Allow building @LoadBalanced RestClient in component constructor.

[OlgaMaciaszek]

Load balanced RestClient with deferring postprocessor.

[ryanjbaxter]

I assume these inner classes get autoconfigured because the outerclass is specified in spring.factories?

[OlgaMaciaszek]

Yes; the new annotation is just same as @Configuration(proxyBeanMethods = false)

[wind57]

I was going nuts why this was deprecated and the bean removed when I initially saw this one. I was going in my head with : "is there now a new way to post-process beans? How can a @LoadBalanced be captured without a BeanPostProcessor?"

I was planning to open this defect today, but then saw you actually reverted and fixed :)

[OlgaMaciaszek]

I'm really sorry for the mess around that deprecation @wind57. In fact, it was being load-balanced with the previous change, however, with the caveat that a component constructor would be to early to build the RestClient instance with a @LoadBalanced RestClient.Builder, which is why it's been reworked again.

[wind57]

My point was rather different, I'm sorry for not being verbose enough.

Before this PR, I saw that LoadBalancerRestClientBuilderBeanPostProcessor that was a @Bean, was removed to be such and deprecated. Now, the question I had, was how is it possible then to find out who is actually annotated with @LoadBalanced, if not a BeanPostProcessor exists?

Yes, you did add SmartInitializingSingleton and a customizer, but doesn't that mean that load-balancing will be applied to every instance of RestClinet.Builder, be that annotated or not with @LoadBalanced, simply because its done for everyone. There is no logical check of "if bean is annotated with @LoadBalanced" : do that...

I hope I make more sense now. And don't worry about the issue at all!

[OlgaMaciaszek]

The @LoadBalanced annotation over in:
@LoadBalanced @Autowired(required = false) private List<RestClient.Builder> restClientBuilders = Collections.emptyList();
works as a qualifier; that's also how it's always been done for RestTemplate, just too early for RestClient for some of the scenarios, since there we work with builder instances and not actual client instances.

[wind57]

oh my, I'm an idiot, you're right! I completely missed the @Qualifier in @LoadBalanced. Thank you for taking the time to explain.

[OlgaMaciaszek]

No worries, it's not very straightforward.