When using a `RestTemplate` instance within a Spring MVC application,
client exceptions may propagate in the MVC stack and can be wrongly
mapped by server `ExceptionHandlers`, leading to a wrong HTTP response
sent to the MVC client.
The `RestTemplate` instance uses `HttpMessageConverter` to decode
the remote service responses; and when those fail decoding an HTTP
response, they can throw an `HttpMessageNotReadableException`. That
exception then bubbles up through the `HttpMessageConverterExtractor`,
`RestTemplate` and the whole MVC stack, later mapped to HTTP 400
responses, since those exceptions can also be throws by the server stack
when the incoming requests can't be deserialized.
This commit wraps all `IOException` and `HttpMessageNotReadableException`
instances thrown by the extractor into `RestClientException`` instances.
It's now easier to consistently handle client exceptions and avoid such
edge cases.
Issue: SPR-13592
b84fefc430