Making UrlFetchServiceImpl as singleton spring bean

Convert http clients into spring singleton components

Context and Scope

In current OSDU core commons there are two http clients

• UrlFetchServiceImpl which is implementation of IUrlFetchService. It uses HttpClientHandler which is a spring with request scope
• HttpClient which is implementation of IHttpClient

UrlFetchServiceImpl is a spring component with request scope and HttpClient is not a spring component.

Questions

• Any specific reason for having UrlFetchServiceImpl as request scoped spring bean? Is this because of injection of JaxRsDpsLogger in HttpClientHandler?
• Any specific reason for not having HttpClient as spring bean?

Proposal

Convert these two http clients to spring bean with singleton as scope.

• Converting the existing UrlFetchServiceImpl and HttpClientHandler to singleton scope
• Converting the HttpClient as singleton scoped spring bean. We still support the constructor way of invoking for backward compatibility.

Rationale

I am working on logging the request/response for external clients at these clients. For this logging I want to use JaxRsDpsLogger which needs to be autowired.

----------------- ADR update based on discussion ---------------

Splitting this ADR into two different issues. This ADR is about converting UrlFetchServiceImpl as singleton spring bean.