Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Cecil Westerhof <Cecil@decebal.nl>
Newsgroups: comp.lang.java.programmer
Subject: Re: Not closing a SQL(ite3) connection
Date: Tue, 15 Aug 2017 08:19:31 +0200
Organization: Decebal Computing
Lines: 58
Message-ID: <87tw19nyj0.fsf@munus.decebal.nl>
References: <87a839um2q.fsf@munus.decebal.nl> <omg0la$1qe3$1@gioia.aioe.org> <874lte1pdj.fsf@munus.decebal.nl> <omli1h$jt7$1@gioia.aioe.org> <87k229z041.fsf@munus.decebal.nl> <omn168$mgs$1@gioia.aioe.org> <877ey8zwtt.fsf@munus.decebal.nl> <omoasj$lmg$2@gioia.aioe.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Injection-Info: mx02.eternal-september.org; posting-host="72fb8bea0235c6b94245dccb186de60d"; logging-data="21168"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX194X2PfB8KQBXqmkK7BtZiwTgaYDXGLr2E="
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux)
Cancel-Lock: sha1:9pAP5tymkIqFuMaF6Ri2MhVuesg= sha1:4mZlTuH0Ohh5yA7v9gIy15vtNDg=
X-Homepage: http://www.decebal.nl/
Xref: csiph.com comp.lang.java.programmer:37230

Arne Vajhøj <arne@vajhoej.dk> writes:

>> I want it to be clear when the closing of the resultSet went OK, but
>> the closing of stmt not. I was thinking about doing it in two tries,
>> but did not do it. And I should do three tries, because the fetching
>> of stmt can also go wrong. So now I have:
>>      @Override
>>      public void close() throws SQLException {
>>          Statement stmt;
>>
>>          try {
>>              stmt = resultSet.getStatement();
>>          } catch (SQLException e) {
>>              SQLException extException = new SQLException("Could not get Statement from ResultSet.");
>>
>>              extException.addSuppressed(e);
>>              e = extException;
>>              throw e;
>>          }
>>          resultSet.close();
>>          try {
>>              stmt.close();
>>          } catch (SQLException e) {
>>              SQLException extException = new SQLException("Could not close Statement after closing ResultSet.");
>>
>>              extException.addSuppressed(e);
>>              e = extException;
>>              throw e;
>>          }
>>      }
>
> I would somewhat expect that the cause of the problem be available in
> the Exception itself, so one could avoid all this. But if not then
> ...

You are right, I rewrote it:
    @Override
    public void close() throws SQLException {
        Statement stmt;

        if (isClosed) {
            throw new SQLException("SQLResultSet is already closed.");
        }
        stmt     = resultSet.getStatement();
        resultSet.close();
        stmt.close();
        isClosed = true;
    }

Much cleaner code.

I check for it being closed, because I think it is an error when you
try to close more as once.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof