Héritage et relations oneToMany/manyToOne

package entity;

@Entity
public class Annonceur {
	
	private Integer id;
	private ArrayList<Annonce> liste_annonces;
	
	
	public ArrayList<Annonce> getListe_annonces() {
		return liste_annonces;
	}

	public void setListe_annonces(ArrayList<Annonce> liste_annonces) {
		this.liste_annonces = liste_annonces;
	}

	public Annonceur(){liste_annonces=new ArrayList<Annonce>();};
	
	@OneToMany(mappedBy = "annonceur", cascade = { CascadeType.PERSIST })
	

	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	
}

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public class Annonce implements Serializable{
	private Integer id;
	private Annonceur  annonceur;
	public Annonce(){};
	
	@ManyToOne(fetch=FetchType.LAZY)
	public Annonceur getAnnonceur() {
		return annonceur;
	}
	public void setAnnonceur(Annonceur annonceur) {
		this.annonceur = annonceur;
	}
	private static final long serialVersionUID = -1560458286223159429L;
	@SuppressWarnings("unused")
	@Version
	private int version;
	
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}	
}

@Entity
public class Evenement extends Annonce {
...
}