Switch defaults for ContentTypeResolver

Now that we have a CompositeContentTypeResolverBuilder with built-in
defaults, we switch to those defaults in places where a
ContentTypeResolver is used.

spring-web-reactive/src/main/java/org/springframework/web/reactive/accept/CompositeContentTypeResolverBuilder.java

@@ -27,7 +27,55 @@ import org.springframework.util.CollectionUtils;
 
 
 /**
- * Builder for {@link CompositeContentTypeResolver}.
+ * Factory to create a {@link CompositeContentTypeResolver} and configure it with
+ * one or more {@link ContentTypeResolver} instances with build style methods.
+ * The following table shows methods, resulting strategy instances, and if in
+ * use by default:
+ *
+ * <table>
+ * <tr>
+ *     <th>Property Setter</th>
+ *     <th>Underlying Strategy</th>
+ *     <th>Default Setting</th>
+ * </tr>
+ * <tr>
+ *     <td>{@link #favorPathExtension}</td>
+ *     <td>{@link PathExtensionContentTypeResolver Path Extension resolver}</td>
+ *     <td>On</td>
+ * </tr>
+ * <tr>
+ *     <td>{@link #favorParameter}</td>
+ *     <td>{@link ParameterContentTypeResolver Parameter resolver}</td>
+ *     <td>Off</td>
+ * </tr>
+ * <tr>
+ *     <td>{@link #ignoreAcceptHeader}</td>
+ *     <td>{@link HeaderContentTypeResolver Header resolver}</td>
+ *     <td>On</td>
+ * </tr>
+ * <tr>
+ *     <td>{@link #defaultContentType}</td>
+ *     <td>{@link FixedContentTypeResolver Fixed content resolver}</td>
+ *     <td>Not set</td>
+ * </tr>
+ * <tr>
+ *     <td>{@link #defaultContentTypeResolver}</td>
+ *     <td>{@link ContentTypeResolver}</td>
+ *     <td>Not set</td>
+ * </tr>
+ * </table>
+ *
+ * <p>The order in which resolvers are configured is fixed. Config methods may only
+ * turn individual resolvers on or off. If you need a custom order for any
+ * reason simply instantiate {@code {@link CompositeContentTypeResolver}} directly.
+ *
+ * <p>For the path extension and parameter resolvers you may explicitly add
+ * {@link #mediaTypes(Map)}. This will be used to resolve path extensions or a
+ * parameter value such as "json" to a media type such as "application/json".
+ *
+ * <p>The path extension strategy will also use the Java Activation framework
+ * (JAF), if available, to resolve a path extension to a MediaType. You may
+ * {@link #useJaf suppress} the use of JAF.
  *
  * @author Rossen Stoyanchev
  */

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/condition/ProducesRequestCondition.java

@@ -28,6 +28,7 @@ import org.springframework.http.MediaType;
 import org.springframework.web.HttpMediaTypeNotAcceptableException;
 import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.reactive.accept.CompositeContentTypeResolverBuilder;
 import org.springframework.web.reactive.accept.ContentTypeResolver;
 import org.springframework.web.reactive.accept.HeaderContentTypeResolver;
 import org.springframework.web.server.ServerWebExchange;
@@ -96,7 +97,8 @@ public final class ProducesRequestCondition extends AbstractRequestCondition<Pro
 
 		this.expressions = new ArrayList<>(expressions);
 		Collections.sort(this.expressions);
-		this.contentTypeResolver = (resolver != null ? resolver : new HeaderContentTypeResolver());
+		this.contentTypeResolver = (resolver != null ?
+				resolver : new CompositeContentTypeResolverBuilder().build());
 	}
 
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/method/annotation/RequestMappingHandlerMapping.java

@@ -27,6 +27,8 @@ import org.springframework.util.Assert;
 import org.springframework.util.StringValueResolver;
 import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.reactive.accept.CompositeContentTypeResolver;
+import org.springframework.web.reactive.accept.CompositeContentTypeResolverBuilder;
 import org.springframework.web.reactive.accept.ContentTypeResolver;
 import org.springframework.web.reactive.accept.HeaderContentTypeResolver;
 import org.springframework.web.reactive.result.condition.RequestCondition;
@@ -49,7 +51,7 @@ public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMappi
 
 	private boolean useTrailingSlashMatch = true;
 
-	private ContentTypeResolver contentTypeResolver = new HeaderContentTypeResolver();
+	private ContentTypeResolver contentTypeResolver = new CompositeContentTypeResolverBuilder().build();
 
 	private StringValueResolver embeddedValueResolver;
 

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

@@ -81,7 +81,7 @@ public class RequestMappingHandlerMappingTests {
 
 		assertTrue(this.handlerMapping.useSuffixPatternMatch());
 		assertTrue(this.handlerMapping.useRegisteredSuffixPatternMatch());
-		assertEquals(Collections.singletonList("json"), this.handlerMapping.getFileExtensions());
+		assertEquals(Collections.singleton("json"), this.handlerMapping.getFileExtensions());
 	}
 
 	@Test