Make it possible to pass method and URL to ResponseErrorHandler [SPR-15511]

[spring-projects-issues]

Dmitry Katsubo opened SPR-15511 and commented

There is a need to create a custom exception that contains method (GET, PUT, ...) and URL information in custom ResponseErrorHandler. Currently the only way to add this information to the exception is to catch and re-wrap it into another exception:

RestTemplate restTemplate = new RestTemplate();
restTemplate.setErrorHandler(new MyRestErrorHandler());

String url = "...";
try {
    String response = restTemplate.getForEntity(url, String.class);
} catch (MyRestException e) {
    throw new MyRestUrlException(HttpMethod.GET, url, e);
}

Consider extending ResponseErrorHandler interface so that the signature is:

void handleError(HttpMethod method, URI url, ClientHttpResponse response) throws IOException;

---

Affects: 4.3.8

Referenced from: commits 805fcc6

[spring-projects-issues]

Rossen Stoyanchev commented

We can look into some way to enable this, through a default method or a new interface.

In the mean time there is another way. A ClientHttpRequestInterceptor wraps the execution with access to both the request and response.

[spring-projects-issues]

Dmitry Katsubo commented

Sorry for my blindness but I don't see any way to do this via ClientHttpRequestInterceptor because it has access only to request, not to response, so it cannot form the exception. The only thing it can do is to call some setter on ResponseErrorHandler, which makes the last one stateful, e.g. not thread-safe.

[spring-projects-issues]

Rossen Stoyanchev commented

I didn't actually try it but shouldn't this work?

@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
	ClientHttpResponse response = execution.execute(request, body);	
	// check response here...	
	return response;
}

[spring-projects-issues]

Rossen Stoyanchev commented

Dmitry Katsubo, I just tried this and it works as expected indeed. Just to be more clear:

public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
	ClientHttpResponse response = execution.execute(request, body);	
	if (response.getStatusCode().is4xxClientError()) {
		throw new IllegalStateException("Failed request to: " + request.getURI());
	}
	return response;
}

So there is a workaround at least. We can probably add an extra method to ResponseErrorHandler in 5.0 with a default implementation delegating to the current one.