Multiple datasources in Spring Boot Repository Annotated Interface

Question

My application is based on Spring Boot, Hibernate, MySQL using Spring Data JPA to stitch them.

Use case is to use slave db node for doing heavy read operations so as to avoid all traffic being served from master mysql node. One way of achieving this is to have multiple Entity Managers pointing to separate data sources(one to master and other to slave node). This way has been explained quite well in below SO questions and blogs.

Spring Boot, Spring Data JPA with multiple DataSources

https://scattercode.co.uk/2016/01/05/multiple-databases-with-spring-boot-and-spring-data-jpa/

Where I am stuck is to understand if there is a way I can inject different entity managers for different use cases in my Repository Annotated Interface.

The only way I see it can be done is extending repository with a custom implementation which gives uses custom entity manager annotated with relevant persistenceContext like below.

public interface CustomerRepository extends JpaRepository<Customer, Integer>, MyCustomCustomerRepository{
}

public class MyCustomCustomerRepositoryImpl implements MyCustomCustomerRepository {

        @PersistenceContext(unitName = "entityManagerFactoryTwo")
        EntityManager entityManager;
}

I would like to avoid doing this custom implementation. Any help around solving this use case(which I feel should be very common) would be appreciated.

NOTE: Entities are same in both databases so giving separate packages for entity scanning and similar solutions might not work.

Demo you shared has two different entities in different dbs. it becomes easier to avoid conflicts when using two entity managers for such a case. For me Entities remain same whether we use them for master or slave db. — Himanshu Virmani
– Himanshu Virmani, Commented Sep 1, 2016 at 16:10

oborovyk · Accepted Answer · 2016-09-05 16:25:48Z

5

+50

Here is a nice sample you can use: dynamic-datasource-routing-with-spring. Inside you can find an AbstractRoutingDatasource + an interceptor for a custom annotation that wires the service method to a required database. However you can just use datasource switch explicitly.

edited Sep 5, 2016 at 16:25

answered Sep 5, 2016 at 16:18

oborovyk

3852 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Himanshu Virmani Over a year ago

Though the sample is doing suff using xml configs and my project is mostly annotation driven, the answer provided gives me good context on how to achieve the functionality. Thanks :)

Himanshu Virmani · Accepted Answer · 2016-09-06 17:07:04Z

2

Below is the pull request that shows the diff and how I made it work with most configurations annotation driven instead of xml. It is based on cra6's answer above. i.e. using spring's RoutingDataSource capability.

https://github.com/himanshuvirmani/rest-webservice-sample/pull/1/files

answered Sep 6, 2016 at 17:07

Himanshu Virmani

2,4601 gold badge25 silver badges34 bronze badges

Collectives™ on Stack Overflow

Multiple datasources in Spring Boot Repository Annotated Interface

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related