@Entity
@Table( name = "T_TABLE_J" )
public class ClasseJ implements Serializable
{
  @Id
  @GeneratedValue( strategy = GenerationType.IDENTITY )
  @Column( name = "J_ID" )
  private Long id;

  @Column( name = "J_REMARQUE" )
  private String remarque;
  
  @ManyToMany( mappedBy = "listeJ" )
  private List< ClasseK > listeK;
...