我想了解并看到为我的服务层创建单元测试的最简单的方法。我已经研究了几天最简单的方法，但不幸的是，我仍然没有找到适合我的特定代码的解决方案。我尝试自己编写测试很多次，但人们告诉我，代码可以做得更好。提前感谢您。
我的实体：

@Entity
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@ToString
@Builder
@Table
public class Appointment {

    @Id
    @SequenceGenerator(
            name = "appointment_sequence",
            sequenceName = "appointment_sequence",
            allocationSize = 1
    )
    @GeneratedValue(
            strategy = GenerationType.SEQUENCE,
            generator = "appointment_sequence"
    )
    private Long appointmentId;
    @Column(
            name = "date_of_appointment",
            nullable = false
    )
    private LocalDate dateOfAppointment;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(
            name = "patient_id",
            referencedColumnName = "patientId"
    )
    private Patient patient;

    public void connectWithPatient(Patient patient) {
        this.patient = patient;
    }
}

我的存储库：

public interface AppointmentRepository extends JpaRepository<Appointment, Long> {
}

我的服务：

@Service
public class AppointmentService implements AppointmentServiceInterface {

    private final AppointmentRepository appointmentRepository;
    private final PatientRepository patientRepository;

    @Autowired
    public AppointmentService(AppointmentRepository appointmentRepository, PatientRepository patientRepository) {
        this.appointmentRepository = appointmentRepository;
        this.patientRepository = patientRepository;
    }

    @Override
    public List<Appointment> getAllAppointments() {
        return appointmentRepository.findAll();
    }

    @Override
    public ResponseEntity<Appointment> getAppointmentById(Long appointmentId) {
        Appointment appointment = appointmentRepository.findById(appointmentId)
                .orElseThrow(()-> new ResourceNotFoundException("Appointment with id " + appointmentId + " doesn't exist."));
        return ResponseEntity.ok(appointment);
    }

    @Override
    public Appointment createNewAppointment(Appointment appointment) {
        return appointmentRepository.save(appointment);
    }

    @Override
    public ResponseEntity<Appointment> updateAppointment(Long appointmentId, Appointment appointmentUpdatedDetails) {
        Appointment updatedAppointment = appointmentRepository.findById(appointmentId)
                .orElseThrow(()-> new ResourceNotFoundException("Appointment with id " + appointmentId + " doesn't exist."));
        updatedAppointment.setDateOfAppointment(appointmentUpdatedDetails.getDateOfAppointment());
        appointmentRepository.save(updatedAppointment);
        return ResponseEntity.ok(updatedAppointment);
    }

    @Override
    public ResponseEntity<Appointment> deleteAppointment(Long appointmentId) {
        Appointment appointment = appointmentRepository.findById(appointmentId)
                .orElseThrow(()-> new ResourceNotFoundException("Appointment with id " + appointmentId + " doesn't exist."));
        appointmentRepository.delete(appointment);
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    }

    @Override
    public Appointment makeAppointmentWithPatient(Long appointmentId, Long patientId) {
        Appointment appointment = appointmentRepository.findById(appointmentId)
                .orElseThrow(()-> new ResourceNotFoundException("Appointment with id " + appointmentId + " doesn't exist."));
        Patient patient = patientRepository.findById(patientId)
                .orElseThrow(()-> new ResourceNotFoundException("Patient with id " + patientId + " doesn't exist."));
        appointment.connectWithPatient(patient);
        return appointmentRepository.save(appointment);
    }
}