Remove SseHttpMessageConverter

CodecHttpMessageConverter is now suitable for SSE since it now
handles default content type.

spring-web-reactive/src/main/java/org/springframework/http/codec/SseEventEncoder.java

@@ -112,11 +112,14 @@ public class SseEventEncoder extends AbstractEncoder<Object> {
 				}
 			}
 
+			// Keep the SSE connection open even for cold stream in order to avoid
+			// unexpected browser reconnection
 			return Flux.concat(
 					encodeString(sb.toString(), bufferFactory),
 					dataBuffer,
 					encodeString("\n", bufferFactory),
-					Mono.just(FlushingDataBuffer.INSTANCE)
+					Mono.just(FlushingDataBuffer.INSTANCE),
+					Flux.never()
 			);
 		});
 

spring-web-reactive/src/main/java/org/springframework/http/converter/reactive/SseHttpMessageConverter.java

-/*
- * Copyright 2002-2016 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.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.http.converter.reactive;
-
-
-import java.util.Arrays;
-import java.util.List;
-
-import org.reactivestreams.Publisher;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-
-import org.springframework.core.ResolvableType;
-import org.springframework.core.codec.Encoder;
-import org.springframework.http.codec.SseEventEncoder;
-import org.springframework.http.MediaType;
-import org.springframework.http.ReactiveHttpOutputMessage;
-import org.springframework.web.reactive.sse.SseEvent;
-
-/**
- * Implementation of {@link HttpMessageConverter} that can stream Server-Sent Events
- * response.
- *
- * It allows to write {@code Flux<ServerSentEvent>}, which is Spring Web Reactive equivalent
- * to Spring MVC {@code SseEmitter}.
- *
- * Sending {@code Flux<String>} or {@code Flux<Pojo>} is equivalent to sending
- * {@code Flux<SseEvent>} with the {@code data} property set to the {@code String} or
- * {@code Pojo} value.
- *
- * @author Sebastien Deleuze
- * @see SseEvent
- * @see <a href="https://www.w3.org/TR/eventsource/">Server-Sent Events W3C recommandation</a>
- */
-public class SseHttpMessageConverter extends CodecHttpMessageConverter<Object> {
-
-	/**
-	 * Constructor that creates a new instance configured with the specified data encoders.
-	 */
-	public SseHttpMessageConverter(List<Encoder<?>> dataEncoders) {
-		super(new SseEventEncoder(dataEncoders), null);
-	}
-
-	@Override
-	public Mono<Void> write(Publisher<?> inputStream, ResolvableType type,
-			MediaType contentType, ReactiveHttpOutputMessage outputMessage) {
-
-		outputMessage.getHeaders().add("Content-Type", "text/event-stream");
-		// Keep the SSE connection open even for cold stream in order to avoid unexpected Browser reconnection
-		return super.write(Flux.from(inputStream).concatWith(Flux.never()), type, contentType, outputMessage);
-	}
-
-}

spring-web-reactive/src/main/java/org/springframework/web/reactive/sse/SseEvent.java

@@ -16,7 +16,7 @@
 
 package org.springframework.web.reactive.sse;
 
-import org.springframework.http.converter.reactive.SseHttpMessageConverter;
+import org.springframework.http.codec.SseEventEncoder;
 import org.springframework.util.MimeType;
 
 /**
@@ -26,7 +26,7 @@ import org.springframework.util.MimeType;
  * {@code SseEmitter} type. It allows to send Server-Sent Events in a reactive way.
  *
  * @author Sebastien Deleuze
- * @see SseHttpMessageConverter
+ * @see SseEventEncoder
  * @see <a href="https://www.w3.org/TR/eventsource/">Server-Sent Events W3C recommandation</a>
  */
 public class SseEvent {
@@ -95,9 +95,9 @@ public class SseEvent {
 	/**
 	 * Set {@code data} SSE field. If a multiline {@code String} is provided, it will be
 	 * turned into multiple {@code data} field lines by  as
-	 * defined in Server-Sent Events W3C recommandation.
+	 * defined in Server-Sent Events W3C recommendation.
 	 *
-	 * If no {@code mediaType} is defined, default {@link SseHttpMessageConverter} will:
+	 * If no {@code mediaType} is defined, default {@link SseEventEncoder} will:
 	 *  - Turn single line {@code String} to a single {@code data} field
 	 *  - Turn multiline line {@code String} to multiple {@code data} fields
 	 *  - Serialize other {@code Object} as JSON
@@ -117,7 +117,7 @@ public class SseEvent {
 
 	/**
 	 * Set the {@link MimeType} used to serialize the {@code data}.
-	 * {@link SseHttpMessageConverter} should be configured with the relevant encoder to be
+	 * {@link SseEventEncoder} should be configured with the relevant encoder to be
 	 * able to serialize it.
 	 */
 	public void setMimeType(MimeType mimeType) {
@@ -147,8 +147,8 @@ public class SseEvent {
 
 	/**
 	 * Set SSE comment. If a multiline comment is provided, it will be turned into multiple
-	 * SSE comment lines by {@link SseHttpMessageConverter} as defined in Server-Sent Events W3C
-	 * recommandation.
+	 * SSE comment lines by {@link SseEventEncoder} as defined in Server-Sent Events W3C
+	 * recommendation.
 	 */
 	public void setComment(String comment) {
 		this.comment = comment;

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/ResponseEntityResultHandlerTests.java

@@ -33,7 +33,6 @@ import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.core.io.buffer.support.DataBufferTestUtils;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
-import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.converter.reactive.CodecHttpMessageConverter;
 import org.springframework.http.converter.reactive.HttpMessageConverter;

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java

@@ -29,6 +29,7 @@ import reactor.core.test.TestSubscriber;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.codec.Encoder;
 import org.springframework.core.codec.support.ByteBufferDecoder;
 import org.springframework.core.codec.support.JacksonJsonDecoder;
 import org.springframework.core.codec.support.JacksonJsonEncoder;
@@ -36,8 +37,9 @@ import org.springframework.core.codec.support.JsonObjectDecoder;
 import org.springframework.core.codec.support.StringDecoder;
 import org.springframework.http.MediaType;
 import org.springframework.http.client.reactive.ReactorHttpClientRequestFactory;
+import org.springframework.http.codec.SseEventEncoder;
+import org.springframework.http.converter.reactive.CodecHttpMessageConverter;
 import org.springframework.http.converter.reactive.HttpMessageConverter;
-import org.springframework.http.converter.reactive.SseHttpMessageConverter;
 import org.springframework.http.server.reactive.AbstractHttpHandlerIntegrationTests;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -165,7 +167,8 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 		@Override
 		protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
-			converters.add(new SseHttpMessageConverter(Arrays.asList(new JacksonJsonEncoder())));
+			Encoder<Object> sseEncoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
+			converters.add(new CodecHttpMessageConverter<>(sseEncoder));
 		}
 	}