package com;
 
import com.pack.AtmEntity;
import com.pack.GroupAtmEntity;
 
import com.vaadin.annotations.Widgetset;
import com.vaadin.server.VaadinRequest;
import com.vaadin.ui.*;
import com.vaadin.v7.ui.TreeTable;
 
 
public class MyVaadinApplication extends UI {
 
 
    @Override
    public void init(VaadinRequest request) {
      GroupAtmEntity group = new GroupAtmEntity();
        group.setNameGroup("Кластер 1");
        group.setCost(0.0);
 
      AtmEntity atm1 = new AtmEntity();
        atm1.setCost(100.0);
        atm1.setNameAtm("Тест 1");
 
        AtmEntity atm2 = new AtmEntity();
        atm2.setCost(200.0);
        atm2.setNameAtm("Тест 2");
 
        VerticalLayout layout = new VerticalLayout();
        setContent(layout);
        
 
        TreeTable tree = new TreeTable();
        tree.addContainerProperty("Наименование", String.class, null);
        tree.addContainerProperty("Стоимость", Double.class, null);
        tree.addItem(new Object[]{group.getNameGroup(),group.getCost()},0);
        tree.addItem(new Object[]{atm1.getNameAtm(),atm1.getCost()},1);
        tree.addItem(new Object[]{atm2.getNameAtm(),atm2.getCost()},2);
        tree.setParent(0,1);
        tree.setParent(0,2);
        layout.addComponent(tree);
 
 
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <servlet>
        <servlet-name>VaadinApplicationServlet</servlet-name>
        <servlet-class>com.vaadin.server.VaadinServlet</servlet-class>
        <init-param>
            <param-name>UI</param-name>
            <param-value>com.MyVaadinApplication</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>VaadinApplicationServlet</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
 
</web-app>