EAGER and Pagination : Spring MVC + JPA Repository + Hibernate

Question

I have a entity A which has a relation @OneToMany with a entity B (fetch mode = EAGER). Entitity A has other relations in LAZY with other entities too, but isn't important for this problem.

Entity B has a relation @ManyToOne with entity A too (fech mode = EAGER). Entitity B has other relations in LAZY with other entities too, but isn't important for this problem.

Later, I have a interface that implements JpaRepository class where I define a @Query with some inner joins between others entities for get a coleccion of Entities A of 10 items with a calculated score, using Page and Pageable elements.

Here this process fail. why?

My table for entity A in Database has +1000 registers that have the conditions of @query. But before Hibernate or JPA return me 10 entities A, internally, exect 1000+ selects for get Entities B data (EAGER realation) and explote.

why dont get 10 entities A and exec 10 "selects" for get 10 entities B only?

The unique solution is change my relations from EAGER to LAZY?? dont work pageable with EAGER?

Why did this happend? any solution?

EDIT: aclaration: +1000 entityA +1000 entityB (in my example one entityA with only one entityB, but entityA can has multiples entitiesB)

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

    @Id
    @GeneratedValue(generator = "uuid")
    @GenericGenerator(name = "uuid", strategy = "uuid2")
    @Column(columnDefinition = "BINARY(16)")
    private UUID id;

    @OneToMany(mappedBy="entityA", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @OrderBy("updatedDate DESC")
    private Set<EntityB> entitiesB = new HashSet<EntityB>();

    ...
}

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

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(generator = "uuid")
    @GenericGenerator(name = "uuid", strategy = "uuid2")
    @Column(columnDefinition = "BINARY(16)")
    private UUID id;

    @ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinColumn(name = "idEntityA", nullable = false)
    private EntityA entityA;

    ...
}

public interface EntityA_DAO  extends JpaRepository<EntityA, UUID>{
    @Query("SELECT DISTINCT a FROM EntityA a INNER JOIN a.entityB b LEFT JOIN b.scoreEntityB s INNER JOIN a.user u INNER JOIN a.properties p INNER JOIN p.category c " +
            "WHERE c.cod IN (:codcats) AND a.user <> :user AND b.codState = '001' AND a.codState NOT IN ('002','004','005') AND p.deleted <> 1 " +
            "GROUP BY b ORDER BY a.createdDate DESC, COUNT(s) DESC")
    public Page<EntityA> findAllByCategories(@Param("user") User user, @Param("codcats") List<Integer> lstCodCats,  Pageable pageable);
}

EDIT 2

this is snippett of my trace error, repeat and repeat same :

at java.util.HashMap.put(Unknown Source) at java.util.HashSet.add(Unknown Source) at java.util.AbstractCollection.addAll(Unknown Source) at org.hibernate.collection.internal.PersistentSet.endRead(PersistentSet.java:327) at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollection(CollectionLoadContext.java:234) at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:221) at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:194) at org.hibernate.loader.plan.exec.process.internal.CollectionReferenceInitializerImpl.endLoading(CollectionReferenceInitializerImpl.java:154) at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishLoadingCollections(AbstractRowReader.java:249) at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishUp(AbstractRowReader.java:212) at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractResults(ResultSetProcessorImpl.java:123) at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:122) at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:86) at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.load(AbstractLoadPlanBasedEntityLoader.java:167) at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:3956) at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:508) at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:478) at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:219) at org.hibernate.event.internal.DefaultLoadEventListener.doOnLoad(DefaultLoadEventListener.java:116) at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:89) at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1129) at org.hibernate.internal.SessionImpl.immediateLoad(SessionImpl.java:997) at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:157) at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:266) at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:68) at com.treebuk.model.Fragment_$$_jvsta55_10.hashCode(Fragment_$$_jvsta55_10.java) at com.treebuk.model.Fragment.hashCode(Fragment.java:210) at sun.reflect.GeneratedMethodAccessor111.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:79) at com.treebuk.model.Fragment_$$_jvsta55_10.hashCode(Fragment_$$_jvsta55_10.java) at com.treebuk.model.TextFragment.hashCode(TextFragment.java:340) at java.util.HashMap.hash(Unknown Source) at java.util.HashMap.put(Unknown Source) at java.util.HashSet.add(Unknown Source) at java.util.AbstractCollection.addAll(Unknown Source) at org.hibernate.collection.internal.PersistentSet.endRead(PersistentSet.java:327) at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollection(CollectionLoadContext.java:234) at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:221) at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:194) at org.hibernate.loader.plan.exec.process.internal.CollectionReferenceInitializerImpl.endLoading(CollectionReferenceInitializerImpl.java:154) at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishLoadingCollections(AbstractRowReader.java:249) at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishUp(AbstractRowReader.java:212) at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractResults(ResultSetProcessorImpl.java:123) at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:122) at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:86) at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.load(AbstractLoadPlanBasedEntityLoader.java:167) at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:3956) at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:508) at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:478) at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:219) at org.hibernate.event.internal.DefaultLoadEventListener.doOnLoad(DefaultLoadEventListener.java:116) at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:89) at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1129) at org.hibernate.internal.SessionImpl.immediateLoad(SessionImpl.java:997) at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:157) at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:266) at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:68) at com.treebuk.model.Fragment_$$_jvsta55_10.hashCode(Fragment_$$_jvsta55_10.java) at com.treebuk.model.Fragment.hashCode(Fragment.java:210) at sun.reflect.GeneratedMethodAccessor111.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:79) at com.treebuk.model.Fragment_$$_jvsta55_10.hashCode(Fragment_$$_jvsta55_10.java) at com.treebuk.model.TextFragment.hashCode(TextFragment.java:340) at java.util.HashMap.hash(Unknown Source)

Answer 1

Finnaly, I found the problem. The problem was th method Entity B hasCode(), that this method had a comparation with Entity A, Then when Spring try to get elements, executes hascode method, and entered in infinite loop. I change the hascode() and equal() methods for delete these comparations (not necessary in my case).