Spring-Boot with Micronaut-Data

This is a sample project that uses Spring for dependency injection and controller, and uses Micronaut-Data for the persistence

TLDR; To inject Micronaut beans into a Spring project

See com.example.springwithmndata.config.MicronautConfig

@Configuration
public class MicronautConfig {
    
    @Bean
    public ApplicationContext micronautApplicationContext() {
        ApplicationContext applicationContext = ApplicationContext.build(emptyMap()).build();
        applicationContext.start();
        return applicationContext;
    }
    
    @Bean
    public BookRepository bookRepository(ApplicationContext applicationContext) {
        return applicationContext.getBean(BookRepository.class);
    }
    
    @Bean
    public SynchronousTransactionManager<Connection> transactionManager(ApplicationContext applicationContext) {
        return (SynchronousTransactionManager<Connection> ) applicationContext.getBean(SynchronousTransactionManager.class);
    }
    
}

Also, you might also want to check com.example.springwithmndata.aspect.MicronautTransactionAspect on how I did transactions. I could not use micronaut's integration with spring transaction (as of this writing) because it seems like I would need to downgrade my spring in order for me to do that. If you want to try that path, check the spring version that your version of io.micronaut.data:micronaut-data-spring depends on. For example, for io.micronaut.data:micronaut-data-spring:1.0.2, it depends on org.springframework.data:spring-data-commons:2.2.6.RELEASE and org.springframework:spring-jdbc:5.2.5.RELEASE, if your current versions of these artifacts are substantially higher than these, then you might encounter some runtime issues (like dependency injection not even working) (see micronaut-projects/micronaut-data#602)

Project Requirements

1. Java 11
2. Docker (to run the tests which uses mysql testcontainer)

Project Structure

`-- src/main/java
    `-- com.example.springwithmndata
        |-- aspect
        |   |-- MicronautTransactionAspect
        |   `-- @Transactional
        |-- config
        |   `-- MicronautConfig
        |-- controller
        |   |-- BookController
        |   `-- Paths
        |-- entity
        |   `-- Book
        |-- repository
        |   `-- BookRepository
        |-- service
        |   `-- BookService
        `-- Application

• Application is the starting class of this application. This starts the Spring Boot application.
• BookController is the entry point for the GET:/book/{id} and POST:/book/ endpoints. This delegates to BookService
• BookService is a simple service. This is just to test if we can inject the spring-managed bean BookService into BookController. This uses the micronaut-data class BookRepository
• BookRepository is micronaut-data JdbcRepository.
• Book is the micronaut-data-based entity used by BookRepository
• MicronautConfig is what exposes the micronaut managed beans into Spring
• MicronautTransactionAspect is a Spring-based aspect in order to intercept method invocations of @Transactional methods in order to start a micronaut transaction.

Commands

Description	Command
Application : Build	./mvnw clean install
Application : Run	./mvnw -Prun
MySQL : Create Database	./mvnw -Pmysql-create
MySQL : Start Database	./mvnw -Pmysql-start
MySQL : Stop Database	./mvnw -Pmysql-stop
MySQL : Destroy Database	./mvnw -Pmysql-destroy
MySQL : Follow Tail	./mvnw -Pmysql-logs

Manual Testing

Creating a Book

curl --location --request POST 'http://localhost:8080/book/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "title" : "My First Book"
}'

Retrieving Saved Book

curl --location --request GET 'http://localhost:8080/book/1'

Postman

I have also added a postman collection under ./postman/ directory. This collection contains the saving and retrieving of book. You can import this into your postman and run the test to see how it exactly works.