2

I need to implement a dynamic menumodel. In the actionlistener, i need to call a backing bean method. When I add the actionListener to the menuItem I am getting an java.lang.InstantiationException. 

@ManagedBean(name = "sampleBean")  
@ViewScoped  
public class Sample1 implements Serializable {

private MenuModel model;

public Sample1() {
    model = new DefaultMenuModel();

    for(int i = 0; i < 3; i++){
        MenuItem item1 = new MenuItem();
        item1.setValue("test1" + i);
        item1.setAjax(false);
        item1.setId("item1" + i);
        item1.addActionListener(this.new MenuActionListener());
        model.addMenuItem(item1);
    }
}

// inner class action listener
class MenuActionListener implements ActionListener{
    @Override
    public void processAction(ActionEvent arg0) throws AbortProcessingException {
     System.out.println("test... " + arg0.getComponent().getClientId());
     test(arg0.getComponent().getClientId());   
    }
}

public void test(String test){
    System.out.println("tested..." + test); 
}

I have also tried using MethodExpressionActionListener. In this case the parameter passed "item1" is alays null. Please let me know on how I could pass a parameter in a methodExpression. 

for(int i = 0; i < 3; i++){
        MenuItem item1 = new MenuItem();
        item1.setValue("test1" + i);
        item1.setAjax(false);
        item1.setId("item1" + i);
        //item1.addActionListener(new MenuActionListener());
        ExpressionFactory factory = FacesContext.getCurrentInstance().getApplication().getExpressionFactory();
        ELContext elContext = FacesContext.getCurrentInstance().getELContext();
        MethodExpression expression = factory.createMethodExpression(elContext, "#{beanName.method(" + item1 + ")}", null, new Class[] {MenuItem.class});
        item1.addActionListener(new MethodExpressionActionListener(expression));
        model.addMenuItem(item1);
    }
4

1 に答える 1

0

Try to make the MenuActionListener a normal class instead of inner class

Also take a look at this Event Driven Programming with JSF

于 2012-10-17T18:07:27.623 に答える