ReferencedColumnNames not mapped to a single property

Question

I have 2 Hibernate entities Entities: LanguageToLocaleJpaImpl that has 2 associations with 2 different instance of LocaleJpaImpl.

LanguageToLocaleJpaImpl has the following Foreign Keys:

when I launch the Tomcat server I receive this Exception:

ReferencedColumnNames in LanguageToLocaleJpaImpl referencing LocaleJpaImpl are not mapped to a single property

I have really no idea what can cause that. Can you help please?

This is the LanguageToLocaleJpaImpl class:

@Entity
@Table(name = "LANGUAGE_TO_LOCALE")
@XmlRootElement

public class LanguageToLocaleJpaImpl extends BaseEntityJpaSupport implements Serializable, LanguageToLocale {
    private static final long serialVersionUID = 1L;
    @Id
    @Basic(optional = false)
    @NotNull
    @GeneratedValue( strategy = GenerationType.AUTO)
    @Column(name = "LANGUAGE_TO_LOCALE_ID")
    private Integer languageToLocaleId;

    @Basic(optional = false)
    @NotNull
    @Column(name = "ACTIVE_FLAG")
    private boolean activeFlag;

    @Basic(optional = false)
    @NotNull
    @Column(name = "DEFAULT_FLAG")
    private boolean defaultFlag;

    @Column(name = "CREATED_DATE")
    @Temporal(TemporalType.TIMESTAMP)
    private Date createdDate;

    @Column(name = "UPDATED_DATE")
    @Temporal(TemporalType.TIMESTAMP)
    private Date updatedDate;

    @JoinColumn(name = "LOCALE_ID", referencedColumnName = "LOCALE_ID")
    @ManyToOne(optional = false)
    private LocaleJpaImpl country;

    @JoinColumn(name = "LANGUAGE_ID", referencedColumnName = "LOCALE_ID")
    @ManyToOne(optional = false)
    private LocaleJpaImpl language;    

    public LanguageToLocaleJpaImpl() {
    }

    // Getters e Setters, Hashcode, Equals, toString...
}

This is LocaleJpaImpl:

@Entity
@Table(name = "LOCALE")
@XmlRootElement
public class LocaleJpaImpl extends BaseEntityJpaSupport implements java.io.Serializable {   

    private static final long serialVersionUID = 1L;

    @Id
    @Basic(optional = false)
    @NotNull
    @Column(name = "LOCALE_ID")
    private int localeId;

    @Basic(optional = false)
    @NotNull
    @Column(name = "CREATED_DATE")
    @Temporal(TemporalType.TIMESTAMP)
    private Date createdDate;

    @Size(max = 2)
    @Column(name = "LANGUAGE_CODE")    
    private String languageCode;

    @Size(max = 2)
    @Column(name = "COUNTRY_CODE")    
    private String countryCode;

    @Size(max = 10)
    @Column(name = "VARIANT_CODE")
    private String variantCode;

    @Size(max = 100)
    @Column(name = "FLAG_ICON_URL")
    private String flagIconUrl;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "language")
    private List<LanguageToLocaleJpaImpl> languageList;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "country")
    private List<LanguageToLocaleJpaImpl> countryList;

    public LocaleJpaImpl() {
    }

    @XmlTransient
    public List<LanguageToLocaleJpaImpl> getLlanguageList() {
        return languageList;
    }

    public void setlanguageListList(List<LanguageToLocaleJpaImpl> languageList) {
        this.languageList = languageList;
    }

    @XmlTransient
    public List<LanguageToLocaleJpaImpl> getCountryList() {
        return countryList;
    }

    public void setCountryList(List<LanguageToLocaleJpaImpl> countryList) {
        this.countryList = countryList;
    }   

    // Getters e Setters, Hashcode, Equals, toString...

}

Answer 1

As I could understand Hibernate already recognise the primary key of the associated LocaleJpa and consequentely thinks that there are 2 foreign keys defining the relation between the two classes. I solved the issue removing the @Id annotation and instead I added

@AttributeOverride(name="id", column=@Column(name="LOCALE_ID"))

before the class signature.