Merge pull request #3399 from dzhw/tvillwock/issue3303-pid-registration

Fix verification error parsing

src/main/java/eu/dzhw/fdz/metadatamanagement/projectmanagement/service/DaraPidClientService.java

@@ -6,7 +6,6 @@
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.node.ArrayNode;
 import eu.dzhw.fdz.metadatamanagement.common.config.MetadataManagementProperties;
 import eu.dzhw.fdz.metadatamanagement.datapackagemanagement.domain.DataPackage;
 import eu.dzhw.fdz.metadatamanagement.projectmanagement.domain.DataAcquisitionProject;
@@ -33,7 +32,6 @@
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.stream.Stream;
 
 /**
  * A client service that's solely responsible for
@@ -122,9 +120,13 @@ RegistrationResponse register(List<VariableMetadata> variables) throws Registrat
         this.config.getDaraPid().getEndpoint() + PATH_VERIFY, entity, String.class);
       var responseNode = this.objectMapper.readTree(response.getBody());
       if (responseNode.path("constraintViolation").isArray()) {
-        var violations = Stream.of((ArrayNode) responseNode.path("constraintViolation"))
-          .map(JsonNode::toPrettyString).toList();
-        throw new VerificationException(violations);
+        var violations = new ArrayList<String>();
+        for (JsonNode jsonNode : responseNode.get("constraintViolation")) {
+          violations.add(jsonNode.toPrettyString());
+        }
+        if (!violations.isEmpty()) {
+          throw new VerificationException(violations);
+        }
       }
       // register variables
       response = this.restTemplate.postForEntity(this.getRegistationEndpoint(), entity, String.class);