Java 在 Spring Boot 中获取 EntityManager 的句柄
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Obtaining handle to EntityManager in Spring Boot
提问by pastafarian
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
有没有办法获得给定实体对象的 EntityManager 句柄？我正在使用带有 JPA starter 的 spring boot 1.2.3，并且我正在进一步明确地配置多个数据源@configuration
I've checked [resolved]SPRING BOOT access to entityManagerand it doesn't seem to answer the question.
我已经检查了[resolved] SPRING BOOT 对 entityManager 的访问，但它似乎没有回答这个问题。
Thanks.
谢谢。
EDIT: I added description of how my data sources are defined:
编辑：我添加了如何定义我的数据源的描述：
@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();
}
}
In my application.yml I have the following sections
在我的 application.yml 我有以下部分
first.datasource:
name: 'first_datasource',
#other attributes...
second.datasource:
name: 'second_datasource',
#other attributes...
third.final.datasource:
name: 'first_datasource',
#other attributes...
So far I've tried both of @Stephane's suggestions but I get NoSuchBeanDefinitionException
到目前为止，我已经尝试了@Stephane 的两个建议，但我得到了 NoSuchBeanDefinitionException
Let's say my entity is called Customerthen I tried
假设我的实体被调用Customer然后我尝试
@Service
public class FooService {
private final EntityManager entityManager;
@Autowired
public FooService(@Qualifier("customerEntityManager") EntityManager entityManager) {
...
}
}
But I also tried
但我也试过
@PersistenceContext(unitName = "customer") // also tried "customers" and "first_datasource"
private EntityManager entityManager;
with no luck.
没有运气。
采纳答案by Stephane Nicoll
It depends how you've been configuring this but have you tried to injectthe EntityManagerwith a qualifier that corresponds to the factory that created it?
这取决于您如何配置它，但是您是否尝试使用与创建它的工厂相对应的限定符注入EntityManager？
Here is a sample project with two data sources. If you want to inject the EntityManagerfor order, just do the following in any Spring bean of the project
这是一个带有两个数据源的示例项目。如果要注入EntityManagerfor命令，只需在项目的任何Spring bean中执行以下操作
@Service
public class FooService {
private final EntityManager entityManager;
@Autowired
public FooService(@Qualifier("orderEntityManager") EntityManager entityManager) {
...
}
}
For customer, use the customerEntityManager.
对于客户，请使用customerEntityManager.
Of course you can use the persistent unit name instead, that is
当然你也可以使用持久化的单元名来代替，即
@PersistenceContext(unitName = "customers")
private EntityManager entityManager;
@PersistenceContext(unitName = "orders")
private EntityManager entityManager;
Check the configuration of the project for more details.
检查项目的配置以获取更多详细信息。
