在Spring Boot中获取EntityManager的句柄 [英] Obtaining handle to EntityManager in Spring Boot

问题描述

是否有任何方法可以获取给定实体对象的EntityManager句柄?我将Spring Boot 1.2.3与JPA Starter结合使用，并且进一步使用@configuration

Is there any way to get a handle to the EntityManager for a given entity object? I'm using spring boot 1.2.3 with JPA starter and i'm further explicitly configuring multiple data sources with @configuration

我已经检查了 [已解决]对BOOTING BOOT的entityManager访问权限，但它没有似乎没有回答这个问题.

I've checked [resolved]SPRING BOOT access to entityManager and it doesn't seem to answer the question.

谢谢.

我添加了有关如何定义数据源的描述:

@Component
@Configuration
public class DataSources {
    @Bean
    @Primary
    @ConfigurationProperties(prefix="first.datasource")
    public DataSource getPrimaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties(prefix="second.datasource")
    public DataSource getSecondDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties(prefix="third.final.datasource")
    public DataSource getThirdFinalDataSource() {
        return DataSourceBuilder.create().build();
    }
}

在我的application.yml中，我有以下部分

In my application.yml I have the following sections

first.datasource:
  name: 'first_datasource',
  #other attributes...
second.datasource:
  name: 'second_datasource',
  #other attributes...
third.final.datasource:
  name: 'first_datasource',
  #other attributes...

到目前为止，我已经尝试了@Stephane的两个建议，但得到了NoSuchBeanDefinitionException

So far I've tried both of @Stephane's suggestions but I get NoSuchBeanDefinitionException

假设我的实体称为Customer，然后我尝试了

Let's say my entity is called Customer then I tried

@Service
public class FooService {

    private final EntityManager entityManager;

    @Autowired
    public FooService(@Qualifier("customerEntityManager") EntityManager entityManager) {
        ...
    }

}

但是我也尝试过

@PersistenceContext(unitName = "customer") // also tried "customers" and "first_datasource"
private EntityManager entityManager;

没有运气.

推荐答案

这取决于您如何进行配置，但是否尝试过使用与创造它的工厂?

It depends how you've been configuring this but have you tried to inject the EntityManager with a qualifier that corresponds to the factory that created it?

这是具有两个数据源的示例项目.如果要按订单注入EntityManager，只需在项目的任何Spring bean中执行以下操作

Here is a sample project with two data sources. If you want to inject the EntityManager for order, just do the following in any Spring bean of the project

@Service
public class FooService {

    private final EntityManager entityManager;

    @Autowired
    public FooService(@Qualifier("orderEntityManager") EntityManager entityManager) {
        ...
    }

}

对于客户，请使用customerEntityManager.

当然，您可以改用持久单元名称，即

Of course you can use the persistent unit name instead, that is

@PersistenceContext(unitName = "customers")
private EntityManager entityManager;

@PersistenceContext(unitName = "orders")
private EntityManager entityManager;

检查项目的配置以获取更多详细信息.

Check the configuration of the project for more details.

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