Handling I/O errors from a rest client's methods

[pavelrappo]

I've been reading USING THE REST CLIENT and Rest Client for MicroProfile, but couldn't quickly find the answer to the following question. How do I know if a method of a rest client interface encounters an I/O error while sending a request?

There's one example in the specification that kind of suggests that I should declare IOException on the method, but I'm not sure. Also, various LLMs suggest that an instance of unchecked jakarta.ws.rs.ProcessingException is thrown with IOException as a cause somewhere in the exception chain. But for that in particular, I couldn't find any evidence in the specification.

Any tips on where I should be looking at?

[quarkus-bot[bot]]

/cc @cescoffier (rest-client), @geoand (rest-client)

[geoand]

If the error is encountered while sending the payload, you'll get a ProcessingException that wraps the IOException. See this

[pavelrappo]

Is it an implementation-specific detail or a specification requirement? Also, what about this method that throws IOException, from the specification example I linked to earlier? Do you know what the reason for declaring that exception is? Thanks!

@POST
@Path("upload/")
void uploadFile(List<EntityPart> entityParts) throws IOException;

[geoand]

I assume the later, but I can't say I remember