Criteria JPA - 特定属性

Question

我需要创建一个代表以下JPQL的条件查询：

我尝试指定RegraContrato类，但没有成功。

SELECT G FROM Grupo G JOIN G.regras R WHERE TYPE（R）= RegraContrato AND R.numeroContrato in（123）

@Entity
@Table(name = "GRUPO_ACESSO")
public class Grupo {

    @OneToMany(mappedBy = "grupo",cascade = CascadeType.ALL,fetch = FetchType.EAGER,orphanRemoval = true)
    private Set<Regra> regras = Sets.newHashSet();
}

@Entity
@Table(name = "REGRA_ACESSO")
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class Regra {

    private static final long serialVersionUID = 5994730323053219858L;

    @Id
    @SequenceGenerator(name = "REGRA_ID_GENERATOR",sequenceName = "REGRA_SEQUENCE",allocationSize = 1)
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "REGRA_ID_GENERATOR")
    @Column(name = "ID")
    private Long id;

}

@Entity
@PrimaryKeyJoinColumn(name = "ID")
@Table(name = "REGRA_CNPJ")
public class RegraCNPJ extends Regra {

    @Column(name = "CNPJ")
    private String cnpj;
}

@Entity
@PrimaryKeyJoinColumn(name = "ID")
@Table(name = "REGRA_CONTRATO")
public class RegraContrato extends Regra {

    private static final long serialVersionUID = -2840125767126128182L;

    @Column(name = "NUMERO_CONTRATO")
    private Long numeroContrato;

}