Org.hibernate.LazyInitializationException: failed to lazily initialize role collection: FQPropretyName, failed to initialize proxy - no session

Question

I am trying to use the ManyToOne bi-directional association using SpringBoot, SpringDataJpa and unit test using SpringBootTest. However, the test fails with the stacktrace scheme below. However, I can not find the reason. Any pointers would be helpful

Below is the Spring JUnit boot test for multi-user bi-directional association does not work.

    @Test
    public void testFindByRegionIdEquals() {
        Region region = regionService.findByRegionIdEquals(1L);
        Region expectedRegion = new Region(1L, "Europe");
        assertThat(region).isNotNull().isEqualTo(expectedRegion);
        assertThat(region.getCountries()).isNotEmpty().doesNotContainNull().size().isEqualTo(8);
    }

StackTrace exception

    org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: zikzakjack.domain.Region.countries, could not initialize proxy - no Session
    at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:587)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:204)
    at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:148)
    at org.hibernate.collection.internal.PersistentSet.isEmpty(PersistentSet.java:149)
    at org.assertj.core.util.IterableUtil.isNullOrEmpty(IterableUtil.java:35)
    at org.assertj.core.internal.Iterables.assertNotEmpty(Iterables.java:152)
    at org.assertj.core.api.AbstractIterableAssert.isNotEmpty(AbstractIterableAssert.java:145)
    at zikzakjack.service.RegionServiceTests.testFindByRegionIdEquals(RegionServiceTests.java:68)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

Owner of ManyToOne

@Data
@Entity
@Table(name = "COUNTRIES")
public class Country implements Serializable, Comparable<Country> {

    private static final long serialVersionUID = 1L;

    @Id
    @Column(name = "COUNTRY_ID")
    private String countryId;

    @Column(name = "COUNTRY_NAME")
    private String countryName;

    @ManyToOne
    @JoinColumn(name = "REGION_ID")
    private Region region;

    public Country() {

    }

    public Country(String countryId, String countryName, Region region) {
        super();
        this.countryId = countryId;
        this.countryName = countryName;
        this.region = region;
    }

}

* Unacceptable OneToMany entity with mappedBy *

@Data
@Entity
@Table(name = "REGIONS")
public class Region implements Serializable, Comparable<Region> {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "REGION_ID")
    private Long regionId;

    @Column(name = "REGION_NAME")
    private String regionName;

    @OneToMany(mappedBy = "region", fetch = FetchType.LAZY)
    private Set<Country> countries = new HashSet<Country>();

    public Region() {
    }

    public Region(Long regionId, String regionName) {
        this.regionId = regionId;
        this.regionName = regionName;
    }

    public Region(String regionName) {
        this.regionName = regionName;
    }

    public void addCountry(Country country) {
        countries.add(country);
        country.setRegion(this);
    }
}

Answer 1

, fooobar.com/questions/1685815/...

application.properties :

spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

, , , , , , .

@Transactional , .

    @Test
    @Transactional
    public void testFindByRegionIdEquals() {
        Region region = regionService.findByRegionIdEquals(1L);
        Region expectedRegion = new Region(1L, "Europe");
        assertThat(region).isNotNull().isEqualTo(expectedRegion);
        assertThat(region.getCountries()).isNotEmpty().doesNotContainNull().size().isEqualTo(8);
    }