ConcurrentModificationException while running the deployed application

Question

Hi,
I am using JDeveloper 11.1.2.0.0 and WebLogic Server Version: 10.3.5.0 with production environment.
My application is based on Customized Dynamic Tab Shell where each task flow is loaded with its own transaction and also it is defined not to share data control.
I use a Collection Object inside TabContext class, which will be accessed and consumed (including modifications) by all dynamic tab loaded taskflow.
I use Customized FactoryClass for every BC4JDataControl to track the request and also to pass parameter to model layer AMs
When i run the application in local, i didn't get any error. But when i check the deployed application, I am getting ConcurrentModificationException frequently as javascript dialog
java.util.ConcurrentModificationException
ADF_FACES-60097: For more information, please see the server's error log for
an entry beginning with: ADF_FACES-60096:Server Exception during PPR, #181When i check the server error log, it didn't say anything about my classes.
[2011-10-04T01:35:33.608-07:00] [MDA1-Server01] [ERROR] [] [oracle.adfinternal.view.faces.config.rich.RegistrationConfigurator] [tid: [ACTIVE].ExecuteThread: '1' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: <anonymous>] [ecid: 11d1def534ea1be0:-38985633:132c98ea02d:-8000-000000000000b88b,0] [APP: CalwinApplication] ADF_FACES-60096:Server Exception during PPR, #55[[
java.util.ConcurrentModificationException
     at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
     at java.util.AbstractList$Itr.next(AbstractList.java:343)
     at org.apache.myfaces.trinidad.render.CoreRenderer.encodeAllChildren(CoreRenderer.java:619)
     at oracle.adf.view.rich.render.RichRenderer.encodeAllChildrenInContext(RichRenderer.java:3062)
     at oracle.adfinternal.view.faces.renderkit.rich.PageTemplateRenderer.encodeAll(PageTemplateRenderer.java:69)
     at oracle.adf.view.rich.render.RichRenderer.encodeAll(RichRenderer.java:1452)
     at org.apache.myfaces.trinidad.render.CoreRenderer.encodeEnd(CoreRenderer.java:493)
     at org.apache.myfaces.trinidad.component.UIXComponentBase.encodeEnd(UIXComponentBase.java:913)
     at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1661)
     at org.apache.myfaces.trinidad.render.CoreRenderer.encodeChild(CoreRenderer.java:607)
     at oracle.adf.view.rich.render.RichRenderer.encodeChild(RichRenderer.java:3201)
     at org.apache.myfaces.trinidad.render.CoreRenderer.encodeAllChildren(CoreRenderer.java:623)
     at oracle.adf.view.rich.render.RichRenderer.encodeAllChildrenInContext(RichRenderer.java:3062)
     at oracle.adfinternal.view.faces.renderkit.rich.RegionRenderer._encodeChildren(RegionRenderer.java:310)
     at oracle.adfinternal.view.faces.renderkit.rich.RegionRenderer.encodeAll(RegionRenderer.java:186)
     at oracle.adf.view.rich.render.RichRenderer.encodeAll(RichRenderer.java:1452)
     at org.apache.myfaces.trinidad.render.CoreRenderer.encodeEnd(CoreRenderer.java:493)
     at org.apache.myfaces.trinidad.component.UIXComponentBase.encodeEnd(UIXComponentBase.java:913)
     at oracle.adf.view.rich.component.fragment.UIXRegion.encodeEnd(UIXRegion.java:323)
     at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1661)
     at org.apache.myfaces.trinidad.component.UIXGroup.encodeChildren(UIXGroup.java:170)
                .....On checking further about this error code in Oracle® Fusion Middleware Error Messages Reference 11g Release 2 (11.1.2.0.0), it is given as
  ADF_FACES-60097: For more information, please see the server's error log for an
entry beginning with: {0}
Cause: An exception was thrown durring a PPR request.
Action: Please look in the servers error log for more details on this error.
Level: 1
Type: ERROR
Impact: LoggingI couldn't get any hint on what may be the issue. Can anyone help on this?
Thanks in Advance.
Perumal S

Answer 1

I've seen this happen before if component objects are stored in managed beans (e.g. using binding="#{someBean.foo}").
Problems like this can happen if the component is stored directly on the bean as a member variable (most commonly if the bean is application-scoped, session-scoped, or pageFlow-scoped but smaller scopes can exhibit the problem too).
Usually just referencing the components from the accessors on JSF event objects during an event handlers or using one of the various component searching APIs (e.g. findComponent) can suffice in locating the components dynamically.
However, if using one of those mechanisms isn't feasible you must use the ComponentReference as the storage mechanism (and follow the caveats noted in its JavaDoc):
http://www.jarvana.com/jarvana/view/org/apache/myfaces/trinidad/trinidad-api/2.0.0-beta-1/trinidad-api-2.0.0-beta-1-javadoc.jar!/org/apache/myfaces/trinidad/util/ComponentReference.html
Hope this helps,
Matt