我无法使用连接表(https://stackoverflow.com/a/7603036& https://en.wikibooks.org/wiki/Java_Persistence/ManyToMany#Mapping_a_Join_Table_with_Additional_Columns)实现多对多关系。当我尝试重现它时,持久性单元无法构建EntityManagerFactory。似乎Envers无法读取映射的属性,尽管它看起来不错。我究竟做错了什么?使用额外列(和Envers)实现多对多关系的正确方法是什么?
Product.java
@Entity
@Audited
public class Product extends UserModel {
...
@OneToMany(mappedBy = "product", orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.EAGER)
public List<ProductForm> forms = new ArrayList<ProductForm>();
...
}
Form.java
@Entity
@Audited
public class Form extends UserModel {
...
@OneToMany(mappedBy = "form", fetch = FetchType.LAZY)
public List<ProductForm> products = new ArrayList<ProductForm>();
...
}
ProductForm.java
@Entity
@Table(name = "Product_Form")
@IdClass(ProductForm.ProductFormId.class)
public class ProductForm {
@Id
@JoinColumn(name = "product_id")
@ManyToOne
public Product product;
@Id
@JoinColumn(name = "form_id")
@ManyToOne
public Form form;
public ProductForm(Product product, Form form) {
this.product = product;
this.form = form;
}
@Embeddable
@SuppressWarnings("serial")
public class ProductFormId implements Serializable {
@Column(name = "product_id")
public Long product;
@Column(name = "form_id")
public Long form;
}
}
堆栈跟踪
play.api.UnexpectedException: Unexpected exception[PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$1.apply(ApplicationProvider.scala:142) ~[play_2.10-2.1.1.jar:2.1.1]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$1.apply(ApplicationProvider.scala:106) ~[play_2.10-2.1.1.jar:2.1.1]
at scala.Option.map(Option.scala:145) ~[scala-library.jar:na]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:106) ~[play_2.10-2.1.1.jar:2.1.1]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:104) ~[play_2.10-2.1.1.jar:2.1.1]
at scala.util.Either$RightProjection.flatMap(Either.scala:523) [scala-library.jar:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:930) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:904) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:72) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63) ~[hibernate-jpa-2.0-api-1.0.1.Final.jar:1.0.1.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47) ~[hibernate-jpa-2.0-api-1.0.1.Final.jar:1.0.1.Final]
at play.db.jpa.JPAPlugin.onStart(JPAPlugin.java:35) ~[play-java-jpa_2.10-2.1.1.jar:2.1.1]
Caused by: org.hibernate.MappingException: Unable to read the mapped by attribute for products in models.ProductForm!
at org.hibernate.envers.configuration.metadata.CollectionMetadataGenerator.getMappedBy(CollectionMetadataGenerator.java:642) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.CollectionMetadataGenerator.addOneToManyAttached(CollectionMetadataGenerator.java:187) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.CollectionMetadataGenerator.addCollection(CollectionMetadataGenerator.java:169) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.addValueInSecondPass(AuditMetadataGenerator.java:223) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.addValue(AuditMetadataGenerator.java:245) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.addProperties(AuditMetadataGenerator.java:258) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
PS我尝试将@AuditMappedBy(mappedBy = "product")
添加到Product:
play.api.UnexpectedException: Unexpected exception[PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$1.apply(ApplicationProvider.scala:142) ~[play_2.10-2.1.1.jar:2.1.1]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$1.apply(ApplicationProvider.scala:106) ~[play_2.10-2.1.1.jar:2.1.1]
at scala.Option.map(Option.scala:145) ~[scala-library.jar:na]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:106) ~[play_2.10-2.1.1.jar:2.1.1]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:104) ~[play_2.10-2.1.1.jar:2.1.1]
at scala.util.Either$RightProjection.flatMap(Either.scala:523) [scala-library.jar:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:930) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:904) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:72) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63) ~[hibernate-jpa-2.0-api-1.0.1.Final.jar:1.0.1.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47) ~[hibernate-jpa-2.0-api-1.0.1.Final.jar:1.0.1.Final]
at play.db.jpa.JPAPlugin.onStart(JPAPlugin.java:35) ~[play-java-jpa_2.10-2.1.1.jar:2.1.1]
Caused by: org.hibernate.MappingException: @AuditMappedBy points to a property that doesn't exist: models.ProductForm.product
at org.hibernate.envers.configuration.ClassesAuditingData.forcePropertyInsertable(ClassesAuditingData.java:84) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.ClassesAuditingData.updateCalculatedFields(ClassesAuditingData.java:70) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.EntitiesConfigurator.configure(EntitiesConfigurator.java:85) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.AuditConfiguration.<init>(AuditConfiguration.java:114) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.AuditConfiguration.getFor(AuditConfiguration.java:164) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.event.EnversIntegrator.integrate(EnversIntegrator.java:64) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
修改
当我向@Audited
添加ProductForm
时仍然会出现相同的错误,下面是最新的堆栈跟踪。
play.api.UnexpectedException: Unexpected exception[PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$1.apply(ApplicationProvider.scala:142) ~[play_2.10-2.1.1.jar:2.1.1]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$1.apply(ApplicationProvider.scala:106) ~[play_2.10-2.1.1.jar:2.1.1]
at scala.Option.map(Option.scala:145) ~[scala-library.jar:na]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:106) ~[play_2.10-2.1.1.jar:2.1.1]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:104) ~[play_2.10-2.1.1.jar:2.1.1]
at scala.util.Either$RightProjection.flatMap(Either.scala:523) [scala-library.jar:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:930) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:904) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:72) ~[hibernate-entitymanager-4.2.0.Final.jar:4.2.0.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63) ~[hibernate-jpa-2.0-api-1.0.1.Final.jar:1.0.1.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47) ~[hibernate-jpa-2.0-api-1.0.1.Final.jar:1.0.1.Final]
at play.db.jpa.JPAPlugin.onStart(JPAPlugin.java:35) ~[play-java-jpa_2.10-2.1.1.jar:2.1.1]
Caused by: org.hibernate.MappingException: Unable to read the mapped by attribute for products in models.ProductForm!
at org.hibernate.envers.configuration.metadata.CollectionMetadataGenerator.getMappedBy(CollectionMetadataGenerator.java:642) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.CollectionMetadataGenerator.addOneToManyAttached(CollectionMetadataGenerator.java:187) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.CollectionMetadataGenerator.addCollection(CollectionMetadataGenerator.java:169) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.addValueInSecondPass(AuditMetadataGenerator.java:223) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.addValue(AuditMetadataGenerator.java:245) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.addProperties(AuditMetadataGenerator.java:258) ~[hibernate-envers-4.2.0.Final.jar:4.2.0.Final]
答案 0 :(得分:2)
如果问题是由复合键引起的,请尽可能将hibernate版本更新为5.2.2。因为此版本中修复了此错误。
答案 1 :(得分:1)
您所寻求的是我所称的&#34;关联实体&#34;。我有一些它们,一般来说我建议不要使用复合id,因为它们周围往往有很多边缘情况。
相反,为关联实体提供自己的id,在外键对上放置唯一索引,然后为两个关联实体添加关联(并省略其ID)。这是一个精简的例子:
@Entity
class A {
@Id
private Integer aId;
@OneToMany(mappedBy="a")
private AtoB aToB;
}
@Entity
class B {
@Id
private Integer bId;
@ManyToOne
@JoinColumn(name="b")
private AtoB aToB;
}
@Entity
class AtoB {
@Id
private Integer aToBId;
@ManyToOne
@JoinColumn(name="aId")
private A a;
@OneToMany(mappedBy="aToB")
private B b;
}
这有意义吗?
答案 2 :(得分:0)
就Hibernate而言,您有三个具有一对多关联的实体。
因此,审核“加入”实体应该可以解决问题:将@Audited
添加到ProductForm
。