Merged from branch

git-svn-id: https://svn.d4science.research-infrastructures.eu/gcube/trunk/data-publishing/gcat-client@179478 82a268e6-3cf1-43bd-a215-b396298e98cf

src/main/java/org/gcube/gcat/client/GCatClient.java

@@ -17,6 +17,8 @@ import java.util.Map;
 import javax.ws.rs.ForbiddenException;
 import javax.ws.rs.NotFoundException;
 import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.core.HttpHeaders;
+import javax.ws.rs.core.MediaType;
 
 import org.gcube.common.gxhttp.reference.GXConnection.HTTPMETHOD;
 import org.gcube.common.gxhttp.request.GXHTTPStringRequest;
@@ -130,6 +132,8 @@ abstract class GCatClient {
 			if(queryParams!=null && queryParams.size()>0) {
 				gxhttpStringRequest.queryParams(queryParams);
 			}
+			gxhttpStringRequest.header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON);
+			gxhttpStringRequest.header(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON);
 			HttpURLConnection httpURLConnection = gxhttpStringRequest.post(body);
 			return parseHttpURLConnection(httpURLConnection);
 		}catch (WebApplicationException e) {