Take in account Rossen and Arjen feedbacks

spring-web-reactive/src/main/java/org/springframework/core/io/buffer/FlushingDataBuffer.java

@@ -33,6 +33,10 @@ public class FlushingDataBuffer implements DataBuffer {
 
 	private final DataBuffer buffer;
 
+	public FlushingDataBuffer() {
+		this.buffer = new DefaultDataBufferFactory().allocateBuffer(0);
+	}
+
 	public FlushingDataBuffer(DataBuffer buffer) {
 		Assert.notNull(buffer);
 		this.buffer = buffer;
@@ -85,7 +89,7 @@ public class FlushingDataBuffer implements DataBuffer {
 
 	@Override
 	public DataBuffer write(byte[] source, int offset, int length) {
-		return this.write(source, offset, length);
+		return this.buffer.write(source, offset, length);
 	}
 
 	@Override
@@ -117,4 +121,5 @@ public class FlushingDataBuffer implements DataBuffer {
 	public OutputStream asOutputStream() {
 		return this.buffer.asOutputStream();
 	}
+
 }

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

@@ -14,8 +14,9 @@
  * limitations under the License.
  */
 
-package org.springframework.core.codec.support;
+package org.springframework.http.codec;
 
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Optional;
 
@@ -26,6 +27,7 @@ import reactor.core.publisher.Mono;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.codec.CodecException;
 import org.springframework.core.codec.Encoder;
+import org.springframework.core.codec.support.AbstractEncoder;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.core.io.buffer.FlushingDataBuffer;
@@ -40,24 +42,22 @@ import org.springframework.web.reactive.sse.SseEvent;
  */
 public class SseEventEncoder extends AbstractEncoder<Object> {
 
-	private final Encoder<String> stringEncoder;
-
 	private final List<Encoder<?>> dataEncoders;
 
 
-	public SseEventEncoder(Encoder<String> stringEncoder, List<Encoder<?>> dataEncoders) {
+	public SseEventEncoder(List<Encoder<?>> dataEncoders) {
 		super(new MimeType("text", "event-stream"));
-		Assert.notNull(stringEncoder, "'stringEncoder' must not be null");
 		Assert.notNull(dataEncoders, "'dataEncoders' must not be null");
-		this.stringEncoder = stringEncoder;
 		this.dataEncoders = dataEncoders;
 	}
 
 	@Override
-	public Flux<DataBuffer> encode(Publisher<?> inputStream, DataBufferFactory bufferFactory, ResolvableType type, MimeType sseMimeType, Object... hints) {
+	public Flux<DataBuffer> encode(Publisher<?> inputStream, DataBufferFactory bufferFactory,
+			ResolvableType type, MimeType sseMimeType, Object... hints) {
 
 		return Flux.from(inputStream).flatMap(input -> {
-			SseEvent event = (SseEvent.class.equals(type.getRawClass()) ? (SseEvent)input : new SseEvent(input));
+			SseEvent event = (SseEvent.class.equals(type.getRawClass()) ?
+					(SseEvent)input : new SseEvent(input));
 
 			StringBuilder sb = new StringBuilder();
 
@@ -87,12 +87,11 @@ public class SseEventEncoder extends AbstractEncoder<Object> {
 
 			Object data = event.getData();
 			Flux<DataBuffer> dataBuffer = Flux.empty();
-			MimeType stringMimeType = this.stringEncoder.getEncodableMimeTypes().get(0);
 			MimeType mimeType = (event.getMimeType() == null ?
-	                (data instanceof String ? stringMimeType : new MimeType("*")) : event.getMimeType());
+					new MimeType("*") : event.getMimeType());
 			if (data != null) {
 				sb.append("data:");
-				if (data instanceof String && mimeType.isCompatibleWith(stringMimeType)) {
+				if (data instanceof String) {
 					sb.append(((String)data).replaceAll("\\n", "\ndata:")).append("\n");
 				}
 				else {
@@ -103,8 +102,9 @@ public class SseEventEncoder extends AbstractEncoder<Object> {
 
 					if (encoder.isPresent()) {
 						dataBuffer = ((Encoder<Object>)encoder.get())
-								.encode(Mono.just(data), bufferFactory, ResolvableType.forClass(data.getClass()), mimeType)
-								.concatWith(encodeString("\n", bufferFactory, stringMimeType));
+								.encode(Mono.just(data), bufferFactory,
+										ResolvableType.forClass(data.getClass()), mimeType)
+								.concatWith(encodeString("\n", bufferFactory));
 					}
 					else {
 						throw new CodecException("No suitable encoder found!");
@@ -112,16 +112,19 @@ public class SseEventEncoder extends AbstractEncoder<Object> {
 				}
 			}
 
-			return Flux
-					.concat(encodeString(sb.toString(), bufferFactory, stringMimeType), dataBuffer)
-					.reduce((buf1, buf2) -> buf1.write(buf2))
-					.concatWith(encodeString("\n", bufferFactory, stringMimeType).map(b -> new FlushingDataBuffer(b)));
+			return Flux.concat(
+					encodeString(sb.toString(), bufferFactory),
+					dataBuffer,
+					encodeString("\n", bufferFactory).map(b -> new FlushingDataBuffer(b))
+			);
 		});
 
 	}
 
-	private Flux<DataBuffer> encodeString(String str, DataBufferFactory bufferFactory, MimeType mimeType) {
-		return stringEncoder.encode(Mono.just(str), bufferFactory, ResolvableType.forClass(String.class), mimeType);
+	private Mono<DataBuffer> encodeString(String str, DataBufferFactory bufferFactory) {
+		byte[] bytes = str.getBytes(StandardCharsets.UTF_8);
+		DataBuffer buffer = bufferFactory.allocateBuffer(bytes.length).write(bytes);
+		return Mono.just(buffer);
 	}
 
 }

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

@@ -26,9 +26,7 @@ import reactor.core.publisher.Mono;
 
 import org.springframework.core.ResolvableType;
 import org.springframework.core.codec.Encoder;
-import org.springframework.core.codec.support.JacksonJsonEncoder;
-import org.springframework.core.codec.support.SseEventEncoder;
-import org.springframework.core.codec.support.StringEncoder;
+import org.springframework.http.codec.SseEventEncoder;
 import org.springframework.http.MediaType;
 import org.springframework.http.ReactiveHttpOutputMessage;
 import org.springframework.web.reactive.sse.SseEvent;
@@ -51,16 +49,10 @@ import org.springframework.web.reactive.sse.SseEvent;
 public class SseHttpMessageConverter extends CodecHttpMessageConverter<Object> {
 
 	/**
-	 * Default constructor that creates a new instance configured with {@link StringEncoder}
-	 * and {@link JacksonJsonEncoder} encoders.
+	 * Constructor that creates a new instance configured with the specified data encoders.
 	 */
-	public SseHttpMessageConverter() {
-		this(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
-	}
-
-	public SseHttpMessageConverter(Encoder<String> stringEncoder, List<Encoder<?>> dataEncoders) {
-		// 1 SseEvent element = 1 DataBuffer element so flush after each element
-		super(new SseEventEncoder(stringEncoder, dataEncoders), null);
+	public SseHttpMessageConverter(List<Encoder<?>> dataEncoders) {
+		super(new SseEventEncoder(dataEncoders), null);
 	}
 
 	@Override

spring-web-reactive/src/test/java/org/springframework/core/codec/support/SseEventEncoderTests.java

@@ -26,6 +26,7 @@ import reactor.core.test.TestSubscriber;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.io.buffer.AbstractDataBufferAllocatingTestCase;
 import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.http.codec.SseEventEncoder;
 import org.springframework.util.MimeType;
 import org.springframework.web.reactive.sse.SseEvent;
 
@@ -40,25 +41,25 @@ public class SseEventEncoderTests extends AbstractDataBufferAllocatingTestCase {
 
 	@Test
 	public void nullMimeType() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		assertTrue(encoder.canEncode(ResolvableType.forClass(Object.class), null));
 	}
 
 	@Test
 	public void unsupportedMimeType() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		assertFalse(encoder.canEncode(ResolvableType.forClass(Object.class), new MimeType("foo", "bar")));
 	}
 
 	@Test
 	public void supportedMimeType() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		assertTrue(encoder.canEncode(ResolvableType.forClass(Object.class), new MimeType("text", "event-stream")));
 	}
 
 	@Test
 	public void encodeServerSentEvent() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		SseEvent event = new SseEvent();
 		event.setId("c42");
 		event.setName("foo");
@@ -82,7 +83,7 @@ public class SseEventEncoderTests extends AbstractDataBufferAllocatingTestCase {
 
 	@Test
 	public void encodeString() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		Flux<String> source = Flux.just("foo", "bar");
 		Flux<DataBuffer> output = encoder.encode(source, this.dataBufferFactory,
 				ResolvableType.forClass(String.class), new MimeType("text", "event-stream"));
@@ -99,7 +100,7 @@ public class SseEventEncoderTests extends AbstractDataBufferAllocatingTestCase {
 
 	@Test
 	public void encodeMultilineString() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		Flux<String> source = Flux.just("foo\nbar", "foo\nbaz");
 		Flux<DataBuffer> output = encoder.encode(source, this.dataBufferFactory,
 				ResolvableType.forClass(String.class), new MimeType("text", "event-stream"));
@@ -117,7 +118,7 @@ public class SseEventEncoderTests extends AbstractDataBufferAllocatingTestCase {
 
 	@Test
 	public void encodePojo() {
-		SseEventEncoder encoder = new SseEventEncoder(new StringEncoder(), Arrays.asList(new JacksonJsonEncoder()));
+		SseEventEncoder encoder = new SseEventEncoder(Arrays.asList(new JacksonJsonEncoder()));
 		Flux<Pojo> source = Flux.just(new Pojo("foofoo", "barbar"), new Pojo("foofoofoo", "barbarbar"));
 		Flux<DataBuffer> output = encoder.encode(source, this.dataBufferFactory,
 						ResolvableType.forClass(Pojo.class), new MimeType("text", "event-stream"));
@@ -125,9 +126,13 @@ public class SseEventEncoderTests extends AbstractDataBufferAllocatingTestCase {
 				.subscribe(output)
 				.assertNoError()
 				.assertValuesWith(
-						stringConsumer("data:{\"foo\":\"foofoo\",\"bar\":\"barbar\"}\n"),
+						stringConsumer("data:"),
+						stringConsumer("{\"foo\":\"foofoo\",\"bar\":\"barbar\"}"),
+						stringConsumer("\n"),
+						stringConsumer("\n"),
+						stringConsumer("data:"),
+						stringConsumer("{\"foo\":\"foofoofoo\",\"bar\":\"barbarbar\"}"),
 						stringConsumer("\n"),
-						stringConsumer("data:{\"foo\":\"foofoofoo\",\"bar\":\"barbarbar\"}\n"),
 						stringConsumer("\n")
 				);
 	}

spring-web-reactive/src/test/java/org/springframework/http/server/reactive/FlushingIntegrationTests.java

@@ -62,6 +62,8 @@ public class FlushingIntegrationTests extends AbstractHttpHandlerIntegrationTest
 		return new FlushingHandler();
 	}
 
+	// Handler that never completes designed to test if flushing is perform correctly when
+	// a FlushingDataBuffer is written
 	private static class FlushingHandler implements HttpHandler {
 
 		@Override

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

@@ -34,14 +34,9 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.codec.support.ByteBufferDecoder;
 import org.springframework.core.codec.support.JacksonJsonDecoder;
+import org.springframework.core.codec.support.JacksonJsonEncoder;
 import org.springframework.core.codec.support.JsonObjectDecoder;
 import org.springframework.core.codec.support.StringDecoder;
-import org.springframework.core.convert.ConversionService;
-import org.springframework.core.convert.support.GenericConversionService;
-import org.springframework.core.convert.support.ReactiveStreamsToCompletableFutureConverter;
-import org.springframework.core.convert.support.ReactiveStreamsToRxJava1Converter;
-import org.springframework.core.io.buffer.DataBufferFactory;
-import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.MediaType;
 import org.springframework.http.client.reactive.ReactorHttpClientRequestFactory;
 import org.springframework.http.converter.reactive.HttpMessageConverter;
@@ -56,7 +51,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.reactive.WebClient;
 import org.springframework.web.reactive.DispatcherHandler;
-import org.springframework.web.reactive.result.SimpleResultHandler;
+import org.springframework.web.reactive.config.WebReactiveConfiguration;
 import org.springframework.web.reactive.sse.SseEvent;
 import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
 
@@ -108,7 +103,7 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 				.perform(get("http://localhost:" + port + "/sse/string")
 				.accept(new MediaType("text", "event-stream")))
 				.extract(bodyStream(String.class))
-				.take(Duration.ofMillis(500))
+				.take(Duration.ofMillis(1000))
 				.reduce((s1, s2) -> s1 + s2);
 
 		TestSubscriber
@@ -123,7 +118,7 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 				.perform(get("http://localhost:" + port + "/sse/person")
 				.accept(new MediaType("text", "event-stream")))
 				.extract(bodyStream(String.class))
-				.take(Duration.ofMillis(500))
+				.take(Duration.ofMillis(1000))
 				.reduce((s1, s2) -> s1 + s2);
 
 		TestSubscriber
@@ -138,7 +133,7 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 				.perform(get("http://localhost:" + port + "/sse/event")
 				.accept(new MediaType("text", "event-stream")))
 				.extract(bodyStream(String.class))
-				.take(Duration.ofMillis(500))
+				.take(Duration.ofMillis(1000))
 				.reduce((s1, s2) -> s1 + s2);
 
 		TestSubscriber
@@ -176,46 +171,17 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 	@Configuration
 	@SuppressWarnings("unused")
-	static class TestConfiguration {
-
-		private DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
+	static class TestConfiguration extends WebReactiveConfiguration {
 
 		@Bean
 		public SseController sseController() {
 			return new SseController();
 		}
 
-		@Bean
-		public RequestMappingHandlerMapping handlerMapping() {
-			return new RequestMappingHandlerMapping();
-		}
-
-		@Bean
-		public RequestMappingHandlerAdapter handlerAdapter() {
-			RequestMappingHandlerAdapter handlerAdapter = new RequestMappingHandlerAdapter();
-			handlerAdapter.setConversionService(conversionService());
-			return handlerAdapter;
-		}
-
-		@Bean
-		public ConversionService conversionService() {
-			GenericConversionService service = new GenericConversionService();
-			service.addConverter(new ReactiveStreamsToCompletableFutureConverter());
-			service.addConverter(new ReactiveStreamsToRxJava1Converter());
-			return service;
-		}
-
-		@Bean
-		public ResponseBodyResultHandler responseBodyResultHandler() {
-			List<HttpMessageConverter<?>> converters = Arrays.asList(new SseHttpMessageConverter());
-			return new ResponseBodyResultHandler(converters, conversionService());
-		}
-
-		@Bean
-		public SimpleResultHandler simpleHandlerResultHandler() {
-			return new SimpleResultHandler(conversionService());
+		@Override
+		protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
+			converters.add(new SseHttpMessageConverter(Arrays.asList(new JacksonJsonEncoder())));
 		}
-
 	}
 
 	private static class Person {