INT-4172: canWrite(mediaType) in SerializingHttpMC

JIRA: https://jira.spring.io/browse/INT-4172

The `SerializingHttpMessageConverter` which can be customized via `setSupportedMediaTypes()`, but at the same time `canWrite(Class<?> clazz, MediaType mediaType)` consult only default `APPLICATION_JAVA_SERIALIZED_OBJECT`

The target application really may face different media types for the `Serialized` objects not just built-in `application/x-java-serialized-object`

Since we can customize `SerializingHttpMessageConverter` via  `setSupportedMediaTypes()` that will be fully consistent to consult `canWrite(mediaType)`

spring-integration-http/src/main/java/org/springframework/integration/http/converter/SerializingHttpMessageConverter.java

@@ -34,11 +34,14 @@
  *
  * @author Mark Fisher
  * @author Gary Russell
+ * @author Artem Bilan
+ *
  * @since 2.0
  */
 public class SerializingHttpMessageConverter extends AbstractHttpMessageConverter<Serializable> {
 
-	private static final MediaType APPLICATION_JAVA_SERIALIZED_OBJECT = new MediaType("application", "x-java-serialized-object");
+	private static final MediaType APPLICATION_JAVA_SERIALIZED_OBJECT =
+			new MediaType("application", "x-java-serialized-object");
 
 
 	/** Creates a new instance of the {@code SerializingHttpMessageConverter}. */
@@ -54,7 +57,7 @@ public boolean supports(Class<?> clazz) {
 
 	@Override
 	public boolean canWrite(Class<?> clazz, MediaType mediaType) {
-		return (Serializable.class.isAssignableFrom(clazz) && APPLICATION_JAVA_SERIALIZED_OBJECT.includes(mediaType));
+		return Serializable.class.isAssignableFrom(clazz) && canWrite(mediaType);
 	}
 
 	@Override

spring-integration-http/src/test/java/org/springframework/integration/http/config/HttpInboundGatewayParserTests.java

@@ -28,6 +28,7 @@
 import static org.springframework.integration.test.util.TestUtils.getPropertyValue;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -37,14 +38,14 @@
 import org.hamcrest.Matcher;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.expression.common.LiteralExpression;
 import org.springframework.expression.spel.standard.SpelExpression;
 import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.integration.core.MessagingTemplate;
 import org.springframework.integration.http.converter.SerializingHttpMessageConverter;
@@ -140,31 +141,35 @@ public void checkConfig() {
 		assertEquals(1001, TestUtils.getPropertyValue(this.gateway, "phase"));
 	}
 
-	@Test @DirtiesContext
+	@Test
+	@DirtiesContext
 	public void checkFlow() throws Exception {
 		this.requests.subscribe(handlerExpecting(any(Message.class)));
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setMethod("GET");
-		request.addHeader("Accept", "application/x-java-serialized-object");
+		request.addHeader("Accept", "application/my-serialized");
 		request.setParameter("foo", "bar");
 
 		MockHttpServletResponse response = new MockHttpServletResponse();
-		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
-		converters.add(new SerializingHttpMessageConverter());
+		List<HttpMessageConverter<?>> converters = new ArrayList<>();
+		SerializingHttpMessageConverter serializingHttpMessageConverter = new SerializingHttpMessageConverter();
+		serializingHttpMessageConverter.setSupportedMediaTypes(
+				Collections.singletonList(new MediaType("application", "my-serialized")));
+		converters.add(serializingHttpMessageConverter);
 		this.gateway.setMessageConverters(converters);
 		this.gateway.afterPropertiesSet();
 		this.gateway.start();
 
 		this.gateway.handleRequest(request, response);
 		assertThat(response.getStatus(), is(HttpServletResponse.SC_OK));
 
-		assertEquals(response.getContentType(), "application/x-java-serialized-object");
+		assertEquals(response.getContentType(), "application/my-serialized");
 	}
 
 	@Test
 	public void testController() throws Exception {
 		DirectFieldAccessor accessor = new DirectFieldAccessor(inboundController);
-		String errorCode =  (String) accessor.getPropertyValue("errorCode");
+		String errorCode = (String) accessor.getPropertyValue("errorCode");
 		assertEquals("oops", errorCode);
 		LiteralExpression viewExpression = (LiteralExpression) accessor.getPropertyValue("viewExpression");
 		assertEquals("foo", viewExpression.getValue());
@@ -173,7 +178,7 @@ public void testController() throws Exception {
 	@Test
 	public void testControllerViewExp() throws Exception {
 		DirectFieldAccessor accessor = new DirectFieldAccessor(inboundControllerViewExp);
-		String errorCode =  (String) accessor.getPropertyValue("errorCode");
+		String errorCode = (String) accessor.getPropertyValue("errorCode");
 		assertEquals("oops", errorCode);
 		SpelExpression viewExpression = (SpelExpression) accessor.getPropertyValue("viewExpression");
 		assertNotNull(viewExpression);
@@ -183,7 +188,7 @@ public void testControllerViewExp() throws Exception {
 	@Test
 	public void requestWithHeaders() throws Exception {
 		DefaultHttpHeaderMapper headerMapper =
-			(DefaultHttpHeaderMapper) TestUtils.getPropertyValue(withMappedHeaders, "headerMapper");
+				(DefaultHttpHeaderMapper) TestUtils.getPropertyValue(withMappedHeaders, "headerMapper");
 
 		HttpHeaders headers = new HttpHeaders();
 		headers.set("foo", "foo");
@@ -207,7 +212,7 @@ public void requestWithHeaders() throws Exception {
 	@Test
 	public void requestWithHeadersWithConversionService() throws Exception {
 		DefaultHttpHeaderMapper headerMapper =
-			(DefaultHttpHeaderMapper) TestUtils.getPropertyValue(withMappedHeadersAndConverter, "headerMapper");
+				(DefaultHttpHeaderMapper) TestUtils.getPropertyValue(withMappedHeadersAndConverter, "headerMapper");
 
 		headerMapper.setUserDefinedHeaderPrefix("X-");
 
@@ -239,7 +244,7 @@ public void requestWithHeadersWithConversionService() throws Exception {
 	public void testInboundGatewayWithMessageConverterDefaults() {
 		@SuppressWarnings("unchecked")
 		List<HttpMessageConverter<?>> messageConverters =
-			TestUtils.getPropertyValue(gatewayWithOneCustomConverter, "messageConverters", List.class);
+				TestUtils.getPropertyValue(gatewayWithOneCustomConverter, "messageConverters", List.class);
 		assertThat("There should be only 1 message converter, by default register-default-converters is off",
 				messageConverters.size(), is(1));