How to run component created with Visual Designer?

General
1

I have created a simpile component, just a button on the screen, and I am trying to figure out how to run that component. I can run it directly so I modified the java class that was created when I created my product, and I still can not run it.

Component code generated with Visual Designer
/**
* The constructor should first build the main layout, set the
* composition root and then do any custom initialization.
*
* The constructor will not be automatically regenerated by the
* visual editor.
*/
public TestComp() {
buildMainLayout();
setCompositionRoot(mainLayout);

    // TODO add user code here
}

@AutoGenerated
private AbsoluteLayout buildMainLayout() {
    // common part: create layout
    mainLayout = new AbsoluteLayout();
    mainLayout.setImmediate(false);
    mainLayout.setWidth("100%");
    mainLayout.setHeight("100%");
    
    // top-level component properties
    setWidth("100.0%");
    setHeight("100.0%");
    
    // button_1
    button_1 = new Button();
    button_1.setCaption("Button");
    button_1.setImmediate(false);
    button_1.setWidth("-1px");
    button_1.setHeight("-1px");
    mainLayout.addComponent(button_1, "top:20.0px;left:20.0px;");
    
    return mainLayout;
}

}

Code generate when project create and then modified by me.

package com.example.testapp;

import javax.servlet.annotation.WebServlet;

import com.vaadin.annotations.Theme;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinServlet;
import com.vaadin.ui.Button;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Label;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;

@SuppressWarnings(“serial”)
@Theme(“testapp”)
public class TestappUI extends UI {

@WebServlet(value = "/*", asyncSupported = true)
@VaadinServletConfiguration(productionMode = false, ui = TestappUI.class)
public static class Servlet extends VaadinServlet {
}

@Override
protected void init(VaadinRequest request) {
    final VerticalLayout layout = new VerticalLayout();
    layout.setMargin(true);
    setContent(layout);
    
    TestComp test = new TestComp();
    layout.addComponent(test);

//
// Button button = new Button(“Click Me”);
// button.addClickListener(new Button.ClickListener() {
// public void buttonClick(ClickEvent event) {
// layout.addComponent(new Label(“Thank you for clicking”));
// }
// });
// layout.addComponent(button);
}

}

Any help you can give me would be appreicated.