Merge branch 'master' of https://github.com/JonCook/tutorials

vaadin/README.md

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+## Vaadin
+
+This module contains articles about Vaadin. 
+
+### Relevant articles:
+
+- [Introduction to Vaadin](https://www.baeldung.com/vaadin)
+- [Sample Application with Spring Boot and Vaadin](https://www.baeldung.com/spring-boot-vaadin)

vaadin/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>org.test</groupId>
+    <artifactId>vaadin</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <name>vaadin</name>
+    <packaging>war</packaging>
+
+    <parent>
+        <artifactId>parent-boot-2</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-boot-2</relativePath>
+    </parent>
+    
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>com.vaadin</groupId>
+                <artifactId>vaadin-bom</artifactId>
+                <version>${vaadin.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    
+    <dependencies>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-server</artifactId>
+            <version>${vaadin-server.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-push</artifactId>
+            <version>${vaadin-push.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-client-compiled</artifactId>
+            <version>${vaadin-client-compiled.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-themes</artifactId>
+            <version>${vaadin-themes.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-spring-boot-starter</artifactId>
+            <version>${vaadin-spring-boot-starter.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-war-plugin</artifactId>
+                <version>${maven-war-plugin.version}</version>
+                <configuration>
+                    <failOnMissingWebXml>false</failOnMissingWebXml>
+                    <!-- Exclude an unnecessary file generated by the GWT compiler. -->
+                    <packagingExcludes>WEB-INF/classes/VAADIN/widgetsets/WEB-INF/**</packagingExcludes>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>com.vaadin</groupId>
+                <artifactId>vaadin-maven-plugin</artifactId>
+                <version>${vaadin.plugin.version}</version>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-clean-plugin</artifactId>
+                <version>${maven-clean-plugin.version}</version>
+                <!-- Clean up also any pre-compiled themes -->
+                <configuration>
+                    <filesets>
+                        <fileset>
+                            <directory>src/main/webapp/VAADIN/themes</directory>
+                            <includes>
+                                <include>**/styles.css</include>
+                                <include>**/styles.scss.cache</include>
+                            </includes>
+                        </fileset>
+                    </filesets>
+                </configuration>
+            </plugin>
+            <!-- The Jetty plugin allows us to easily test the development build by running jetty:run on the command line. -->
+            <plugin>
+                <groupId>org.eclipse.jetty</groupId>
+                <artifactId>jetty-maven-plugin</artifactId>
+                <version>${jetty.plugin.version}</version>
+                <configuration>
+                    <scanIntervalSeconds>2</scanIntervalSeconds>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>vaadin-addons</id>
+            <url>http://maven.vaadin.com/vaadin-addons</url>
+        </repository>
+    </repositories>
+
+    <profiles>
+        <profile>
+            <!-- Vaadin pre-release repositories -->
+            <id>vaadin-prerelease</id>
+            <activation>
+                <activeByDefault>false</activeByDefault>
+            </activation>
+
+            <repositories>
+                <repository>
+                    <id>vaadin-prereleases</id>
+                    <url>http://maven.vaadin.com/vaadin-prereleases</url>
+                </repository>
+                <repository>
+                    <id>vaadin-snapshots</id>
+                    <url>https://oss.sonatype.org/content/repositories/vaadin-snapshots/</url>
+                    <releases>
+                        <enabled>false</enabled>
+                    </releases>
+                    <snapshots>
+                        <enabled>true</enabled>
+                    </snapshots>
+                </repository>
+            </repositories>
+            <pluginRepositories>
+                <pluginRepository>
+                    <id>vaadin-prereleases</id>
+                    <url>http://maven.vaadin.com/vaadin-prereleases</url>
+                </pluginRepository>
+                <pluginRepository>
+                    <id>vaadin-snapshots</id>
+                    <url>https://oss.sonatype.org/content/repositories/vaadin-snapshots/</url>
+                    <releases>
+                        <enabled>false</enabled>
+                    </releases>
+                    <snapshots>
+                        <enabled>true</enabled>
+                    </snapshots>
+                </pluginRepository>
+            </pluginRepositories>
+        </profile>
+    </profiles>
+
+    <properties>
+        <vaadin.version>13.0.9</vaadin.version>
+        <vaadin.plugin.version>13.0.9</vaadin.plugin.version>
+        <vaadin-spring-boot-starter.version>13.0.9</vaadin-spring-boot-starter.version>
+        <vaadin-server.version>8.8.5</vaadin-server.version>
+        <vaadin-push.version>8.8.5</vaadin-push.version>
+        <vaadin-client-compiled.version>8.8.5</vaadin-client-compiled.version>
+        <vaadin-themes.version>8.8.5</vaadin-themes.version>
+        <jetty.plugin.version>9.3.9.v20160517</jetty.plugin.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <vaadin.widgetset.mode>local</vaadin.widgetset.mode>
+        <vaadin.theme>mytheme</vaadin.theme>
+        <maven-clean-plugin.version>3.0.0</maven-clean-plugin.version>
+    </properties>
+
+</project>

vaadin/src/main/java/com/baeldung/Application.java

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+package com.baeldung;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class Application {
+
+    private static final Logger log = LoggerFactory.getLogger(Application.class);
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class);
+    }
+
+    @Bean
+    public CommandLineRunner loadData(EmployeeRepository repository) {
+        return (args) -> {
+            repository.save(new Employee("Bill", "Gates"));
+            repository.save(new Employee("Mark", "Zuckerberg"));
+            repository.save(new Employee("Sundar", "Pichai"));
+            repository.save(new Employee("Jeff", "Bezos"));
+        };
+    }
+}

vaadin/src/main/java/com/baeldung/Employee.java

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+package com.baeldung;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class Employee {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private String firstName;
+
+    private String lastName;
+
+    protected Employee() {
+    }
+
+    public Employee(String firstName, String lastName) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Employee[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
+    }
+
+}

vaadin/src/main/java/com/baeldung/EmployeeEditor.java

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+package com.baeldung;
+
+import com.vaadin.flow.component.Key;
+import com.vaadin.flow.component.KeyNotifier;
+import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.icon.VaadinIcon;
+import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
+import com.vaadin.flow.component.orderedlayout.VerticalLayout;
+import com.vaadin.flow.component.textfield.TextField;
+import com.vaadin.flow.data.binder.Binder;
+import com.vaadin.flow.spring.annotation.SpringComponent;
+import com.vaadin.flow.spring.annotation.UIScope;
+import org.springframework.beans.factory.annotation.Autowired;
+
+@SpringComponent
+@UIScope
+public class EmployeeEditor extends VerticalLayout implements KeyNotifier {
+
+    private final EmployeeRepository repository;
+
+    private Employee employee;
+
+    TextField firstName = new TextField("First name");
+    TextField lastName = new TextField("Last name");
+
+    Button save = new Button("Save", VaadinIcon.CHECK.create());
+    Button cancel = new Button("Cancel");
+    Button delete = new Button("Delete", VaadinIcon.TRASH.create());
+    HorizontalLayout actions = new HorizontalLayout(save, cancel, delete);
+
+    Binder<Employee> binder = new Binder<>(Employee.class);
+    private ChangeHandler changeHandler;
+
+    @Autowired
+    public EmployeeEditor(EmployeeRepository repository) {
+        this.repository = repository;
+
+        add(firstName, lastName, actions);
+
+        binder.bindInstanceFields(this);
+
+        setSpacing(true);
+
+        save.getElement().getThemeList().add("primary");
+        delete.getElement().getThemeList().add("error");
+
+        addKeyPressListener(Key.ENTER, e -> save());
+
+        save.addClickListener(e -> save());
+        delete.addClickListener(e -> delete());
+        cancel.addClickListener(e -> editEmployee(employee));
+        setVisible(false);
+    }
+
+    void delete() {
+        repository.delete(employee);
+        changeHandler.onChange();
+    }
+
+    void save() {
+        repository.save(employee);
+        changeHandler.onChange();
+    }
+
+    public interface ChangeHandler {
+        void onChange();
+    }
+
+    public final void editEmployee(Employee c) {
+        if (c == null) {
+            setVisible(false);
+            return;
+        }
+        final boolean persisted = c.getId() != null;
+        if (persisted) {
+            employee = repository.findById(c.getId()).get();
+        } else {
+            employee = c;
+        }
+
+        cancel.setVisible(persisted);
+        binder.setBean(employee);
+        setVisible(true);
+        firstName.focus();
+    }
+
+    public void setChangeHandler(ChangeHandler h) {
+        changeHandler = h;
+    }
+}

vaadin/src/main/java/com/baeldung/EmployeeRepository.java

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+package com.baeldung;
+
+import java.util.List;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface EmployeeRepository extends JpaRepository<Employee, Long> {
+
+    List<Employee> findByLastNameStartsWithIgnoreCase(String lastName);
+}

vaadin/src/main/java/com/baeldung/MainView.java

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+package com.baeldung;
+
+import org.springframework.util.StringUtils;
+
+import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.grid.Grid;
+import com.vaadin.flow.component.icon.VaadinIcon;
+import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
+import com.vaadin.flow.component.orderedlayout.VerticalLayout;
+import com.vaadin.flow.component.textfield.TextField;
+import com.vaadin.flow.data.value.ValueChangeMode;
+import com.vaadin.flow.router.Route;
+
+@Route
+public class MainView extends VerticalLayout {
+
+    private final EmployeeRepository employeeRepository;
+
+    private final EmployeeEditor editor;
+
+    final Grid<Employee> grid;
+
+    final TextField filter;
+
+    private final Button addNewBtn;
+
+    public MainView(EmployeeRepository repo, EmployeeEditor editor) {
+        this.employeeRepository = repo;
+        this.editor = editor;
+        this.grid = new Grid<>(Employee.class);
+        this.filter = new TextField();
+        this.addNewBtn = new Button("New employee", VaadinIcon.PLUS.create());
+
+        HorizontalLayout actions = new HorizontalLayout(filter, addNewBtn);
+        add(actions, grid, editor);
+
+        grid.setHeight("200px");
+        grid.setColumns("id", "firstName", "lastName");
+        grid.getColumnByKey("id").setWidth("50px").setFlexGrow(0);
+
+        filter.setPlaceholder("Filter by last name");
+
+        filter.setValueChangeMode(ValueChangeMode.EAGER);
+        filter.addValueChangeListener(e -> listEmployees(e.getValue()));
+
+        grid.asSingleSelect().addValueChangeListener(e -> {
+            editor.editEmployee(e.getValue());
+        });
+
+        addNewBtn.addClickListener(e -> editor.editEmployee(new Employee("", "")));
+
+        editor.setChangeHandler(() -> {
+            editor.setVisible(false);
+            listEmployees(filter.getValue());
+        });
+
+        listEmployees(null);
+    }
+
+    void listEmployees(String filterText) {
+        if (StringUtils.isEmpty(filterText)) {
+            grid.setItems(employeeRepository.findAll());
+        } else {
+            grid.setItems(employeeRepository.findByLastNameStartsWithIgnoreCase(filterText));
+        }
+    }
+}

vaadin/src/main/java/com/baeldung/introduction/BindData.java

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+package com.baeldung.introduction;
+
+public class BindData {
+
+    private String bindName;
+
+    public BindData(String bindName){
+            this.bindName = bindName;
+    }
+    
+    public String getBindName() {
+            return bindName;
+    }
+
+    public void setBindName(String bindName) {
+            this.bindName = bindName;
+    }
+
+    
+}

vaadin/src/main/java/com/baeldung/introduction/Row.java

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+package com.baeldung.introduction;
+
+public class Row {
+    
+    private String column1;
+    
+    private String column2;
+
+    private String column3;
+    
+    public Row() {
+       
+    }
+
+    public Row(String column1, String column2, String column3) {
+        super();
+        this.column1 = column1;
+        this.column2 = column2;
+        this.column3 = column3;
+    }
+
+    public String getColumn1() {
+        return column1;
+    }
+
+    public void setColumn1(String column1) {
+        this.column1 = column1;
+    }
+
+    public String getColumn2() {
+        return column2;
+    }
+
+    public void setColumn2(String column2) {
+        this.column2 = column2;
+    }
+
+    public String getColumn3() {
+        return column3;
+    }
+
+    public void setColumn3(String column3) {
+        this.column3 = column3;
+    }    
+}

vaadin/src/main/java/com/baeldung/introduction/VaadinUI.java

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+package com.baeldung.introduction;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import javax.servlet.annotation.WebServlet;
+
+import com.vaadin.annotations.Push;
+import com.vaadin.annotations.Theme;
+import com.vaadin.annotations.VaadinServletConfiguration;
+import com.vaadin.data.Binder;
+import com.vaadin.data.validator.StringLengthValidator;
+import com.vaadin.icons.VaadinIcons;
+import com.vaadin.server.ExternalResource;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.server.VaadinServlet;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.CheckBox;
+import com.vaadin.ui.ComboBox;
+import com.vaadin.ui.DateField;
+import com.vaadin.ui.FormLayout;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.GridLayout;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.InlineDateField;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.Link;
+import com.vaadin.ui.ListSelect;
+import com.vaadin.ui.NativeButton;
+import com.vaadin.ui.NativeSelect;
+import com.vaadin.ui.Panel;
+import com.vaadin.ui.PasswordField;
+import com.vaadin.ui.RichTextArea;
+import com.vaadin.ui.TextArea;
+import com.vaadin.ui.TextField;
+import com.vaadin.ui.TwinColSelect;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.VerticalLayout;
+
+@SuppressWarnings("serial")
+@Push
+@Theme("mytheme")
+public class VaadinUI extends UI {
+
+    private Label currentTime;
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @Override
+    protected void init(VaadinRequest vaadinRequest) {
+        final VerticalLayout verticalLayout = new VerticalLayout();
+        verticalLayout.setSpacing(true);
+        verticalLayout.setMargin(true);
+        final GridLayout gridLayout = new GridLayout(3, 2);
+        gridLayout.setSpacing(true);
+        gridLayout.setMargin(true);
+        final HorizontalLayout horizontalLayout = new HorizontalLayout();
+        horizontalLayout.setSpacing(true);
+        horizontalLayout.setMargin(true);
+        final FormLayout formLayout = new FormLayout();
+        formLayout.setSpacing(true);
+        formLayout.setMargin(true);
+        final GridLayout buttonLayout = new GridLayout(3, 5);
+        buttonLayout.setMargin(true);
+        buttonLayout.setSpacing(true);
+
+        final Label label = new Label();
+        label.setId("Label");
+        label.setValue("Label Value");
+        label.setCaption("Label");
+        gridLayout.addComponent(label);
+
+        final Link link = new Link("Baeldung", new ExternalResource("http://www.baeldung.com/"));
+        link.setId("Link");
+        link.setTargetName("_blank");
+        gridLayout.addComponent(link);
+
+        final TextField textField = new TextField();
+        textField.setId("TextField");
+        textField.setCaption("TextField:");
+        textField.setValue("TextField Value");
+        textField.setIcon(VaadinIcons.USER);
+        gridLayout.addComponent(textField);
+
+        final TextArea textArea = new TextArea();
+        textArea.setCaption("TextArea");
+        textArea.setId("TextArea");
+        textArea.setValue("TextArea Value");
+        gridLayout.addComponent(textArea);
+
+        final DateField dateField = new DateField("DateField", LocalDate.ofEpochDay(0));
+        dateField.setId("DateField");
+        gridLayout.addComponent(dateField);
+
+        final PasswordField passwordField = new PasswordField();
+        passwordField.setId("PasswordField");
+        passwordField.setCaption("PasswordField:");
+        passwordField.setValue("password");
+        gridLayout.addComponent(passwordField);
+
+        final RichTextArea richTextArea = new RichTextArea();
+        richTextArea.setCaption("Rich Text Area");
+        richTextArea.setValue("<h1>RichTextArea</h1>");
+        richTextArea.setSizeFull();
+
+        Panel richTextPanel = new Panel();
+        richTextPanel.setContent(richTextArea);
+
+        final InlineDateField inlineDateField = new InlineDateField();
+        inlineDateField.setValue(LocalDate.ofEpochDay(0));
+        inlineDateField.setCaption("Inline Date Field");
+        horizontalLayout.addComponent(inlineDateField);
+
+        Button normalButton = new Button("Normal Button");
+        normalButton.setId("NormalButton");
+        normalButton.addClickListener(e -> {
+            label.setValue("CLICK");
+        });
+        buttonLayout.addComponent(normalButton);
+
+        Button tinyButton = new Button("Tiny Button");
+        tinyButton.addStyleName("tiny");
+        buttonLayout.addComponent(tinyButton);
+
+        Button smallButton = new Button("Small Button");
+        smallButton.addStyleName("small");
+        buttonLayout.addComponent(smallButton);
+
+        Button largeButton = new Button("Large Button");
+        largeButton.addStyleName("large");
+        buttonLayout.addComponent(largeButton);
+
+        Button hugeButton = new Button("Huge Button");
+        hugeButton.addStyleName("huge");
+        buttonLayout.addComponent(hugeButton);
+
+        Button disabledButton = new Button("Disabled Button");
+        disabledButton.setDescription("This button cannot be clicked");
+        disabledButton.setEnabled(false);
+        buttonLayout.addComponent(disabledButton);
+
+        Button dangerButton = new Button("Danger Button");
+        dangerButton.addStyleName("danger");
+        buttonLayout.addComponent(dangerButton);
+
+        Button friendlyButton = new Button("Friendly Button");
+        friendlyButton.addStyleName("friendly");
+        buttonLayout.addComponent(friendlyButton);
+
+        Button primaryButton = new Button("Primary Button");
+        primaryButton.addStyleName("primary");
+        buttonLayout.addComponent(primaryButton);
+
+        NativeButton nativeButton = new NativeButton("Native Button");
+        buttonLayout.addComponent(nativeButton);
+
+        Button iconButton = new Button("Icon Button");
+        iconButton.setIcon(VaadinIcons.ALIGN_LEFT);
+        buttonLayout.addComponent(iconButton);
+
+        Button borderlessButton = new Button("BorderLess Button");
+        borderlessButton.addStyleName("borderless");
+        buttonLayout.addComponent(borderlessButton);
+
+        Button linkButton = new Button("Link Button");
+        linkButton.addStyleName("link");
+        buttonLayout.addComponent(linkButton);
+
+        Button quietButton = new Button("Quiet Button");
+        quietButton.addStyleName("quiet");
+        buttonLayout.addComponent(quietButton);
+
+        horizontalLayout.addComponent(buttonLayout);
+
+        final CheckBox checkbox = new CheckBox("CheckBox");
+        checkbox.setValue(true);
+        checkbox.addValueChangeListener(e -> checkbox.setValue(!checkbox.getValue()));
+        formLayout.addComponent(checkbox);
+
+        List<String> numbers = new ArrayList<String>();
+        numbers.add("One");
+        numbers.add("Ten");
+        numbers.add("Eleven");
+        ComboBox comboBox = new ComboBox("ComboBox");
+        comboBox.setItems(numbers);
+        formLayout.addComponent(comboBox);
+
+        ListSelect listSelect = new ListSelect("ListSelect");
+        listSelect.setItems(numbers);
+        listSelect.setRows(2);
+        formLayout.addComponent(listSelect);
+
+        NativeSelect nativeSelect = new NativeSelect("NativeSelect");
+        nativeSelect.setItems(numbers);
+        formLayout.addComponent(nativeSelect);
+
+        TwinColSelect twinColSelect = new TwinColSelect("TwinColSelect");
+        twinColSelect.setItems(numbers);
+
+        Grid<Row> grid = new Grid(Row.class);
+        grid.setColumns("column1", "column2", "column3");
+        Row row1 = new Row("Item1", "Item2", "Item3");
+        Row row2 = new Row("Item4", "Item5", "Item6");
+        List<Row> rows = new ArrayList();
+        rows.add(row1);
+        rows.add(row2);
+        grid.setItems(rows);
+
+        Panel panel = new Panel("Panel");
+        panel.setContent(grid);
+        panel.setSizeUndefined();
+
+        Panel serverPushPanel = new Panel("Server Push");
+        FormLayout timeLayout = new FormLayout();
+        timeLayout.setSpacing(true);
+        timeLayout.setMargin(true);
+        currentTime = new Label("No TIME...");
+        timeLayout.addComponent(currentTime);
+        serverPushPanel.setContent(timeLayout);
+        serverPushPanel.setSizeUndefined();
+        ScheduledExecutorService scheduleExecutor = Executors.newScheduledThreadPool(1);
+        Runnable task = () -> {
+            currentTime.setValue("Current Time : " + Instant.now());
+        };
+        scheduleExecutor.scheduleWithFixedDelay(task, 0, 1, TimeUnit.SECONDS);
+
+        FormLayout dataBindingLayout = new FormLayout();
+        dataBindingLayout.setSpacing(true);
+        dataBindingLayout.setMargin(true);
+
+        Binder<BindData> binder = new Binder<>();
+        BindData bindData = new BindData("BindData");
+        binder.readBean(bindData);
+        TextField bindedTextField = new TextField();
+        bindedTextField.setWidth("250px");
+        binder.forField(bindedTextField).bind(BindData::getBindName, BindData::setBindName);
+        dataBindingLayout.addComponent(bindedTextField);
+
+        FormLayout validatorLayout = new FormLayout();
+        validatorLayout.setSpacing(true);
+        validatorLayout.setMargin(true);
+
+        HorizontalLayout textValidatorLayout = new HorizontalLayout();
+        textValidatorLayout.setSpacing(true);
+        textValidatorLayout.setMargin(true);
+
+        
+        BindData stringValidatorBindData = new BindData("");
+        TextField stringValidator = new TextField();
+        Binder<BindData> stringValidatorBinder = new Binder<>();
+        stringValidatorBinder.setBean(stringValidatorBindData);
+        stringValidatorBinder.forField(stringValidator)
+        .withValidator(new StringLengthValidator("String must have 2-5 characters lenght", 2, 5))
+        .bind(BindData::getBindName, BindData::setBindName);
+        
+        textValidatorLayout.addComponent(stringValidator);
+        Button buttonStringValidator = new Button("Validate String");
+        buttonStringValidator.addClickListener(e -> stringValidatorBinder.validate());
+        textValidatorLayout.addComponent(buttonStringValidator);
+
+        validatorLayout.addComponent(textValidatorLayout);
+        verticalLayout.addComponent(gridLayout);
+        verticalLayout.addComponent(richTextPanel);
+        verticalLayout.addComponent(horizontalLayout);
+        verticalLayout.addComponent(formLayout);
+        verticalLayout.addComponent(twinColSelect);
+        verticalLayout.addComponent(panel);
+        verticalLayout.addComponent(serverPushPanel);
+        verticalLayout.addComponent(dataBindingLayout);
+        verticalLayout.addComponent(validatorLayout);
+        setContent(verticalLayout);
+    }
+
+    @WebServlet(urlPatterns = "/VAADIN/*", name = "MyUIServlet", asyncSupported = true)
+    @VaadinServletConfiguration(ui = VaadinUI.class, productionMode = false)
+    public static class MyUIServlet extends VaadinServlet {
+    }
+}

vaadin/src/main/resources/README

@@ -0,0 +1 @@
+Please add your static resources here

vaadin/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+#Vaadin supports spring-boot 2.1 properly from V8 onwards (according to this comment https://github.com/vaadin/spring/issues/331#issuecomment-435128475)
+spring.main.allow-bean-definition-overriding=true

vaadin/src/main/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

vaadin/src/main/webapp/VAADIN/themes/mytheme/addons.scss

@@ -0,0 +1,7 @@
+/* This file is automatically managed and will be overwritten from time to time. */
+/* Do not manually edit this file. */
+
+/* Import and include this mixin into your project theme to include the addon themes */
+@mixin addons {
+}
+

vaadin/src/main/webapp/VAADIN/themes/mytheme/mytheme.scss

@@ -0,0 +1,38 @@
+// If you edit this file you need to compile the theme. See README.md for details.
+
+// Global variable overrides. Must be declared before importing Valo.
+
+// Defines the plaintext font size, weight and family. Font size affects general component sizing.
+//$v-font-size: 16px;
+//$v-font-weight: 300;
+//$v-font-family: "Open Sans", sans-serif;
+
+// Defines the border used by all components.
+//$v-border: 1px solid (v-shade 0.7);
+//$v-border-radius: 4px;
+
+// Affects the color of some component elements, e.g Button, Panel title, etc
+//$v-background-color: hsl(210, 0%, 98%);
+// Affects the color of content areas, e.g  Panel and Window content, TextField input etc
+//$v-app-background-color: $v-background-color;
+
+// Affects the visual appearance of all components
+//$v-gradient: v-linear 8%;
+//$v-bevel-depth: 30%;
+//$v-shadow-opacity: 5%;
+
+// Defines colors for indicating status (focus, success, failure)
+//$v-focus-color: valo-focus-color(); // Calculates a suitable color automatically
+//$v-friendly-color: #2c9720;
+//$v-error-indicator-color: #ed473b;
+
+// For more information, see: https://vaadin.com/book/-/page/themes.valo.html
+// Example variants can be copy/pasted from https://vaadin.com/wiki/-/wiki/Main/Valo+Examples
+
+@import "../valo/valo.scss";
+
+@mixin mytheme {
+  @include valo;
+
+  // Insert your own theme rules here
+}

vaadin/src/main/webapp/VAADIN/themes/mytheme/styles.scss

@@ -0,0 +1,11 @@
+@import "mytheme.scss";
+@import "addons.scss";
+
+// This file prefixes all rules with the theme name to avoid causing conflicts with other themes.
+// The actual styles should be defined in mytheme.scss
+
+.mytheme {
+  @include addons;
+  @include mytheme;
+
+}