Java 通用 Spring Data JPA 存储库实现按类类型加载数据
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Generic Spring Data JPA repository implementation to load data by class type
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 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