From 44ceecc8b39f73c47770ec52960c13b166af2837 Mon Sep 17 00:00:00 2001
From: Sebastien Deleuze <sdeleuze@pivotal.io>
Date: Tue, 27 Sep 2016 09:27:23 +0200
Subject: [PATCH] Imply text/event-stream when serializing ServerSentEvent

Issue: SPR-14748
---
 .../config/WebReactiveConfiguration.java       |  2 +-
 .../method/annotation/SseIntegrationTests.java | 18 ++++++++++++++++++
 .../ServerSentEventHttpMessageWriter.java      |  3 ++-
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/spring-web-reactive/src/main/java/org/springframework/web/reactive/config/WebReactiveConfiguration.java b/spring-web-reactive/src/main/java/org/springframework/web/reactive/config/WebReactiveConfiguration.java
index 643da2ef10c..4c00d3a9409 100644
--- a/spring-web-reactive/src/main/java/org/springframework/web/reactive/config/WebReactiveConfiguration.java
+++ b/spring-web-reactive/src/main/java/org/springframework/web/reactive/config/WebReactiveConfiguration.java
@@ -405,12 +405,12 @@ public class WebReactiveConfiguration implements ApplicationContextAware {
 		if (jaxb2Present) {
 			writers.add(new EncoderHttpMessageWriter<>(new Jaxb2XmlEncoder()));
 		}
+		writers.add(new Jackson2ServerHttpMessageWriter(new ServerSentEventHttpMessageWriter(sseDataEncoders)));
 		if (jackson2Present) {
 			Jackson2JsonEncoder jacksonEncoder = new Jackson2JsonEncoder();
 			writers.add(new Jackson2ServerHttpMessageWriter(new EncoderHttpMessageWriter<>(jacksonEncoder)));
 			sseDataEncoders.add(jacksonEncoder);
 		}
-		writers.add(new Jackson2ServerHttpMessageWriter(new ServerSentEventHttpMessageWriter(sseDataEncoders)));
 	}
 	/**
 	 * Override this to modify the list of message writers after it has been
diff --git a/spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java b/spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java
index 3e3d5e43235..40f4552ffd4 100644
--- a/spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java
+++ b/spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java
@@ -120,6 +120,24 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 				);
 	}
 
+	@Test
+	public void sseAsEventWithoutAcceptHeader() throws Exception {
+		Flux<String> result = this.webClient
+				.perform(get("http://localhost:" + port + "/sse/event"))
+				.extract(bodyStream(String.class))
+				.filter(s -> !s.equals("\n"))
+				.map(s -> s.replace("\n", ""))
+				.take(2);
+
+		TestSubscriber
+				.subscribe(result)
+				.await(Duration.ofSeconds(5))
+				.assertValues(
+						"id:0:bardata:foo",
+						"id:1:bardata:foo"
+				);
+	}
+
 	@RestController
 	@SuppressWarnings("unused")
 	static class SseController {
diff --git a/spring-web/src/main/java/org/springframework/http/codec/ServerSentEventHttpMessageWriter.java b/spring-web/src/main/java/org/springframework/http/codec/ServerSentEventHttpMessageWriter.java
index cf944ea6531..d5348a1b663 100644
--- a/spring-web/src/main/java/org/springframework/http/codec/ServerSentEventHttpMessageWriter.java
+++ b/spring-web/src/main/java/org/springframework/http/codec/ServerSentEventHttpMessageWriter.java
@@ -63,7 +63,8 @@ public class ServerSentEventHttpMessageWriter implements HttpMessageWriter<Objec
 
 	@Override
 	public boolean canWrite(ResolvableType elementType, MediaType mediaType) {
-		return mediaType == null || TEXT_EVENT_STREAM.isCompatibleWith(mediaType);
+		return mediaType == null || TEXT_EVENT_STREAM.isCompatibleWith(mediaType) ||
+				ServerSentEvent.class.isAssignableFrom(elementType.getRawClass());
 	}
 
 	@Override