Ignore tags with null value. Fixes #18.

Set default for tags with NOTE value. Fixes #19.

Author: mvanbrab

src/main/java/com/github/informatievlaanderen/oslo_ea_to_rdf/convert/TagHelper.java

@@ -161,7 +161,7 @@ public String getSingleValue(EAObject object, String tag, String backup, boolean
     private List<String> getTagValues(List<EATag> tags, String key) {
         return tags.stream()
                 .filter(t -> key.equals(t.getKey()))
-                .map(t -> USE_NOTE_VALUE.equals(t.getValue()) ? t.getNotes() : t.getValue())
+                .map(t -> USE_NOTE_VALUE.equals(t.getValue()) ? (t.getNotes() == null ? "TODO" : t.getNotes()) : t.getValue())
                 .collect(Collectors.toList());
     }
 

src/main/java/com/github/informatievlaanderen/oslo_ea_to_rdf/ea/impl/MemoryRepositoryBuilder.java

@@ -281,7 +281,7 @@ private Map<Integer, MemoryEAAttribute> loadAttributes(Connection connection, Ma
      */
     private void loadObjectTags(Connection connection, Map<Integer, MemoryEAElement> elements, Map<Integer, MemoryEAPackage> packages) throws SQLException {
         try (Statement s = connection.createStatement()) {
-            ResultSet rs = s.executeQuery("SELECT Property, Value, Object_ID, Notes FROM t_objectproperties ORDER BY PropertyID ASC");
+            ResultSet rs = s.executeQuery("SELECT Property, Value, Object_ID, Notes FROM t_objectproperties WHERE Value IS NOT NULL ORDER BY PropertyID ASC");
 
             while (rs.next()) {
                 String key = rs.getString("Property");
@@ -307,7 +307,7 @@ private void loadObjectTags(Connection connection, Map<Integer, MemoryEAElement>
      */
     private void loadAttributeTags(Connection connection, Map<Integer, MemoryEAAttribute> attributes) throws SQLException {
         try (Statement s = connection.createStatement()) {
-            ResultSet rs = s.executeQuery("SELECT Property, VALUE, NOTES, ElementID FROM t_attributetag ORDER BY PropertyID ASC");
+            ResultSet rs = s.executeQuery("SELECT Property, VALUE, NOTES, ElementID FROM t_attributetag WHERE VALUE IS NOT NULL ORDER BY PropertyID ASC");
 
             while (rs.next()) {
                 String key = rs.getString("Property");
@@ -330,7 +330,7 @@ private void loadAttributeTags(Connection connection, Map<Integer, MemoryEAAttri
      */
     private void loadConnectorTags(Connection connection, Map<Integer, MemoryEAConnector> connectors) throws SQLException {
         try (Statement s = connection.createStatement()) {
-            ResultSet rs = s.executeQuery("SELECT Property, VALUE, NOTES, ElementID FROM t_connectortag ORDER BY PropertyID ASC");
+            ResultSet rs = s.executeQuery("SELECT Property, VALUE, NOTES, ElementID FROM t_connectortag WHERE VALUE IS NOT NULL ORDER BY PropertyID ASC");
 
             while (rs.next()) {
                 String key = rs.getString("Property");