通用Spring Data JPA存储库实现通过类类型加载数据 [英] Generic Spring Data JPA repository implementation to load data by class type

问题描述

我使用Spring Data JPA 1.4.3.RELEASE和Hibernate 4.2.7.Final
我能够成功地创建一个Base Repository类，其行数如下：
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扩展了BaseEntity，ID扩展了Serializable> 
扩展JpaRepository< T，ID> 
 
 @NoRepositoryBean 
 public class BaseRepositoryImpl< T扩展了BaseEntity，ID扩展了Serializable> 
扩展了SimpleJpaRepository< T，ID>实现BaseRepository< T，ID> {
  

我可以成功处理：

  public interface FlowerRepository扩展BaseRepository< Flower，Long> {
  

现在，我正在尝试编写一个通用实现（扩展基础知识库）像Flower类型的参考数据。
这是因为我不想为每个类型数据或参考数据建立一个存储库。
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）来使用通用存储库来管理该类型。例如

  loadAll（FlowerType.class）
  

我使用HBM映射hibernate实体，所以我有：

 <？xml version =1.0？> 
<！DOCTYPE hibernate-mapping PUBLIC -  // Hibernate / Hibernate映射DTD 3.0 // EN
http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd > 
< hibernate-mapping> 
< class name =xxx.FlowerTypetable =FLWTYP> 
< meta attribute =extendsinherit =false> xxx.BaseReferenceType< / meta> 
< id name =primaryKeytype =string> 
< column name =TYP_CDElength =5/> 
< generator class =assigned/> 
< / id> 
 
 public class FlowerType extends BaseReferenceType< String>实现ReferenceEntity< String> 
 
 public abstract class BaseReferenceEntity< T extends Serializable>扩展BaseEntity实现
 ReferenceEntity< T> 
 
 public abstract class BaseEntity implements DomainEntity 
 
 public interface ReferenceEntity< PK extends Serializable> {b $ b  

持久性XML：

 <？xml version =1.0encoding =UTF-8standalone =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> 
<属性> 
< property name =hibernate.dialectvalue =org.hibernate.dialect.Oracle10gDialect/> 
< property name =hibernate.hbm2ddl.autovalue =none/> 
< property name =hibernate.ejb.naming_strategyvalue =org.hibernate.cfg.ImprovedNamingStrategy/> 
< property name =hibernate.connection.charSetvalue =UTF-8/> 
< property name =hibernate.jdbc.batch_sizevalue =100/> 
< property name =hibernate.show_sqlvalue =false/> 
< property name =hibernate.format_sqlvalue =false/> 
< property name =hibernate.transaction.flush_before_completion
 value =false/> 
< property name =hibernate.connection.autocommitvalue =false/> 
< property name =hibernate.ejb.cfgfilevalue =hibernate.cfg.xml/> 
< property name =jadira.usertype.autoRegisterUserTypesvalue =true/> 
< property name =jadira.usertype.databaseZonevalue =jvm/> 
< property name =jadira.usertype.javaZonevalue =jvm/> 
< / properties> 
< / persistence-unit> 
< /余辉> 
  

Hibernate配置：

 <？xml version =1.0encoding =UTF-8？> 
<！DOCTYPE hibernate-configuration PUBLIC -  // Hibernate / Hibernate配置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> 
  

因此，我查看了一些教程链接和SO帖子，并根据以下内容开展了一些工作：

Spring Jpa将定制功能添加到所有存储库，同时将其他自定义功能添加到单个存储库中

我有：

  @NoRepositoryBean 
公共接口CustomReferenceDataRepository< T扩展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> 
实现CustomReferenceDataRepository< T，PK> {
 
 @PersistenceContext 
私人EntityManager em; 
 
 
 @覆盖
 public Map< PK，T> findAll（Class< T> clz）{
 //做任何
返回null; 
} 
 
} 
  

结束了一个例外：

 原因：java.lang.IllegalArgumentException：不是托管类型：class xxx.BaseEntity 
位于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] 
  

我理解Hibernate不管理BaseEntity，但无法弄清楚我缺少什么。

是否需要为参考数据实现通用存储库甚至可能？
如果是，我做错了什么？
任何指导赞赏。
Thanks。

解决方案

您还必须为BaseEntity添加映射：

 < class name =xxx.BaseEntityabstract =true> 
  

您也可以尝试使用注释并设置packagesToScan属性

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

            @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 :

            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

            loadAll(FlowerType.class)

I use HBMs to map hibernate entities so I have :

            <?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 :

            <?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 :

            <?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 :

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

I have :

            @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 :

            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.

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

解决方案

You have to add mapping for BaseEntity as well:

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

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

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