Apply RestClient properties (base-url, default headers, API version inserter)

[PandelisZ]

Problem

• Properties under spring.http.client.restclient (for example apiversion.insert.header) were not being applied to RestClient instances, causing settings like X-Version not to be applied.

What I changed

• Enabled configuration properties for the restclient module by adding @EnableConfigurationProperties(RestClientProperties.class) to RestClientAutoConfiguration.
• Added RestClientProperties (extends HttpClientProperties) bound to spring.http.client.restclient so base-url, default headers and apiversion settings can be configured.
• Injected RestClientProperties into RestClientBuilderConfigurer and applied its values when building a RestClient:
  • baseUrl -> builder.baseUrl
  • defaultHeader -> builder.defaultHeaders (merges headers)
  • apiversion.defaultVersion -> builder.defaultApiVersion
  • apiversion.insert -> builder.apiVersionInserter (via PropertiesApiVersionInserter)
• Minor plumbing: added PropertyMapper usage and a helper to copy default headers into HttpHeaders.

Files changed

• RestClientAutoConfiguration: enable properties and pass RestClientProperties to the configurer.
• RestClientBuilderConfigurer: accept and apply RestClientProperties; use PropertyMapper to map values; add header merging and api-version inserter wiring.
• RestClientProperties: new ConfigurationProperties class for spring.http.client.restclient.

Effect

• Properties like spring.http.client.restclient.apiversion.insert.header=X-Version and spring.http.client.restclient.default-header.* will now be applied to RestClient instances.

Notes

• The code guards against null properties and reuses existing defaults when properties are not provided.
• No behavioral changes to customizers; they are still applied after properties.

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This pull request was co-created with Cosine Genie

Original Task: spring-boot/y90vpvvwwjwp
Author: Pandelis Zembashis