Fix error on Jaxb2RootElementHttpMessageConverter

Can encode can now support child class of JAXBElement

Author: deblockt

spring-web/src/main/java/org/springframework/http/converter/xml/Jaxb2RootElementHttpMessageConverter.java

@@ -121,7 +121,7 @@ public boolean canRead(Class<?> clazz, @Nullable MediaType mediaType) {
 
 	@Override
 	public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType) {
-		boolean supportedType = (JAXBElement.class.isAssignableFrom(clazz) ||
+		boolean supportedType = (clazz.isAssignableFrom(JAXBElement.class) ||
 				AnnotationUtils.findAnnotation(clazz, XmlRootElement.class) != null);
 		return (supportedType && canWrite(mediaType));
 	}