Develop the Business Service Tier

@RunWith( SpringJUnit4ClassRunner.class )
@ContextConfiguration( locations = { "classpath:context.xml" } )
@TransactionConfiguration( defaultRollback = true )
@Transactional
public class CategoryServiceImplTest {
	@Autowired
	private CategoryService service;
	@Test
	public void testFindAll() {
		Assert.assertEquals(0L, service.findAll().size());
	}
}

@Service
@Transactional
public class CategoryServiceImpl implements CategoryService{
	@Autowired
	private CategoryDao dao;
	@Autowired
	private CategoryMapper mapper;
	@Override
	public List<CategoryDto> findAll() {
		List<Category> categories = dao.getAll();
		List<CategoryDto> categoryDtos = new ArrayList<CategoryDto>();
		if(null !=categories && categories.size() > 0){
			for(Category category : categories){
				categoryDtos.add(mapper.mapEntityToDto(category));
			}
		}
		return categoryDtos;
	}
}