在一个 Spring Boot 中创建存储库，从另一个 Spring Boot 访问实体和数据库源

Question

I have created Spring Boot no.1 connecting to H2 databse (containing entities). Now I have to create Spring Boot no.2 and Spring Boot no.3 and next Spring Boots which will connect to database Spring Boot no.1. How can I do that? Morever, is it possible to create repositories and services in Spring Boot no.2 and 3 ? How would they create Spring Data - queries no knowing entities ? Or should Spring Boot no.1 contain repositories and services ? In that case what's the architecture point of doing 2nd and 3rd Spring Boots to use no. 1 ?

Sping Boot no. contains database connection H2 and entities.

Answer 1

Hi please see this example, they did exactly what you asked

https://www.baeldung.com/spring-boot-access-h2-database-multiple-apps

The key point here is overriding the default data source created by Spring Boot's auto-configuration feature by adding a few properties to the application.properties file:

spring.datasource.url=jdbc:h2:mem:mydb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.hibernate.ddl-auto=create

note : I will be giving a detailed answer here soon in case the link is broken.

Answer 2

you can: in Spring Boot n1 you create the repository, that communicates with h2 db , and the entities associated, then you create a Rest controller where you set some enpoint that allows you to do the crud operation (insert,delete ecc), in other Spring Boot (n2,n3) you can access that endpoint using Feign rest client. so in n2 or n3 you can for example call the get enpoint for retrieves a specific entity of the db. of course you can customized your endpoint and add specific logic. this is one , at my opinion, solution. enjoy.