Java 通用 Spring Data JPA 存储库实现按类类型加载数据

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时间:2020-08-13 08:36:53  来源:igfitidea点击:

Generic Spring Data JPA repository implementation to load data by class type

javaspringhibernatespring-data-jpa

提问by souser

I am using Spring Data JPA 1.4.3.RELEASE with Hibernate 4.2.7.Final I was able to successfully create a Base Repository class, something on the lines of : http://docs.spring.io/spring-data/jpa/docs/1.4.2.RELEASE/reference/html/repositories.html#repositories.custom-behaviour-for-all-repositories

我正在使用 Spring Data JPA 1.4.3.RELEASE 和 Hibernate 4.2.7.Final 我能够成功创建一个 Base Repository 类,内容如下:http: //docs.spring.io/spring-data/jpa /docs/1.4.2.RELEASE/reference/html/repositories.html#repositories.custom-behaviour-for-all-repositories

            @NoRepositoryBean
            public interface BaseRepository <T extends BaseEntity, ID extends Serializable>
            extends JpaRepository<T, ID>

            @NoRepositoryBean
            public class BaseRepositoryImpl<T extends BaseEntity, ID extends Serializable>
            extends SimpleJpaRepository<T, ID> implements BaseRepository<T, ID> {

I am able to sucessfully work with :

我能够成功地与:

            public interface FlowerRepository extends BaseRepository<Flower, Long> {

Now, I am trying to write an generic implementation(that extends the base repository) to load all reference data like Flower types. That is because I do not want to have a repository for every single "type" data or "reference" data. I want to be able to manage that using a generic repository by passing a specific "class" type(that implements a interface specific to reference data type).For E-g

现在,我正在尝试编写一个通用实现(扩展基本存储库)来加载所有参考数据,如 Flower 类型。那是因为我不想为每个“类型”数据或“参考”数据都建立一个存储库。我希望能够通过传递特定的“类”类型(实现特定于引用数据类型的接口)使用通用存储库来管理它。例如

            loadAll(FlowerType.class)

I use HBMs to map hibernate entities so I have :

我使用 HBM 来映射休眠实体,所以我有:

            <?xml version="1.0"?>
            <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
            "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
            <hibernate-mapping>
                <class name="xxx.FlowerType" table="FLWTYP">
                <meta attribute="extends" inherit="false">xxx.BaseReferenceType</meta>
                <id name="primaryKey" type="string">
                    <column name="TYP_CDE" length="5" />
                    <generator class="assigned" />
                </id>

            public class FlowerType extends BaseReferenceType<String> implements ReferenceEntity<String>

            public abstract class BaseReferenceEntity<T extends Serializable> extends BaseEntity implements
    ReferenceEntity<T>

            public abstract class BaseEntity implements DomainEntity

            public interface ReferenceEntity<PK extends Serializable> {

Persistence XML :

持久性 XML :

            <?xml version="1.0" encoding="UTF-8" standalone="no"?>
            <persistence xmlns="http://java.sun.com/xml/ns/persistence"
                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0"
                xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
                <persistence-unit name="xxxPU"
                    transaction-type="RESOURCE_LOCAL">
                    <provider>org.hibernate.ejb.HibernatePersistence</provider>
                    <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
                    <properties>
                        <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
                        <property name="hibernate.hbm2ddl.auto" value="none" />
                        <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
                        <property name="hibernate.connection.charSet" value="UTF-8" />
                        <property name="hibernate.jdbc.batch_size" value="100" />
                        <property name="hibernate.show_sql" value="false" />
                        <property name="hibernate.format_sql" value="false" />
                        <property name="hibernate.transaction.flush_before_completion"
                            value="false" />
                        <property name="hibernate.connection.autocommit" value="false" />
                        <property name="hibernate.ejb.cfgfile" value="hibernate.cfg.xml"/>
                        <property name="jadira.usertype.autoRegisterUserTypes" value="true" />
                        <property name="jadira.usertype.databaseZone" value="jvm" />
                        <property name="jadira.usertype.javaZone" value="jvm" />
                    </properties>
                </persistence-unit>
            </persistence>

Hibernate config :

休眠配置:

            <?xml version="1.0" encoding="UTF-8"?>
            <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                 "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
            <hibernate-configuration>
                <session-factory>
                    <mapping resource="FlowerType.hbm.xml"/>
                    <mapping resource="Flower.hbm.xml"/>
                </session-factory>
            </hibernate-configuration>

So I looked at some tutorial links and SO posts and did some work based on :

所以我查看了一些教程链接和 SO 帖子,并基于以下内容做了一些工作:

Spring Jpa adding custom functionality to all repositories and at the same time other custom funcs to a single repository

Spring Jpa 向所有存储库添加自定义功能,同时向单个存储库添加其他自定义功能

I have :

我有 :

            @NoRepositoryBean
            public interface CustomReferenceDataRepository<T extends BaseEntity & ReferenceEntity<PK>, PK extends Serializable> {
                public Map<PK, T> findAll(Class<T> clz);
            }

            public interface ReferenceDataRepository extends BaseRepository, CustomReferenceDataRepository {
            }

            public class ReferenceDataRepositoryImpl<T extends BaseEntity & ReferenceEntity<PK>, PK extends Serializable>
                    implements CustomReferenceDataRepository<T, PK> {

                @PersistenceContext
                private EntityManager em;


                @Override
                public Map<PK, T> findAll(Class<T> clz) {
                //do whatever
                    return null;
                }

            }

Ended up with a exception :

结束了一个例外:

            Caused by: java.lang.IllegalArgumentException: Not an managed type: class xxx.BaseEntity
                at org.hibernate.ejb.metamodel.MetamodelImpl.managedType(MetamodelImpl.java:200) ~[hibernate-entitymanager-4.2.7.Final.jar:4.2.7.Final]
                at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.<init>(JpaMetamodelEntityInformation.java:68) ~[spring-data-jpa-1.4.3.RELEASE.jar:na]
                at org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getMetadata(JpaEntityInformationSupport.java:65) ~[spring-data-jpa-1.4.3.RELEASE.jar:na]
                at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation(JpaRepositoryFactory.java:146) ~[spring-data-jpa-1.4.3.RELEASE.jar:na]

I understand Hibernate does not manage "BaseEntity" but am not able to figure out what I am missing.

我知道 Hibernate 不管理“BaseEntity”,但无法弄清楚我缺少什么。

Is my requirement of implementing a generic repository for reference data even possible ? If yes, what am I doing wrong ? Any guidance appreciated. Thanks.

我是否可能需要为参考数据实现通用存储库?如果是,我做错了什么?任何指导表示赞赏。谢谢。

采纳答案by Jakub Kubrynski

You have to add mapping for BaseEntity as well:

您还必须为 BaseEntity 添加映射:

<class name="xxx.BaseEntity " abstract="true">

You can also try to use annotations and just set packagesToScan property

您也可以尝试使用注释并设置 packagesToScan 属性