Fix EncoderHttpMessageWriter.isStreamingMediaType()

Closes gh-22936

Author: sdeleuze

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

@@ -38,6 +38,7 @@
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
  * {@code HttpMessageWriter} that wraps and delegates to an {@link Encoder}.
@@ -166,19 +167,29 @@ private static MediaType addDefaultCharset(MediaType main, @Nullable MediaType d
 		return main;
 	}
 
-	private boolean isStreamingMediaType(@Nullable MediaType contentType) {
-		if (contentType == null || !(this.encoder instanceof HttpMessageEncoder)) {
+	private boolean isStreamingMediaType(@Nullable MediaType mediaType) {
+		if (mediaType == null || !(this.encoder instanceof HttpMessageEncoder)) {
 			return false;
 		}
-		for (MediaType mediaType : ((HttpMessageEncoder<?>) this.encoder).getStreamingMediaTypes()) {
-			if (contentType.isCompatibleWith(mediaType) &&
-					contentType.getParameters().keySet().containsAll(mediaType.getParameters().keySet())) {
+		for (MediaType streamingMediaType : ((HttpMessageEncoder<?>) this.encoder).getStreamingMediaTypes()) {
+			if (mediaType.isCompatibleWith(streamingMediaType) && matchParameters(mediaType, streamingMediaType)) {
 				return true;
 			}
 		}
 		return false;
 	}
 
+	private boolean matchParameters(MediaType streamingMediaType, MediaType mediaType) {
+		for (String name : streamingMediaType.getParameters().keySet()) {
+			String s1 = streamingMediaType.getParameter(name);
+			String s2 = mediaType.getParameter(name);
+			if (StringUtils.hasText(s1) && StringUtils.hasText(s2) && !s1.equalsIgnoreCase(s2)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
 
 	// Server side only...
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -16,6 +16,8 @@
 
 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;
@@ -31,13 +33,13 @@
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
-import org.springframework.core.codec.Encoder;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.MediaType;
 import org.springframework.mock.http.server.reactive.test.MockServerHttpResponse;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
+import org.springframework.util.ReflectionUtils;
 
 import static java.nio.charset.StandardCharsets.*;
 import static org.junit.Assert.*;
@@ -59,7 +61,7 @@ public class EncoderHttpMessageWriterTests {
 
 
 	@Mock
-	private Encoder<String> encoder;
+	private HttpMessageEncoder<String> encoder;
 
 	private ArgumentCaptor<MediaType> mediaTypeCaptor;
 
@@ -172,6 +174,17 @@ public void emptyBodyWritten() {
 		assertEquals(0, this.response.getHeaders().getContentLength());
 	}
 
+	@Test  // gh-22936
+	public void isStreamingMediaType() throws InvocationTargetException, IllegalAccessException {
+		HttpMessageWriter<String> writer = getWriter(TEXT_HTML);
+		MediaType streamingMediaType = new MediaType(TEXT_PLAIN, Collections.singletonMap("streaming", "true"));
+		when(this.encoder.getStreamingMediaTypes()).thenReturn(Arrays.asList(streamingMediaType));
+		Method method = ReflectionUtils.findMethod(writer.getClass(), "isStreamingMediaType", MediaType.class);
+		ReflectionUtils.makeAccessible(method);
+		assertTrue((Boolean) method.invoke(writer, streamingMediaType));
+		assertFalse((Boolean) method.invoke(writer, new MediaType(TEXT_PLAIN, Collections.singletonMap("streaming", "false"))));
+		assertFalse((Boolean) method.invoke(writer, TEXT_HTML));
+	}
 
 	private HttpMessageWriter<String> getWriter(MimeType... mimeTypes) {
 		return getWriter(Flux.empty(), mimeTypes);