Optimize WebClientUtils

Use constant Predicate for exception wrapping.
Use ResponseEntity constructor instead of builder.

See gh-26069

spring-web/src/main/java/org/springframework/http/ResponseEntity.java

@@ -113,9 +113,18 @@ public class ResponseEntity<T> extends HttpEntity<T> {
 	 * @param status the status code
 	 */
 	public ResponseEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers, HttpStatus status) {
-		super(body, headers);
+		this(body, headers, (Object) status);
-		Assert.notNull(status, "HttpStatus must not be null");
+	}
-		this.status = status;
+
+	/**
+	 * Create a new {@code HttpEntity} with the given body, headers, and status code.
+	 * @param body the entity body
+	 * @param headers the entity headers
+	 * @param rawStatus the status code value
+	 * @since 5.3.2
+	 */
+	public ResponseEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers, int rawStatus) {
+		this(body, headers, (Object) rawStatus);
 	}
 
 	/**

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

@@ -543,16 +543,10 @@ class DefaultWebClient implements WebClient {
 			return this.responseMono.flatMap(response -> handleBodyMono(response, response.bodyToMono(elementTypeRef)));
 		}
 
-		private <T> Mono<T> handleBodyMono(ClientResponse response, Mono<T> bodyPublisher) {
+		private <T> Mono<T> handleBodyMono(ClientResponse response, Mono<T> body) {
+			body = body.onErrorResume(WebClientUtils.WRAP_EXCEPTION_PREDICATE, exceptionWrappingFunction(response));
 			Mono<T> result = statusHandlers(response);
-			Mono<T> wrappedExceptions = bodyPublisher.onErrorResume(WebClientUtils::shouldWrapException,
+			return (result != null ? result.switchIfEmpty(body) : body);
-							t -> wrapException(t, response));
-			if (result != null) {
-				return result.switchIfEmpty(wrappedExceptions);
-			}
-			else {
-				return wrappedExceptions;
-			}
 		}
 
 		@Override
@@ -567,16 +561,10 @@ class DefaultWebClient implements WebClient {
 			return this.responseMono.flatMapMany(response -> handleBodyFlux(response, response.bodyToFlux(elementTypeRef)));
 		}
 
-		private <T> Publisher<T> handleBodyFlux(ClientResponse response, Flux<T> bodyPublisher) {
+		private <T> Publisher<T> handleBodyFlux(ClientResponse response, Flux<T> body) {
+			body = body.onErrorResume(WebClientUtils.WRAP_EXCEPTION_PREDICATE, exceptionWrappingFunction(response));
 			Mono<T> result = statusHandlers(response);
-			Flux<T> wrappedExceptions = bodyPublisher.onErrorResume(WebClientUtils::shouldWrapException,
+			return (result != null ? result.flux().switchIfEmpty(body) : body);
-					t -> wrapException(t, response));
-			if (result != null) {
-				return result.flux().switchIfEmpty(wrappedExceptions);
-			}
-			else {
-				return wrappedExceptions;
-			}
 		}
 
 		@Nullable
@@ -608,10 +596,8 @@ class DefaultWebClient implements WebClient {
 			return result.checkpoint(description);
 		}
 
-		private <T> Mono<T> wrapException(Throwable throwable, ClientResponse response) {
+		private <T> Function<Throwable, Mono<? extends T>> exceptionWrappingFunction(ClientResponse response) {
-			return response.createException()
+			return t -> response.createException().flatMap(ex -> Mono.error(ex.initCause(t)));
-					.map(responseException -> responseException.initCause(throwable))
-					.flatMap(Mono::error);
 		}
 
 		@Override

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

@@ -104,7 +104,7 @@ public abstract class ExchangeFunctions {
 					.connect(httpMethod, url, httpRequest -> clientRequest.writeTo(httpRequest, this.strategies))
 					.doOnRequest(n -> logRequest(clientRequest))
 					.doOnCancel(() -> logger.debug(logPrefix + "Cancel signal (to close connection)"))
-					.onErrorResume(WebClientUtils::shouldWrapException, t -> wrapException(t, clientRequest))
+					.onErrorResume(WebClientUtils.WRAP_EXCEPTION_PREDICATE, t -> wrapException(t, clientRequest))
 					.map(httpResponse -> {
 						logResponse(httpResponse, logPrefix);
 						return new DefaultClientResponse(

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

@@ -17,6 +17,7 @@
 package org.springframework.web.reactive.function.client;
 
 import java.util.List;
+import java.util.function.Predicate;
 
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
@@ -26,7 +27,8 @@ import org.springframework.core.codec.CodecException;
 import org.springframework.http.ResponseEntity;
 
 /**
- * Internal methods shared between {@link DefaultWebClient} and {@link DefaultClientResponse}.
+ * Internal methods shared between {@link DefaultWebClient} and
+ * {@link DefaultClientResponse}.
  *
  * @author Arjen Poutsma
  * @since 5.2
@@ -35,6 +37,12 @@ abstract class WebClientUtils {
 
 	private static final String VALUE_NONE = "\n\t\t\n\t\t\n\uE000\uE001\uE002\n\t\t\t\t\n";
 
+	/**
+	 * Predicate that returns true if an exception should be wrapped.
+	 */
+	public final static Predicate<? super Throwable> WRAP_EXCEPTION_PREDICATE =
+			t -> !(t instanceof WebClientException) && !(t instanceof CodecException);
+
 
 	/**
 	 * Map the given response to a single value {@code ResponseEntity<T>}.
@@ -42,9 +50,10 @@ abstract class WebClientUtils {
 	@SuppressWarnings("unchecked")
 	public static <T> Mono<ResponseEntity<T>> mapToEntity(ClientResponse response, Mono<T> bodyMono) {
 		return ((Mono<Object>) bodyMono).defaultIfEmpty(VALUE_NONE).map(body ->
-				ResponseEntity.status(response.rawStatusCode())
+				new ResponseEntity<>(
-						.headers(response.headers().asHttpHeaders())
+						body != VALUE_NONE ? (T) body : null,
-						.body(body != VALUE_NONE ? (T) body : null));
+						response.headers().asHttpHeaders(),
+						response.rawStatusCode()));
 	}
 
 	/**
@@ -52,15 +61,7 @@ abstract class WebClientUtils {
 	 */
 	public static <T> Mono<ResponseEntity<List<T>>> mapToEntityList(ClientResponse response, Publisher<T> body) {
 		return Flux.from(body).collectList().map(list ->
-				ResponseEntity.status(response.rawStatusCode())
+				new ResponseEntity<>(list, response.headers().asHttpHeaders(), response.rawStatusCode()));
-						.headers(response.headers().asHttpHeaders())
-						.body(list));
 	}
 
-	/**
-	 * Indicates whether the given exception should be wrapped.
-	 */
-	public static boolean shouldWrapException(Throwable t) {
-		return !(t instanceof WebClientException) && !(t instanceof CodecException);
-	}
 }