Spring 用于2个不同数据源的多entityManagerFactory

我想为2个不同的数据库保留2个数据源（都是mysql），如下所示：

<bean id="jpaVendorAdapter"
    class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
    <property name="showSql" value="true" />
    <property name="generateDdl" value="true" />
    <property name="database" value="MYSQL" />
</bean>

     <bean id="dataSource-A"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url-A}" />
    <property name="username" value="${jdbc.username}" />
    <property name="password" value="${jdbc.password}" />
</bean>

<bean id="entityManagerFactory-A"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource-A" />
    <property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
    <!-- spring based scanning for entity classes -->
    <property name="packagesToScan" value="com.package-A" />
</bean>

    <bean id="dataSource-B"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url-B}" />
    <property name="username" value="${jdbc.username}" />
    <property name="password" value="${jdbc.password}" />
</bean>

<bean id="entityManagerFactory-B"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource-B" />
    <property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
    <!-- spring based scanning for entity classes -->
    <property name="packagesToScan" value="com.package-B" />
</bean>

现在，当我简单地执行此操作时，beanInitializer会给出一个错误，即找不到entityManagerFactory

如何让多个entityManagerFactory用于多个数据库，以及使用xml的最佳方式是什么

我在谷歌上搜索了很多，但没有一个能解决我的问题

---

如果我只定义了一个entityManagerFactory，那么它工作得很好，我只是坚持在相同的应用程序上下文中使用多个entityManagerFactory

下面是为不同类型的数据库保留多个持久性单元的示例。同样，两个sql数据库都可以保留2个单元

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="oraPersistent" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <class>com.kulhade.us.ora.entity.BilltoAddress</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
        <validation-mode>AUTO</validation-mode>
        <properties>
            <property name="javax.persistence.jdbc.driver" value="${db.driver}"/>
            <property name="javax.persistence.jdbc.url" value="${db.url}"/>
            <property name="javax.persistence.jdbc.user" value="${db.username}"/>
            <property name="javax.persistence.jdbc.password" value="${db.password}"/>
            <property name="hibernate.cache.use_query_cache" value="true"/>
            <property name="hibernate.cache.use_second_level_cache" value="true"/>
            <property name="hibernate.generate_statistics" value="true"/>
            <property name="hibernate.cache.region.factory_class" value="org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory"/>
            <property name="hibernate.jdbc.batch_size" value="50"/>
        </properties>
    </persistence-unit>
    <persistence-unit name="mongoPersistent" transaction-type="JTA">
        <!-- Use Hibernate OGM provider: configuration will be transparent -->
        <provider>org.hibernate.ogm.jpa.HibernateOgmPersistence</provider>
        <class>com.kulhade.us.mongo.entity.Sample</class>
        <class>com.kulhade.us.mongo.entity.SampleLine</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <properties>
            <property name="hibernate.ogm.datastore.provider" value="mongodb" />
            <property name="hibernate.ogm.datastore.database" value="${mongodb.name}"/>
            <property name="hibernate.ogm.mongodb.host" value="${mongodb.host}"/>
            <property name="hibernate.ogm.datastore.port" value="${mongodb.port}"/>
            <!--<property name="hibernate.ogm.datastore.document.association_storage" value="ASSOCIATION_DOCUMENT"/>
            <property name="hibernate.ogm.mongodb.association_document_storage" value="COLLECTION_PER_ASSOCIATION"/>-->
            <property name="hibernate.transaction.jta.platform" value="org.hibernate.service.jta.platform.internal.JBossStandAloneJtaPlatform"/>
        </properties>
    </persistence-unit>
</persistence>

org.hibernate.jpa.HibernatePersistenceProvider
com.kulhade.us.ora.entity.BilltoAddress
真的
启用\u选择性
自动的
org.hibernate.ogm.jpa.hibernateogm持久性
com.kulhade.us.mongo.entity.Sample
com.kulhade.us.mongo.entity.SampleLine
真的

这些多持久性单元可以在Spring orm中使用。下面是一个例子

<bean id="pum" class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
    <property name="persistenceXmlLocations">
        <list>
            <value>org/springframework/orm/jpa/domain/persistence-multi.xml</value>
            <value>classpath:/my/package/**/custom-persistence.xml</value>
            <value>classpath*:META-INF/persistence.xml</value>
        </list>
    </property>
    <property name="dataSources">
        <map>
            <entry key="localDataSource" value-ref="local-db"/>
            <entry key="remoteDataSource" value-ref="remote-db"/>
        </map>
    </property>
    <!-- if no datasource is specified, use this one -->
    <property name="defaultDataSource" ref="remoteDataSource"/>
</bean>

<bean id="emf" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceUnitManager" ref="pum"/>
    <property name="persistenceUnitName" value="myCustomUnit"/>
</bean>

org/springframework/orm/jpa/domain/persistence-multi.xml
类路径：/my/package/**/custom-persistence.xml
classpath*：META-INF/persistence.xml

请看一下这篇文章