JPA with Multiple database and application.yml - spring-boot

Question

My application (spring-boot) need to access multiple databases.
For some reason, I can't find a propper example using application.yml
This example: http://smasue.github.io/spring-yml-datasources
-> application.yml but not jpa
this example: https://www.baeldung.com/spring-data-jpa-multiple-databases
-> jpa but not application.yml
So I created a very simple project based on this gs: https://spring.io/guides/gs/accessing-data-jpa/
You can find my simple example here: https://github.com/Tyvain/JpaMultipleDatabaseAndApplicationYml
spring:
datasource:
db-1:
url: jdbc:postgresql://10.10.100.100:5432/db1
username: db1
password: db1
driver-class-name: org.postgresql.Driver
db-2:
url: jdbc:postgresql://10.10.100.100:5432/db2
username: db2
password: db2
driver-class-name: org.postgresql.Driver
From here, I am not sure how to affect my repositories to each database.
This example https://www.baeldung.com/spring-data-jpa-multiple-databases is unclear as it's based on properties... and I am not sure how to adapt all code
#PropertySource({ "classpath:persistence-multiple-db.properties" })
[...]
properties.put("hibernate.hbm2ddl.auto",
env.getProperty("hibernate.hbm2ddl.auto"));
properties.put("hibernate.dialect",
env.getProperty("hibernate.dialect"));
How would you assign each repo (CustomerRepositoryDB1 and CustomerRepositoryDB2) to their database ?

Answer 1

Properties and yaml are two absolutely equal means of configuration. The format is only slgihtly different.
You could just replace foo.properties with foo.yml and
com.foobar.var1=value
com.foobar.var2=value2
simply becomes
com.foobar:
var1: value
var2: value2
Plus there is an official Spring Data Repository on Github full of examples. There is even one with two datasources, configured completely in code, no yaml or properties needed:
https://github.com/spring-projects/spring-data-examples/tree/master/jpa/multiple-datasources
In Application.java they exclude the AutoConfig classes and then in each package (Order, Customer), they have a Config class, configuring the datasource. Then there is no need to set the datasource on the repository itself, as that is handled by package scanning with:
factoryBean.setPackagesToScan(OrderConfig.class.getPackage().getName());
in the config. To reiterate: it's datasource per java package, no annotation on the Repository needed.