MCR-3198 event handler for merging duplicate categories

mycore-base/src/main/java/org/mycore/common/xml/MCRURIResolver.java

@@ -1026,7 +1026,7 @@ public Source resolve(String href, String base) {
                 }
             } catch (Exception ex) {
                 LOGGER.info("MCRNotNullResolver caught exception: {}", ex.getLocalizedMessage());
-                LOGGER.debug(ex.getStackTrace());
+                LOGGER.debug(ex);
                 LOGGER.debug("MCRNotNullResolver returning empty xml");
                 return new JDOMSource(new Element("null"));
             }

mycore-mods/src/main/java/org/mycore/mods/merger/MCRCategoryMergeEventHandler.java

@@ -0,0 +1,64 @@
+package org.mycore.mods.merger;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.jdom2.Element;
+import org.mycore.common.events.MCREvent;
+import org.mycore.common.events.MCREventHandlerBase;
+import org.mycore.datamodel.metadata.MCRObject;
+import org.mycore.mods.MCRMODSSorter;
+import org.mycore.mods.MCRMODSWrapper;
+import org.mycore.mods.classification.MCRClassMapper;
+
+import java.util.List;
+
+/**
+ * Checks for and removes redundant classifications in Mods-Documents. If a classification category and
+ * the classification's child category are both present in the document, the parent classification will
+ * be removed. The processed document will be finally be sorted using {@link MCRMODSSorter}.
+ */
+public class MCRCategoryMergeEventHandler extends MCREventHandlerBase {
+
+    private static final Logger LOGGER = LogManager.getLogger(MCRCategoryMergeEventHandler.class);
+
+    @Override
+    protected void handleObjectCreated(MCREvent evt, MCRObject obj) {
+        mergeCategories(obj);
+    }
+
+    @Override
+    protected void handleObjectUpdated(MCREvent evt, MCRObject obj) {
+        mergeCategories(obj);
+    }
+
+    @Override
+    protected void handleObjectRepaired(MCREvent evt, MCRObject obj) {
+        mergeCategories(obj);
+    }
+
+    private void mergeCategories(MCRObject obj) {
+        MCRMODSWrapper mcrmodsWrapper = new MCRMODSWrapper(obj);
+        if (mcrmodsWrapper.getMODS() == null) {
+            return;
+        }
+        LOGGER.info("merge redundant classification categories for {}", obj.getId());
+
+        Element filledMods = mcrmodsWrapper.getMODS();
+        List<Element> supportedElements = filledMods.getChildren().stream()
+            .filter(element -> MCRClassMapper.getCategoryID(element) != null).toList();
+
+        for (int i = 0; i < supportedElements.size(); i++) {
+            for (int j = i + 1; j < supportedElements.size(); j++) {
+
+                Element element1 = supportedElements.get(i);
+                Element element2 = supportedElements.get(j);
+                Element parentElement = MCRCategoryMerger.getElementWithParentCategory(element1, element2);
+                if (parentElement != null) {
+                    parentElement.detach();
+                }
+            }
+        }
+
+        MCRMODSSorter.sort(filledMods);
+    }
+}

mycore-mods/src/main/java/org/mycore/mods/merger/MCRCategoryMerger.java

@@ -19,8 +19,11 @@
 package org.mycore.mods.merger;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 
+import org.jdom2.Element;
 import org.mycore.common.config.MCRConfiguration2;
 import org.mycore.datamodel.classifications2.MCRCategory;
 import org.mycore.datamodel.classifications2.MCRCategoryDAO;
@@ -88,12 +91,39 @@ static boolean oneIsDescendantOfTheOther(MCRCategoryID idThis, MCRCategoryID idO
     }
 
     private static List<MCRCategory> getAncestorsAndSelf(MCRCategoryID categoryID) {
-        List<MCRCategory> ancestorsAndSelf = new ArrayList<>(DAO.getParents(categoryID));
+        List<MCRCategory> ancestorsAndSelf = new ArrayList<>(Optional.ofNullable(DAO.getParents(categoryID)).orElse(
+            Collections.emptyList()));
         ancestorsAndSelf.remove(DAO.getRootCategory(categoryID, 0));
         ancestorsAndSelf.add(DAO.getCategory(categoryID, 0));
         return ancestorsAndSelf;
     }
 
+    /**
+     * Compares two {@link Element Elements} that are assumed to be categories.
+     * If it is determined that one Element is a parent category of the other, return the parent, else return null.
+     * @param element1 first Element to compare
+     * @param element2 second Element to compare
+     * @return the parent Element or null
+     */
+    public static Element getElementWithParentCategory(Element element1, Element element2) {
+        MCRCategoryID idThis = MCRClassMapper.getCategoryID(element1);
+        MCRCategoryID idOther = MCRClassMapper.getCategoryID(element2);
+        if (idThis == null || idOther == null) {
+            return null;
+        }
+
+        final String p = CONFIG_PREFIX + idThis.getRootID();
+        if (idThis.getRootID().equals(idOther.getRootID()) && !MCRConfiguration2.getBoolean(p).orElse(true)) {
+            return null;
+        }
+
+        if (idThis.equals(idOther) || !oneIsDescendantOfTheOther(idThis, idOther)) {
+            return null;
+        }
+
+        return getAncestorsAndSelf(idThis).containsAll(getAncestorsAndSelf(idOther)) ? element2 : element1;
+    }
+
     @Override
     public void mergeFrom(MCRMerger other) {
         MCRCategoryMerger cmo = (MCRCategoryMerger) other;

mycore-mods/src/main/resources/components/mods/config/mycore.properties

@@ -1,6 +1,7 @@
 MCR.Metadata.Type.mods=true
 MCR.Metadata.ShareAgent.mods=org.mycore.mods.MCRMODSMetadataShareAgent
 MCR.EventHandler.MCRObject.040.Class=org.mycore.mods.MCRMODSLinksEventHandler
+# MCR.EventHandler.MCRObject.016a.Class=org.mycore.mods.merger.MCRCategoryMergeEventHandler
 MCR.MODS.NewObjectType=mods
 MCR.MODS.Types=mods
 

mycore-mods/src/test/java/org/mycore/mods/merger/MCRCategoryMergeEventHandlerTest.java

@@ -0,0 +1,81 @@
+package org.mycore.mods.merger;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.jdom2.Document;
+import org.jdom2.Element;
+import org.jdom2.JDOMException;
+import org.jdom2.input.SAXBuilder;
+import org.junit.Test;
+import org.mycore.common.MCRConstants;
+import org.mycore.common.MCRJPATestCase;
+import org.mycore.common.MCRSessionMgr;
+import org.mycore.common.MCRTransactionHelper;
+import org.mycore.common.content.MCRJDOMContent;
+import org.mycore.datamodel.classifications2.MCRCategory;
+import org.mycore.datamodel.classifications2.MCRCategoryDAO;
+import org.mycore.datamodel.classifications2.MCRCategoryDAOFactory;
+import org.mycore.datamodel.classifications2.utils.MCRXMLTransformer;
+import org.mycore.datamodel.metadata.MCRObject;
+import org.mycore.mods.MCRMODSWrapper;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class MCRCategoryMergeEventHandlerTest extends MCRJPATestCase {
+
+    public static final String TEST_DIRECTORY = "MCRCategoryMergeEventHandlerTest/";
+
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    public MCRCategoryDAO getDAO() {
+        return MCRCategoryDAOFactory.getInstance();
+    }
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+    }
+
+    /**
+     * Tests if parent genres are succesfully removed from mods.
+     */
+    @Test
+    public void testHandleObjectCreatedMultipleGenres() throws IOException, JDOMException, URISyntaxException {
+
+        MCRSessionMgr.getCurrentSession();
+        MCRTransactionHelper.isTransactionActive();
+        ClassLoader classLoader = getClass().getClassLoader();
+        SAXBuilder saxBuilder = new SAXBuilder();
+
+        MCRCategory category = MCRXMLTransformer
+            .getCategory(saxBuilder.build(classLoader.getResourceAsStream(TEST_DIRECTORY + "genre.xml")));
+        getDAO().addCategory(null, category);
+
+        Document document = saxBuilder.build(classLoader.getResourceAsStream(TEST_DIRECTORY + "testMods.xml"));
+        MCRObject mcro = new MCRObject();
+
+        MCRMODSWrapper mw = new MCRMODSWrapper(mcro);
+        mw.setMODS(document.getRootElement().detach());
+        mw.setID("junit", 1);
+
+        MCRCategoryMergeEventHandler mergeEventHandler = new MCRCategoryMergeEventHandler();
+        mergeEventHandler.handleObjectCreated(null, mcro);
+        Document xml = mcro.createXML();
+
+        LOGGER.info(new MCRJDOMContent(xml).asString());
+
+        List<Element> genres = mw.getMODS().getChildren("genre", MCRConstants.MODS_NAMESPACE);
+        assertEquals(2, genres.size());
+        String url = genres.get(0).getAttribute("valueURI").getValue();
+        String genre = url.substring(url.indexOf('#') + 1);
+        assertEquals("book", genre);
+
+        url = genres.get(1).getAttribute("valueURI").getValue();
+        genre = url.substring(url.indexOf('#') + 1);
+        assertEquals("subchapter", genre);
+    }
+}

mycore-mods/src/test/resources/MCRCategoryMergeEventHandlerTest/genre.xml

@@ -0,0 +1,157 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<mycoreclass xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="MCRClassification.xsd" ID="mir_genres">
+  <label xml:lang="en" text="genre" description="A list of publication types" />
+  <label xml:lang="x-uri" text="http://www.mycore.org/classifications/mir_genres" />
+  <label xml:lang="de" text="Genre" description="Liste der Publikationsarten" />
+  <categories>
+    <category ID="article" counter="1">
+      <label xml:lang="en" text="Article / Chapter" />
+      <label xml:lang="x-mapping" text="diniPublType:article" />
+      <label xml:lang="de" text="Artikel / Aufsatz" />
+      <label xml:lang="x-hosts" text="journal newspaper collection festschrift proceedings standalone" />
+      <category ID="chapter" counter="0">
+        <label xml:lang="en" text="Book chapter" />
+        <label xml:lang="de" text="Buchkapitel" />
+        <label xml:lang="x-hosts" text="book collection" />
+        <category ID="subchapter" counter="0">
+          <label xml:lang="en" text="Book subchapter" />
+          <label xml:lang="de" text="Buchunterkapitel" />
+          <label xml:lang="x-hosts" text="book collection" />
+        </category>
+      </category>
+      <category ID="entry" counter="0">
+        <label xml:lang="en" text="Encyclopedia entry" />
+        <label xml:lang="x-hosts" text="lexicon" />
+        <label xml:lang="de" text="Lexikoneintrag" />
+      </category>
+      <category ID="preface" counter="0">
+        <label xml:lang="de" text="Vorwort / Nachwort" />
+        <label xml:lang="x-hosts" text="journal collection festschrift proceedings lexicon" />
+        <label xml:lang="en" text="Preface (foreword) / Postface" />
+      </category>
+      <category ID="speech" counter="0">
+        <label xml:lang="en" text="Lecture / Speech" />
+        <label xml:lang="de" text="Vortrag" />
+        <label xml:lang="x-hosts" text="proceedings standalone" />
+      </category>
+      <category ID="review" counter="0">
+        <label xml:lang="de" text="Rezension" />
+        <label xml:lang="en" text="Review" />
+        <label xml:lang="x-hosts" text="journal newspaper collection festschrift proceedings standalone" />
+      </category>
+    </category>
+    <category ID="thesis" counter="2">
+      <label xml:lang="en" text="Thesis" />
+      <label xml:lang="de" text="Hochschulschriften" />
+      <label xml:lang="x-hosts" text="series standalone" />
+      <label xml:lang="x-editor" text="false" />
+      <category ID="exam" counter="0">
+        <label xml:lang="de" text="Examensarbeit" />
+        <label xml:lang="en" text="Exam" />
+        <label xml:lang="x-hosts" text="series standalone" />
+      </category>
+      <category ID="dissertation" counter="0">
+        <label xml:lang="de" text="Dissertation" />
+        <label xml:lang="x-hosts" text="series standalone" />
+        <label xml:lang="en" text="Dissertation" />
+      </category>
+      <category ID="habilitation" counter="0">
+        <label xml:lang="de" text="Habilitation" />
+        <label xml:lang="x-hosts" text="series standalone" />
+        <label xml:lang="en" text="Habilitation" />
+      </category>
+      <category ID="diploma_thesis" counter="0">
+        <label xml:lang="x-hosts" text="series standalone" />
+        <label xml:lang="en" text="Diploma thesis" />
+        <label xml:lang="de" text="Diplomarbeit" />
+      </category>
+      <category ID="master_thesis" counter="0">
+        <label xml:lang="x-mapping" text="diniPublType:masterThesis" />
+        <label xml:lang="en" text="Master thesis" />
+        <label xml:lang="de" text="Abschlussarbeit (Master)" />
+        <label xml:lang="x-hosts" text="series standalone" />
+      </category>
+      <category ID="bachelor_thesis" counter="2">
+        <label xml:lang="x-mapping" text="diniPublType:StudyThesis" />
+        <label xml:lang="de" text="Abschlussarbeit (Bachelor)" />
+        <label xml:lang="en" text="Bachelor thesis" />
+        <label xml:lang="x-hosts" text="series standalone" />
+      </category>
+      <category ID="student_resarch_project" counter="0">
+        <label xml:lang="en" text="Student research project" />
+        <label xml:lang="x-hosts" text="series standalone" />
+        <label xml:lang="de" text="Studienarbeit" />
+      </category>
+      <category ID="magister_thesis" counter="0">
+        <label xml:lang="en" text="Magister thesis" />
+        <label xml:lang="de" text="Magisterarbeit" />
+        <label xml:lang="x-hosts" text="series standalone" />
+      </category>
+    </category>
+    <category ID="collection" counter="0">
+      <label xml:lang="de" text="Sammelwerk" />
+      <label xml:lang="x-hosts" text="series standalone" />
+      <label xml:lang="en" text="Collection" />
+      <category ID="festschrift" counter="0">
+        <label xml:lang="en" text="Festschrift" />
+        <label xml:lang="x-hosts" text="series standalone" />
+        <label xml:lang="de" text="Festschrift" />
+      </category>
+      <category ID="proceedings" counter="0">
+        <label xml:lang="en" text="Proceedings" />
+        <label xml:lang="de" text="Tagungsband" />
+        <label xml:lang="x-hosts" text="series standalone" />
+      </category>
+      <category ID="lexicon" counter="0">
+        <label xml:lang="x-hosts" text="series standalone" />
+        <label xml:lang="en" text="Lexicon" />
+        <label xml:lang="de" text="Lexikon" />
+      </category>
+    </category>
+    <category ID="report" counter="0">
+      <label xml:lang="x-hosts" text="standalone" />
+      <label xml:lang="de" text="Report" />
+      <label xml:lang="en" text="Report" />
+      <category ID="research_results" counter="0">
+        <label xml:lang="x-hosts" text="standalone" />
+        <label xml:lang="en" text="Research Results" />
+        <label xml:lang="de" text="Forschungsergebnisse" />
+      </category>
+      <category ID="in_house" counter="0">
+        <label xml:lang="x-hosts" text="standalone" />
+        <label xml:lang="en" text="In house" />
+        <label xml:lang="de" text="Hausinterne Veröffentlichung" />
+      </category>
+      <category ID="press_release" counter="0">
+        <label xml:lang="x-hosts" text="standalone" />
+        <label xml:lang="de" text="Presseerklärung" />
+        <label xml:lang="en" text="Press release" />
+      </category>
+      <category ID="declaration" counter="0">
+        <label xml:lang="x-hosts" text="standalone" />
+        <label xml:lang="de" text="Fachliche Stellungnahme" />
+        <label xml:lang="en" text="Professional declaration" />
+      </category>
+    </category>
+    <category ID="teaching_material" counter="0">
+      <label xml:lang="de" text="Lehrmaterial" />
+      <label xml:lang="x-hosts" text="standalone lecture" />
+      <label xml:lang="en" text="Teaching Resource" />
+      <category ID="lecture_resource" counter="0">
+        <label xml:lang="x-hosts" text="standalone lecture" />
+        <label xml:lang="de" text="Vorlesungsmaterial" />
+        <label xml:lang="en" text="Lecture Resource" />
+      </category>
+      <category ID="course_resources" counter="0">
+        <label xml:lang="x-hosts" text="standalone lecture" />
+        <label xml:lang="de" text="Kurs- und Seminarmaterial" />
+        <label xml:lang="en" text="Course Resources" />
+      </category>
+    </category>
+    <category ID="book" counter="0">
+      <label xml:lang="de" text="Buch" />
+      <label xml:lang="x-hosts" text="series standalone" />
+      <label xml:lang="en" text="Book" />
+    </category>
+  </categories>
+</mycoreclass>

mycore-mods/src/test/resources/MCRCategoryMergeEventHandlerTest/testMods.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <mods:genre type="intern" authorityURI="http://www.mycore.org/classifications/mir_genres" valueURI="http://www.mycore.org/classifications/mir_genres#chapter"/>
+  <mods:genre type="intern" authorityURI="http://www.mycore.org/classifications/mir_genres" valueURI="http://www.mycore.org/classifications/mir_genres#article"/>
+  <mods:genre type="intern" authorityURI="http://www.mycore.org/classifications/mir_genres" valueURI="http://www.mycore.org/classifications/mir_genres#book"/>
+  <mods:genre type="intern" authorityURI="http://www.mycore.org/classifications/mir_genres" valueURI="http://www.mycore.org/classifications/mir_genres#subchapter"/>
+  <mods:titleInfo xml:lang="de" xlink:type="simple">
+    <mods:title>Test-Titel</mods:title>
+  </mods:titleInfo>
+  <mods:relatedItem type="series" xlink:href="host">
+    <mods:classification authority="sdnb" displayLabel="sdnb">000</mods:classification>
+    <mods:genre type="intern" authorityURI="http://www.mycore.org/classifications/mir_genres" valueURI="http://www.mycore.org/classifications/mir_genres#collection"/>
+  </mods:relatedItem>
+  <mods:language>
+    <mods:languageTerm authority="rfc5646" type="code">de</mods:languageTerm>
+  </mods:language>
+  <mods:accessCondition type="use and reproduction" xlink:type="simple">cc_by-nc</mods:accessCondition>
+  <mods:typeOfResource>text</mods:typeOfResource>
+</mods:mods>