AbstractWizardDialog throws nullPointerException when executing onNext

[grimfromghent]

Hi there,

I'm trying to create a wizard consisting of multiple pages.
Here is part of the code (rest is not important):

public class CSVWizard extends AbstractWizard{
    public CSVWizard(){
               
    }       
    @Override
    public void addPages(){

        CSVWizardPage1 csv1WizardPage = new CSVWizardPage1("page1");        
        CSVWizardPage2 csv2WizardPage = new CSVWizardPage2("page1");                
        addPage(csv1WizardPage);
        addPage(csv2WizardPage);         
        
    }

    @Override
    protected boolean onFinish() {
        return true;
    }
}

The pages load correctly (so the logs show), but when I push the button "next"-button
a nullpointerexception is thrown:

[DEBUG,MessagesDialogExceptionHandler,AWT-EventQueue-0] Uncaught throwable handled
java.lang.NullPointerException
	at org.springframework.richclient.wizard.WizardDialog.onNext(WizardDialog.java:163)
	at org.springframework.richclient.wizard.WizardDialog$1.doExecuteCommand(WizardDialog.java:100)
	at org.springframework.richclient.command.ActionCommand.execute(ActionCommand.java:195)
	at org.springframework.richclient.command.ActionCommand$1.actionPerformed(ActionCommand.java:126)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
	at java.awt.Component.processMouseEvent(Component.java:6288)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
	at java.awt.Component.processEvent(Component.java:6053)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4651)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
	at java.awt.Container.dispatchEventImpl(Container.java:2085)
	at java.awt.Window.dispatchEventImpl(Window.java:2478)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
	at java.awt.EventQueue.access$000(EventQueue.java:84)
	at java.awt.EventQueue$1.run(EventQueue.java:602)
	at java.awt.EventQueue$1.run(EventQueue.java:600)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
	at java.awt.EventQueue$2.run(EventQueue.java:616)
	at java.awt.EventQueue$2.run(EventQueue.java:614)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:178)
	at java.awt.Dialog$1.run(Dialog.java:1046)
	at java.awt.Dialog$3.run(Dialog.java:1098)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.Dialog.show(Dialog.java:1096)
	at java.awt.Component.show(Component.java:1584)
	at java.awt.Component.setVisible(Component.java:1536)
	at java.awt.Window.setVisible(Window.java:842)
	at java.awt.Dialog.setVisible(Dialog.java:986)
	at gov.loc.repository.bagger.ui.handlers.CSVExecutor.execute(CSVExecutor.java:20)
	at org.springframework.richclient.command.support.AbstractActionCommandExecutor.execute(AbstractActionCommandExecutor.java:124)
	at org.springframework.richclient.command.TargetableActionCommand.doExecuteCommand(TargetableActionCommand.java:140)
	at org.springframework.richclient.command.ActionCommand.execute(ActionCommand.java:195)
	at org.springframework.richclient.command.ActionCommand$1.actionPerformed(ActionCommand.java:126)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
	at java.awt.Component.processMouseEvent(Component.java:6288)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
	at java.awt.Component.processEvent(Component.java:6053)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4651)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
	at java.awt.Container.dispatchEventImpl(Container.java:2085)
	at java.awt.Window.dispatchEventImpl(Window.java:2478)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
	at java.awt.EventQueue.access$000(EventQueue.java:84)
	at java.awt.EventQueue$1.run(EventQueue.java:602)
	at java.awt.EventQueue$1.run(EventQueue.java:600)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
	at java.awt.EventQueue$2.run(EventQueue.java:616)
	at java.awt.EventQueue$2.run(EventQueue.java:614)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

Looking at the source code of AbstractWizardDialog, the attribute currentPage is null.
Is there a way to fix this? Or is my code wrong?

Thanks in advance

[grimfromghent]

Ok, meanwhile I solved the problem myself. This is what is did:

CSVWizardDialog wdialog = new CSVWizardDialog();
wdialog.getDialog.setVisible(true);

That way, the method showPage of AbstractWizard was never called for the first time, and currentPage
remained empty.

better:

CSVWizardDialog wdialog = new CSVWizardDialog();
wdialog.openDialog();