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From "Lance J. Andersen" <Lance.Ander...@Sun.COM>
Subject Re: [jira] Commented: (DERBY-1095) Closing an embedded connection does not seem to close associated EmbedStatements
Date Mon, 13 Mar 2006 14:33:25 GMT


Kristian Waagan (JIRA) wrote:
>     [ http://issues.apache.org/jira/browse/DERBY-1095?page=comments#action_12370077 ]

>
> Kristian Waagan commented on DERBY-1095:
> ----------------------------------------
>
> I see your point, but I still think Derby is buggy. The repro script executes a statement,
closes the connection then asks the resultset if it is closed. The resultset says it is not,
and based on this the repro then executes an operation that causes an exception to be thrown.
A correct answer from ResultSet.isClosed() would not have caused an exception in the repro.
>
> According to the JDBC4 spec: "A ResultSet is closed if the method close has been called
on it, or if it is automatically closed."
> I thought closing the underlying connection should close all associated resources, including
the resultset(s). Am I mistaken?
>   
Yes, closing the connection should result in any Statement objects and 
associated ResultSets being closed.

lance
> I notice that ResultSet.isClosed() simply returns a variable ('isClosed'), and to me
it seems that the state of this variable is not maintained correctly (have not looked at the
code), thus the ResultSet.isClosed() method suffers the same problem as Statement.isClosed().
We must either ensure the internal state is kept correct, or we must add extra checks to the
isClosed methods.
> Although the latter solution is very simple (at least for Statement), I personally think
it would be better if the close methods were executed also when the resources are automatically
"closed".
>
> Dan, since you have assigned yourself to this issue, can you tell me how your (planned)
solution would affect the internal state variables in ResultSet and Statment, so that I can
fix Statement.isClosed accordingly?
>
>   
>> Closing an embedded connection does not seem to close associated EmbedStatements
>> --------------------------------------------------------------------------------
>>
>>          Key: DERBY-1095
>>          URL: http://issues.apache.org/jira/browse/DERBY-1095
>>      Project: Derby
>>         Type: Bug
>>   Components: JDBC
>>     Versions: 10.2.0.0
>>     Reporter: Kristian Waagan
>>     Assignee: Daniel John Debrunner
>>     Priority: Minor
>>  Attachments: Derby1095Repro.java
>>
>> Closing an embedded connection (calling EmbedConnection.close()) does not seem to
close associated EmbedStatements. 
>> The severity of the bug is not determined. The least severe case is that the internal
EmbedStatement variable 'active' is not updated accordingly, the most severe case is that
the the resources bound to EmbedStatement will not be viable for garbage collection until
the EmbedStatement itself is (if user keeps references to it).
>> If methods on the statement are called, Derby will correctly throw an NoCurrentConnection
exception, but the close() method is still never called automatically.
>> The problem also seem to extend down to ResultSet.isClosed(), but this is probably
due to the bug in EmbedStatement.
>> Problem detected while fixing DERBY-953; implement Statement.isClosed().
>>     
>
>   

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