Polishing external contribution

See gh-32622

Author: poutsma

Diff for: spring-web/src/main/java/org/springframework/http/codec/EncoderHttpMessageWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,15 +16,20 @@
 
 package org.springframework.http.codec;
 
+import java.util.List;
+import java.util.Map;
+
 import org.apache.commons.logging.Log;
 import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
 import org.springframework.core.ResolvableType;
 import org.springframework.core.codec.AbstractEncoder;
 import org.springframework.core.codec.Encoder;
 import org.springframework.core.codec.Hints;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferUtils;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpLogging;
 import org.springframework.http.MediaType;
 import org.springframework.http.ReactiveHttpOutputMessage;
@@ -33,11 +38,6 @@
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-
-import java.util.List;
-import java.util.Map;
 
 /**
  * {@code HttpMessageWriter} that wraps and delegates to an {@link Encoder}.
@@ -127,7 +127,7 @@ public Mono<Void> write(Publisher<? extends T> inputStream, ResolvableType eleme
 			return body
 					.singleOrEmpty()
 					.switchIfEmpty(Mono.defer(() -> {
-						message.getHeaders().remove(HttpHeaders.CONTENT_TYPE);
+						message.getHeaders().setContentType(null);
 						message.getHeaders().setContentLength(0);
 						return message.setComplete().then(Mono.empty());
 					}))

Diff for: spring-web/src/test/java/org/springframework/http/codec/EncoderHttpMessageWriterTests.java

@@ -16,36 +16,33 @@
 
 package org.springframework.http.codec;
 
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
 import org.junit.jupiter.api.Test;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoSettings;
 import org.mockito.quality.Strictness;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+
 import org.springframework.core.ResolvableType;
 import org.springframework.core.codec.CharSequenceEncoder;
 import org.springframework.core.codec.Encoder;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
-import org.springframework.http.ReactiveHttpOutputMessage;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.ReflectionUtils;
-import org.springframework.web.testfixture.http.client.reactive.MockClientHttpRequest;
 import org.springframework.web.testfixture.http.server.reactive.MockServerHttpResponse;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-import reactor.test.StepVerifier;
-
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
 
 import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -205,32 +202,27 @@ void isStreamingMediaType() throws InvocationTargetException, IllegalAccessExcep
 	}
 
 	@Test
-	public void ifBodyPublisherEmpty_noContentTypeHeader() {
+	public void noContentTypeWithEmptyBody() {
 		Encoder<CharSequence> encoder = CharSequenceEncoder.textPlainOnly();
-		EncoderHttpMessageWriter<CharSequence> writer = new EncoderHttpMessageWriter<>(encoder);
-		ReactiveHttpOutputMessage outputMessage = new MockClientHttpRequest(HttpMethod.POST, "/");
+		HttpMessageWriter<CharSequence> writer = new EncoderHttpMessageWriter<>(encoder);
 		Mono<Void> writerMono = writer.write(Mono.empty(), ResolvableType.forClass(String.class),
-				null, outputMessage, NO_HINTS);
+				null, this.response, NO_HINTS);
 
 		StepVerifier.create(writerMono)
 				.verifyComplete();
-		assertThat(outputMessage.getHeaders()).doesNotContainKey(HttpHeaders.CONTENT_TYPE);
+		assertThat(response.getHeaders().getContentType()).isNull();
 	}
 
 	@Test
-	public void ifBodyPublisherEmpty_contentLengthZero() {
+	public void zeroContentLengthWithEmptyBody() {
 		Encoder<CharSequence> encoder = CharSequenceEncoder.textPlainOnly();
-		EncoderHttpMessageWriter<CharSequence> writer = new EncoderHttpMessageWriter<>(encoder);
-		ReactiveHttpOutputMessage outputMessage = new MockClientHttpRequest(HttpMethod.POST, "/");
+		HttpMessageWriter<CharSequence> writer = new EncoderHttpMessageWriter<>(encoder);
 		Mono<Void> writerMono = writer.write(Mono.empty(), ResolvableType.forClass(String.class),
-				null, outputMessage, NO_HINTS);
+				null, this.response, NO_HINTS);
 
 		StepVerifier.create(writerMono)
 				.verifyComplete();
-		List<String> contentLengthValues = outputMessage.getHeaders().get(HttpHeaders.CONTENT_LENGTH);
-		assertThat(contentLengthValues).hasSize(1);
-		int contentLength = Integer.parseInt(contentLengthValues.get(0));
-		assertThat(contentLength).isEqualTo(0);
+		assertThat(this.response.getHeaders().getContentLength()).isEqualTo(0);
 	}
 
 	private void configureEncoder(MimeType... mimeTypes) {