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From: Cecil Westerhof <Cecil@decebal.nl>
Newsgroups: comp.lang.java.programmer
Subject: Re: Is this the way to work with try with resources
Date: Wed, 09 Aug 2017 22:20:28 +0200
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Andreas Leitgeb <avl@logic.at> writes:

> Cecil Westerhof <Cecil@decebal.nl> wrote:
>> I had there the following function:
>>     public ResultSet executeQuery(String query) throws SQLException {
>>         return conn.createStatement().executeQuery(query);
>>     }
>> but I now changed that to:
>>     public ResultSet executeQuery(String query) throws SQLException {
>>         try (Statement stmt = conn.createStatement()) {
>>             return stmt.executeQuery(query);
>>         }
>>     }
>> This should take care of the leakage.
>
> I fear, next trouble is right ahead.
>
> try doesn't only close it's resource on failure, but also on completion!
>
> That means, it will (because closing the statement will also close the
> ResultSet) return an already closed ResultSet.

I have in my code:
    private static void displayOldestUsed() {
        try (ResultSet rsOldest = sqlite3Conn.executeQuery(OLDEST_USED)) {
            if (rsOldest.next()) {
                giveMessage("Oldest used: " + rsOldest.getString("used") + ".");
            }
        } catch (SQLException e) {
            giveError("Error in displayOldestUsed");
            e.printStackTrace();
            fatalError("");
        }
    }

And rsOldest.getString("used") gives the result I would expect. Or am
I just ‘lucky’?

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