Fix HttpMessageConverter lookup in PersistentEntityResourceHandlerMethodArgumentResolver.

We now ask the candidate converters whether they can read RepresentationModel instead of the domain type as that's the key type we register the individual ObjectMappers for in Spring HATEOAS.

Fixes: GH-2425.
Related ticket: GH-2419.

Author: odrotbohm

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/config/PersistentEntityResourceHandlerMethodArgumentResolver.java

@@ -39,6 +39,7 @@
 import org.springframework.data.rest.webmvc.json.BindContextFactory;
 import org.springframework.data.rest.webmvc.json.DomainObjectReader;
 import org.springframework.data.rest.webmvc.support.BackendIdHandlerMethodArgumentResolver;
+import org.springframework.hateoas.RepresentationModel;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.HttpMessageNotReadableException;
@@ -114,7 +115,7 @@ public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer m
 
 		for (HttpMessageConverter converter : messageConverters) {
 
-			if (!converter.canRead(domainType, contentType)) {
+			if (!converter.canRead(RepresentationModel.class, contentType)) {
 				continue;
 			}