get the component created in the table help

Hello:

on my table I have created a text field as follows


public class myTable extends Table implements ValueChangeListener {
	

	public myTable(MyApplication app) {

		setSizeFull();
		this.app = app;
		setStyleName(Reindeer.TABLE_STRONG);
		setSelectable(true);
		setImmediate(true);
		addListener((ValueChangeListener) this);
		//is column here create
          [b]
     addContainerProperty("Caracteristica",  TextField.class, null);
[/b]
		setNullSelectionAllowed(false);
		
	}

        my function generate textfield
     
      public void setCompTabla(){
		this.addGeneratedColumn("Caracteristica", new Table.ColumnGenerator() {
            	public Component generateCell(Table source, Object itemId,
                    Object columnId) {
                  VerticalLayout layout = new VerticalLayout();
                final TextField textField = new TextField();
                layout.addComponent(textField);
                return layout  ;
       }

work fine, but need reference using ValueChange in table

@Override
public void valueChange(com.vaadin.data.Property.ValueChangeEvent event) {
Item item = this.getItem(this.getValue());
//need reference textfield here ???

	}
}

help