GH-4622 preserve blank node IDs with shacl validation reports from remote repository

Author: hmottestad

core/http/client/src/main/java/org/eclipse/rdf4j/http/client/shacl/RemoteValidation.java

@@ -16,8 +16,12 @@
 
 import org.eclipse.rdf4j.common.annotation.InternalUseOnly;
 import org.eclipse.rdf4j.model.Model;
+import org.eclipse.rdf4j.model.impl.SimpleValueFactory;
+import org.eclipse.rdf4j.rio.ParserConfig;
 import org.eclipse.rdf4j.rio.RDFFormat;
 import org.eclipse.rdf4j.rio.Rio;
+import org.eclipse.rdf4j.rio.helpers.BasicParserSettings;
+import org.eclipse.rdf4j.rio.helpers.ParseErrorLogger;
 
 @InternalUseOnly
 class RemoteValidation {
@@ -37,7 +41,9 @@ class RemoteValidation {
 	Model asModel() {
 		if (model == null) {
 			try {
-				model = Rio.parse(stringReader, baseUri, format);
+				ParserConfig parserConfig = new ParserConfig().set(BasicParserSettings.PRESERVE_BNODE_IDS, true);
+				model = Rio.parse(stringReader, baseUri, format, parserConfig, SimpleValueFactory.getInstance(),
+						new ParseErrorLogger());
 			} catch (IOException e) {
 				throw new RuntimeException(e);
 			}

tools/server-spring/src/main/java/org/eclipse/rdf4j/http/server/ProtocolExceptionResolver.java

@@ -78,15 +78,14 @@ public ModelAndView resolveException(HttpServletRequest request, HttpServletResp
 
 			StringWriter stringWriter = new StringWriter();
 
-			// We choose NQUADS because we want to support streaming in the future, and because there could be a use for
-			// different graphs in the future
-			Rio.write(validationReportModel, stringWriter, RDFFormat.NQUADS);
+			// We choose RDFJSON because this format doesn't rename blank nodes.
+			Rio.write(validationReportModel, stringWriter, RDFFormat.RDFJSON);
 
 			statusCode = HttpServletResponse.SC_CONFLICT;
 			errMsg = stringWriter.toString();
 
 			Map<String, String> headers = new HashMap<>();
-			headers.put("Content-Type", "application/shacl-validation-report+n-quads");
+			headers.put("Content-Type", "application/shacl-validation-report+rdf+json");
 			model.put(SimpleResponseView.CUSTOM_HEADERS_KEY, headers);
 		}