如何处理 Web 客户端抛出的异常?

Question

我正在尝试弄清楚如何记录来自 Web 客户端的异常，无论从调用的 api 返回的错误状态代码是什么。

我看到了以下实现：

.onStatus(status -> status.value() != HttpStatus.OK.value(),
rs -> rs.bodyToMono(String.class).map(body -> new IOException(String.format(
"Response HTTP code is different from 200: %s, body: '%s'", rs.statusCode(), body))))

我看到的另一个例子使用过滤器。我想这个过滤器也可以用来记录错误，除了像这个例子中的请求：

public MyClient(WebClient.Builder webClientBuilder) {
webClient = webClientBuilder // you can also just use WebClient.builder()
.baseUrl("https://httpbin.org")
.filter(logRequest()) // here is the magic
.build();
}

但是我们是认真的，没有专门的异常处理程序来处理这件事吗？

Answer 1

找到了。
如果状态代码为 4xx(客户端错误(或 5xx(服务器错误(，bodyToMono将引发 WebClientException。

服务的全面实施：

@Service
public class FacebookService {
private static final Logger LOG = LoggerFactory.getLogger(FacebookService.class);
private static final String URL_DEBUG = "https://graph.facebook.com/debug_token";
private WebClient webClient;
public FacebookService() {
webClient = WebClient.builder()
.filter(logRequest())
.build();
}
public Mono<DebugTokenResponse> verifyFbAccessToken(String fbAccessToken, String fbAppToken) {
LOG.info("verifyFacebookToken for " + String.format("fbAccessToken: %s and fbAppToken: %s", fbAccessToken, fbAppToken));
UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(URL_DEBUG)
.queryParam("input_token", fbAccessToken)
.queryParam("access_token", fbAppToken);
return this.webClient.get()
.uri(builder.toUriString())
.retrieve()
.bodyToMono(DebugTokenResponse.class);
}
private static ExchangeFilterFunction logRequest() {
return ExchangeFilterFunction.ofRequestProcessor(clientRequest -> {
LOG.info("Request: {} {}", clientRequest.method(), clientRequest.url());
clientRequest.headers().forEach((name, values) -> values.forEach(value -> LOG.info("{}={}", name, value)));
return Mono.just(clientRequest);
});
}
@ExceptionHandler(WebClientResponseException.class)
public ResponseEntity<String> handleWebClientResponseException(WebClientResponseException ex) {
LOG.error("Error from WebClient - Status {}, Body {}", ex.getRawStatusCode(), ex.getResponseBodyAsString(), ex);
return ResponseEntity.status(ex.getRawStatusCode()).body(ex.getResponseBodyAsString());
}
}