有几个具有共同属性的实体,因此提取了常见的参数,如下面的代码段。
@MappedSuperclass()
public class BaseCustomerDemographicDetails {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
protected long id;
@ManyToOne
@JoinColumn(name = "GROUP")
protected Group group;
}
实体摘录如下。
@Entity
@Table(name = "INDIVIDUAL_CUSTOMER")
@Access(AccessType.FIELD)
public class IndividualCustomer extends BaseCustomerDemographicDetails {
@NotNull
@Embedded
private PersonalInformation personalInformation;
@Column(precision = 16, scale = 2)
private BigDecimal annualIncome;
private Boolean vip;
private Boolean isStaff;
...
}
@Entity
@Access(AccessType.FIELD)
@Table(name = "GROUP")
public class Group {
protected Group(){}
@Id
@NotNull
@Column(name = "GROUPID")
private String groupId;
@NotNull
@Column(name="GROUPNAME")
private String groupName;
@OneToMany(fetch = FetchType.LAZY, mappedBy = "group")
private List<BaseCustomerDemographicDetails> customerDemographicDetails;
}
同样的OneToMany映射会在statrtup期间导致Hibernate异常,如下所示。
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:1249)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.access$600(EntityManagerFactoryBuilderImpl.java:120)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:860)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:425)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:849)
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:343)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:319)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
... 16 common frames omitted
Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: xx.xxx.xxxxxxx.xxxxxxxxx.domain.model.Group.customerDemographicDetails[xx.xxx.xxxxx.xxxxxxx.domain.model.BaseCustomerDemographicDetails]
at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1135)
at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:794)
at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:729)
at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:70)
at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1697)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1426)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1846)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:857)
... 24 common frames omitted
官方文档与我尝试的内容同步,但没有运气,请帮助!!!!
http://docs.oracle.com/javaee/5/api/javax/persistence/MappedSuperclass.html Stack:Spring Boot with Spring Data JPA
答案 0 :(得分:1)
您无法将关系映射到@MappedSuperclass。请查看参考文档here。 @MappedSuperclass
允许您仅在域模型中实现继承。从数据库的角度来看,这使它成为一个实现细节。 @Inheritance
可以很容易地将通用字段和注释分组到一个通常是抽象的超类中,但是你不能与它建立关系。
如果您使用import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
@Entity(name = "BaseCustomerDemographicDetails")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
public class BaseCustomerDemographicDetails {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
protected long id;
@ManyToOne
@JoinColumn(name = "GROUP_OF_CUSTOMERS")
protected Group groupOfCustomers;
}
,您可以放弃此映射(请注意我必须将GROUP更改为其他内容,因为它是大多数数据库中的保留字):
BaseCustomerDemographicDetails.java
import java.util.List;
import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
@Entity
@Access(AccessType.FIELD)
@Table(name = "GROUP_OF_CUSTOMERS")
public class Group {
protected Group() {
}
@Id
@NotNull
@Column(name = "GROUPID")
private String groupId;
@NotNull
@Column(name = "GROUPNAME")
private String groupName;
@OneToMany(fetch = FetchType.LAZY, mappedBy = "groupOfCustomers")
private List<BaseCustomerDemographicDetails> customerDemographicDetails;
}
Group.java
import java.math.BigDecimal;
import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.Column;
import javax.persistence.Entity;
@Entity
@Access(AccessType.FIELD)
public class IndividualCustomer extends BaseCustomerDemographicDetails {
@NotNull
@Embedded
private PersonalInformation personalInformation;
@Column(precision = 16, scale = 2)
private BigDecimal annualIncome;
private Boolean vip;
private Boolean isStaff;
}
IndividualCustomer.java(无变化)
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