JPA - OneToMany persist - EntityExistsException

Question

Searched through SO but I wasn't able to find my case.

There is an entity Card, like this:

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.ForeignKey;
import javax.persistence.Id;
import javax.persistence.Index;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;

import lombok.AccessLevel;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

import org.hibernate.validator.constraints.NotBlank;
import org.hibernate.validator.constraints.NotEmpty;

@Entity
@ToString(exclude={"playRequirements"})
@Table(name = "CARD",
       indexes = {@Index(name = "CARD_IDX_1", columnList="ID", unique = true)})
public class Card implements Serializable {

    @Getter
    @Setter
    @NotEmpty
    @NotBlank
    @Id
    @Column(name = "ID", unique = true, nullable = false)
    private String id;

    @Getter
    @Setter
    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy="card")
    private List<CardPlayRequirementsRel> playRequirements;
}

that as an inverse relation with the entity CardPlayRequirementsRel:

import java.io.Serializable;

import hscli.entities.domain.PlayRequirement;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.ForeignKey;
import javax.persistence.Id;
import javax.persistence.Index;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

import org.hibernate.validator.constraints.NotEmpty;

@Entity
@ToString
@EqualsAndHashCode(of={"card", "playRequirement"})
@Table(name = "CARD_PLAY_REQUIREMENT_REL", 
       indexes=@Index(name="CARD_PLAY_REQ_REL_IDX_1", unique=true, columnList="CARD,PLAY_REQUIREMENT"))
public class CardPlayRequirementsRel implements Serializable {

    @Id
    @Getter
    @Setter
    @NotEmpty
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "CARD", nullable = false, foreignKey = @ForeignKey(name = "FK_CARD_PLAY_REQ_REL_CARD"))
    private Card card;

    @Id
    @Getter
    @Setter
    @NotEmpty
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "PLAY_REQUIREMENT", nullable = false, foreignKey = @ForeignKey(name = "FK_CARD_PLAY_REQ_REL_PLAY_REQ"))
    private PlayRequirement playRequirement;

    @Getter
    @Setter
    @NotEmpty
    @Column(name = "VALUE", nullable = false)
    private Long value;
}

I want to persist a list of Card:

[...]

List<CardDTO> dtoList = connectionService.getCardDTO();
List<Card> toSave = new ArrayList<Card>();
for(CardDTO dto : dtoList) {
    log.debug("----------------> id: [" + dto.getId() + "]");
    Card entity = new Card();
    dtoToCardEntity(dto, entity);
    toSave.add(entity);
}
cardRepository.save(toSave);

[...]

private void dtoToCardEntity(CardDTO dto, Card entity) {
    entity.setId(dto.getId());

    if(dto.getPlayRequirements() != null && CollectionUtils.isNotEmpty(dto.getPlayRequirements().keySet())) {
        entity.setPlayRequirements(new ArrayList<CardPlayRequirementsRel>());
        for(String playReq : dto.getPlayRequirements().keySet()) {
            CardPlayRequirementsRel rel = new CardPlayRequirementsRel();
            rel.setCard(entity);
            rel.setPlayRequirement(domainBaseService.findOneByCodice(playReq, PlayRequirement.class));
            rel.setValue(dto.getPlayRequirements().get(playReq));
            entity.getPlayRequirements().add(rel);
        }
    }
}

But on save I get this exception:

13398 02:04:41,679 [main] DEBUG [org.hibernate.SQL:92] - 
    select
        cardplayre0_.PLAY_REQUIREMENT as PLAY_REQUIREMENT2_7_0_,
        cardplayre0_.CARD as CARD3_7_0_,
        cardplayre0_.VALUE as VALUE1_7_0_ 
    from
        CARD_PLAY_REQUIREMENT_REL cardplayre0_ 
    where
        cardplayre0_.PLAY_REQUIREMENT=? 
        and cardplayre0_.CARD=?
13398 02:04:41,679 [main] TRACE [org.hibernate.type.descriptor.sql.BasicBinder:65] - binding parameter [1] as [VARCHAR] - [REQ_MINION_TARGET]
13399 02:04:41,680 [main] TRACE [org.hibernate.type.descriptor.sql.BasicBinder:65] - binding parameter [2] as [VARCHAR] - [AT_024]
13404 02:04:41,685 [main] ERROR [hscli.HearthStoneCardListImporter:56] - A different object with the same identifier value was already associated with the session : [hscli.entities.cards.CardPlayRequirementsRel#CardPlayRequirementsRel(card=null, playRequirement=null, value=0)]; nested exception is javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [hscli.entities.cards.CardPlayRequirementsRel#CardPlayRequirementsRel(card=null, playRequirement=null, value=0)]
org.springframework.dao.DataIntegrityViolationException: A different object with the same identifier value was already associated with the session : [hscli.entities.cards.CardPlayRequirementsRel#CardPlayRequirementsRel(card=null, playRequirement=null, value=0)]; nested exception is javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [hscli.entities.cards.CardPlayRequirementsRel#CardPlayRequirementsRel(card=null, playRequirement=null, value=0)]
    at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:410)
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:246)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:491)
    at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59)
    at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:133)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy41.save(Unknown Source)
    at hscli.services.impl.CardServiceImpl.updateCards(CardServiceImpl.java:52)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy44.updateCards(Unknown Source)
    at hscli.HearthStoneCardListImporter.updateCards(HearthStoneCardListImporter.java:54)
    at hscli.HearthStoneCardListImporter.main(HearthStoneCardListImporter.java:29)
Caused by: javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [hscli.entities.cards.CardPlayRequirementsRel#CardPlayRequirementsRel(card=null, playRequirement=null, value=0)]
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1664)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1608)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1171)
    at sun.reflect.GeneratedMethodAccessor36.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298)
    at com.sun.proxy.$Proxy39.merge(Unknown Source)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:509)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:540)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:72)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:503)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:488)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:460)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    ... 23 more

Answer 1

If you have multiple columns annotated with @Id in your entity you must use a @IdClass annotation or replace it with an embedded @EmbeddedId. See How to map a composite key with Hibernate? for an excellent explanation, that seems to be independent of hibernate.

I'm not completely sure this is actually the problem you are seeing right now, since the Exception seems to complain about multiple instances with the id fields being null, so since you don't specify any generator, you should ensure that the id columns are set to actual values and aren't null.