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Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound

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On Aug 12, 1:31 pm, Patricia Shanahan <p...@acm.org> wrote:
> On 8/12/2011 8:39 AM, KevinSimonson wrote:
> ...> Finally, if I have some code that has constructors for _both
> > <PrintWriter>  and_<Scanner>, I have to have a<catch>  clause for
> > _both<IOException>  and_<FileNotFoundException>, in order to keep the
> > compiler happy.
>
> ...
>
> This is the most puzzling part of your question. FileNotFoundException
> is a subclass of IOException, so a catch clause for IOException should
> be sufficient.
>
> Of course, if you want to deal with FileNotFoundException separately you
> do have the option of putting in a separate catch clause for it, but the
> compiler should not be requiring both.
>
> Patricia

Patricia, you were absolutely right!  Following up on your puzzlement,
I rewrote the program I posted, taking out the <import> of
<FileNotFoundException> and consolidating my <catch> blocks into:

      catch (IOException excptn)
      { System.out.println();
        System.out.println( "Couldn't open file!");
        System.out.println( "<srcOpnd> == " + srcOpnd + '.');
      }

This works just fine.  All I can think of is that when I tried to
compile a program that just took input the compiler complained about
<FileNotFound> and when I tried to compile a program that just wrote
output the compiler complained about <IOException>, so maybe I just
_assumed_ that a program that both read input and wrote output would
need both exceptions!

Anyhow, thanks for pointing me in the right direction.

Kevin Simonson

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Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound KevinSimonson <kvnsmnsn@hotmail.com> - 2011-08-12 08:39 -0700
  Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound Knute Johnson <september@knutejohnson.com> - 2011-08-12 08:54 -0700
  Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound markspace <-@.> - 2011-08-12 08:57 -0700
    Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound KevinSimonson <kvnsmnsn@hotmail.com> - 2011-08-12 11:19 -0700
      Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound markspace <-@.> - 2011-08-12 12:08 -0700
        Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound Patricia Shanahan <pats@acm.org> - 2011-08-12 12:26 -0700
      Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-12 19:35 +0000
  Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound Patricia Shanahan <pats@acm.org> - 2011-08-12 12:31 -0700
    Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound KevinSimonson <kvnsmnsn@hotmail.com> - 2011-08-12 13:10 -0700
  Re: Trying to Understand Purpose of a Catch Block for IOException in the Presence of One for FileNotFound Lew <lewbloch@gmail.com> - 2011-08-12 14:27 -0700

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