Declarative Restclient Interfaces not compatible with the Property Placeholder in Spring Boot 4.0

[yigsvnsla]

Hi team,

I noticed that property placeholders (${...}) are not being resolved inside @HttpExchange(url = "...") when using declarative RestClient interfaces in Spring Boot 4.0.

Even though placeholders work correctly in other annotations (e.g., @JmsListener(destination = "${mq.config.requestQueue}")), the following fails:

@HttpExchange(url = "${provider.auth.url}")
public interface AuthClient { ... }

This results in:

java.lang.IllegalArgumentException: Map has no value for 'provider.auth.url'
    at org.springframework.web.util.UriComponents$MapTemplateVariables.getValue(UriComponents.java:336)
    ...

Is placeholder resolution currently supported for @HttpExchange and @ImportHttpServices?
Or is this a missing feature that will be added later?

Thanks!

[rstoyanchev]

Property placeholders are supported, but the HttpServiceProxyFactory builder needs to be set up with an EmbeddedValueResolver, essentially the ApplicationContext.

HttpServiceProxyRegistryFactoryBean that's used with @ImportHttpServices doesn't do that, and Boot doesn't either through any of its HttpServiceGroupConfigurers, so that seems to be missing at the moment, but we can add it.

This is specially when using @ImportHttpServices I presume since otherwise with direct use of HttpServiceProxyFactory, you would need to set the embeddedValueResolver yourself on its builder.