Problem with lazy initialization in inhereted class

Question

Hi. I have a strange problem. I have 2 classes CMRCommandInputPanel (view ) , class CommandInputFieldsModel (view's model) and 2 classes that inherets from them: CMRDerivitiveCommandInputPanel and DerivativeCommandInputFieldsModel.
the Views looks like:
public class FormPanel extends JPanel {
    protected AbstractFormDataModel mFormModel = null;
    public FormPanel(AbstractFormDataModel formModel) {
        super();
        initialize(formModel);
    private void initialize(AbstractFormDataModel formModel) {
        mFormModel = formModel;
public class CMRCommandInputPanel extends FormPanel {
     public CMRCommandInputPanel(AbstractFormDataModel formModel) {
          super(formModel);
          initialize();
     private void initialize() {
          initLocalModels();
        JPanel mainPanel =  new JPanel () ;
         mainPanel.setLayout(new BorderLayout());
        mainPanel.add(getUpperButtonsPanel(), BorderLayout.NORTH);
        mainPanel.add(getFormPanel(), BorderLayout.CENTER);
        mainPanel.add(getDownButtonsPanelDefault(), BorderLayout.SOUTH);
        mainPanel.addMouseListener(new MouseAdapter(){
            public void mouseClicked(MouseEvent e) {
                 // set focus on the formPanel in order to set the entered value on mouse click.
                    getFormPanel().requestFocus();
        this.setLayout(new BorderLayout());
        this.add(mainPanel);
        this.setBorder(UIConstants.DEFAULT_PANEL_BORDER);
     protected CMRPanel getFormPanel() {
          if (mFormPanel == null) {
                adding editable TextFields to the panel.
         return mFormPanel;
     protected void initLocalModels(){
          new CommandInputFieldsModel(mFormModel,this);
public class CMRDerivitiveCommandInputPanel extends CMRCommandInputPanel {
     private JTitledTextField mRealizationPriceField = null;
     public CMRDerivitiveCommandInputPanel(AbstractFormDataModel formModel) {
          super(formModel);
// override of  super method
     protected CMRPanel getFormPanel() {
          if (mFormPanel == null) {
                adding super classes  editable TextFields to the panel and some new ones
          return mFormPanel;
     /* (non-Javadoc)
      * @see cmr.client.ui.CMRCommandInputPanel#initLocalModels()
     protected void initLocalModels() {
          new DerivativeCommandInputFieldsModel(mFormModel,this);
     public JTextField getRealizationDateField() {
          if (mRealizationDateField == null) {
               mRealizationDateField = new JTextField();
          return mRealizationDateField;
public class CommandInputFieldsModel extends AbstractFieldsDataModel {
     protected CMRCommonDataModel mFormModel = null;
     protected CMRCommandInputPanel mView = null;
     public CommandInputFieldsModel(CMRCommonDataModel data,CMRCommandInputPanel aView){
          mFormModel = data;
          mView = aView;
          mFormModel.registryModel(this,ExBaseDataController.META_KEY);
          mFormModel.registryModel(this,CompanyMessagesController.META_KEY);
          mFormModel.registryModel(this,DefaultFinancialValueController.META_KEY);
          mFormModel.registryModel(this,QuantityValueController.META_KEY);
          mFormModel.registryModel(this,RateForPercentController.META_KEY);
     /* (non-Javadoc)
      * @see cmr.client.ui.data.CMRUpdatable#updateData(java.lang.Object)
     public void updateData(Object aNewData) {
            updating relevant fields by using getters of View
public class DerivativeCommandInputFieldsModel extends CommandInputFieldsModel {
     public DerivativeCommandInputFieldsModel(CMRCommonDataModel data,CMRDerivitiveCommandInputPanel aView){
          super(data,aView);
     /* (non-Javadoc)
      * @see cmr.client.ui.data.CMRUpdatable#updateData(java.lang.Object)
     public void updateData(Object aNewData) {
          if (aNewData instanceof RealizationData){
               RealizationData realizationData =  (RealizationData)aNewData;
               CMRDerivitiveCommandInputPanel theView = (CMRDerivitiveCommandInputPanel)mView;
               theView.getRealizationDateField().setValue(realizationData.getRealizationDate());
               theView.getRealizationPriceField().setValue(realizationData.getRealizationPrice());
          }else
               super.updateData(aNewData);
}The problem is , that when the field's getter of inhereted view's class is called from model for updating field,the fields are beeing initialized for second time. they simply somehow are equal to NULL again. I've checked reference to the view and it's the same,but only new fields still equals to NULL from model.
is someone can help me with that?

Answer 1

The only thing that springs to mind is that you're
exporting the newly created fields model object in
the superclass constructor (at least I assume that's
what the registry calls do).
That can cause problems, especially in a
multi-threaded environment (though it's often
tempting). Again there's a risk that the
partly-initialized object may be used.
Actually this is a bit of a weakness of Java as
opposed to C++. In C++ a new object has the virtual
method table set to the superclass VMT during
superclass initialisation. In Java it acquires its
ultimate class indentity immediately.
You'd be safer to extract all that kind of stuff from
the superclass constructor and have some kind of
init() method called after the object was
constructed.
In fact whenever you see a new whose result
you don't do anything with, then you should take it
as a warning.thank you for your replies. ;) I've managed to solve this matter. Simply fully redefined my panel with fields in child-class and added to it's constructor local initialization() method as well, which creates UI of child-class. Even that I initialize UI twice, but all fields are initialized with "lazy initialization" , so there is only once NEW will be called. but there is something weird going in constructors with ovverwritten methods.