[Vaadin/Spring Boot] Problema con service

[fermat]

ciao!

sostanzialmente ho questo problema con spring boot, anche sto usando vaadin:

There was an exception while trying to navigate to '' with the root cause 'java.lang.NullPointerException: Cannot invoke "org.vaadin.example.services.PersonaService.getAll()" because "this.personaService" is null'

ho aggiungo nell'application proberties la connessione.
ho installato queste due dipendenze:

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>


    <dependency>
      <groupId>com.mysql</groupId>
      <artifactId>mysql-connector-j</artifactId>
      <scope>runtime</scope>
    </dependency>

questo il mio service:

package org.vaadin.example.services;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;
import org.vaadin.example.entities.Persona;


import java.util.ArrayList;
import java.util.List;


@Service
public class PersonaService {


  @Autowired
  private JdbcTemplate jdbcTemplate;


  public List<Persona> getAll() {
    try {
      return jdbcTemplate.query(
          "SELECT * FROM persone",
          (rs, rowNum) -> new Persona(
              rs.getInt("id"),
              rs.getString("noma"),
              rs.getString("email")
          )
      );
    } catch (Exception e) {
      return new ArrayList<>();
    }
  }


}

e poi nel controller:

package org.vaadin.example;


import com.vaadin.flow.component.grid.Grid;
import com.vaadin.flow.component.grid.GridVariant;
import com.vaadin.flow.component.grid.dataview.GridListDataView;
import com.vaadin.flow.component.html.Div;
import com.vaadin.flow.component.orderedlayout.FlexComponent.Alignment;
import com.vaadin.flow.component.html.Span;
import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
import com.vaadin.flow.data.renderer.ComponentRenderer;
import com.vaadin.flow.router.Route;
import org.springframework.beans.factory.annotation.Autowired;
import org.vaadin.example.entities.Persona;
import org.vaadin.example.services.PersonaService;


@Route
public class MainView extends Div {


  private Grid<Persona> grid;


  @Autowired
  private PersonaService personaService;


  public MainView() {
    createGrid();
    add(grid);
  }


  private void createGrid() {
    grid = new Grid<>();
    grid.addThemeVariants(GridVariant.LUMO_NO_BORDER, GridVariant.LUMO_COLUMN_BORDERS);
    grid.setHeight("100%");
    grid.setItems(personaService.getAll());


	..............
  }




}

ma non riesco a capire il perchè di quell'errore!