[FIXED] Added Vaadin to Java Spring project in IntelliJ and getting build error with add()

Issue

I have created a new project with Spring Initializr:

• Project: Gradle Project
• Language: Java
• Spring Boot: 2.7.4
• Packaging: JAR
• Java: 8
• Dependencies: Spring Boot Actuator, Spring Data JPA, Spring Web, H2 Database, PostgresSQL Driver, Spring Configuration Processor

After this I added some code to be able to interact with REST APIs (GET & POST). I was able to build, run, & test the project.

The next step was add Vaading, so I did the following:

• Created a new package "views.main" package under the source section.

• Added a MainView.java class with the following contents:

  package io.enfuse.demo.fundemo.views.main;
  
  import com.vaadin.flow.component.Key;
  import com.vaadin.flow.component.button.Button;
  import com.vaadin.flow.component.checkbox.Checkbox;
  import com.vaadin.flow.component.html.H1;
  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.router.Route;
  
  @Route("")
  public class MainView {
      public MainView() {
          VerticalLayout todosList = new VerticalLayout();
          TextField taskField = new TextField();
          Button addButton = new Button("Add");
          addButton.addClickListener(click -> {
              Checkbox checkbox = new Checkbox(taskField.getValue());
              todosList.add(checkbox);
          });
          addButton.addClickShortcut(Key.ENTER);
  
          add(
                  new H1("Vaadin Todo"),
                  todosList,
                  new HorizontalLayout(
                          taskField,
                          addButton
                  )
          );
      }
  }
  

  • I also updated the build.gradle file to include Vaadin items:

  plugins {
      id 'org.springframework.boot' version '2.7.4'
      id 'io.spring.dependency-management' version '1.0.14.RELEASE'
      id 'com.vaadin' version '23.2.1'
      id 'java'
  }
  
  group = 'io.enfuse.demo'
  version = '0.0.1-SNAPSHOT'
  sourceCompatibility = '1.8'
  
  configurations {
      compileOnly {
          extendsFrom annotationProcessor
      }
  }
  
  repositories {
      mavenCentral()
  }
  
  ext {
      set('vaadinVersion', "23.2.1")
  }
  
  dependencies {
      implementation 'org.springframework.boot:spring-boot-starter-actuator'
      implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
      implementation 'org.springframework.boot:spring-boot-starter-web'
      implementation 'com.vaadin:vaadin-spring-boot-starter'
      runtimeOnly 'com.h2database:h2'
      runtimeOnly 'org.postgresql:postgresql'
      annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
      testImplementation 'org.springframework.boot:spring-boot-starter-test'
  }
  
  dependencyManagement {
      imports {
          mavenBom "com.vaadin:vaadin-bom:${vaadinVersion}"
      }
  }
  
  tasks.named('test') {
      useJUnitPlatform()
  }
  
  

• Restart IntelliJ

At this point when I go to build I get the following error:

```
    C:\Temp\fundemo_v2\fundemo\src\main\java\io\enfuse\demo\fundemo\views\main\MainView.java:24: error: cannot find symbol
            add(
            ^
      symbol:   method add(H1,VerticalLayout,HorizontalLayout)
      location: class MainView
```

I can look at the dependecies that show Vaadin is included:

What is missing exactly is not setup correctly?

Solution

Your MainView does not extend a Vaadin component and that's why there is no add method.

Try this:

public class MainView extends Div() {

Answered By - Simon Martinelli
Answer Checked By - Robin (JavaFixing Admin)