Java.lang.ClassCastException problem with ApplicationModuleImpl

Question

Hi, to whom this may be familiar:
This is from a oracle.adf.controller.struts.actions.DataAction class:
public class SwitchDAAction extends DataAction
  protected void findForward(DataActionContext actionContext) throws Exception
    super.findForward(actionContext);
    ZBModuleImpl svc = (ZBModuleImpl) actionContext.getBindingContext().findDataControl("ZBModuleDataControl").getDataProvider();
    BillViewImpl oneUser = svc.getBillView1();
...ZBModuleImpl is an application module which extends oracle.lbo.server.ApplicationModuleImpl.
As the last statement indicates, the purpose is to obtain an instance of a view object that is already in the application.
There is no error at compilation. However, when the application runs, the embedded oc4j gives an error:
WARNING: Unhandled Exception thrown: class java.lang.ClassCastExceptionand in the browser the first line in the "500 Internal Server Error", shown below, pin-points to the line of code that cast Object to ZBModuleImpl:
at zb.view.SwitchDAAction.findForward(SwitchDAAction.java:18)I broke up the line into multiple lines to see where exactly the problem is:
public class SwitchDAAction extends DataAction
  protected void findForward(DataActionContext actionContext) throws Exception
    super.findForward(actionContext);
    BindingContext bdCtx = actionContext.getBindingContext();
    DCDataControl dc = bdCtx.findDataControl("ZBModuleDataControl");
    Object dpd = dc.getDataProvider();
    ZBModuleImpl svc = (ZBModuleImpl) dpd;
    BillViewImpl oneUser = svc.getBillView1();
...The error messages always point to that line that does data type casting.
What is the problem and what can be done to fix it? (I am using JDeveloper 10.1.2.0.0).
Thanks for your help!
Newman

Answer 1

Hi, Valery and Anton:
Sorry I did not mention the version of Jdev I am using in my last posting. It is 10.1.2. It is so precious someone around still know the older versions.
Anton, since mine is an older version, I tried to set the custom properties. The name of my application is ZB and the name of the application module is ZBModuleImpl. The name of the view object I am trying to get an instance of is BillViewimpl.
In the Application Module Editor for ZBModule, at the Custom Properties node, there are names for three properties in the drop-down list: DESCRIPTION, FILE_NAME, DATA_CONTROL_NAME. Not knowing what they are and what they are for, I tried to add two name/value pairs: DESCRIPTION/ZB and DATA_CONTROL_NAME/ZBModuleDataControl. And for the last method on the problem line of code I tried both getDataProvider() and getApplicationModule(), in the following combinations, and none of them work out:
                                               getDataProvider()     getApplicationModule()
DESCRIPTION/ZB (only)                                   X                       X
DATA_CONTROL_NAME/ZBModuleDataControl (only)            X                       X
(both)                                                  X                       XPlease correct me where I did wrong. I wonder what oracle.jbo.common.ws.WSApplicationModuleImpl is. I even tried
BillViewImpl oneUser = (ZBModuleImpl) actionContext.getBindingContext().findDataControl("ZBModuleDataControl").getApplicationModule().findApplicationModule("ZBModuleImpl");
and
BillViewImpl oneUser = ((ZBModuleImpl) actionContext.getBindingContext().findDataControl("ZBModuleDataControl").getApplicationModule()getApplicationModule()).findViewObject("BillViewImpl");But the problem is always with the typecasting from ApplicationModule to ZBModuleImpl. Is there anything that WSApplicationModuleImpl can do to help out?
Thanks a lot for your help!
Newman