title: ReferencedColumnNames not mapped to a single property
body: <p>I have 2 Hibernate entities Entities: <strong><code>LanguageToLocaleJpaImpl</code></strong> that has 2 associations with 2 different instance of <strong><code>LocaleJpaImpl</code></strong>.</p>
  
  <p><code>LanguageToLocaleJpaImpl</code> has the following Foreign Keys:</p>
  
  <p><img src="https://i.stack.imgur.com/iRZZI.jpg" alt="enter image description here"></p>
  
  <p>when I launch the Tomcat server I receive this Exception:</p>
  
  <p>ReferencedColumnNames in <strong><code>LanguageToLocaleJpaImpl</code></strong> referencing <strong><code>LocaleJpaImpl</code></strong> are not mapped to a single property</p>
  
  <p>I have really no idea what can cause that. 
  Can you help please?</p>
  
  <p>This is the <strong><code>LanguageToLocaleJpaImpl</code></strong> class:</p>
  
  <pre><code>@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...
  }
  </code></pre>
  
  <p>This is <strong><code>LocaleJpaImpl</code></strong>:</p>
  
  <pre><code>@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&lt;LanguageToLocaleJpaImpl&gt; languageList;
  
      @OneToMany(cascade = CascadeType.ALL, mappedBy = "country")
      private List&lt;LanguageToLocaleJpaImpl&gt; countryList;
  
      public LocaleJpaImpl() {
      }
  
      @XmlTransient
      public List&lt;LanguageToLocaleJpaImpl&gt; getLlanguageList() {
          return languageList;
      }
  
      public void setlanguageListList(List&lt;LanguageToLocaleJpaImpl&gt; languageList) {
          this.languageList = languageList;
      }
  
      @XmlTransient
      public List&lt;LanguageToLocaleJpaImpl&gt; getCountryList() {
          return countryList;
      }
  
      public void setCountryList(List&lt;LanguageToLocaleJpaImpl&gt; countryList) {
          this.countryList = countryList;
      }   
  
      // Getters e Setters, Hashcode, Equals, toString...
  
  }
  </code></pre>