java - How to save nested JSON into entities with one-to-one relationship that shares primary key?

Question

I basically want the following:

1. primary key to be generated by the user
2. the primary key is passed to the login as pk/fk

I have found similar problems but can't seem to find a solution that works.

@Entity
public class User{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column(nullable = false)
    private String firstName;
    private String middleName;
    @Column(nullable = false)
    private String lastName;
    @Column(nullable = false)
    private LocalDate dateOfBirth;
    @Column(nullable = false)
    private String socialSecurity;
    @Column(nullable = false)
    private String email;
    @Column(nullable = false)
    private String phoneNumber;

    @OneToOne(mappedBy = "user", cascade = CascadeType.ALL, fetch =  FetchType.LAZY)
    @PrimaryKeyJoinColumn 

    public Login getLogin() {
        return login;
    }

    public void setLogin(Login login) {
        this.login = login;
    }

@Entity
public class Login{
    @Id
    private Long id;
    @Column(nullable = false)
    private String username;
    @Column(nullable = false)
    private String password;

    @MapsId
    @OneToOne
    private User user;

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

public class UserServices {
   
    @Autowired
    private UserRepo userRepo;

    public User createUser(User user) {
        return userRepo.save(user);
    }

This is the error I am getting:

org.hibernate.id.IdentifierGenerationException: attempted to assign id from null one-to-one property [runner.entities.Login.user]
    at org.hibernate.id.ForeignGenerator.generate(ForeignGenerator.java:87) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:115) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:185) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:128) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:113) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:744) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:712) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.engine.spi.CascadingActions$7.cascade(CascadingActions.java:298) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:492) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:416) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:218) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:151) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:427) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:264) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:123) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:185) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:128) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:55) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:102) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:720) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:706) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_271]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_271]

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_271]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_271]
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:362) ~[spring-orm-5.3.2.jar:5.3.2]
    at com.sun.proxy.$Proxy89.persist(Unknown Source) ~[na:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_271]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_271]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_271]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_271]
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:311) ~[spring-orm-5.3.2.jar:5.3.2]
    at com.sun.proxy.$Proxy89.persist(Unknown Source) ~[na:na]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:557) ~[spring-data-jpa-2.4.2.jar:2.4.2]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_271]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_271]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_271]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_271]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker$RepositoryFragmentMethodInvoker.lambda$new$0(RepositoryMethodInvoker.java:289) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:137) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:121) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:524) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:285) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:531) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.2.jar:5.3.2]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:156) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:131) ~[spring-data-commons-2.4.2.jar:2.4.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.2.jar:5.3.2]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-5.3.2.jar:5.3.2]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388) ~[spring-tx-5.3.2.jar:5.3.2]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.2.jar:5.3.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.2.jar:5.3.2]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137) ~[spring-tx-5.3.2.jar:5.3.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.2.jar:5.3.2]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:174) ~[spring-data-jpa-2.4.2.jar:2.4.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.2.jar:5.3.2]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.2.jar:5.3.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.2.jar:5.3.2]

I am trying to post the JSON below through postman but keep getting the error above

{
    "firstName": "firstname",
    "middleName": null,
    "lastName": "lastname",
    "dateOfBirth": "1990-01-01",
    "socialSecurity": "112555545",
    "email": "[email protected]",
    "phoneNumber": "123-345-6789",
    "login":{
        "username":"username",
        "password":"password"
    }
}

Answer 1

mappedBy = "user", means the class Login manage the cascade. your should persist Login.