Import RemovePNGThumbnailsForPDFs.java

Written by Andrea Schweer under the BSD license. I will use this
as a base to do other thumbnail-related tasks.

See: https://github.com/UoW-IRRs/DSpace-Scripts

src/main/java/io/github/ilri/cgspace/scripts/RemovePNGThumbnailsForPDFs.java

@@ -0,0 +1,103 @@
+package nz.ac.waikato.its.irr.scripts;
+
+import org.apache.commons.lang.StringUtils;
+import org.dspace.authorize.AuthorizeException;
+import org.dspace.content.*;
+import org.dspace.core.Constants;
+import org.dspace.core.Context;
+import org.dspace.handle.HandleManager;
+
+import java.io.IOException;
+import java.sql.SQLException;
+import java.util.Arrays;
+
+/**
+ * @author Andrea Schweer schweer@waikato.ac.nz for the LCoNZ Institutional Research Repositories
+ */
+public class RemovePNGThumbnailsForPDFs {
+
+	public static void main(String[] args) {
+		String parentHandle = null;
+		if (args.length >= 1) {
+			parentHandle = args[0];
+		}
+
+		Context context = null;
+		try {
+			context = new Context();
+			context.turnOffAuthorisationSystem();
+
+			if (StringUtils.isBlank(parentHandle)) {
+				process(context, Item.findAll(context));
+			} else {
+				DSpaceObject parent = HandleManager.resolveToObject(context, parentHandle);
+				if (parent != null) {
+					switch (parent.getType()) {
+						case Constants.COLLECTION:
+							process(context, ((Collection) parent).getAllItems()); // getAllItems because we want to work on non-archived ones as well
+							break;
+						case Constants.COMMUNITY:
+							Collection[] collections = ((Community) parent).getCollections();
+							for (Collection collection : collections) {
+								process(context, collection.getAllItems()); // getAllItems because we want to work on non-archived ones as well
+							}
+							break;
+						case Constants.SITE:
+							process(context, Item.findAll(context));
+							break;
+						case Constants.ITEM:
+							processItem((Item) parent);
+							context.commit();
+							break;
+					}
+				}
+			}
+		} catch (SQLException | AuthorizeException | IOException e) {
+			e.printStackTrace(System.err);
+		} finally {
+			if (context != null && context.isValid()) {
+				context.abort();
+			}
+		}
+	}
+
+	private static void process(Context context, ItemIterator items) throws SQLException, IOException, AuthorizeException {
+		while (items.hasNext()) {
+			Item item = items.next();
+			processItem(item);
+			context.commit();
+			item.decache();
+		}
+	}
+
+	private static void processItem(Item item) throws SQLException, AuthorizeException, IOException {
+		Bundle[] thumbnailBundles = item.getBundles("THUMBNAIL");
+		for (Bundle bundle : thumbnailBundles) {
+			//System.out.println(Arrays.toString(bundle.getItems()));
+			//[org.dspace.content.Item@92944ff4]
+			Bitstream[] bitstreams = bundle.getBitstreams();
+			for (Bitstream bitstream : bitstreams) {
+				//System.out.println(bitstream.getName());
+				//AgricSystems.jpg.jpg
+				if ("image/png".equals(bitstream.getFormat().getMIMEType()) && "Generated Thumbnail".equals(bitstream.getDescription())) {
+					String bitstreamName = bitstream.getName();
+					if (hasJpegThumbnail(thumbnailBundles, bitstreamName)) {
+						bundle.removeBitstream(bitstream);
+						System.out.println("Removed generated PDF thumbnail " + bitstreamName + " from item id=" + item.getID() + ", it has a new JPG thumbnail");
+					}
+				}
+			}
+		}
+	}
+
+	private static boolean hasJpegThumbnail(Bundle[] thumbnailBundles, String bitstreamName) {
+		String jpgName = StringUtils.removeEndIgnoreCase(bitstreamName, ".png") + ".jpg";
+		for (Bundle bundle : thumbnailBundles) {
+			Bitstream candidate = bundle.getBitstreamByName(jpgName);
+			if (candidate != null) {
+				return true;
+			}
+		}
+		return false;
+	}
+}