[JavaEE] Data Validation

When we create Entity and Respority, we also need to do validations to protect our data.

In Java, validations are built-in, using decorators. For Typescript, found a useful libaray to do the similar validation as well. Checkout class-validator

Entity:

@Entity
public class Book {

    // ======================================
    // =             Attributes             =
    // ======================================

    @Id
    @GeneratedValue
    private Long id;

    @Column(length = 200)
    @NotNull
    @Size(min = 1, max = 200)
    private String title;

    @Column(length = 10000)
    @Size(min = 1, max = 10000)
    private String description;

    @Column(name = "unit_cost")
    @Min(1)
    private Float unitCost;

    @Column(length = 50)
    @NotNull
    @Size(min = 1, max = 50)
    private String isbn;

    @Column(name = "publication_date")
    @Temporal(TemporalType.DATE)
    @Past
    private Date publicationDate;

    ....    
}

Testing:

We want to test, if we give title as null, it should throw exception.

@RunWith(Arquillian.class)
public class BookRepositoryTest {

    @Inject
    private BookRepository bookRepository;

    // We want the test throw exception
    @Test(expected = Exception.class)
    public void createInvalidBook() {
        Book book = new Book("isbn", null, 12F, 123, Language.ENGLISH, new Date(), "imageURL", "description");
        bookRepository.create(book);
    }

    @Deployment
    public static JavaArchive createDeployment() {
        return ShrinkWrap.create(JavaArchive.class)
                .addClass(BookRepository.class)
                .addClass(Book.class)
                .addClass(Language.class)
                .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml")
                .addAsManifestResource("META-INF/test-persistence.xml", "persistence.xml");
    }

    @org.junit.Test
    public void create() {
    }
}

Respority:

@Transactional(SUPPORTS)
public class BookRepository {

    // ======================================
    // =          Injection Points          =
    // ======================================

    @PersistenceContext(unitName = "bookStorePU")
    private EntityManager em;

    // ======================================
    // =          Business methods          =
    // ======================================

    public Book find(@NotNull Long id) {
        return em.find(Book.class, id);
    }

    // For creating and deleting methods, we want to use REQUIRED
    @Transactional(REQUIRED)
    public Book create(@NotNull Book book) {
        em.persist(book);
        return book;
    }

}

Testing:

    @Test(expected = Exception.class)
    public void findWithInvalidId() {
        bookRepository.find(null);
    }