RepositoryNotFoundException thrown in the method objectToMapKey for java.lang.Long

Retrieving a map resource of a class repository where the key of the map is of type Long, it fails due to a RepositoryNotFoundException that is thrown in the method objectToMapKey. The following piece of code is always throwing the exception looking for a repository for the class java.lang.Long:

 protected RepositoryMetadata repositoryMetadataFor(Class<?> domainType) {
   for(RepositoryExporter exporter : repositoryExporters) {
     RepositoryMetadata repoMeta = exporter.repositoryMetadataFor(domainType);
     if(null != repoMeta) {
       return repoMeta;
     }
   }
   throw new RepositoryNotFoundException("No repository found for type " + domainType.getName());
 }

This method is called in the objectToMapKey method of RestController:

if(ClassUtils.isAssignable(obj.getClass(), String.class)) {
     key = (String)obj;
   } else if(null != (repoMeta = repositoryMetadataFor(obj.getClass()))) {
     AttributeMetadata attrMeta = repoMeta.entityMetadata().idAttribute();
     String id = attrMeta.get(obj).toString();
     key = "@" + buildUri(config.getBaseUri(), repoMeta.name(), id);
   } else {
     key = conversionService.convert(obj, String.class);
   }

The conversionService is never executed.

Start in RestController.objectToMapKey and trace repositoryMetadataFor for a map resource whose key type is java.lang.Long. Reproduce the failure and inspect why the conversionService branch is unreachable. Done means Long map keys no longer trigger RepositoryNotFoundException and are converted as intended.