Support wildcard style media types in JSON converters

Add "application/*+json" to supported media types for both Jackson
message converters.

Issue: SPR-7905

spring-web/src/main/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverter.java

@@ -69,7 +69,7 @@ public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConv
 	 * Construct a new {@code MappingJackson2HttpMessageConverter}.
 	 */
 	public MappingJackson2HttpMessageConverter() {
-		super(new MediaType("application", "json", DEFAULT_CHARSET));
+		super(new MediaType("application", "json", DEFAULT_CHARSET), new MediaType("application", "*+json", DEFAULT_CHARSET));
 	}
 
 	/**

spring-web/src/main/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverter.java

@@ -69,7 +69,7 @@ public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConve
 	 * Construct a new {@code MappingJacksonHttpMessageConverter}.
 	 */
 	public MappingJacksonHttpMessageConverter() {
-		super(new MediaType("application", "json", DEFAULT_CHARSET));
+		super(new MediaType("application", "json", DEFAULT_CHARSET), new MediaType("application", "*+json", DEFAULT_CHARSET));
 	}
 
 	/**

spring-web/src/test/java/org/springframework/http/converter/json/AbstractMappingJacksonHttpMessageConverterTests.java

@@ -45,7 +45,6 @@ public abstract class AbstractMappingJacksonHttpMessageConverterTests<T extends
 
 	protected static final String NEWLINE_SYSTEM_PROPERTY = System.getProperty("line.separator");
 
-
 	private T converter;
 
 	@Before
@@ -71,6 +70,14 @@ public abstract class AbstractMappingJacksonHttpMessageConverterTests<T extends
 		assertTrue(converter.canWrite(Map.class, new MediaType("application", "json")));
 	}
 
+	// SPR-7905
+
+	@Test
+	public void canReadAndWriteMicroformats() {
+		assertTrue(converter.canRead(MyBean.class, new MediaType("application", "vnd.test-micro-type+json")));
+		assertTrue(converter.canWrite(MyBean.class, new MediaType("application", "vnd.test-micro-type+json")));
+	}
+
 	@Test
 	public void readTyped() throws IOException {
 		String body =