add @BeforeRetry

[Ladicek]

Fixes #259

[Ladicek]

This is a draft, because tests are missing. Documentation probably also needs some improvement.

Publishing early to solicit feedback from @cescoffier and @geoand. I don't think you need to review everything, just look at the api module (especially the @BeforeRetry annotation). I'm especially interested in knowing whether these 2 aspects work for you:

• the before retry method is always void and has no parameters
• it must not block, it must be short and it must not throw

It would be possible to add parameters, similarly to how @Fallback works. It would probably also be possible to make it return CompletionStage<Void> (and other async types) so that async work is possible (in addition to void if async work is not necessary).

That's probably all.

[geoand]

Nice!

I'll have a look soon

[Ladicek]

Added some tests. Documentation should still be improved.

[cescoffier]

LGTM,

We will likely automatically inject that annotation in Quarkus langchain4j.

[geoand]

Lovely, we will certainly make use of it!

[Ladicek]

OK, I take it the current API is good for you. I'll merge this and release. If it turns out the API is not sufficient, we can come back to it.