Optimize some iterations in BodyExtractor and BodyInserter

spring-web/src/main/java/org/springframework/http/client/reactive/AbstractClientHttpRequest.java

@@ -147,8 +147,10 @@ protected Mono<Void> doCommit(@Nullable Supplier<? extends Publisher<Void>> writ
 this.commitActions.add(writeAction);
 }
 
-List<? extends Publisher<Void>> actions = this.commitActions.stream()
-.map(Supplier::get).toList();
+List<Publisher<Void>> actions = new ArrayList<>(this.commitActions.size());
+for (Supplier<? extends Publisher<Void>> commitAction : this.commitActions) {
+actions.add(commitAction.get());
+}
 
 return Flux.concat(actions).then();
 }

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

@@ -194,18 +194,16 @@ private static <T, S extends Publisher<T>> S readWithMessageReaders(
 MediaType contentType = Optional.ofNullable(message.getHeaders().getContentType())
 .orElse(MediaType.APPLICATION_OCTET_STREAM);
 
-return context.messageReaders().stream()
-.filter(reader -> reader.canRead(elementType, contentType))
-.findFirst()
-.map(BodyExtractors::<T>cast)
-.map(readerFunction)
-.orElseGet(() -> {
-List<MediaType> mediaTypes = context.messageReaders().stream()
-.flatMap(reader -> reader.getReadableMediaTypes(elementType).stream())
-.toList();
-return errorFunction.apply(
-new UnsupportedMediaTypeException(contentType, mediaTypes, elementType));
-});
+for (HttpMessageReader<?> messageReader : context.messageReaders()) {
+if (messageReader.canRead(elementType, contentType)) {
+return readerFunction.apply(cast(messageReader));
+}
+}
+List<MediaType> mediaTypes = context.messageReaders().stream()
+.flatMap(reader -> reader.getReadableMediaTypes(elementType).stream())
+.toList();
+return errorFunction.apply(
+new UnsupportedMediaTypeException(contentType, mediaTypes, elementType));
 }
 
 private static <T> Mono<T> readToMono(ReactiveHttpInputMessage message, BodyExtractor.Context context,
@@ -245,12 +243,13 @@ private static <T> Flux<T> unsupportedErrorHandler(
 private static <T> HttpMessageReader<T> findReader(
 ResolvableType elementType, MediaType mediaType, BodyExtractor.Context context) {
 
-return context.messageReaders().stream()
-.filter(messageReader -> messageReader.canRead(elementType, mediaType))
-.findFirst()
-.map(BodyExtractors::<T>cast)
-.orElseThrow(() -> new IllegalStateException(
-"No HttpMessageReader for \"" + mediaType + "\" and \"" + elementType + "\""));
+for (HttpMessageReader<?> messageReader : context.messageReaders()) {
+if (messageReader.canRead(elementType, mediaType)) {
+return cast(messageReader);
+}
+}
+throw new IllegalStateException(
+"No HttpMessageReader for \"" + mediaType + "\" and \"" + elementType + "\"");
 }
 
 @SuppressWarnings("unchecked")

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

@@ -373,12 +373,13 @@ else if (adapter != null) {
 publisher = Mono.just(body);
 }
 MediaType mediaType = outputMessage.getHeaders().getContentType();
-return context.messageWriters().stream()
-.filter(messageWriter -> messageWriter.canWrite(bodyType, mediaType))
-.findFirst()
-.map(BodyInserters::cast)
-.map(writer -> write(publisher, bodyType, mediaType, outputMessage, context, writer))
-.orElseGet(() -> Mono.error(unsupportedError(bodyType, context, mediaType)));
+for (HttpMessageWriter<?> messageWriter : context.messageWriters()) {
+if (messageWriter.canWrite(bodyType, mediaType)) {
+HttpMessageWriter<Object> typedMessageWriter = cast(messageWriter);
+return write(publisher, bodyType, mediaType, outputMessage, context, typedMessageWriter);
+}
+}
+return Mono.error(unsupportedError(bodyType, context, mediaType));
 }
 
 private static UnsupportedMediaTypeException unsupportedError(ResolvableType bodyType,
@@ -406,12 +407,13 @@ private static <T> Mono<Void> write(Publisher<? extends T> input, ResolvableType
 private static <T> HttpMessageWriter<T> findWriter(
 BodyInserter.Context context, ResolvableType elementType, @Nullable MediaType mediaType) {
 
-return context.messageWriters().stream()
-.filter(messageWriter -> messageWriter.canWrite(elementType, mediaType))
-.findFirst()
-.map(BodyInserters::<T>cast)
-.orElseThrow(() -> new IllegalStateException(
-"No HttpMessageWriter for \"" + mediaType + "\" and \"" + elementType + "\""));
+for (HttpMessageWriter<?> messageWriter : context.messageWriters()) {
+if (messageWriter.canWrite(elementType, mediaType)) {
+return cast(messageWriter);
+}
+}
+throw new IllegalStateException(
+"No HttpMessageWriter for \"" + mediaType + "\" and \"" + elementType + "\"");
 }
 
 @SuppressWarnings("unchecked")