我需要使用一个数据库进行查询(非修改性操作),另一个数据库进行命令(修改操作)。我正在使用Spring Data JPA,因此我有两个配置类:
@Configuration
@EnableJpaRepositories(value = "com.company.read",
entityManagerFactoryRef = "readingEntityManagerFactory",
transactionManagerRef = "readingTransactionManager")
@EnableTransactionManagement
public class SpringDataJpaReadingConfiguration {
@Bean(name = "readingEntityManagerFactory")
public EntityManagerFactory readingEntityManagerFactory() {
return Persistence.createEntityManagerFactory("persistence.reading");
}
@Bean(name = "readingExceptionTranslator")
public HibernateExceptionTranslator readingHibernateExceptionTranslator() {
return new HibernateExceptionTranslator();
}
@Bean(name = "readingTransactionManager")
public JpaTransactionManager readingTransactionManager() {
return new JpaTransactionManager();
}
}
@Configuration
@EnableJpaRepositories(value = "com.company.write",
entityManagerFactoryRef = "writingEntityManagerFactory",
transactionManagerRef = "writingTransactionManager")
@EnableTransactionManagement
public class SpringDataJpaWritingConfiguration {
@Bean(name = "writingEntityManagerFactory")
public EntityManagerFactory writingEntityManagerFactory() {
return Persistence.createEntityManagerFactory("persistence.writing");
}
@Bean(name = "writingExceptionTranslator")
public HibernateExceptionTranslator writingHibernateExceptionTranslator() {
return new HibernateExceptionTranslator();
}
@Bean(name = "writingTransactionManager")
public JpaTransactionManager writingTransactionManager() {
return new JpaTransactionManager();
}
}
在我的代码库中,有时需要决定要使用哪个EntityManager,例如:
@Repository
public class UserReadingRepository {
@PersistenceContext(unitName = "persistence.reading")
private EntityManager em;
// some useful queries here
}
我正在使用在我的 persistence.xml 文件中定义的持久化单元名称:
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="persistence.reading" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<non-jta-data-source>ReadingDS</non-jta-data-source>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
<property name="hibernate.show_sql" value="true" />
</properties>
</persistence-unit>
<persistence-unit name="persistence.writing" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<non-jta-data-source>WritingDS</non-jta-data-source>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
<property name="hibernate.show_sql" value="true" />
</properties>
</persistence-unit>
</persistence>
Spring抛出org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'persistence.reading'
未定义。奇怪的是,它似乎尝试用持久化单元名称实例化一个bean? 我是否配置错误了?
更新: 当我从@PersistenceContext注释中删除unitName = "persistence.reading"
时,我会得到以下错误:
org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: readingEntityManagerFactory,writingEntityManagerFactory
更新2: Rohit建议(在评论中)改为使用EntityManagerFactory
。所以我尝试了以下操作:
@PersistenceUnit(unitName = "persistence.reading")
private EntityManagerFactory emf;
但是 Spring 只报告:org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'persistence.reading' is defined
最终修复:
感谢 Vlad 的答案,我能够更新代码并使用以下内容(只需确保定义您的 dataSource
bean):
@Bean(name = "readingEntityManagerFactory")
public EntityManagerFactory readingEntityManagerFactory() {
LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
em.setPersistenceUnitName("persistence.reading");
em.setDataSource(dataSource());
em.setPackagesToScan("com.company");
em.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
em.afterPropertiesSet();
return em.getObject();
}
transactionManager
的entityManagerFactory
属性?您的persistence.xml
文件在哪里? - Rohit Jainpersistence.xml
在META-INF
文件夹下,位于类路径中。我尝试在transactionManager
bean 上设置entityManagerFactories
,但结果完全相同。 - Xortypersistence.xml
是可见的,如果我回退到只使用一个 entityManager,那么 Spring 就可以成功地组装所有的 bean。 - Xortypersistence.reading
和persistence.writing
中用-
替换.
? - Rohit Jain