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Re: Good practice or not to close the file before System.exit(1)?

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On 11-04-22 08:56 AM, Merciadri Luca wrote:
> The fact is that when some specific values of variables are
> encountered, the program can't continue. I would have preferred
> throwing an exception, but there is apparently no reason to throw an
> exception because the variables that need to be checked come directly
> from the arguments that the user passed to the JVM:
> 
> java myprogram 1 2 3
> 
> It it thus not an `internal error' when some values are encountered,
> because they come from the user.
> 
> As a result, I don't throw an exception when some specific values of
> the variables are encountered, but I make a System.err.println("Some
> text") followed by a System.exit(1).
> 
> If everything is right (i.e. variables' values are correct) I then
> need to close the file, but need to open again the file to do some
> other things. As a result, the double opening is inside *one* try
> block, so that I only need one catch.
> 
> I could put the inputFile.close() in a finally block, but as
> inputFile.close() is useless (i.e. not executed) if System.exit(1) is
> executed before, I would need to put System.exit(1) in the finally
> block. But the problem is that as finally will always be executed,
> System.exit(1) will always be executed (even if variables have no
> problem), so that the program will always end. But I need to end only
> if there was some problem with the variables' values!
> 
> I could also make two try blocks: one for the first opening, and one
> for the second opening. But as only the first one will maybe cause
> troubles, the only one that would need to be catched would be the
> first try block. Or I would need to put exactly the same catch after
> the second try, which would be ugly. As a result, I don't know what to
> do.
> 

I don't think I understand this. Why open the file (as you stated,
"open" meaning a Java mechanism for accessing file contents, like
BufferedReader) *before* knowing that you have satisfied all the
necessary conditions for being able to process it, like having good
command-line arguments?

AHS

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Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 00:13 +0200
  Re: Good practice or not to close the file before System.exit(1)? rossum <rossum48@coldmail.com> - 2011-04-22 00:11 +0100
    Re: Good practice or not to close the file before System.exit(1)? rossum <rossum48@coldmail.com> - 2011-04-22 12:39 +0100
      Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 05:09 -0700
        Re: Good practice or not to close the file before System.exit(1)? Lew <noone@lewscanon.com> - 2011-04-22 09:39 -0400
          Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-23 13:20 +0200
    Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 16:37 +0200
  Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 04:55 -0700
  Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 13:56 +0200
    Re: Good practice or not to close the file before System.exit(1)? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-04-22 09:36 -0300
    Re: Good practice or not to close the file before System.exit(1)? markspace <-@.> - 2011-04-22 08:20 -0700
      Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 09:04 -0700
        Re: Good practice or not to close the file before System.exit(1)? markspace <-@.> - 2011-04-22 15:24 -0700
          Re: Good practice or not to close the file before System.exit(1)? markspace <-@.> - 2011-04-22 18:11 -0700
            Re: Good practice or not to close the file before System.exit(1)? markspace <-@.> - 2011-04-23 08:25 -0700
      Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 18:55 +0200
        Re: Good practice or not to close the file before System.exit(1)? Lew <noone@lewscanon.com> - 2011-04-22 13:40 -0400
        Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 10:55 -0700
          Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 22:58 +0200
            Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 23:09 +0200
              Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 14:30 -0700
                Re: Good practice or not to close the file before System.exit(1)? markspace <-@.> - 2011-04-22 15:38 -0700
                Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 17:00 -0700
                Re: Good practice or not to close the file before System.exit(1)? Lew <noone@lewscanon.com> - 2011-04-22 22:10 -0400
                Re: Good practice or not to close the file before System.exit(1)? Patricia Shanahan <pats@acm.org> - 2011-04-22 19:46 -0700
                Re: Good practice or not to close the file before System.exit(1)? Lew <noone@lewscanon.com> - 2011-04-23 09:54 -0400
  Re: Good practice or not to close the file before System.exit(1)? Roedy Green <see_website@mindprod.com.invalid> - 2011-04-22 12:45 -0700
    Re: Good practice or not to close the file before System.exit(1)? Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> - 2011-04-22 23:20 +0200

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