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Groups > comp.lang.java.programmer > #38755

Re: it's Closeable, but I don't want to close() it yet.

Newsgroups comp.lang.java.programmer
Date 2019-02-28 11:33 -0800
References (7 earlier) <f71c1d05-cc27-4ecb-bea0-c32f03cd698e@googlegroups.com> <692da128-9302-41cf-a8f7-2a2a5903bf82@googlegroups.com> <3a4ed199-10a5-4ea3-882e-8d598a82dccf@googlegroups.com> <ab24ddfd-0235-4d43-8b9c-20cb8083df28@googlegroups.com> <6f5e7b36-af8f-4f1b-b7fe-f53305b8d591@googlegroups.com>
Message-ID <263782da-7ef6-466c-8cb3-da394bef0501@googlegroups.com> (permalink)
Subject Re: it's Closeable, but I don't want to close() it yet.
From bursejan@gmail.com

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Since Eclipse says "potential", it is not sure about its
judgement. Probably it uses some heuristics to find
close leaking, and in your case,

it produces maybe a false positive. All these checks
that different IDEs offer work by inspecting a small
part of your code and work by producing

a best guess, through some hand coded heuristics,
that there could be a problem.

They are not theorem provers that 100% can tell
whether something is a problem or not.

On Thursday, February 28, 2019 at 8:26:34 PM UTC+1, Eric Douglas wrote:
> On Thursday, February 28, 2019 at 2:12:55 PM UTC-5, burs...@gmail.com wrote:
> > Yes in the old code you had:
> > 
> >                          while (rs.next()) {
> >                               r++;
> >                          }
> >                          rs.close();
> > 
> > And since rs.next() can throw an exception,
> > it could escape a closing.
> > 
> > But try-resource has the ability to close
> > as well, when the try-resource block
> > 
> > has an exception.
> > 
> > There were nice blog entries in the past
> > from Oracle John Rose, but cant find any
> > of them anymore. The Oracle blogs currently
> > 
> > look like shit, what did they do?
> > 
> 
> 1) Is the confusion with Eclipse or Oracle?  I googled it and it went straight to Oracle (https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html) which even specifically mentioned my scenario, simply putting an executeQuery inside the try block, for which Eclipse complains not explicitly closing a ResultSet is a potential resource leak.
> 
> 2) I don't see the scenario in the Oracle doc for re-using a variable.  Should I be able to close a RecordSet and call executeQuery again to that same variable in that same method?
> 
> 3) How should we close a resource such as InputStream or OutputStream?  I had written the API in such a way if I'm passing them into a method to be read once, that method is closing them.  We should never close them while reading/writing them and expect them to get closed after the call by the method that opened them?

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Thread

it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-02-27 15:51 +0000
  Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-27 08:48 -0800
    Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-02-27 19:03 +0000
      Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-27 11:09 -0800
        Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-02-28 12:20 +0000
          Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 06:19 -0800
            Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 06:52 -0800
              Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 08:24 -0800
                Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 08:34 -0800
                Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 09:00 -0800
                Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 11:12 -0800
                Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 11:26 -0800
                Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 11:33 -0800
                Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 11:37 -0800
                Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 11:41 -0800
                Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 11:48 -0800
                Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 12:51 -0800
                Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-03-01 08:47 +0000
                Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-03-01 09:31 +0000
                Re: it's Closeable, but I don't want to close() it yet. Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2019-03-03 02:01 +0100
                Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-03-04 09:38 +0000
                Re: it's Closeable, but I don't want to close() it yet. Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2019-03-04 12:26 +0100
                Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-03-05 14:34 +0000
                Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-03-05 07:34 -0800
                Re: it's Closeable, but I don't want to close() it yet. Arne Vajhøj <arne@vajhoej.dk> - 2019-03-04 13:59 -0500
  Re: it's Closeable, but I don't want to close() it yet. Marcel Mueller <news.5.maazl@spamgourmet.org> - 2019-02-28 08:30 +0100
    Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-02-28 19:10 +0000
      Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 11:34 -0800
      Re: it's Closeable, but I don't want to close() it yet. Marcel Mueller <news.5.maazl@spamgourmet.org> - 2019-02-28 22:24 +0100
        Re: it's Closeable, but I don't want to close() it yet. Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2019-02-28 23:25 +0100
          Re: it's Closeable, but I don't want to close() it yet. Andreas Leitgeb <avl@logic.at> - 2019-03-01 09:43 +0000
  Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 12:11 -0800
    Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 13:49 -0800
      Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 13:52 -0800
        Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 13:59 -0800
          Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-02-28 16:17 -0800
  Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 12:26 -0800
  Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-02-28 13:44 -0800
  Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-03-01 07:40 -0800
    Re: it's Closeable, but I don't want to close() it yet. bursejan@gmail.com - 2019-03-01 08:34 -0800
  Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-03-11 06:27 -0700
    Re: it's Closeable, but I don't want to close() it yet. Eric Douglas <e.d.programmer@gmail.com> - 2019-03-11 07:24 -0700

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