Software Architecture in Java: Design & Development/

...

/

Develop the Business Service Tier

Develop the Business Service Tier

Let's see how the business service can be developed for a one-to-one bi-directional relationship scenario.

We'll cover the following...

Find all records operation

To develop the business service tier, first look at the test for the “fetching all records” operation.

Java
@RunWith( SpringJUnit4ClassRunner.class )

@ContextConfiguration( locations = { "classpath:context.xml" } )

@TransactionConfiguration( defaultRollback = true )

@Transactional

public class CustomerServiceImplTest {

	@Autowired

	private CustomerService service ;

	@Test

	public void testFindAll() {

		Assert.assertEquals(0L, service.findAll().size());

	}

}

Code the identical method in the business service by retrieving all the records using the data access operation and converting the entity to data transfer objects using the mapper.

Java
@Service

@Transactional

public class CustomerServiceImpl implements CustomerService{

	@Autowired

	private CustomerDao dao ;

	@Autowired

	private CustomerMapper mapper ;

	@Override

	public List<CustomerDto> findAll() {

		List<CustomerDto> customerDtos = new ArrayList<CustomerDto>();

		List<Customer> customers = dao.getAll();

		for(Customer customer:customers){

			customerDtos.add(mapper.mapEntityToDto(customer));

		}

		return customerDtos;

	}

}

Mappers

The business service tier uses data access objects, but the data access tier uses entities. The mapper typically has two ...