autowired annotation in spring nullpointerexception code example

Example 1: NullpointerException while autowire

@Controller
public class Controller {

  @Autowired
  MyService service;

  @GetMapping("/example")
  public String example() {
    service.doStuff();
  }
}

@Service
public class MyService() {

  @Autowired
  MyRepository repo;

  public void doStuff() {
    repo.findByName( "steve" );
  }
}

@Repository
public interface MyRepository extends CrudRepository<My, Long> {

  List<My> findByName( String name );
}

Example 2: NullpointerException while autowire

@Controller
public class Controller {

  @GetMapping("/example")
  public String example() {
    MyService my = new MyService();
    my.doStuff();
  }
}

@Service
public class MyService() {

  @Autowired
  MyRepository repo;

  public void doStuff() {
    repo.findByName( "steve" );
  }
}

 

@Repository
public interface MyRepository extends CrudRepository<My, Long> {

  List<My> findByName( String name );
}