Question

I’m trying the following:

labelconfig.xhtml:

<h:form id="ok">
    <h:commandButton value="click">
        <f:ajax event="click" listener="#{canvasController.oeps}" /> 
    </h:commandButton>
</h:form>

And I’m trying to get it here:

CanvasController.java

@ManagedBean(name = "canvasController")
@SessionScoped
public class CanvasController

    public void oeps(AjaxBehaviorEvent event) {
        JOptionPane.showMessageDialog(null, "SUCCES3");
    }

}

But when I click the button, I get:

serverError: class java.awt.HeadlessException

How is this caused and how can I solve it?

Answer 1

You are trying to call Swing from server application without any desktop GUI. Instead of JOptionPane use logger or FacesContext.addMessage to get feedback. If for some reason you do want to control Swing app through JSF make sure DISPLAY etc are set but then I suggest rephrasing your question.