remove unnecessary exceptions, fixed a warning message

src/main/java/de/landsh/opendata/csw2dcat/MDMetadata2Dataset.java

@@ -14,7 +14,6 @@ import org.apache.jena.vocabulary.DCTerms;
 import org.apache.jena.vocabulary.RDF;
 import org.apache.jena.vocabulary.VCARD4;
 import org.dom4j.Document;
-import org.dom4j.DocumentException;
 import org.dom4j.Element;
 import org.dom4j.Node;
 import org.json.JSONArray;
@@ -24,7 +23,6 @@ import org.json.JSONTokener;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLEncoder;
@@ -630,7 +628,7 @@ public class MDMetadata2Dataset {
     /**
      * Convert a {@link Document} containin a gmd:MD_Metadata element into a DCAT-AP.de compliant dcat:Dataset {@link Resource}.
      */
-    public Resource convert(Document input) throws DocumentException, IOException {
+    public Resource convert(Document input) {
         return convert(input.getRootElement());
     }
 
@@ -829,7 +827,7 @@ public class MDMetadata2Dataset {
                 try {
                     dataset.addProperty(DCATAP.hvdCategory, model.createResource(anchorRef.getStringValue()));
                 } catch (IllegalArgumentException e) {
-                    log.warn("Invalid HVD category {} for dataset {}", characterString.getStringValue(), id);
+                    log.warn("Invalid HVD category {} for dataset {}", anchorRef.getStringValue(), id);
                 }
             }
         }
@@ -851,7 +849,7 @@ public class MDMetadata2Dataset {
     /**
      * Convert a gmd:MD_Metadata {@link Element} into a DCAT-AP.de compliant dcat:Dataset {@link Resource}.
      */
-    public Resource convert(Element metadata) throws DocumentException, IOException {
+    public Resource convert(Element metadata) {
 
         if ("GetRecordByIdResponse".equals(metadata.getName())) {
             metadata = metadata.element("MD_Metadata");
@@ -892,7 +890,6 @@ public class MDMetadata2Dataset {
 
         convertDataResource(metadata, dataset);
 
-
         final Element mdIdentifier = (Element) metadata.selectSingleNode("gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation/gmd:identifier/gmd:MD_Identifier/gmd:code/gco:CharacterString");
         final String searchId = mdIdentifier != null ? mdIdentifier.getTextTrim() : id;