db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Edson Carlos Ericksson Richter <edson.rich...@mgrinformatica.com.br>
Subject Re: ClassCastException in CountAggregator
Date Thu, 15 Dec 2005 16:37:08 GMT
In NetBeans environment, you could define your Resources under 
server.xml (bad option) under META-INF/context.xml file (better, project 
based - allow several projects in one installation without interference 
between projects). So I put it in META-INF/context.xml.


Thanks for your attention,

Edson Richter


Stanley Bradbury escreveu:

> 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