D-Net

based on the sparql templates competency is a string, in the model it is a PE36_Competency_Type

Let\s check if we do not get the following warning at client side by setting the response status in void GET methods that write directly on the output stream. The warning is: 'org.springframework.http.converter.json.MappingJackson2HttpMessageConverter- Failed to evaluate serialization for type [void]: java.lang.IllegalStateException: Failed to instantiate standard serializer (of type com.fasterxml.jackson.databind.ser.std.NullSerializer): Class com.fasterxml.jackson.databind.ser.BasicSerializerFactory can not access a member of class com.fasterxml.jackson.databind.ser.std.NullSerializer with modifiers "private"'

better error logging

Added crm:P2_has_type for all sparql query templates

Yes, let's use union everywhere

Looks like using UNION is much more performant than using OPTIONAL. See http://www.snee.com/bobdc.blog/2014/10/dropping-optional-blocks-from.html

removed todo, because I did it

Using specific queries for Software and Dataset: the one for DigitalObject has been deleted as it could not be executed because of timeout exception during tests. I do not want to run such heavy query on the production virtuoso

Removed deprecated classes

logging