Add Smallrye Mutiny support

[hantsy]

aligned to Spring 5.3.10 which added SmallRye Mutiny support, see: spring-projects/spring-framework#27331

[hantsy]

depends on spring-projects/spring-data-build#1545

[mp911de]

Thanks a lot for your contribution. For the time being we would like to include only the addition of Mutiny to our registry and adapter infrastructure. Care to remove the repository base interfaces as these aren't required and we do not have native implementations using Mutiny?

[hantsy]

Is there any Repository implementations using RxJava 2/3?

I would like to add it firstly, and then add a standalone spring data hibernate module(reactive and blocking).

Currently Spring Data JPA does not support reactive APIs, but Hibernate Reative provides JPA like APIs to reactive world, Hibernate Reactive has built-in SmallRye Mutiny support.

For those RDBMS developers who are familiar with JPA, migrating to Hibernate Reactive is more reasonable than using R2dbc(not mature as JPA/Jdbc till now).

[mp911de]

would like to add it firstly, and then add a standalone spring data hibernate module(active and blocking).

For the time being, it can be a local interface in a Spring Data Hibernate Reactive module.

Is there any Repository implementations using RxJava 2/3?

Kind of. With Spring Data 2.x we support RxJava 1 while there is no base RxJava 1 base repository. Generally, Spring Data creates adapters around reactive types so one can use e.g. MongoDB through RxJava 2/3. In the early days, Couchbase was built on RxJava 1 but the repository could be used through ReactiveCrudRepository.

[hantsy]

I see, the ReactiveAdapter can convert between them, for Spring projects, Reactor is enough.

[mp911de]

Do you want to remove both repository base interfaces from the PR or should I take care of this?

[hantsy]

@mp911de I will remove them soon.

[hantsy]

@mp911de Updated and rebased on main.

[mp911de]

Thank you for your contribution. That's merged and polished now.