SPR-16819 - Improve handling of unknown status codes by WebClient

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ClientResponse.java

@@ -60,9 +60,22 @@ public interface ClientResponse {
 
 	/**
 	 * Return the status code of this response.
+	 * @return the status as an HttpStatus enum value
+	 * @throws IllegalArgumentException in case of an unknown HTTP status code
+	 * @see HttpStatus#valueOf(int)
 	 */
 	HttpStatus statusCode();
 
+	/**
+	 * Return the status code (potentially non-standard and not resolvable
+	 * through the {@link HttpStatus} enum) as an integer.
+	 * @return the status as an integer
+	 * @since 5.0.7
+	 * @see #statusCode()
+	 * @see HttpStatus#resolve(int)
+	 */
+	int rawStatusCode();
+
 	/**
 	 * Return the headers of this response.
 	 */
@@ -172,6 +185,17 @@ static Builder create(HttpStatus statusCode) {
 		return create(statusCode, ExchangeStrategies.withDefaults());
 	}
 
+	/**
+	 * Create a response builder with the given status code and using default strategies for
+	 * reading the body.
+	 * @param statusCode the status code
+	 * @return the created builder
+	 * @since 5.0.7
+	 */
+	static Builder create(int statusCode) {
+		return create(statusCode, ExchangeStrategies.withDefaults());
+	}
+
 	/**
 	 * Create a response builder with the given status code and strategies for reading the body.
 	 * @param statusCode the status code
@@ -182,6 +206,17 @@ static Builder create(HttpStatus statusCode, ExchangeStrategies strategies) {
 		return new DefaultClientResponseBuilder(strategies).statusCode(statusCode);
 	}
 
+	/**
+	 * Create a response builder with the given status code and strategies for reading the body.
+	 * @param statusCode the status code
+	 * @param strategies the strategies
+	 * @return the created builder
+	 * @since 5.0.7
+	 */
+	static Builder create(int statusCode, ExchangeStrategies strategies) {
+		return new DefaultClientResponseBuilder(strategies).statusCode(statusCode);
+	}
+
 	/**
 	 * Create a response builder with the given status code and message body readers.
 	 * @param statusCode the status code
@@ -202,6 +237,27 @@ public List<HttpMessageWriter<?>> messageWriters() {
 		});
 	}
 
+	/**
+	 * Create a response builder with the given status code and message body readers.
+	 * @param statusCode the status code
+	 * @param messageReaders the message readers
+	 * @return the created builder
+	 * @since 5.0.7
+	 */
+	static Builder create(int statusCode, List<HttpMessageReader<?>> messageReaders) {
+		return create(statusCode, new ExchangeStrategies() {
+			@Override
+			public List<HttpMessageReader<?>> messageReaders() {
+				return messageReaders;
+			}
+			@Override
+			public List<HttpMessageWriter<?>> messageWriters() {
+				// not used in the response
+				return Collections.emptyList();
+			}
+		});
+	}
+
 
 	/**
 	 * Represents the headers of the HTTP response.
@@ -247,6 +303,14 @@ interface Builder {
 		 */
 		Builder statusCode(HttpStatus statusCode);
 
+		/**
+		 * Set the status code of the response.
+		 * @param statusCode the new status code.
+		 * @return this builder
+		 * @since 5.0.7
+		 */
+		Builder statusCode(int statusCode);
+
 		/**
 		 * Add the given header value(s) under the given name.
 		 * @param headerName  the header name

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultClientResponse.java

@@ -72,6 +72,11 @@ public HttpStatus statusCode() {
 		return this.response.getStatusCode();
 	}
 
+	@Override
+	public int rawStatusCode() {
+		return this.response.getRawStatusCode();
+	}
+
 	@Override
 	public Headers headers() {
 		return this.headers;
@@ -173,11 +178,11 @@ public <T> Mono<ResponseEntity<T>> toEntity(ParameterizedTypeReference<T> typeRe
 
 	private <T> Mono<ResponseEntity<T>> toEntityInternal(Mono<T> bodyMono) {
 		HttpHeaders headers = headers().asHttpHeaders();
-		HttpStatus statusCode = statusCode();
+		int status = rawStatusCode();
 		return bodyMono
-				.map(body -> new ResponseEntity<>(body, headers, statusCode))
+				.map(body -> createEntity(body, headers, status))
 				.switchIfEmpty(Mono.defer(
-						() -> Mono.just(new ResponseEntity<>(headers, statusCode))));
+						() -> Mono.just(createEntity(headers, status))));
 	}
 
 	@Override
@@ -192,10 +197,24 @@ public <T> Mono<ResponseEntity<List<T>>> toEntityList(ParameterizedTypeReference
 
 	private <T> Mono<ResponseEntity<List<T>>> toEntityListInternal(Flux<T> bodyFlux) {
 		HttpHeaders headers = headers().asHttpHeaders();
-		HttpStatus statusCode = statusCode();
+		int status = rawStatusCode();
 		return bodyFlux
 				.collectList()
-				.map(body -> new ResponseEntity<>(body, headers, statusCode));
+				.map(body -> createEntity(body, headers, status));
+	}
+
+	private <T> ResponseEntity<T> createEntity(HttpHeaders headers, int status) {
+		HttpStatus resolvedStatus = HttpStatus.resolve(status);
+		return resolvedStatus != null
+				? new ResponseEntity<>(headers, resolvedStatus)
+				: ResponseEntity.status(status).headers(headers).build();
+	}
+
+	private <T> ResponseEntity<T> createEntity(T body, HttpHeaders headers, int status) {
+		HttpStatus resolvedStatus = HttpStatus.resolve(status);
+		return resolvedStatus != null
+				? new ResponseEntity<>(body, headers, resolvedStatus)
+				: ResponseEntity.status(status).headers(headers).body(body);
 	}
 
 

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultClientResponseBuilder.java

@@ -44,7 +44,7 @@ final class DefaultClientResponseBuilder implements ClientResponse.Builder {
 
 	private ExchangeStrategies strategies;
 
-	private HttpStatus statusCode = HttpStatus.OK;
+	private int statusCode = HttpStatus.OK.value();
 
 	private final HttpHeaders headers = new HttpHeaders();
 
@@ -61,7 +61,7 @@ public DefaultClientResponseBuilder(ExchangeStrategies strategies) {
 	public DefaultClientResponseBuilder(ClientResponse other) {
 		Assert.notNull(other, "ClientResponse must not be null");
 		this.strategies = other.strategies();
-		statusCode(other.statusCode());
+		statusCode(other.rawStatusCode());
 		headers(headers -> headers.addAll(other.headers().asHttpHeaders()));
 		cookies(cookies -> cookies.addAll(other.cookies()));
 	}
@@ -70,6 +70,12 @@ public DefaultClientResponseBuilder(ClientResponse other) {
 	@Override
 	public DefaultClientResponseBuilder statusCode(HttpStatus statusCode) {
 		Assert.notNull(statusCode, "HttpStatus must not be null");
+		this.statusCode = statusCode.value();
+		return this;
+	}
+
+	@Override
+	public DefaultClientResponseBuilder statusCode(int statusCode) {
 		this.statusCode = statusCode;
 		return this;
 	}
@@ -137,15 +143,15 @@ public ClientResponse build() {
 
 	private static class BuiltClientHttpResponse implements ClientHttpResponse {
 
-		private final HttpStatus statusCode;
+		private final int statusCode;
 
 		private final HttpHeaders headers;
 
 		private final MultiValueMap<String, ResponseCookie> cookies;
 
 		private final Flux<DataBuffer> body;
 
-		public BuiltClientHttpResponse(HttpStatus statusCode, HttpHeaders headers,
+		public BuiltClientHttpResponse(int statusCode, HttpHeaders headers,
 				MultiValueMap<String, ResponseCookie> cookies, Flux<DataBuffer> body) {
 
 			this.statusCode = statusCode;
@@ -156,12 +162,12 @@ public BuiltClientHttpResponse(HttpStatus statusCode, HttpHeaders headers,
 
 		@Override
 		public HttpStatus getStatusCode() {
-			return this.statusCode;
+			return HttpStatus.valueOf(this.statusCode);
 		}
 
 		@Override
 		public int getRawStatusCode() {
-			return this.statusCode.value();
+			return this.statusCode;
 		}
 
 		@Override

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultWebClient.java

@@ -59,6 +59,7 @@
  * Default implementation of {@link WebClient}.
  *
  * @author Rossen Stoyanchev
+ * @author Denys Ivano
  * @since 5.0
  */
 class DefaultWebClient implements WebClient {
@@ -369,11 +370,12 @@ public ResponseSpec retrieve() {
 	private static class DefaultResponseSpec implements ResponseSpec {
 
 		private static final StatusHandler DEFAULT_STATUS_HANDLER =
-				new StatusHandler(HttpStatus::isError, DefaultResponseSpec::createResponseException);
+				new StatusHandler(StatusCodePredicates.isError(),
+						DefaultResponseSpec::createResponseException);
 
 		private final Mono<ClientResponse> responseMono;
 
-		private List<StatusHandler> statusHandlers = new ArrayList<>(1);
+		private final List<StatusHandler> statusHandlers = new ArrayList<>(1);
 
 		DefaultResponseSpec(Mono<ClientResponse> responseMono) {
 			this.responseMono = responseMono;
@@ -384,12 +386,26 @@ private static class DefaultResponseSpec implements ResponseSpec {
 		public ResponseSpec onStatus(Predicate<HttpStatus> statusPredicate,
 				Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
 
+			removeDefaultStatusHandler();
+			this.statusHandlers.add(new HttpStatusHandler(statusPredicate, exceptionFunction));
+
+			return this;
+		}
+
+		@Override
+		public ResponseSpec onStatusCode(Predicate<Integer> statusCodePredicate,
+				Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
+
+			removeDefaultStatusHandler();
+			this.statusHandlers.add(new StatusHandler(statusCodePredicate, exceptionFunction));
+
+			return this;
+		}
+
+		private void removeDefaultStatusHandler() {
 			if (this.statusHandlers.size() == 1 && this.statusHandlers.get(0) == DEFAULT_STATUS_HANDLER) {
 				this.statusHandlers.clear();
 			}
-			this.statusHandlers.add(new StatusHandler(statusPredicate, exceptionFunction));
-
-			return this;
 		}
 
 		@Override
@@ -435,7 +451,7 @@ private <T extends Publisher<?>> T bodyToPublisher(ClientResponse response,
 				T bodyPublisher, Function<Mono<? extends Throwable>, T> errorFunction) {
 
 			return this.statusHandlers.stream()
-					.filter(statusHandler -> statusHandler.test(response.statusCode()))
+					.filter(statusHandler -> statusHandler.test(response.rawStatusCode()))
 					.findFirst()
 					.map(statusHandler -> statusHandler.apply(response))
 					.map(errorFunction::apply)
@@ -453,14 +469,16 @@ private static Mono<WebClientResponseException> createResponseException(ClientRe
 					})
 					.defaultIfEmpty(new byte[0])
 					.map(bodyBytes -> {
-						String msg = String.format("ClientResponse has erroneous status code: %d %s", response.statusCode().value(),
-								response.statusCode().getReasonPhrase());
+						int status = response.rawStatusCode();
+						HttpStatus resolvedStatus = HttpStatus.resolve(status);
+						String msg = "ClientResponse has erroneous status code: " + status +
+								(resolvedStatus != null ? " " + resolvedStatus.getReasonPhrase() : "");
 						Charset charset = response.headers().contentType()
 								.map(MimeType::getCharset)
 								.orElse(StandardCharsets.ISO_8859_1);
 						return new WebClientResponseException(msg,
-								response.statusCode().value(),
-								response.statusCode().getReasonPhrase(),
+								status,
+								resolvedStatus != null ? resolvedStatus.getReasonPhrase() : null,
 								response.headers().asHttpHeaders(),
 								bodyBytes,
 								charset
@@ -471,11 +489,11 @@ private static Mono<WebClientResponseException> createResponseException(ClientRe
 
 		private static class StatusHandler {
 
-			private final Predicate<HttpStatus> predicate;
+			private final Predicate<Integer> predicate;
 
 			private final Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction;
 
-			public StatusHandler(Predicate<HttpStatus> predicate,
+			public StatusHandler(Predicate<Integer> predicate,
 					Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
 
 				Assert.notNull(predicate, "Predicate must not be null");
@@ -484,14 +502,30 @@ public StatusHandler(Predicate<HttpStatus> predicate,
 				this.exceptionFunction = exceptionFunction;
 			}
 
-			public boolean test(HttpStatus status) {
+			public boolean test(int status) {
 				return this.predicate.test(status);
 			}
 
 			public Mono<? extends Throwable> apply(ClientResponse response) {
 				return this.exceptionFunction.apply(response);
 			}
 		}
+
+		private static class HttpStatusHandler extends StatusHandler {
+
+			public HttpStatusHandler(Predicate<HttpStatus> predicate,
+					Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
+
+				super(statusCodePredicate(predicate), exceptionFunction);
+			}
+
+			private static Predicate<Integer> statusCodePredicate(Predicate<HttpStatus> predicate) {
+				return status -> {
+					HttpStatus resolvedStatus = HttpStatus.resolve(status);
+					return resolvedStatus != null && predicate.test(resolvedStatus);
+				};
+			}
+		}
 	}
 
 }