java - hibernate/JPA : QueryException when hibernate generates metamodel for @ElementCollection

Question

我尝试使用 hibernate 4.3.1.Final 在实体中保留 @ElementCollection。该实体如下所示:

import javax.persistence.*;
import java.util.Map;
@Entity
public class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    @ElementCollection
    private Map<CompositeKey, CompositeValue> map;

    @Embeddable
    public static class CompositeKey {
        @Basic
        private Integer key1;
        @Basic
        private Integer key2;
    }

    @Embeddable
    public static class CompositeValue {
        @Basic
        private Integer val1;
        @Basic
        private Integer val2;
    }
}

Hibernate 正确生成架构:

create table MyEntity (id integer not null, primary key (id)) ENGINE=InnoDB;
create table MyEntity_map (MyEntity_id integer not null, val1 integer, val2 integer, key1 integer, key2 integer, primary key (MyEntity_id, key1, key2)) ENGINE=InnoDB;
create table ReferencedEntity (id integer not null, primary key (id)) ENGINE=InnoDB;
alter table MyEntity_map add constraint FK_mhu8q8dtieguddm0w4gxfwhnc foreign key (MyEntity_id) references MyEntity (id);

但是当我更改 CompositeKey 以引用另一个 Entity 时，当 hibernate 在启动时生成元模型时，我会收到 QueryException 。

更改后的代码:

@Embeddable
public static class CompositeKey {
    @ManyToOne
    private ReferencedEntity key1;
    @Basic
    private Integer key2;
}

引用的实体:

import javax.persistence.*;
@Entity
public class ReferencedEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
}

异常(exception):

Caused by: org.hibernate.QueryException: could not resolve property: key1 of: component[val1,val2]
    at org.hibernate.persister.entity.AbstractPropertyMapping.propertyException(AbstractPropertyMapping.java:83) ~[AbstractPropertyMapping.class:4.3.1.Final]
    at org.hibernate.persister.entity.AbstractPropertyMapping.toColumns(AbstractPropertyMapping.java:98) ~[AbstractPropertyMapping.class:4.3.1.Final]
    at org.hibernate.persister.collection.AbstractCollectionPersister.toColumns(AbstractCollectionPersister.java:1625) ~[AbstractCollectionPersister.class:4.3.1.Final]
    at org.hibernate.loader.plan.build.internal.spaces.CompositePropertyMapping.toColumns(CompositePropertyMapping.java:124) ~[CompositePropertyMapping.class:4.3.1.Final]
    at org.hibernate.loader.plan.build.internal.spaces.CompositeQuerySpaceImpl.toAliasedColumns(CompositeQuerySpaceImpl.java:52) ~[CompositeQuerySpaceImpl.class:4.3.1.Final]
    at org.hibernate.loader.plan.build.internal.spaces.JoinImpl.resolveAliasedLeftHandSideJoinConditionColumns(JoinImpl.java:79) ~[JoinImpl.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.addJoins(LoadQueryJoinAndFetchProcessor.java:261) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.renderEntityJoin(LoadQueryJoinAndFetchProcessor.java:193) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.renderJoin(LoadQueryJoinAndFetchProcessor.java:158) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoin(LoadQueryJoinAndFetchProcessor.java:137) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:132) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoin(LoadQueryJoinAndFetchProcessor.java:138) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:132) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:113) ~[LoadQueryJoinAndFetchProcessor.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.AbstractLoadQueryDetails.generate(AbstractLoadQueryDetails.java:171) ~[AbstractLoadQueryDetails.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.BasicCollectionLoadQueryDetails.<init>(BasicCollectionLoadQueryDetails.java:60) ~[BasicCollectionLoadQueryDetails.class:4.3.1.Final]
    at org.hibernate.loader.plan.exec.internal.BatchingLoadQueryDetailsFactory.makeCollectionLoadQueryDetails(BatchingLoadQueryDetailsFactory.java:101) ~[BatchingLoadQueryDetailsFactory.class:4.3.1.Final]
    at org.hibernate.loader.collection.plan.AbstractLoadPlanBasedCollectionInitializer.<init>(AbstractLoadPlanBasedCollectionInitializer.java:77) ~[AbstractLoadPlanBasedCollectionInitializer.class:4.3.1.Final]
    at org.hibernate.loader.collection.plan.CollectionLoader.<init>(CollectionLoader.java:112) ~[CollectionLoader.class:4.3.1.Final]
    at org.hibernate.loader.collection.plan.CollectionLoader$Builder.byKey(CollectionLoader.java:105) ~[CollectionLoader$Builder.class:4.3.1.Final]
    at org.hibernate.loader.collection.plan.AbstractBatchingCollectionInitializerBuilder.buildNonBatchingLoader(AbstractBatchingCollectionInitializerBuilder.java:45) ~[AbstractBatchingCollectionInitializerBuilder.class:4.3.1.Final]
    at org.hibernate.loader.collection.BatchingCollectionInitializerBuilder.createBatchingCollectionInitializer(BatchingCollectionInitializerBuilder.java:71) ~[BatchingCollectionInitializerBuilder.class:4.3.1.Final]
    at org.hibernate.persister.collection.BasicCollectionPersister.createCollectionInitializer(BasicCollectionPersister.java:343) ~[BasicCollectionPersister.class:4.3.1.Final]
    at org.hibernate.persister.collection.AbstractCollectionPersister.postInstantiate(AbstractCollectionPersister.java:676) ~[AbstractCollectionPersister.class:4.3.1.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:484) ~[SessionFactoryImpl.class:4.3.1.Final]
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1857) ~[Configuration.class:4.3.1.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850) ~[EntityManagerFactoryBuilderImpl$4.class:4.3.1.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:843) ~[EntityManagerFactoryBuilderImpl$4.class:4.3.1.Final]
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:399) ~[ClassLoaderServiceImpl.class:4.3.1.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842) ~[EntityManagerFactoryBuilderImpl.class:4.3.1.Final]
    at org.hibernate.jpa.HibernatePersistenceProvider.createContainerEntityManagerFactory(HibernatePersistenceProvider.java:150) ~[HibernatePersistenceProvider.class:4.3.1.Final]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:336) ~[LocalContainerEntityManagerFactoryBean.class:4.0.1.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:318) ~[AbstractEntityManagerFactoryBean.class:4.0.1.RELEASE]
    ...

我的映射出了什么问题？如何防止这种异常？

有趣的是，BasicCollectionPersister 似乎已正确初始化。调试表明，例如sqlUpdateRowString 是 update MyEntity_map set val1=?, val2=?其中 MyEntity_id=?和 key1_id=?和 key2=?.

Answer 1

来自 JPA 2.0 规范:

Relationship mappings defined within an embedded id class are not supported.

另请参阅JPA - EmbeddedId with @ManytoOne .

编辑:

Hibernate 4.3.1.Final 实现了 JPA 2.1，所以我的第一个猜测是错误的。抱歉。

映射的问题在于使用了 @ElementCollection 以及引用实体 ReferencedEntity 的可嵌入 CompositeKey。当 Hibernate 查找从 CompositeValue(原文如此!)到 ReferencedEntity 的引用时，会引发 AbstractPropertyMapping 中的异常。然而，由于不存在这样的关系，因此抛出异常。对我来说，不清楚这是一个 Hibernate bug 还是根据 JPA 2.1 规范。

我看到以下解决方案。

解决方案1

将 CompositeKey 更改为添加 id 字段的 Entity。在这种情况下，可以使用 @OneToMany 注释:

@Entity
public class CompositeKey {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    @ManyToOne(targetEntity = ReferencedEntity.class)
    private ReferencedEntity key1;

    @Basic
    private Integer key2;

}

解决方案2

添加一个附加实体 CompositeSampler，其中包含 CompositeKey 作为 ID，并包含 CompositeValue 作为附加属性。 MyEntity 将包含 CompositeSampler 列表。

解决方案3

添加从 CompositeValue 到 ReferencedEntity 的引用。

顺便说一句，根据 JPA 2.1 规范:“如果将可嵌入类用作映射键，则可嵌入类必须实现与可嵌入类映射到的数据库列一致的 hashCode 和 equals 方法”。