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Re: unnecessary code in Oracle example?

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From	ram@zedat.fu-berlin.de (Stefan Ram)
Newsgroups	comp.lang.java.programmer
Subject	Re: unnecessary code in Oracle example?
Date	9 Oct 2013 19:04:04 GMT
Organization	Stefan Ram
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Daniel Pitts <newsgroup.nospam@virtualinfinity.net> writes:
>MyResource r1 = null;
>MyResource r2 = null;
>try {
>   r1 = openResource1();
>   r2 = openResource2();
>} finally {
>   if (r1 != null) r1.close();
>   if (r2 != null) r2.close();
>}

  Which also might be written as follows
  (execution would start at r() below,
  code was never syntax-checked nor tested).

void use
( final MyResource r1,
  final MyResource r2 )
{ /* insert the code that needs r1 und r2 here */ }

void r2
( final MyResource r1,
  final MyResource r2 )
{ try
  { use( r1, r2 ); } 
  finally
  { r2.close(); }}

void r1( final MyResource r1 )
{ try
  { r2( r1, openRessource2() ); }
  catch( final OpenResource2Exception exception )
  { /* add possible exception handling here */ }
  finally
  { r1.close(); }}}

void r()
{ try
  { r1( openRessource1() ); }
  catch( final OpenResource1Exception exception )
  { /* add possible exception handling here */ }}

  The function calls are a trick that I have invented to
  bypass the need for non-final null-initialized variables
  when the reference of a resource just obtained is to be
  stored in a variable.

  I also do not have to compare the resources with null before
  closing them, since the functions with the close() calls are
  only called when the corresponding open calls did not throw.

Thread

unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 10:38 -0600
  Re: unnecessary code in Oracle example? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-10-09 11:19 -0700
    Re: unnecessary code in Oracle example? ram@zedat.fu-berlin.de (Stefan Ram) - 2013-10-09 19:04 +0000
    Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 13:08 -0600
      Re: unnecessary code in Oracle example? markspace <markspace@nospam.nospam> - 2013-10-09 12:27 -0700
        Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 14:21 -0600
          Re: unnecessary code in Oracle example? markspace <markspace@nospam.nospam> - 2013-10-09 14:56 -0700
            Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 20:56 -0600
              Re: unnecessary code in Oracle example? Arivald <NOSPAMarivald@interia.pl> - 2013-10-10 06:42 +0200
                Re: unnecessary code in Oracle example? Sebastian <news@seyweiler.dyndns.org> - 2013-10-10 07:47 +0200
                Re: unnecessary code in Oracle example? Arivald <arivald_@AT_interia_DOT_.pl> - 2013-10-10 10:26 +0200
                Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-10 08:47 -0600
    Re: unnecessary code in Oracle example? Robert Klemme <shortcutter@googlemail.com> - 2013-10-09 21:11 +0200
      Re: unnecessary code in Oracle example? cuzdav@gmail.com - 2013-10-10 08:49 -0700

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