spring-data-jdbc | Spring Data JDBC - image : https : //spring | Object-Relational Mapping library

So after a few tries to reproduce and make it work, i could get it done with the following changes:

In schema.sql:

The important bit of the stacktrace is "javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)"

It sounds like you're using an older MySQL version that doesn't support recent TLS versions (recent Java versions disabled older TLS versions and less secure ciphersuites). Either you need to upgrade MySQL (or tweak the security settings of Java to enable support for older TLS versions and/or cipher suites).

Your CurrencyExchange_Logic class has two constructors: the required args constructor, which has parameters corresponding to the 3 final fields, and the all args constructor, with parameters corresponding to those 3 fields as well as start and end.

When you only have one constructor defined, Spring knows how to implicitly choose it for injection. However, when you have more than one, you have to tell it which one you want it to use, using the @Autowired or @Inject annotation.

I would guess you want Spring to use the required args constructor, as I doubt Spring has any way of knowing how to resolve the start or end fields. This can be done in lombok (@RequiredArgsConstructor(onConstructor_ = @Autowired)), or by just explicitly writing the constructor yourself and annotating it. Note you could also get rid of the all args constructor, if you don't need it, and Spring's implicit constructor injection should "just work."

The issue was that I was using a ForkJoinPool which doesn't transfer Classloader from main thread (where Spring Boot app is loading) to its child threads. Switched to an ExecutorService and all is good.

Maps do get special handling in Spring Data JDBC so you can't simple use converters for them. Instead wrap the map in a custom type and register converters for that type.

Spring Data JDBC does not offer automatic schema generation. You need to write the DDL yourself. See e.g. https://www.baeldung.com/spring-data-jdbc-intro

You may be thinking of Spring Data JPA, that does offer schema generation.

It will be fixed with the upcoming Spring-data-jdbc 2.3.x. Relevant issue 974 has been closed.

Populating the auditing information is done by the RelationalAuditingCallback and IsNewAwareAuditingHandler.

The first one basically is the adapter to the module specific part (Spring Data Relational in this case) while the second modifies the entity.

You can implement your own variant of the IsNewAwareAuditingHandler stuff it in a RelationalAuditingCallback and register it as a bean. I did something similar a short time ago in this project on GitHub:

Having two separate interfaces one for repository and another for mybatis mapper is just how mybatis integration in spring-data-jdbc works as of now (version 2.2.1).

Mapper is just an implemenation detail of the spring data repository and just should not be used by the clients, so it should not be an issue.

What you want can be probably done but will require quite some work and might not be worth it.

@Repository annotation instructs spring-data-jdbc to create a proxy implementing PersonRepository with all the machinery of fetching/saving objects to the database.

@Mapper on the other hand instructs mybatis-spring to create another proxy that will handle queries from the mapping provided in xml or via annotations on the interface method.

Only one of this proxies can be injected in the places where you are going to use PersonRepository. What you can do is to create your own proxy for PersonRepository that will create both spring-data-jdbc and mybatis proxy and will dispatch calls to them. But the complexity of this solution will be rather high compared to a simple class that delegates to two separate PersonRepository and PersonMapper.

Update: it seems there is a way to combine mybatis mapper with repository as described in this comment https://github.com/spring-projects/spring-data-jdbc/pull/152#issuecomment-660151636

This approach uses repository fragments to add mybatis fragment to the repository implementation.