Hibernate @LazyToOne(LazyToOneOption.NO_PROXY) @OneToOne(fetch = FetchType.LAZY) 总是急切获取

Question

我的目标是在关联的 parent-side 上为双向 ono-to-one 关联启用延迟加载。考虑以下两个实体：

Parent Vendor.java:

@Entity
@Audited
@NoArgsConstructor
@Getter
public class Vendor extends User {

    @JoinColumn(nullable = false, unique = true, updatable = false)
    @LazyToOne(LazyToOneOption.NO_PROXY)
    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "vendor", optional = false, orphanRemoval = true)
    private Operator operator;

}

Child Operator.java:

@Entity
@Audited
@Builder
@AllArgsConstructor
@NoArgsConstructor
@Getter
public class Operator {

    @Id
    private Long id;

    @JoinColumn(name = "id")
    @MapsId
    @OneToOne(fetch = FetchType.LAZY, optional = false)
    private Vendor vendor;

}

注意： 为了简洁起见，我省略了其他字段、构造函数和 equals/hashCode 函数。

如前所述，我的目标是延迟加载供应商的运营商。因此，在 Hibernate user guide and Vlad Mihalcea's tutorial on how to enable bytecode enhancement in Hibernate 之后，除了 @OneToOne 和 fetch = FetchType.LAZY 之外，我还注释了 parent-side 与 @LazyToOne(LazyToOneOption.NO_PROXY) 的关联。将以下插件添加到我的 pom.xml 后，操作员仍然在获取供应商时急切地加载。

插件配置：

      <plugin>
        <groupId>org.hibernate.orm.tooling</groupId>
        <artifactId>hibernate-enhance-maven-plugin</artifactId>
        <version>${hibernate.version}</version>
        <executions>
          <execution>
            <configuration>
              <failOnError>true</failOnError>
              <enableLazyInitialization>true</enableLazyInitialization>
              <enableDirtyTracking>true</enableDirtyTracking>
              <enableAssociationManagement>true</enableAssociationManagement>
            </configuration>
            <goals>
              <goal>enhance</goal>
            </goals>
          </execution>
        </executions>
      </plugin>

当我获取供应商时，会生成以下 SQL：

2019-10-18 13:43:16.138  INFO 12212 --- [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:8, Time:2, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select vendor0_.id as id1_39_0_, vendor0_1_.created_at as created_2_39_0_, vendor0_1_.version as version3_39_0_, vendor0_1_.account_non_locked as account_4_39_0_, vendor0_1_.email as email5_39_0_, vendor0_1_.email_verified as email_ve6_39_0_, vendor0_1_.enabled as enabled7_39_0_, vendor0_1_.last_password_reset_date as last_pas8_39_0_, vendor0_1_.password as password9_39_0_, vendor0_.address_district as address_1_43_0_, vendor0_.address_latitude as address_2_43_0_, vendor0_.address_longitude as address_3_43_0_, vendor0_.address_city as address_4_43_0_, vendor0_.address_country_code as address_5_43_0_, vendor0_.address_street as address_6_43_0_, vendor0_.address_street_no as address_7_43_0_, vendor0_.address_zip_code as address_8_43_0_, vendor0_.contact_details_email as contact_9_43_0_, vendor0_.contact_details_phone as contact10_43_0_, vendor0_.customer_no_customer_no as custome17_43_0_, vendor0_.description as descrip11_43_0_, vendor0_.hidden as hidden12_43_0_, vendor0_.name as name13_43_0_, vendor0_.slug as slug14_43_0_, vendor0_.verified as verifie15_43_0_ from vendor vendor0_ inner join users vendor0_1_ on vendor0_.id=vendor0_1_.id where vendor0_.id=?"]
Params:[(4)]

2019-10-18 13:43:16.141  INFO 12212 --- [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:8, Time:1, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select operator0_.id as id1_17_0_, operator0_.address_city as address_2_17_0_, operator0_.address_country_code as address_3_17_0_, operator0_.address_street as address_4_17_0_, operator0_.address_street_no as address_5_17_0_, operator0_.address_zip_code as address_6_17_0_, operator0_.bank_account_bic as bank_acc7_17_0_, operator0_.bank_account_iban as bank_acc8_17_0_, operator0_.bank_account_owner as bank_acc9_17_0_, operator0_.company as company10_17_0_, operator0_.contact_details_email as contact11_17_0_, operator0_.contact_details_phone as contact12_17_0_, operator0_.contact_person_first_name as contact13_17_0_, operator0_.contact_person_gender as contact14_17_0_, operator0_.contact_person_last_name as contact15_17_0_, operator0_.tax_id as tax_id16_17_0_, operator0_.vat_id as vat_id17_17_0_ from operator operator0_ where operator0_.id=?"]
Params:[(4)]

当我注释掉Vendor.java中的运算符字段时，只生成了第一条语句。我也尝试按照建议设置 spring.jpa.properties.hibernate.ejb.use_class_enhancer 属性 , but it didn't change the generated SQL. My apprehension is that this issue might be related to the mapping with @MapsId in Operator.java as this is not used in the Hibernate example.

使用的框架版本：
Spring开机2.1.9.RELEASE
休眠 5.3.12.Final

Answer 1

我的错误是将 hibernate-enhance-maven-plugin 放在 pom.xml 中 <build> 部分的插件列表的前面，即 maven-compiler-plugin 之前。将它放在 <plugins> 列表的末尾后，它按预期工作。

Hibernate @LazyToOne(LazyToOneOption.NO_PROXY) @OneToOne(fetch = FetchType.LAZY) 总是急切获取

Hibernate @LazyToOne(LazyToOneOption.NO_PROXY) @OneToOne(fetch = FetchType.LAZY) always fetched eagerly

spring

hibernate

spring-boot

hibernate-mapping

byte-code-enhancement