JPA，在连接表上挽救值时遇到麻烦

Question

我在JPA上遇到了一些麻烦。当我试图从联接表中捕获列

@Entity
@Table(name = "servicio")
@XmlRootElement
@NamedQueries({ @NamedQuery(name = "Servicio.findAll", query = "SELECT 
s FROM Servicio s JOIN AreaAplicacion a ON s.id_area_aplicacion = 
a.id")})


public class Servicio implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "id")
private Integer id;
@Basic(optional = false)
@NotNull
@Column(name = "id_area_aplicacion")
private Integer id_area_aplicacion;
@Basic(optional = false)
@NotNull
@Size(min = 1, max = 50)
@Column(name = "servicio")
private String servicio;
@Basic(optional = false)
@NotNull
@Size(min = 1, max = 255)
@Column(name = "descripcion")
private String descripcion;

@Basic(optional = false)
@NotNull
@Size(min = 1, max = 255)
@Column(name = "area")
private String area;

我知道如何捕获主表的字段，但是我不知道如何捕获一个字段，这不是第二个表的外来值。