Two relationships to single-table inheritance sub classes failing with Hibernate 5.3.*

Hibernate ORM
1

Hello all.

I have a simple single table mapping, a ship with images and documents (both sub classes of an attachment) attached to it:

@Entity
@Table(name = "SHIPS")
public class Ship implements Serializable {

	private static final long serialVersionUID = 1L;

	@Id
	@Column(name = "ID")
	private Long id;

	@Basic(optional = false)
	@Column(name = "NAME")
	private String name;

	@OneToMany(mappedBy = "ship", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	// @Where(clause = "DISCR = 'I'")
	private List<Image> images = new ArrayList<>();

	@OneToMany(mappedBy = "ship", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	// @Where(clause = "DISCR = 'D'")
	private List<Document> documents = new ArrayList<>();

	public Ship() {}

	public Ship(Long id, String name) {
		this.id = id;
		this.name = name;
	}

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public List<Image> getImages() {
		return images;
	}

	public void setImages(List<Image> images) {
		this.images = images;
	}

	public List<Document> getDocuments() {
		return documents;
	}

	public void setDocuments(List<Document> documents) {
		this.documents = documents;
	}
}

@Entity
@Table(name = "ATTACHMENTS")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "DISCR")
public abstract class BaseAttachment implements Serializable {

	private static final long serialVersionUID = 1L;

	@Id
	@Column(name = "ID")
	protected Long id;

	@Basic(optional = false)
	@Column(name = "DISCR", insertable = false, updatable = false)
	protected String discr;

	@Basic(optional = false)
	@Column(name = "FILE_NAME")
	protected String fileName;

//	@Lob
//	@Basic(optional = false)
//	@Column(name = "ORIGINAL_DATA")
//	protected byte[] originalData;

	@ManyToOne(optional = false, fetch = FetchType.LAZY)
	@JoinColumn(name = "SHIP_ID", referencedColumnName = "ID")
	protected Ship ship;

	public BaseAttachment() {}

	public BaseAttachment(Long id, String fileName) {
		this.id = id;
		this.fileName = fileName;
	}

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getDiscr() {
		return discr;
	}

	public void setDiscr(String discr) {
		this.discr = discr;
	}

	public String getFileName() {
		return fileName;
	}

	public void setFileName(String fileName) {
		this.fileName = fileName;
	}

//	public byte[] getOriginalData() {
//		return originalData;
//	}
//
//	public void setOriginalData(byte[] originalData) {
//		this.originalData = originalData;
//	}

	public Ship getShip() {
		return ship;
	}

	public void setShip(Ship ship) {
		this.ship = ship;
	}
}

@Entity
@DiscriminatorValue("I")
public class Image extends BaseAttachment {

	private static final long serialVersionUID = 1L;

	@Column(name = "ALTERNATIVE_TEXT")
	private String alternativeText;

	public Image() {}

	public Image(Long id, String fileName) {
		super(id, fileName);
	}

	public String getAlternativeText() {
		return alternativeText;
	}

	public void setAlternativeText(String alternativeText) {
		this.alternativeText = alternativeText;
	}
}

@Entity
@DiscriminatorValue("D")
public class Document extends BaseAttachment {

	private static final long serialVersionUID = 1L;

	public Document() {}

	public Document(Long id, String fileName) {
		super(id, fileName);
	}
}

I created a test case:

@TestForIssue( jiraKey = "HHH-99999")
public class TwoRelationshipsToSubclassTest extends BaseEntityManagerFunctionalTestCase {

    @Override
    public Class<?>[] getAnnotatedClasses() {
        return new Class<?>[]{Ship.class, BaseAttachment.class, Image.class, Document.class};
    }

    @Override
    protected void addConfigOptions(Map options) {
        options.put( AvailableSettings.USE_SECOND_LEVEL_CACHE, "false" );
        options.put( AvailableSettings.SHOW_SQL, "true" );
        options.put( AvailableSettings.FORMAT_SQL, "true" );
        options.put( AvailableSettings.ENABLE_LAZY_LOAD_NO_TRANS, "true" );
    }

    @Before
    public void prepare() {
        doInJPA( this::entityManagerFactory, em -> {
            Ship ship = new Ship(1L, "Titanic");
            // images
            Image image1 = new Image(1L, "abc.png");
            image1.setShip(ship);
            Image image2 = new Image(2L, "def.jpg");
            image2.setShip(ship);
            // documents
            Document document1 = new Document(3L, "ghi.docx");
            document1.setShip(ship);
            Document document2 = new Document(4L, "jkl.pdf");
            document2.setShip(ship);
            Document document3 = new Document(5L, "mno.txt");
            document3.setShip(ship);
            // images relationship
            ship.getImages().add(image1);
            ship.getImages().add(image2);
            // documents relationship
            ship.getDocuments().add(document1);
            ship.getDocuments().add(document2);
            ship.getDocuments().add(document3);
            // persist
            em.persist( ship );
        });
    }

    /**
     * Use --debug to see the SQL being run + the sysouts.
     */
    @Test
    public void test() {
        doInJPA( this::entityManagerFactory, em -> {
            Ship ship = em.find( Ship.class, 1L );
            Assert.assertNotNull("Ship not found!", ship);
            List<Image> images = ship.getImages();
            Assert.assertEquals(2, images.size());
            List<Document> documents = ship.getDocuments();
            Assert.assertEquals(3, documents.size());
        } );
    }
}

Fails with:


expected:<2> but was:<5>
Expected :2
Actual   :5
<Click to see difference>

java.lang.AssertionError: expected:<2> but was:<5>
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:834)
	at org.junit.Assert.assertEquals(Assert.java:645)
	at org.junit.Assert.assertEquals(Assert.java:631)
	at org.hibernate.jpa.test.inheritance.singletable.TwoRelationshipsToSubclassTest.lambda$test$3(TwoRelationshipsToSubclassTest.java:68)
	at org.hibernate.testing.transaction.TransactionUtil.doInJPA(TransactionUtil.java:206)
	at org.hibernate.testing.transaction.TransactionUtil.doInJPA(TransactionUtil.java:247)
	at org.hibernate.jpa.test.inheritance.singletable.TwoRelationshipsToSubclassTest.test(TwoRelationshipsToSubclassTest.java:64)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.hibernate.testing.junit4.ExtendedFrameworkMethod.invokeExplosively(ExtendedFrameworkMethod.java:45)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)
	at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.lang.Thread.run(Thread.java:832)


org.hibernate.jpa.test.inheritance.singletable.TwoRelationshipsToSubclassTest > test FAILED
    java.lang.AssertionError at TwoRelationshipsToSubclassTest.java:68
1 test completed, 1 failed
> Task :hibernate-core:test FAILED
> Task :hibernate-core:buildDashboard UP-TO-DATE
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':hibernate-core:test'.
> There were failing tests. See the report at: file:///C:/projects/hibernate-orm/hibernate-core/target/reports/tests/test/index.html
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org

What happens here (Hibernate 5.3.25.Final branch) is that the subclass instances for ALL types are fetched, which is wrong.

EDIT: this test fails with all 5.x branches!

I’ve also tested this with the main branch (Hibernate 6.0.0.RC1) where this test is OK.

Does anyone happen to know which issue HHH-??? fixed this?

We currently have to add @Where(clause = "DISCR = 'D'") and @Where(clause = "DISCR = 'I'") to get around this, which is… um… kinda stoopid, ya know.

Thanks
Karsten

2

I think you can achieve the same by annotating @DiscriminatorOptions(force = true) on the entity type. I don’t know which HHH fixed this or if we even tagged a commit properly. We just figured that this was wrong in Hibernate 5.x so we fixed it at some point.

3

Thanks for the answer.

Are there any plans to fix this for the 5.x branches?

We frequently have SINGLE_TABLE mappings and relationships to sub classes, so this would be a pity not to be backported.

I could create an HHH-xxxxx issue and add the test case to any 5.x branch if desired, but someone/you would have to find the commits etc. to fix this (if possible).

4

Unless someone from the community steps up to fix this, I don’t think this will be backported as the Hibernate Team will not be investing a lot into 5.x anymore.