如何在复合主：Hibernate中使用生成的序列

我在复合主键中使用序列生成器，使用它的正确格式是什么？ 当我持久化两个对象时，我有一个org.hibernate.unUniqueObjectException

提前谢谢

实体

复合类：

方法

@Entity
@Table(name="EXT_TB_TITULAR")
public class ExtTbTitular implements Serializable {
private static final long serialVersionUID = 1L;
@EmbeddedId
private ExtTbTitularPK id;

@Column(name="CTITU_NOMB")
private String ctituNomb;

public ExtTbTitular() {
}

public ExtTbTitularPK getId() {
    return this.id;
}

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

public String getCtituNomb() {
    return this.ctituNomb;
}

public void setCtituNomb(String ctituNomb) {
    this.ctituNomb = ctituNomb;
}
}

   @Embeddable
   public class ExtTbTitularPK implements Serializable {
    private static final long serialVersionUID = 1L;

    private long ntituCodigo;

    private long numeSecue;

    private long solicitudId;

    public ExtTbTitularPK() {
    }

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "entity_titular")
    @SequenceGenerator(name = "entity_titular", sequenceName = "SEQ_EXT_TB_TITULAR",                                allocationSize = 1)
    @Column(name = "NTITU_CODIGO", unique = true, nullable = false)
    public long getNtituCodigo() {
        return this.ntituCodigo;
    }
    //ETC..............

   ExtTbTitulartitular titular = new ExtTbTitular();
   ExtTbTitularPK id = new ExtTbTitularPK(); 
   titular.setId(id);
   titular.getId().setSolicitudId(bean.getSolicitud().getSolicitudId());
   titular.getId().setNumeSecue(bean.getNumeSecue);
   sessionFactory.getCurrentSession().persist(titular);