Navigator throws ServiceException with unknown state''

Vaadin 6 / 7 / 8
1

Hi there,
I just started Vaadin and so far so good - it really looks promising, however I really struggle with the Navigator. I tried so many things I found on the internet, but none seems to work. I would appreciate it, if you guys can tell me, what I am doing wrong. Here is my source code

@Theme("mytheme")
@Widgetset("de.javahouse.jobwiz.MyAppWidgetset")
public class BasicInformation extends UI {

    public static final String VIEW_NAME_BASIC = "basic_view";
    public static final String VIEW_NAME_ADV = "advanced_view";

    private Navigator nav;
    private static final long serialVersionUID = 2548993131483469880L;

    @Override
    protected void init(VaadinRequest vaadinRequest) {

        HorizontalLayout layout = generateContent();
        nav = new Navigator(this,this);
        nav.addView(VIEW_NAME_ADV, new AdditionalInformation());
        
        //this doesnt work either
        //nav.addView(VIEW_NAME_BASIC,  (Class<? extends View>) BasicInformation.class);
        
        setContent(layout);
    

    }
    
    private HorizontalLayout generateContent(){
        
        HorizontalLayout layout = new HorizontalLayout();
        
        FormLayout form = new FormLayout();

        OptionGroup single = new OptionGroup("Gender");
        single.addItems("Male", "Female");
        form.addComponent(single);

        TextField tfFirstname = new TextField("First Name");
        tfFirstname.setRequired(true);
        form.addComponent(tfFirstname);

        TextField tfFamilyName = new TextField("Family Name");
        tfFamilyName.setRequired(true);
        form.addComponent(tfFamilyName);

        TextField tfEmail = new TextField("E-mail");
        tfEmail.setRequired(true);
        form.addComponent(tfEmail);

        Button btSave = new Button("Save and Proceed");

        
        btSave.addClickListener(new Button.ClickListener() {

            private static final long serialVersionUID = 1L;

            @Override
            public void buttonClick(ClickEvent event) {
                nav.navigateTo(VIEW_NAME_ADV);
            }
        });
        form.addComponent(btSave);
        
        layout.addComponent(form);
        
        
        
        return layout;
    }

    @WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
    @VaadinServletConfiguration(ui = BasicInformation.class, productionMode = false)
    public static class MyUIServlet extends VaadinServlet {

        /**
         * 
         */
        private static final long serialVersionUID = 1L;
    }

}



public class AdditionalInformation extends VerticalLayout implements View {

    private static final long serialVersionUID = 1578488973205488083L;
    
    public AdditionalInformation(){
        Label lbl = new Label("Whatever");
        addComponent(lbl);
        
    }
            
    @Override
    public void enter(ViewChangeListener.ViewChangeEvent event) {
        // TODO Auto-generated method stub
        
    }

}
2

You didn’t assign a view for the empty URI/view name/state

Add something like

nav.addView("", new AdditionalInformation()); or set a new start view during the UI.init() with

nav.getStateManager().setState(VIEW_NAME_ADV); But this will not prevent you from users that type in a wrong URI.
Therefore you should at least set an ErrorView which is the navigator’s fallback if no URI matches:

nav.setErrorView(VIEW_NAME_ADV);