在Hibernate中的复合@JoinClons上使用属性转换器

Question

当目标实体使用复合连接时，其中一列是使用转换器的自定义类型，Hibernate（使用Spring Boot JPA）无法插入。

简化实体定义：

@Entity
data class MyConfiguration(
    @Id
    val configurationId: Long,
    val enabled: Boolean,
    @OneToMany(
        cascade = [CascadeType.ALL],
        fetch = FetchType.EAGER,
        orphanRemoval = true,
        mappedBy = "id.configurationId"
    )
    val tables: Set<SourceTable>
)

@Embeddable
data class SourceTableId(
    val configurationId: Long,
    @Convert(converter = TableIdConverter::class)
    val tableId: TableId
) : Serializable

@Entity
data class SourceTable(
    @EmbeddedId
    val id: SourceTableId,
    @OneToMany(
        cascade = [CascadeType.ALL],
        fetch = FetchType.EAGER,
        orphanRemoval = true
    )
    @JoinColumns(
        JoinColumn(name = "configurationId", referencedColumnName = "configurationId", updatable = false),
        JoinColumn(name = "tableId", referencedColumnName = "tableId", updatable = false)
    )
    val groupingFields: Set<TableGroupField> = emptySet()
)

@Embeddable
data class TableGroupFieldId(
    val configurationId: Long,
    @Convert(converter = TableIdConverter::class)
    val tableId: TableId,
    val fieldName: String
) : Serializable

@Entity
data class TableGroupField(
    @EmbeddedId
    val id: TableGroupFieldId
)

converter类使用简单的字符串操作，TableId类实现可序列化。从Spring Boot应用程序的上下文中保存元素时，出现以下异常：

... Omitted for readability ...
Caused by: javax.persistence.RollbackException: Error while committing the transaction
    at org.hibernate.internal.ExceptionConverterImpl.convertCommitException(ExceptionConverterImpl.java:81) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
    at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:104) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:562) ~[spring-orm-5.3.8.jar:5.3.8]
    ... 33 common frames omitted
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Comparator.compare(Object, Object)" because the return value of "org.hibernate.type.descriptor.java.JavaTypeDescriptor.getComparator()" is null
    at org.hibernate.type.AbstractStandardBasicType.compare(AbstractStandardBasicType.java:211) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
    at org.hibernate.type.ComponentType.compare(ComponentType.java:217) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
... Omitted for readability ...

我验证了将TableId列更改为简单字符串可以解决问题。我还应该应用什么来使其与此连接查询一起工作吗？

Answer 1

在这种情况下，id或id部分上的转换器只能意外工作。这方面有一个悬而未决的问题：https://hibernate.atlassian.net/browse/HHH-8820