[Building Sakai] ClassCastException implementing CourseGradesToSpreadsheetConverter

[Bryan Holladay]

I just ran into this issue again today... I seriously just copied a
Class Cast line of code from a line above it and it complained...  I
was able to fix it by building edu-services_trunk in my own tomcat,
then building gradebook again.  I think it's an issue w/the
edu-service dependency jar's being compiled w/a different compiler.

-Bryan

On Wed, Aug 17, 2011 at 1:41 PM, Gross,Christopher <ufchrisg at ufl.edu> wrote:
> Your emails gave me one idea, and that was to remove the
> <scope>provided</scope> from the following dependency in the pom.xml for
> both converters:
>
> <dependency>
>        <groupId>org.sakaiproject.edu-services.gradebook</groupId>
>        <artifactId>gradebook-service-hibernate</artifactId>
>        <scope>provided</scope>
> </dependency>
>
> At the very least it did one thing I was expecting and that was it placed
> the gradebook-service-hibernate-1.1.2.jar in the WEB-INF/lib for the
> converters.  Unfortunately, this did not resolve the issue and the
> exception persists.
>
> -Chris
>
>
> On 8/17/11 10:28 AM, "Bryan Holladay" <holladay at longsight.com> wrote:
>
>>A recent example I ran into was
>>https://jira.sakaiproject.org/browse/SAM-1121
>>
>>Just adding this one line:
>>
>>Calendar calendar =
>>org.sakaiproject.calendar.cover.CalendarService.getCalendar("/calendar/cal
>>endar/"
>>+ siteId + "/main");
>>
>>Threw this exception:
>>
>>Bean named 'org.sakaiproject.calendar.api.CalendarService' must be of
>>type [org.sakaiproject.calendar.api.CalendarService], but was actually
>>of type [org.sakaiproject.calendar.impl.DbCalendarService]
>>
>>
>>You can look at my patch to get an idea of an approach to take
>>(hopefully).  It basically comes down to: move it to a different part
>>of the architecture.
>>
>>-Bryan
>>
>>
>>On Wed, Aug 17, 2011 at 10:23 AM, Bryan Holladay <holladay at longsight.com>
>>wrote:
>>> This is an issue I see a lot.  It basically comes down to this:
>>>
>>> "The class objects were loaded in different classloaders, therefore
>>> the instances created from in each of classes are seen as
>>> 'incompatible'. This is a common issue in a an environment where there
>>> are many different classloaders being used and objects are being
>>> passed around. These issues can easily arise in JEE and portal
>>> environments."
>>>
>>> -Source: Internet/Google
>>>
>>>  just throwing out quick ideas w/o knowing how your code is set up:
>>>
>>> Try to implement this in the same layer as the API or don't import
>>> jars, but instead use what's already there or access it from
>>> Edu-services if that's where it's create, ect...
>>>
>>>
>>> Thanks,
>>> Bryan
>>>
>>>
>>>
>>> On Wed, Aug 17, 2011 at 10:12 AM, Gross,Christopher <ufchrisg at ufl.edu>
>>>wrote:
>>>> The jars are there (the converters appear in tomcat/components/).
>>>> Besides, a missing jar would likely give me some problems when tomcat
>>>>is
>>>> starting up and/or result in a bean failing to initialize.
>>>>
>>>> Thanks!
>>>>
>>>> -Chris
>>>>
>>>> On 8/17/11 4:26 AM, "DAVID ROLDAN MARTINEZ" <darolmar at upvnet.upv.es>
>>>>wrote:
>>>>
>>>>>I suggest checking if you have all the *.jar you need available.
>>>>>
>>>>>Hope this helps.
>>>>>
>>>>>David
>>>>>________________________________________
>>>>>De: sakai-dev-bounces at collab.sakaiproject.org
>>>>>[sakai-dev-bounces at collab.sakaiproject.org] En nombre de
>>>>>Gross,Christopher [ufchrisg at ufl.edu]
>>>>>Enviado el: martes, 16 de agosto de 2011 22:54
>>>>>Para: sakai-dev at collab.sakaiproject.org
>>>>>Asunto: [Building Sakai] ClassCastException implementing
>>>>>CourseGradesToSpreadsheetConverter
>>>>>
>>>>>Hello!
>>>>>
>>>>>We are attempting to create our own implementation of the
>>>>>CourseGradesToSpreadsheetConverter interface (gradebook service),
>>>>>however
>>>>>we are receiving a ClassCastException when attempting to export course
>>>>>grades from the gradebook tool. To ensure this was not a problem in our
>>>>>code we set gradebook.coursegrades.converter to
>>>>>"org.sakaiproject.gradebooksample.CourseGradesToSpreadsheetConverterSam
>>>>>ple
>>>>>"
>>>>> in sakai.properties, which is the sample that is included in the
>>>>>gradebook tool's source. The result is that both implementations are
>>>>>causing the same ClassCastException when a user attempts to export the
>>>>>course grades in the gradebook.
>>>>>
>>>>>This setup is using gradebook 2.8.x and edu-services 1.1.x
>>>>>
>>>>>A small snippet of the output is below.
>>>>>
>>>>>I am hoping that someone may see something that I am not or will
>>>>>confirm
>>>>>that this is something that needs to be submitted to the JIRA.
>>>>>
>>>>>Thanks!
>>>>>
>>>>>----
>>>>>
>>>>>2011-08-16 16:28:05.634 [ERROR]
>>>>>org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/sakai-g
>>>>>rad
>>>>>e
>>>>>book-tool].[sakai.gradebook.tool]:691 - Servlet.service() for servlet
>>>>>sakai.gradebook.tool threw exception
>>>>>java.lang.ClassCastException:
>>>>>org.sakaiproject.gradebooksample.CourseGradesToSpreadsheetConverterSamp
>>>>>le
>>>>>cannot be cast to
>>>>>org.sakaiproject.tool.gradebook.CourseGradesToSpreadsheetConverter
>>>>>        at
>>>>>org.sakaiproject.tool.gradebook.ui.CourseGradeDetailsBean.getSpreadshee
>>>>>tDa
>>>>>t
>>>>>a(CourseGradeDetailsBean.java:322)
>>>>>        at
>>>>>org.sakaiproject.tool.gradebook.ui.CourseGradeDetailsBean.exportCsv(Cou
>>>>>rse
>>>>>G
>>>>>radeDetailsBean.java:296)
>>>>>...
>>>>>
>>>>>
>>>>>--
>>>>>
>>>>>Christopher Gross
>>>>>University of Florida
>>>>>
>>>>>_______________________________________________
>>>>>sakai-dev mailing list
>>>>>sakai-dev at collab.sakaiproject.org
>>>>>http://collab.sakaiproject.org/mailman/listinfo/sakai-dev
>>>>>
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>>>>
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>
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