MySQL Bugs: #68916: closeOnCompletion doesn't work

Bug #68916	closeOnCompletion doesn't work
Submitted:	10 Apr 2013 11:04	Modified:	21 Nov 2013 16:31
Reporter:	Nepomuk Seiler	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / J	Severity:	S2 (Serious)
Version:	5.1.24	OS:	Any
Assigned to:	Jess Balint	CPU Architecture:	Any
Tags:	closeOnCompletion, java7, jdbc

Description:
The method call _closeOnCompletion_ seems to have no effect. I posted a question of stackoverflow [1].

The corresponding code at

StatementImpl.class Line 3041

My IDE couldn't find any usages of the _isCloseOnCompletion_ method or the private field.

cheers,
Muki

[1] http://stackoverflow.com/questions/15923135/mysql-jdbc-closeoncompletion-has-no-effect-on-...

How to repeat:
public final PreparedStatement statement(Connection connection) throws SQLException {
    PreparedStatement stmt = connection.prepareStatement(query, ResultSet.TYPE_FORWARD_ONLY,
            ResultSet.CONCUR_READ_ONLY);
    stmt.closeOnCompletion();
    return stmt;
}
No I'm calling this method as follows

@Test
public void testCloseOnCompletionSemiManually() throws SQLException {
    PreparedStatement stmt = shards.statement(db);
    assertTrue("Statement must be closeOnAutoCompletion", stmt.isCloseOnCompletion());

    try (ResultSet rs = stmt.executeQuery()) {
        while (rs.next()) {
            //System.out.println("Shard id: " + rs.getInt("SHARD_ID"));
        }
    }
    assertTrue("Statement must be closed after all results sets have been processed", stmt.isClosed());
}

Hi Nepomuk,

Thanks for your report.

JDBC spec describes functionality of this method as:

"Specifies that this Statement will be closed when all its dependent result sets are closed. If execution of the Statement does not produce any result sets, this method has no effect.

Note: Multiple calls to closeOnCompletion do not toggle the effect on this Statement. However, a call to closeOnCompletion does effect both the subsequent execution of statements, and statements that currently have open, dependent, result sets."

It isn't implemented in Connector/J. So verified as described.

Added the following entry to the Connector/J 5.1.28 changelog:

"The method Statement.closeOnCompletion() was not working."