對可能為null或不為null的屬性應用限制

Question

以下是偵聽器類的類定義，該類也是數據庫實體。 它與TLS實體有關系。

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
@Entity
@Table(name = "LISTENER")
@IdClass(EntityId.class)

public class Listener implements MultitenantEntity, AuditedEntity {

    @Id
    @Column(name = "LISTENER_ID")
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    public String id;

    @Id
    @Column(name = "LISTENER_INSTANCE_ID")
    private String instanceId;

    @OneToMany(mappedBy="listener", cascade=CascadeType.ALL, fetch=FetchType.EAGER)
    @Fetch(value= FetchMode.SELECT)
    private List<Path> paths;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns ({
        @JoinColumn(name="TLS_NAME"),
        @JoinColumn(name="INSTANCE_ID")
    })
    @Fetch(value=FetchMode.SELECT)
    private TlsDescriptor tlsDescriptor;

    @Embedded
    @Builder.Default private AuditMetadata audit = new AuditMetadata();
}

以下是TLS的類定義，它也是一個數據庫實體：

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
@Entity
@Table(name = "TLS_DESCRIPTOR")
@IdClass(EntityId.class)
public class TlsDescriptor implements MultitenantEntity, AuditedEntity        {
    @Id
    @Column(name = "TLS_NAME")
    public String id;

    @Id
    @Column(name = "INSTANCE_ID")
    private String instanceId;

    @Column(name = "TLS_PROTOCOL")
    public String tlsProtocol;

    @Column(name = "CIPHERS")
    public String ciphers;

    @Lob
    @Column(name = "CERTIFICATE", nullable = false)
    public String certificate;

    @Lob
    @Column(name = "PRIVATE_KEY", nullable = false)
    public String privateKey;

    @Embedded
    @Builder.Default private AuditMetadata audit = new AuditMetadata();
}

在這里，AuditMetadata是一個類，其中包含諸如createdTimestamp和ModifyedTimestamp之類的屬性，本質上跟蹤與之關聯的對象的創建時間和修改時間。

現在，我編寫了下面的Hibernate查詢，該查詢嘗試為其獲取偵聽器對象：

1. 在“時間戳記”中提到的時間過去之后，要么更新偵聽器本身

2. 或者在“時間戳記”中提到的時間過去之后，相關路徑已更新

3. 或者相關的tlsDescriptor在“時間戳記”中提到的時間過去之后已更新

     public List<Listener> findAll(long timestamp, long now, Pageable pageable) { return super.find(currentSession() .createCriteria(Listener.class, "listener") .createAlias("listener.paths", "path") .add(Restrictions.or( Restrictions.between("audit.modifyTimestamp", new Date(timestamp), new Date(now)), Restrictions.between("path.audit.modifyTimestamp", new Date(timestamp), new Date(now)), Restrictions.between("listener.tlsDescriptor.audit.modifyTimestamp", new Date(timestamp), new Date(now)))) .add(Restrictions.isNotEmpty("listener.paths")), pageable); 

   }

現在的問題是，path是必填字段，而tlsDescriptor是可選字段。 因此，當存在tlsDescriptor時，該查詢工作正常，但如果不存在，則會出現以下錯誤：

org.hibernate.QueryException: could not resolve property: tlsDescriptor.audit.modifyTimestamp of:Listener

我試圖嘗試使用Hibernate的合取，析取，AND和OR語句解決此問題，但此錯誤不斷重復！

Answer 1

對帶有JoinType.LEFT_OUTER_JOIN的tlsDescriptor使用別名（因此，如果相關模型為null，則結果不會為空）：

public List<Listener> findAll(long timestamp, long now, Pageable pageable) {
return super.find(currentSession()
                .createCriteria(Listener.class, "listener")
                .createAlias("listener.paths", "path")
                .createAlias("listener.tlsDescriptor", "tls", JoinType.LEFT_OUTER_JOIN)
                .add(Restrictions.or(
                        Restrictions.between("audit.modifyTimestamp", new Date(timestamp), new Date(now)),
                        Restrictions.between("path.audit.modifyTimestamp", new Date(timestamp), new Date(now)),
                        Restrictions.between("tls.audit.modifyTimestamp", new Date(timestamp), new Date(now)))),
        pageable);