urchin.earth.li> <96dvubFalpU1@mid.individual.net>

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On Wed, 22 Jun 2011, Nigel Wade wrote:

> On 21/06/11 22:49, Tom Anderson wrote:
>> On Tue, 21 Jun 2011, Esmond Pitt wrote:
>>
>>> On 21/06/2011 8:09 AM, Martin Gregorie wrote:
>>>
>>>> The Java language system does case-sensitive comparisons between class
>>>> names and the files that contain them when checking that a class name
>>>> matches the file name that contains it
>>>
>>> Nitpicking, but it doesn't really do that, does it. It opens a .class 
>>> file of the name the user specified, loads the class(es) it contains, 
>>> and tries to find the classname it was looking for among those 
>>> classes. It doesn't explicitly compare the filename and the classname. 
>>> The operating system gave it HelloWorld.class in response to 
>>> 'helloworld.class' because that's how the OS file system happened to 
>>> work.
>>
>> The way Java does this at the moment means that 'java helloworld', 
>> where there is no class 'helloworld', does different things on Windows 
>> depending on whether there is a class HelloWorld, hElLoWoRlD, 
>> HelloworlD, etc.
>
> Does it? What different thing does it do?

To clarify, i meant that it does different things in these three 
situations:

(1) helloworld exists
(2) HelloWorld, hElLoWoRlD, HelloworlD, or similar exists
(3) no class case-insensitively called helloworld exists

I think that cases (2) and (3) should do the same thing. Or, as you 
describe it:

> Java actually throws ClassNotFoundException in all cases, on all OS, 
> just as it should. The only difference is that in a case-insensitive 
> filesystem Java actually opens the case-insensitive filename before it 
> discovers that it does not contain the class required. On case-sensitive 
> filesystems the correct case filename won't be found. The actual result 
> is the same in both cases, a ClassNotFoundException.

Now, this is where i think i've gone wrong. Back when i used Windows, java 
did *not* do the same thing in cases (2) and (3). For the nonexistent file 
in (3), it would throw a NoClassDefFoundError. But for the misnamed file 
in (2), it would throw something else - a ClassFormatError, i think.

It seems that this has been fixed without me noticing, and i failed to 
interpret Gene's original post correctly. If this is the case, then i 
withdraw my complaint entirely!

tom

-- 
It is a formal cultural policy to show unreasonable bias towards any
woman who is both attractive and weird.

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Thread

CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-20 14:24 -0700
  Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-20 14:48 -0700
  Re: CLI Java Glitch Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-06-20 18:49 -0300
  Re: CLI Java Glitch Martin Gregorie <martin@address-in-sig.invalid> - 2011-06-20 22:09 +0000
    Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-21 10:16 +1000
      Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:49 +0100
        Re: CLI Java Glitch Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-06-21 15:11 -0700
          Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 16:37 -0700
            Re: CLI Java Glitch Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-06-21 17:54 -0700
            Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-22 09:02 -0700
              Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 10:12 -0700
                Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-22 10:39 -0700
          Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-22 09:50 -0700
          Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-22 19:44 +0100
            Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-23 12:31 -0400
              Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-23 23:04 +0100
                Re: CLI Java Glitch Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-06-23 21:40 -0700
                Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-24 09:43 -0400
          Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-23 12:24 -0400
            Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-23 14:32 -0700
            Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-24 09:12 -0700
              Re: CLI Java Glitch Bent C Dalager <bcd@pvv.ntnu.no> - 2011-06-24 22:49 +0000
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-26 20:29 -0700
        Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 16:29 -0700
        Re: CLI Java Glitch Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-06-22 11:54 +0100
          Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 10:16 -0700
            Re: CLI Java Glitch Patricia Shanahan <pats@acm.org> - 2011-06-22 11:06 -0700
              Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 11:46 -0700
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 12:50 -0700
                Re: CLI Java Glitch Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-06-23 15:23 +0100
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-23 08:58 -0700
                Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-24 08:58 -0700
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-24 11:36 -0700
                Re: CLI Java Glitch Paul Cager <paul.cager@googlemail.com> - 2011-06-22 14:45 -0700
                Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-22 23:29 +0100
                Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-22 18:08 -0700
                Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-23 23:20 +0100
                Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-24 10:28 +1000
                Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-25 22:58 +0100
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-26 20:31 -0700
                Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-24 09:00 -0700
          Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-22 20:00 +0100
            Re: CLI Java Glitch Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-06-23 15:18 +0100
        Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-23 11:40 +1000
          Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-23 20:21 +1000
          Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-23 09:00 -0700
            Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-24 10:24 +1000
    Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:52 +0100
  Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 19:11 -0400
    Re: CLI Java Glitch Lew Bloch <lewisbloch@google.com> - 2011-06-20 16:25 -0700
      Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 19:45 -0400
        Re: CLI Java Glitch Lew Bloch <lewisbloch@google.com> - 2011-06-20 18:28 -0700
        Ping: Lew Bloch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 23:26 -0400
          Re: Ping: Lew Bloch Lew Bloch <lewisbloch@google.com> - 2011-06-21 10:25 -0700
            Re: Ping: Lew Bloch Jeff Higgins <jeff@invalid.invalid> - 2011-06-21 14:36 -0400
      Re: CLI Java Glitch Patricia Shanahan <pats@acm.org> - 2011-06-20 17:02 -0700
        Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 20:37 -0400
          Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 20:44 -0400
            Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:45 +0100
  Re: CLI Java Glitch Roedy Green <see_website@mindprod.com.invalid> - 2011-06-20 16:55 -0700
    Re: CLI Java Glitch Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-20 20:44 -0400
      Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-20 19:26 -0700
      Re: CLI Java Glitch Paul Cager <paul.cager@googlemail.com> - 2011-06-21 02:34 -0700
        Re: CLI Java Glitch Silvio <silvio@moc.com> - 2011-06-21 16:50 +0200
        Re: CLI Java Glitch "Gavino" <invalid@invalid.invalid> - 2011-06-21 21:35 +0200
      Re: CLI Java Glitch Roedy Green <see_website@mindprod.com.invalid> - 2011-06-21 11:59 -0700
        Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 13:03 -0700
          Re: CLI Java Glitch BGB <cr88192@hotmail.com> - 2011-06-21 14:21 -0700
  Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-20 19:29 -0700
  Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:42 +0100
    Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 14:48 -0700
  Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-21 21:52 -0400
    Re: CLI Java Glitch Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-06-22 07:56 -0300
      Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-22 08:02 -0400
        Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 10:18 -0700
          Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-22 15:01 -0400
            Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 12:54 -0700
          Re: CLI Java Glitch Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-06-22 18:52 -0300
          Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-23 15:13 -0400

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