Operation hasNext is invalid for a working set view object

Question

Can someone point me to soem documentation to why I'm getting this error? I'm obviously misunderstanding something fundamental.
Thanks

Answer 1

I have an application module with a client method as follows:
public void setUserCredentials(String username, String password)
UserAccountViewImpl vo = getUserAccountView1();
vo.setWhereClauseParam(0, username);
vo.setWhereClauseParam(1, password);
vo.executeQuery();
if (vo.hasNext()) (BREAK POINT TWO)
vo.next();
I have a struts action that is based on the BasicADFAction class in the tech paper "Oracle ADF Data Binding Primer and ADF/Struts Overview"
by Steve Muench.
public class IsLoginValidAction extends BasicADFAction
protected ActionForward performActionLogic(ActionMapping mapping,
ActionForm form, HttpServletRequest request, HttpServletResponse response)
throws Exception
.... other code that gets username and password from form
DatamartModule am = (DatamartModule)getApplicationModule("DatamartModuleDataControl", request);
am.setUserCredentials(username, password);
ViewObject vo = am.findViewObject("UserAccountView1");
if (vo.getCurrentRow() == null) -- BREAK POINT ONE
ae.add("InvalidDetails", new ActionError("error.IsLoginValidAction.InvalidDetails"));
return mapping.findForward("LoginError");
UserAccountViewRowClient vr = (UserAccountViewRowClient)vo.getCurrentRow();
.... do some other checks with the user account
As you can see the above Action calls setUserCredentials(). What is driving me mad is the following. If I enter a valid username and password in the login page and reach break point one the method vo.getCurrentRow() returns null which is not what I expect!
If I re-submit my login details again, when I reach break point one for the second time vo.getCurrentRow() is not null??
I have also set a break point two just to make sure setUserCredentials is working and it always brings back a row when I enter the correct details. So why in the action when I select the same view object the current row is not available to me but is available the second time round?? I'm I missing something fundamental??
I had some feedback on metalink where oracle support set check that the vo.isExecuted() == true and if it isn't then re-execute the query. I couldn't see why I should do this but I did. I found that vo.isExecuted is false the first time round but true the second time. It appears the first time round I am implicitly getting the query to execute for the first time even though I believe I have already done this in the setUserCredentials method.
After adding a vo.executeQuery() I obviously needed to add code that obtained the row. As soon as vo.hasNext() is called I get:
oracle.jbo.InvalidOperException: JBO-25048: Operation hasNext is invalid for a working set view object.
     at oracle.jbo.common.ws.WSObject.invalidOperation(WSObject.java:44)
     at oracle.jbo.common.ws.WSRowSetIteratorBase.hasNext(WSRowSetIteratorBase.java:381)
     at view.IsLoginValidAction.performActionLogic(IsLoginValidAction.java:66)
     at view.BasicADFAction.handleLifecycle(BasicADFAction.java:64)
     at view.BasicADFAction.execute(BasicADFAction.java:46)
     at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
     at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
     at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
     at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)
     at oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.EvermindFilterChain.doFilter(EvermindFilterChain.java:16)
     at oracle.adf.model.servlet.ADFBindingFilter.doFilter(ADFBindingFilter.java:228)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:600)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:317)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
     at java.lang.Thread.run(Thread.java:534)
I must misunderstand something fundamental. Any help would be really appreciated. Basically in my client code (The struts action) I want to access a single record that is based on a view. I prepare the view object by calling a custom service level method to set the username and password and execute the query.