Fix ResourceRegion HttpMessageConverter write checks

This commit fixes the write checks for
`ResourceRegionHttpMessageConverter`, which was previously not checking
properly the parameterized type (e.g. in case of a `List<Something>`).

Issue: SPR-16932

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -119,7 +119,7 @@ public class ResourceRegionHttpMessageConverter extends AbstractGenericHttpMessa
 		}
 
 		Class<?> typeArgumentClass = (Class<?>) typeArgument;
-		return typeArgumentClass.isAssignableFrom(ResourceRegion.class);
+		return ResourceRegion.class.isAssignableFrom(typeArgumentClass);
 	}
 
 	@Override

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -64,6 +64,7 @@ public class ResourceRegionHttpMessageConverterTests {
 	public void canWriteResource() {
 		assertTrue(converter.canWrite(ResourceRegion.class, null, MediaType.APPLICATION_OCTET_STREAM));
 		assertTrue(converter.canWrite(ResourceRegion.class, null, MediaType.ALL));
+		assertFalse(converter.canWrite(Object.class, null, MediaType.ALL));
 	}
 
 	@Test
@@ -74,6 +75,8 @@ public class ResourceRegionHttpMessageConverterTests {
 
 		assertFalse(converter.canWrite(List.class, MediaType.APPLICATION_OCTET_STREAM));
 		assertFalse(converter.canWrite(List.class, MediaType.ALL));
+		Type resourceObjectList = new ParameterizedTypeReference<List<Object>>() {}.getType();
+		assertFalse(converter.canWrite(resourceObjectList, null, MediaType.ALL));
 	}
 
 	@Test