如何在使用Spring时注入多个JPAEntityManager(持久性单元)

我需要使用一个数据库进行查询(非修改),一个用于命令(修改).我使用的是Spring Data JPA,所以我有两个配置类:

@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();
    }

}

在我的存储库中,我有时需要决定使用EntityManager这样使用:

@Repository
public class UserReadingRepository {

    @PersistenceContext(unitName = "persistence.reading")
    private EntityManager em;

    // some useful queries here
}

我使用在我的定义持久性单元的名称的persistence.xml:

    
        org.hibernate.jpa.HibernatePersistenceProvider
        ReadingDS
        
            
            
        
    

    
        org.hibernate.jpa.HibernatePersistenceProvider
        WritingDS
        
            
            
        
    

Spring throws org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'persistence.reading'是定义的.奇怪的是,看起来Spring试图用持久性单元名实例化一个bean？我错误配置了什么吗？

更新:当我unitName = "persistence.reading"从@PersistenceContext注释中删除时,我将得到以下错误: 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)改为连线EntityManagerFactory.所以我尝试做以下事情:

@PersistenceUnit(unitName = "persistence.reading")
private EntityManagerFactory emf;

但春天只报道: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'persistence.reading' is defined

最后修复:感谢Vlad的回答,我能够更新代码以使用以下内容(只需确保定义你的dataSourcebean):

@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();
}

Vlad Mihalce.. 8

在EntityManageFactory没有正确配置.你应该用一个LocalContainerEntityManagerFactoryBean代替:

@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();
}

也是JpaTransactionManager错过配置.它应该是这样的:

@Bean(name = "readingTransactionManager")
public PlatformTransactionManager readingTransactionManager(){
    JpaTransactionManager transactiOnManager= new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(readingEntityManagerFactory());
    return transactionManager;
}

您需要对读取和写入EntityManager配置执行相同的操作.

在EntityManageFactory没有正确配置.你应该用一个LocalContainerEntityManagerFactoryBean代替:

@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();
}

也是JpaTransactionManager错过配置.它应该是这样的:

@Bean(name = "readingTransactionManager")
public PlatformTransactionManager readingTransactionManager(){
    JpaTransactionManager transactiOnManager= new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(readingEntityManagerFactory());
    return transactionManager;
}

您需要对读取和写入EntityManager配置执行相同的操作.