db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Stanley Bradbury <Stan.Bradb...@gmail.com>
Subject Re: ClassCastException in CountAggregator
Date Thu, 15 Dec 2005 16:16:11 GMT
Edson Carlos Ericksson Richter wrote:

> As stated in my previous mail, the connection pool is declared
> <Resource auth="Container" description="Biblio" name="jdbc/Biblio"
> type="javax.sql.DataSource" username="" password=""
> driverClassName="org.apache.derby.jdbc.EmbeddedDriver"
> url="jdbc:derby:c:/projects/biblio/database;" maxActive="10" 
> maxIdle="2"/>
>
>
> And in web.xml I just have a resource-ref, as required by specs:
>
>  <resource-ref>
>    <description></description>
>    <res-ref-name>jdbc/Biblio</res-ref-name>
>    <res-type>javax.sql.DataSource</res-type>
>    <res-auth>Container</res-auth>
>  </resource-ref>
>
>
> The code running is (it's a generic code I use to test queries, so 
> don't be afraid about weird coding):
>
>        <sql:query var="result" dataSource="jdbc/Biblio">
>          select count(*) from my_table
>        </sql:query>
>        <table border='1' cellspacing='0' cellpadding='2'>
>          <tr>
>        <c:forEach items="${result.columnNames}" var="col">
>          <th>${col}</th>
>        </c:forEach>
>          </tr>
>        <c:forEach items="${result.rows}" var="row">
>          <tr>
>            <c:forEach items="${result.columnNames}" var="col">
>              <td>${mgr:stripClob(row[col])}</td>
>            </c:forEach>
>          </tr>
>        </c:forEach>
>        </table>
>
>
> The error occur at <sql:query...>, so rest of code is just here to 
> illustrate usage.
>
> At last, the derby.jar and derbypt_BR.jar are in 
> $NETBEANS_HOME/enterprise2/jakarta-tomcat-5.5.9/commons/lib/, so 
> classes are avaliable to the pool. If I remove them, I get problems 
> with connection (and plain queries stop working).
>
>
> I expect this helps... I will not have much time free help, but from 
> times to times I'll check to see if there is anything I could contribute.
>
> Best regards,
>
> Edson Richter
>
>
>
> Stanley Bradbury escreveu:
>
>> edson.richter@mgrinformatica.com.br wrote:
>>
>>> Thank you all for the tips.
>>>
>>> Before giving up using derby, I have: 1) checked for older versions. 
>>> No, there are none (in
>>> real, I tried a fresh install of Tomcat). I double checked 
>>> $JAVA_HOME/jre/lib/ext, and
>>> tryied including install a new version of JDK (I was using 1.5.0_04 
>>> and made a try with
>>> 1.5.0_06 - no differences).
>>> I tryied a simple JSP that take a connection from the pool and 
>>> executed a simple select
>>> count(*) from some_table and error is the same.
>>>
>>> Interesting is that I tryied Ij, and the error didn't occured.
>>> But, Ij is not using pt_BR messages, and I suspect error is related 
>>> (but then I give up: I
>>> could not spent more than a couple of hours without sucess searching 
>>> on the net - I searched
>>> Google, MSN, Altavista). db.apache.org was unavaliable yesterday, 
>>> and I could not search
>>> mailing lists.
>>>
>>> So, without web support (even from the list), I could not defend 
>>> Derby anymore in the
>>> project, and manager directed all development to a comercial 
>>> database, unfortunatelly.
>>>
>>> At all, thank you... But don't forget to check what could be wrong - 
>>> there is a serious
>>> erro/bugr in there.
>>>
>>> Details:
>>>
>>> - Tomcat 5.5.9 embedded in NetBeans 5.0 Beta 2
>>> - Tomcat 5.5.7 embedded in NetBeans 4.1
>>> - Connection obtained with 'jdbc:derby:c:/projects/biblio/database' 
>>> (it's embedded) - Plain
>>> queries works fine (select * from some_table)
>>> - Aggregate count throw ClassCastException (select count(*) from 
>>> some_table)
>>>
>>> Connection declaration:
>>>
>>> <Resource auth="Container" description="Biblio" name="jdbc/Biblio"
>>> type="javax.sql.DataSource" username="" password=""
>>> driverClassName="org.apache.derby.jdbc.EmbeddedDriver"
>>> url="jdbc:derby:c:/projects/biblio/database;" maxActive="10" 
>>> maxIdle="2"/>
>>>
>>> Here is stack trace:
>>>
>>> 08/12/2005 16:29:24 org.apache.catalina.core.ApplicationDispatcher 
>>> invoke
>>> SEVERE: Servlet.service() for servlet jsp threw exception
>>> ERROR 38000: A exceção 'java.lang.ClassCastException:
>>> org.apache.derby.impl.sql.execute.CountAggregator' foi emitida ao 
>>> avaliar uma expressão.
>>>        at 
>>> org.apache.derby.iapi.error.StandardException.newException(Unknown 
>>> Source)
>>>        at 
>>> org.apache.derby.iapi.error.StandardException.unexpectedUserException(Unknown

>>>
>>> Source)
>>>        at 
>>> org.apache.derby.impl.sql.execute.GenericAggregator.getAggregatorInstance(Unknown

>>>
>>> Source)
>>>        at 
>>> org.apache.derby.impl.sql.execute.GenericAggregator.initialize(Unknown 
>>> Source)
>>>  
>>>
>> ......  SNIP ...
>>
>> Hi Edson -
>>
>> Could you help me setup a test case for this problem?  It would be 
>> great if  you could provide a test case for the problem and file a 
>> JIRA entry with the test case attached (please let me know if you can 
>> do this).  It sounds, however, that you are working to a tight 
>> timeframe so I am willing to attempt to create a test case but need 
>> some additional information.
>> I have not used NetBeans but know a bit about JSPs with Tomcat.  
>> Could you post the information I will need to perform the test you 
>> describe as:
>>
>> ".. I tryied a simple JSP that take a connection from the pool and 
>> executed a simple select count(*) from some_table and error is the 
>> same .."
>>
>> Here are the things I can think of that will be very helpful: + 
>> Having the JSP code would be very helpful - would you post it?
>> +  I need to know how the connection pool was defined (what entries 
>> were placed in server.xml, the application deployment XML file and 
>> the web.xml file). +  If there any other settings needed to setup the 
>> connection pool in the Tomcat/NetBeans environment please include 
>> those also.
>> I have located another report of this stack trace when performing 
>> 'select count(*)' in a different server that did not seem to relate 
>> to codesets so I am hoping that  pt_BR is not required to debug this 
>> problem.
>>
>> Thanks in advance
>>
>>
>>
>
Hi Edson -

Thanks for the reply - I certainly understand being busy and appreciate 
your time to respond to my questions.  My newbie-academic understanding 
of Tomcat is that the pool can be defined in a couple of places but most 
commonly is declared in the server.xml file.  Within server.xml it can 
be declared as a <CONTEXT> element inside the <HOST> element or in the 
GlobalNaming space within the <Server> element.  I have always worked 
with datasources defined in the Global-Server space and will setup my 
test in that manner.  Please let me know if this not how your system is 
configured and I will adjust my testing..


Mime
View raw message