vaadin Getting started with vaadin First program - "Hello World"

Example

Copy paste this code and launch your program :

@Theme(ValoTheme.THEME_NAME) //[optional] adds Vaadin built in theming 
public class SampleUI extends UI {
    
@Override
protected void init(VaadinRequest request) {
         final VerticalLayout rootLayout = new VerticalLayout();
         Label label = new Label("Hello World"!);
         rootLayout.addComponent(label);
         setContent(rootLayout);
     }
 }

After lauching was successful, please navigate to localhost:8080/yourApplicationName or http://localhost:8080/ to see your app is up and running.