所以我有这个kotlin项目:
package com.example.demo
import org.springframework.data.jpa.repository.JpaRepository
import org.springframework.data.repository.CrudRepository
import java.util.*
import javax.persistence.*
@MappedSuperclass
abstract class ContainerEntity<TData : DataEntity> {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Int = 0
@OneToOne(fetch = FetchType.EAGER, cascade = [CascadeType.ALL], optional = false)
lateinit var data: TData
}
@MappedSuperclass
abstract class DataEntity {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Int = 0
val created = Date()
}
@Entity
class Car : ContainerEntity<CarData>()
@Entity
class CarData : DataEntity() {
var color = "red"
}
@Entity
class Apple : ContainerEntity<AppleData>()
@Entity
class AppleData : DataEntity() {
var age = 32
}
/**
* WORKS
*/
interface CarRepository : CrudRepository<Car, Int> {
fun findByDataColor(color: String): Car?
}
/**
* FAILS
*/
interface AppleRepository : CrudRepository<Apple, Int> {
fun findByDataAge(age: Int): Apple?
}
获取此异常:
Caused by: java.lang.IllegalArgumentException: Unable to locate Attribute with the the given name [age] on this ManagedType [com.example.demo.DataEntity]
at org.hibernate.metamodel.internal.AbstractManagedType.checkNotNull(AbstractManagedType.java:128) ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final]
at org.hibernate.metamodel.internal.AbstractManagedType.getAttribute(AbstractManagedType.java:113) ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final]
at org.hibernate.metamodel.internal.AbstractManagedType.getAttribute(AbstractManagedType.java:111) ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final]
at org.hibernate.query.criteria.internal.path.SingularAttributePath.locateAttributeInternal(SingularAttributePath.java:71) ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final]
at org.hibernate.query.criteria.internal.path.AbstractPathImpl.locateAttribute(AbstractPathImpl.java:204) ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final]
at org.hibernate.query.criteria.internal.path.AbstractPathImpl.get(AbstractPathImpl.java:177) ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final]
at org.springframework.data.jpa.repository.query.QueryUtils.toExpressionRecursively(QueryUtils.java:673) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.QueryUtils.toExpressionRecursively(QueryUtils.java:606) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.QueryUtils.toExpressionRecursively(QueryUtils.java:578) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.JpaQueryCreator$PredicateBuilder.getTypedPath(JpaQueryCreator.java:381) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.JpaQueryCreator$PredicateBuilder.build(JpaQueryCreator.java:304) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.JpaQueryCreator.toPredicate(JpaQueryCreator.java:209) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.JpaQueryCreator.create(JpaQueryCreator.java:122) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.JpaQueryCreator.create(JpaQueryCreator.java:57) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.repository.query.parser.AbstractQueryCreator.createCriteria(AbstractQueryCreator.java:119) ~[spring-data-commons-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:95) ~[spring-data-commons-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:81) ~[spring-data-commons-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.<init>(PartTreeJpaQuery.java:147) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$CountQueryPreparer.<init>(PartTreeJpaQuery.java:270) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:79) ~[spring-data-jpa-2.1.8.RELEASE.jar:2.1.8.RELEASE]
... 98 common frames omitted
有一个小型演示项目:https://github.com/TomGrill/spring-hibernate-bug
根据要求:
//@MappedSuperclass
@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
abstract class ContainerEntity<TData : DataEntity> {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Int = 0
@OneToOne(fetch = FetchType.EAGER, cascade = [CascadeType.ALL], optional = false)
lateinit var data: TData
}
//@MappedSuperclass
@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
abstract class DataEntity {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Int = 0
val created = Date()
}
答案 0 :(得分:0)
您将@MappedSuperclass与DataEntity一起使用,但应使用@Inheritance。
@MappedSuperclass是告诉JPA的注释,所有子类必须具有继承的属性,但与JPA继承无关。
要在JPA中使用继承,必须使用@Inheritance。
有三种策略定义了如何将initritit树存储到数据库中:SINGLE_TABLE,JOINED和TABLE_PER_CLASS。