Bidirectional @OneToOne with JoinTable

[Subhendu Mahanta]

I have 2 entities :Customer & Address.

With @OneToOne and @JoinTable Customer.java looks like this:

package com.hibernaterecipes.chapter5;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name="CUSTOMER")
public class Customer {
@Column (name="ID")
@Id
@GeneratedValue (strategy=GenerationType.AUTO)
private Long id;

@Column (name="COUNTRY_CODE")
private String countryCode;

@Column (name="ID_CARD_NO")
private String idCardNo;

@Column (name="FIRST_NAME")
private String firstName;

@Column (name="LAST_NAME")
private String lastName;

@Column (name="EMAIL")
private String email;

@OneToOne (cascade=CascadeType.ALL)
@JoinTable (name="CustomerAddress", 
        joinColumns=@JoinColumn(name="ID"),
        inverseJoinColumns=@JoinColumn(name="ADDRESS_ID"))
private Address address;

public Long getId() {
    return id;
}
public void setId(Long id) {
    this.id = id;
}
public String getCountryCode() {
    return countryCode;
}
public void setCountryCode(String countryCode) {
    this.countryCode = countryCode;
}
public String getIdCardNo() {
    return idCardNo;
}
public void setIdCardNo(String idCardNo) {
    this.idCardNo = idCardNo;
}
public String getFirstName() {
    return firstName;
}
public void setFirstName(String firstName) {
    this.firstName = firstName;
}
public String getLastName() {
    return lastName;
}
public void setLastName(String lastName) {
    this.lastName = lastName;
}

public String getEmail() {
    return email;
}
public void setEmail(String email) {
    this.email = email;
}
public Address getAddress() {
    return address;
}
public void setAddress(Address address) {
    this.address = address;
}

}

Now Address.java

package com.hibernaterecipes.chapter5;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name="ADDRESS")
public class Address {
@Id
@Column (name="ADDRESS_ID")
@GeneratedValue (strategy=GenerationType.AUTO)
private Long id;

@Column(name="CITY")
private String city;

@Column(name="STREET")
private String street;

@Column(name="DOOR_PLATE")
private String doorplate;

@OneToOne (mappedBy="address")
private Customer customer;

public Customer getCustomer() {
    return customer;
}
public void setCustomer(Customer customer) {
    this.customer = customer;
}
public Long getId() {
    return id;
}
public void setId(Long id) {
    this.id = id;
}
public String getCity() {
    return city;
}
public void setCity(String city) {
    this.city = city;
}
public String getStreet() {
    return street;
}
public void setStreet(String street) {
    this.street = street;
}
public String getDoorplate() {
    return doorplate;
}
public void setDoorplate(String doorplate) {
    this.doorplate = doorplate;
}

 }

When I try to persist a customer I get the following stack-trace:

Exception in thread "main" org.hibernate.PropertyValueException: not-null property references a null or transient value: com.hibernaterecipes.chapter5.Address.customer
at org.hibernate.engine.Nullability.checkNullability(Nullability.java:72)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:284)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:180)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:108)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:98)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:507)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:499)
at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:218)
at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:268)
at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:216)
at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:169)
at org.hibernate.engine.Cascade.cascade(Cascade.java:130)
at org.hibernate.event.def.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:412)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:261)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:180)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:108)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
at com.hibernaterecipes.chapter5.Launch5_6A.main(Launch5_6A.java:29)

I have tried this change in Address entity:

@OneToOne(mappedBy="address",optional=true)
	@JoinTable(name="CustomerAddress",
		joinColumns=
		     @JoinColumn(name="ADDRESS_ID", referencedColumnName="ADDRESS_ID",unique=true),
		inverseJoinColumns=
		     @JoinColumn(name="ID", referencedColumnName="ID"))

with no effect. Surely this could be done without using JoinTable.But I want to do it this way for academic interest.Is it possibe?

[Ran Pleasant]

I assume that this design is part of a learning experience. However, if this is a production design then you should ask yourself, Does an address really need to point back to its owner?

[Subhendu Mahanta]

Thanks Ron.
You are correct that this is part of a learning experience.There is no need for address to point back to customer.Let's say there are 2 entities A & B which have a bi-directional association. In that case I think shared primary key will be the preferred technique.

[Subhendu Mahanta]

I wanted to mean "Thanks Ran".Sorry for the typo.