OkHttp RestTemplate adapter uses inappropriate async requests [SPR-13942]

[spring-projects-issues]

Kenny MacLeod opened SPR-13942 and commented

OkHttpClientHttpRequestFactory implements both ClientHttpRequestFactory and AsyncClientHttpRequestFactory, but regardless of whether it's called via createRequest or createAsyncRequest it always creates an OkHttpClientHttpRequest, which uses OkHttp's async API.

There's no obvious issue with this, since calls to the synchronous method of OkHttpClientHttpRequest just block until the OkHttp async API returns the goods, but there are scenarios where using the OkHttp async API breaks things, e.g. when the client code is using thread-local-based request interceptors.

I suggest that OkHttpClientHttpRequest is altered to use the OkHttp sync API when invoked via the ClientHttpRequest interface, and the OkHttp async API when invoked through the {[AsyncClientHttpRequest}} interface.

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Affects: 4.2.4

Referenced from: pull request #963, and commits e36b753, 37b32d3

[spring-projects-issues]

Arjen Poutsma commented

FWIW, Netty has the same "issue" (i.e. async API i used for sync requests), but unlike OkHttp, Netty doesn't have a synchronous API to use instead.

[spring-projects-issues]

Arjen Poutsma commented

PR at #963

[spring-projects-issues]

Juergen Hoeller commented

Arjen Poutsma, that approach looks fine to me. Merged into master now.

Juergen