Property 'dataSource' is required in Spring, Java

I just started learning Spring, and now I try to crate Spring JDBC based DAO application.
I created config class in this way

@Configuration
@ComponentScan("com.foxminded.university")
public class SpringJdbcConfig {

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("org.postgresql.Driver");
        dataSource.setUrl("jdbc:postgresql://127.0.0.1:5432/university");
        dataSource.setUsername("maintainer");
        dataSource.setPassword("12345678");
        return dataSource;
    }
 }

And dao-class uses this bean

@Component
public class BuildingDao implements Dao<Building> {
    
    @Autowired
    private DataSource dataSource;
    private final JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
    
    private static final String SAVE_BUILDING = "Insert into buildings (name, floors) values (?,?)";

    @Override
    public void save(Building building) {
        jdbcTemplate.update(SAVE_BUILDING, building.getName(), building.getFloors());
    }
}

But when I try to run this query i get

Exception in thread "main" java.lang.IllegalArgumentException: Property 'dataSource' is required

How I can fix it? As I can see, I use @Autowired incorrectly, because everything works fine when I use

    private DataSource dataSource = new SpringJdbcConfig().dataSource();

But it is extra relation and mistake in terms of IoC.

By the way in main I also have to use this in this way

public class Main {
    public static void main(String[] args) {
        Building building = new SpringJdbcConfig().building();
        building.setName("hghgf");
        building.setFloors(2);
        BuildingDao buildingDao = new SpringJdbcConfig().buildingDao();
        buildingDao.save(building);
    }
}

I would be very grateful if you could explain how to use @autowired correctly and inject beans into the main class.

I would suggest you to use spring boot to configure your application as below. This will initialize and auto-configure most of your needs.

@SpringBootApplication
@EnableAutoConfiguration
@ComponentScan("com.foxminded.university")
public class SpringBootWebApp {
  public static void main(String[] args) {
    ConfigurableApplicationContext context = SpringApplication.run(SpringBootWebApp.class, args);
    context.registerShutdownHook();
  }
}

After this, you can use @Autowire for all those spring managed beans you configure.

Write the ComponentScan attribute as follows and make sure SpringJdbcConfig class is under the package com.foxminded.university*

@ComponentScan(basePackages = "com.foxminded.university")