测试中的Jpa和LazyInitializationException

Question

@Entity
@Table(name = "product")
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "product_id")
    private Long id;
    private String productName;
    private Long productPrice;
    private String productDescription;
    @ManyToOne(cascade = CascadeType.PERSIST)
    @JoinColumn(name = "product_type_id")
    private ProductType productType;
    //getters and setters

@Entity
@Table(name = "product_type")
public class ProductType {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "product_type_id")
    private Long id;
    private String productTypeName;
    private String productTypeDescription;
    @OneToMany(mappedBy = "productType", cascade = CascadeType.ALL)
    private List<Product> products;
    //getters and setters

@Service
public class ProductService {
    ProductRepository productRepository;
    ProductTypeRepository productTypeRepository;

    public ProductService(ProductRepository productRepository, ProductTypeRepository productTypeRepository) {
        this.productRepository = productRepository;
        this.productTypeRepository = productTypeRepository;
    }

    @Transactional
    public Product saveProduct(Product product){
        return productRepository.save(product);
    }

    @Transactional
    public List<Product> findAllByProductTypeName(String type){
        ProductType productType = productTypeRepository.findByProductTypeName(type);
        return productType.getProducts();
    }

@SpringBootTest
class ProductServiceTest extends BaseDAOTest {
    @Autowired
    ProductService productService;
    @Autowired
    ProductTypeService productTypeService;

    @Test
    void findAllByProductTypeTest(){
        Product product = new Product("Test product", 100L, "Test product description");
        product.setProductType(new ProductType("Test type", "Test description"));
        productService.saveProduct(product);
        List<Product> productList = productService.findAllByProductTypeName("Test type");
        productList.get(0);
    }
}

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.krasovsky.warehouse.models.ProductType.products, could not initialize proxy - no Session

    at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:606)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:218)
    at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:585)
    at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:149)
    at org.hibernate.collection.internal.PersistentBag.get(PersistentBag.java:561)

解决这个问题的正确方法是什么？如果你需要任何额外的信息，请说。提前谢了。

Answer 1

您正试图在事务之外进行提取。您需要使用@datajpatest注释您的测试类：

默认情况下，数据JPA测试是事务性的，并在每个测试结束时回滚

https://docs.spring.io/spring-boot/docs/1.5.2.release/reference/html/boot-features-testing.html#boot-features-testing-spring-boot-applications-testing-autocomputed-jpa-test