传递给persist:Profile的java分离实体
我有以下两个实体：
@Entity
public class Profile implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue
private int id;
@OneToOne
@JoinColumn(nullable = false, name = "USERNAME_FK")
private RegisteredUser user;
...
及
@Entity
public class RegisteredUser implements Serializable {
private static final long serialVersionUID = 1L;
@Id
private int id;
@OneToOne
@JoinColumn(nullable = false, name = "USERNAME_FK")
private User user;
@OneToOne(cascade = CascadeType.ALL, mappedBy = "user")
private Profile profile;
...
我使用“存储库”和hibernate将实体存储到数据库中。我希望通过使用注释，我的实体尽可能健壮，但这只会给我带来很多问题
目前，我有以下代码：
@Autowired
private RegisteredUserRepository rur;
@Autowired
private UserRepository ur;
...
// Creating a user
User root = new User("root", "1234", "root@root.com");
root.setFirstName("root");
root.setLastName("root");
root = ur.save(root);
Profile profile = new Profile(String.format("%s", root.getFullName()));
RegisteredUser registeredUser = new RegisteredUser(profile);
root.setRegisteredUser(registeredUser);
registeredUser = rur.save(registeredUser);
registeredUser = rur.save(registeredUser); // PROBLEM HERE!
问题的追溯是：
Caused by: org.hibernate.PersistentObjectException: detached entity passed to persist: com.mycompany.app.models.Profile
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:139) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:801) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:794) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.jpa.event.internal.core.JpaPersistEventListener$1.cascade(JpaPersistEventListener.java:97) ~[hibernate-entitymanager-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:350) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:293) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:161) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:118) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:470) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:295) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:195) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:138) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.jpa.event.internal.core.JpaPersistEventListener.saveWithGeneratedId(JpaPersistEventListener.java:84) ~[hibernate-entitymanager-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:206) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:149) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:75) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:811) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:784) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:789) ~[hibernate-core-4.3.11.Final.jar:4.3.11.Final]
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:1181) ~[hibernate-entitymanager-4.3.11.Final.jar:4.3.11.Final]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_40]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_40]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_40]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_40]
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:294) ~[spring-orm-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at com.sun.proxy.$Proxy88.persist(Unknown Source) ~[na:na]
at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:439) ~[spring-data-jpa-1.9.4.RELEASE.jar:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_40]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_40]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_40]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_40]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:483) ~[spring-data-commons-1.11.4.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:468) ~[spring-data-commons-1.11.4.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:440) ~[spring-data-commons-1.11.4.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.11.4.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.2.5.RELEASE.jar:4.2.5.RELEASE]
... 21 common frames omitted
我试图做到的是，当我试图保存注册用户的第二次数据时，它会正确地更新表
我怎样才能解决这个问题？我已经看到，这可能是因为我如何实现setter和getter，所以它们是：
类^{
public Profile getProfile() {
return profile;
}
public void setProfile(Profile profile) {
if (sameAsFormer(profile)) {
return;
}
Profile oldProfile = this.profile;
this.profile = profile;
if (oldProfile != null) {
oldProfile.setRegisteredUser(null);
}
if (this.profile != null) {
this.profile.setRegisteredUser(this);
}
}
在Profile中的setter和getter：
public RegisteredUser getRegisteredUser() {
return user;
}
public void setRegisteredUser(RegisteredUser u) {
user = u;
}
# 1 楼答案
未为
RegisteredUser实体指定Id生成器，这意味着生成策略为assigned（保存前必须提供Id值）因为没有指定id值，
registeredUser实例在第二个save调用中也被认为是暂时的。Persist操作被级联到关联的Profile中，该操作已在第一次调用中以正确的自动生成id保存（它在其id字段上有@GeneratedValue注释），因此在新事务中被认为是分离的最简单的解决方案是为
RegisteredUser定义id生成器：