* due to permission issues File.listFiles() can return null

source/net/filebot/Main.java

@@ -48,8 +48,6 @@ import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.xml.parsers.DocumentBuilderFactory;
 
-import net.miginfocom.swing.MigLayout;
-import net.sf.ehcache.CacheManager;
 import net.filebot.cli.ArgumentBean;
 import net.filebot.cli.ArgumentProcessor;
 import net.filebot.cli.CmdlineOperations;
@@ -63,6 +61,8 @@ import net.filebot.util.ByteBufferInputStream;
 import net.filebot.util.PreferencesMap.PreferencesEntry;
 import net.filebot.util.TeePrintStream;
 import net.filebot.web.CachedResource;
+import net.miginfocom.swing.MigLayout;
+import net.sf.ehcache.CacheManager;
 
 import org.w3c.dom.NodeList;
 
@@ -464,7 +464,7 @@ public class Main {
 						isNewCache = true;
 
 						// delete all files related to previous cache instances
-						for (File it : cache.listFiles()) {
+						for (File it : getChildren(cache)) {
 							if (!it.equals(lockFile)) {
 								delete(cache);
 							}

source/net/filebot/cli/ArgumentBean.java

@@ -165,7 +165,7 @@ public class ArgumentBean {
 				if (recursive) {
 					files.addAll(listFiles(file));
 				} else {
-					files.addAll(asList(file.listFiles()));
+					files.addAll(getChildren(file));
 				}
 			} else {
 				files.add(file);

source/net/filebot/cli/ScriptShellMethods.java

@@ -57,11 +57,7 @@ public class ScriptShellMethods {
 	}
 
 	public static List<File> listFiles(File self, Closure<?> closure) {
-		File[] files = self.listFiles();
+		return (List<File>) DefaultGroovyMethods.findAll(FileUtilities.getChildren(self), closure);
-		if (files == null)
-			return emptyList();
-
-		return (List<File>) DefaultGroovyMethods.findAll(asList(files), closure);
 	}
 
 	public static boolean isVideo(File self) {
@@ -101,11 +97,7 @@ public class ScriptShellMethods {
 	}
 
 	public static boolean hasFile(File self, Closure<?> closure) {
-		File[] files = self.listFiles();
+		return DefaultGroovyMethods.find(FileUtilities.getChildren(self), closure) != null;
-		if (files == null)
-			return false;
-
-		return DefaultGroovyMethods.find(asList(files), closure) != null;
 	}
 
 	public static List<File> getFiles(File self) {
@@ -163,7 +155,7 @@ public class ScriptShellMethods {
 			public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
 				File folder = dir.toFile();
 
-				if (FileUtilities.filter(asList(folder.listFiles()), VIDEO_FILES).size() > 0 || MediaDetection.isDiskFolder(folder)) {
+				if (FileUtilities.filter(FileUtilities.getChildren(folder), VIDEO_FILES).size() > 0 || MediaDetection.isDiskFolder(folder)) {
 					mediaFolders.add(folder);
 					return FileVisitResult.SKIP_SUBTREE;
 				}

source/net/filebot/ui/analyze/FileTreeTransferablePolicy.java

@@ -1,8 +1,7 @@
-
 package net.filebot.ui.analyze;
 
-
 import static net.filebot.ui.NotificationLogging.*;
+import static net.filebot.util.FileUtilities.*;
 
 import java.io.File;
 import java.util.List;
@@ -14,25 +13,20 @@ import net.filebot.ui.analyze.FileTree.FolderNode;
 import net.filebot.ui.transfer.BackgroundFileTransferablePolicy;
 import net.filebot.util.ExceptionUtilities;
 import net.filebot.util.FastFile;
-import net.filebot.util.FileUtilities;
-
 
 class FileTreeTransferablePolicy extends BackgroundFileTransferablePolicy<AbstractTreeNode> {
 
 	private final FileTree tree;
 
-	
 	public FileTreeTransferablePolicy(FileTree tree) {
 		this.tree = tree;
 	}
 
-	
 	@Override
 	protected boolean accept(List<File> files) {
 		return true;
 	}
 
-	
 	@Override
 	protected void clear() {
 		super.clear();
@@ -40,7 +34,6 @@ class FileTreeTransferablePolicy extends BackgroundFileTransferablePolicy<Abstra
 		tree.clear();
 	}
 
-	
 	@Override
 	protected void process(List<AbstractTreeNode> chunks) {
 		FolderNode root = tree.getRoot();
@@ -52,13 +45,11 @@ class FileTreeTransferablePolicy extends BackgroundFileTransferablePolicy<Abstra
 		tree.getModel().reload();
 	}
 
-	
 	@Override
 	protected void process(Exception e) {
 		UILogger.log(Level.WARNING, ExceptionUtilities.getRootCauseMessage(e), e);
 	}
 
-	
 	@Override
 	protected void load(List<File> files) {
 		try {
@@ -74,14 +65,13 @@ class FileTreeTransferablePolicy extends BackgroundFileTransferablePolicy<Abstra
 		}
 	}
 
-	
 	private AbstractTreeNode getTreeNode(File file) throws InterruptedException {
 		if (Thread.interrupted())
 			throw new InterruptedException();
 
-		File[] files = file.listFiles();
+		if (file.isDirectory()) {
-		if (files != null && file.isDirectory()) {
+			List<File> files = getChildren(file);
-			FolderNode node = new FolderNode(FileUtilities.getFolderName(file), files.length);
+			FolderNode node = new FolderNode(getFolderName(file), files.size());
 
 			// add folders first
 			for (File f : files) {
@@ -102,7 +92,6 @@ class FileTreeTransferablePolicy extends BackgroundFileTransferablePolicy<Abstra
 		return new FileNode(file);
 	}
 
-	
 	@Override
 	public String getFileFilterDescription() {
 		return "files and folders";

source/net/filebot/ui/rename/FilesListTransferablePolicy.java

@@ -1,6 +1,5 @@
 package net.filebot.ui.rename;
 
-import static java.util.Arrays.*;
 import static net.filebot.MediaTypes.*;
 import static net.filebot.ui.transfer.FileTransferable.*;
 import static net.filebot.util.FileUtilities.*;
@@ -11,7 +10,6 @@ import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Scanner;
-import java.util.TreeSet;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -91,10 +89,7 @@ class FilesListTransferablePolicy extends FileTransferablePolicy {
 			} else if (!recursive || f.isFile() || MediaDetection.isDiskFolder(f)) {
 				entries.add(f);
 			} else if (f.isDirectory()) {
-				File[] children = f.listFiles();
+				queue.addAll(0, sortByUniquePath(getChildren(f))); // FORCE NATURAL FILE ORDER
-				if (children != null) {
-					queue.addAll(0, new TreeSet<File>(asList(children))); // FORCE NATURAL FILE ORDER
-				}
 			}
 		}
 

source/net/filebot/ui/sfv/ChecksumTableTransferablePolicy.java

@@ -1,7 +1,5 @@
-
 package net.filebot.ui.sfv;
 
-
 import static java.util.Collections.*;
 import static net.filebot.hash.VerificationUtilities.*;
 import static net.filebot.ui.NotificationLogging.*;
@@ -22,25 +20,21 @@ import net.filebot.hash.VerificationFileReader;
 import net.filebot.ui.transfer.BackgroundFileTransferablePolicy;
 import net.filebot.util.ExceptionUtilities;
 
-
 class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<ChecksumCell> {
 
 	private final ChecksumTableModel model;
 	private final ChecksumComputationService computationService;
 
-
 	public ChecksumTableTransferablePolicy(ChecksumTableModel model, ChecksumComputationService checksumComputationService) {
 		this.model = model;
 		this.computationService = checksumComputationService;
 	}
 
-
 	@Override
 	protected boolean accept(List<File> files) {
 		return true;
 	}
 
-
 	@Override
 	protected void clear() {
 		super.clear();
@@ -49,7 +43,6 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 		model.clear();
 	}
 
-
 	@Override
 	protected void prepare(List<File> files) {
 		if (files.size() == 1 && getHashType(files.get(0)) != null) {
@@ -57,23 +50,19 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 		}
 	}
 
-
 	@Override
 	protected void process(List<ChecksumCell> chunks) {
 		model.addAll(chunks);
 	}
 
-
 	@Override
 	protected void process(Exception e) {
 		UILogger.log(Level.WARNING, ExceptionUtilities.getRootCauseMessage(e), e);
 	}
 
-
 	private final ThreadLocal<ExecutorService> executor = new ThreadLocal<ExecutorService>();
 	private final ThreadLocal<VerificationTracker> verificationTracker = new ThreadLocal<VerificationTracker>();
 
-
 	@Override
 	protected void load(List<File> files) throws IOException {
 		// initialize drop parameters
@@ -87,7 +76,7 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 			}
 			// handle single folder drop
 			else if (files.size() == 1 && files.get(0).isDirectory()) {
-				for (File file : files.get(0).listFiles()) {
+				for (File file : getChildren(files.get(0))) {
 					load(file, null, files.get(0));
 				}
 			}
@@ -109,7 +98,6 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 		}
 	}
 
-
 	protected void loadVerificationFile(File file, HashType type) throws IOException, InterruptedException {
 		VerificationFileReader parser = new VerificationFileReader(createTextReader(file), type.getFormat());
 
@@ -137,7 +125,6 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 		}
 	}
 
-
 	protected void load(File absoluteFile, File relativeFile, File root) throws IOException, InterruptedException {
 		if (Thread.interrupted())
 			throw new InterruptedException();
@@ -151,7 +138,7 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 
 		if (absoluteFile.isDirectory()) {
 			// load all files in the file tree
-			for (File child : absoluteFile.listFiles()) {
+			for (File child : getChildren(absoluteFile)) {
 				load(child, relativeFile, root);
 			}
 		} else {
@@ -170,7 +157,6 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 		}
 	}
 
-
 	protected ChecksumCell createComputationCell(String name, File root, HashType hash) {
 		ChecksumCell cell = new ChecksumCell(name, root, new ChecksumComputationTask(new File(root, name), hash));
 
@@ -180,13 +166,11 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 		return cell;
 	}
 
-
 	@Override
 	public String getFileFilterDescription() {
 		return "files, folders and sfv files";
 	}
 
-
 	private static class VerificationTracker {
 
 		private final Map<File, Integer> seen = new HashMap<File, Integer>();
@@ -195,12 +179,10 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 
 		private final int maxDepth;
 
-
 		public VerificationTracker(int maxDepth) {
 			this.maxDepth = maxDepth;
 		}
 
-
 		public Map<File, String> getHashByVerificationFile(File file) throws IOException {
 			// cache all verification files
 			File folder = file.getParentFile();
@@ -250,12 +232,10 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 			return result;
 		}
 
-
 		public HashType getVerificationFileType(File verificationFile) {
 			return types.get(verificationFile);
 		}
 
-
 		/**
 		 * Completely read a verification file and resolve all relative file paths against a given base folder
 		 */

source/net/filebot/util/FileUtilities.java

@@ -380,6 +380,17 @@ public final class FileUtilities {
 		return f;
 	}
 
+	public static List<File> getChildren(File file) {
+		File[] files = file.listFiles();
+
+		// children array may be null if folder permissions do not allow listing of files
+		if (files == null) {
+			return asList(new File[0]);
+		}
+
+		return asList(files);
+	}
+
 	public static List<File> listFiles(File... folders) {
 		return listFiles(asList(folders));
 	}
@@ -417,11 +428,7 @@ public final class FileUtilities {
 		if (depth > maxDepth)
 			return;
 
-		File[] children = folder.listFiles();
+		for (File it : getChildren(folder)) {
-		if (children == null)
-			return;
-
-		for (File it : children) {
 			if (!addHidden && it.isHidden()) // ignore hidden files
 				continue;
 

source/net/filebot/util/TemporaryFolder.java

@@ -1,6 +1,6 @@
-
 package net.filebot.util;
 
+import static net.filebot.util.FileUtilities.*;
 
 import java.io.File;
 import java.io.IOException;
@@ -10,19 +10,15 @@ import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 
-
 public final class TemporaryFolder {
 
 	private static final Map<String, TemporaryFolder> folders = new HashMap<String, TemporaryFolder>();
 
-
 	/**
-	 * Get a {@link TemporaryFolder} instance for a given name. The actual directory will be
+	 * Get a {@link TemporaryFolder} instance for a given name. The actual directory will be created lazily (e.g. when a file is created). The name of the directory will start with the given name (lower-case) and contain a unique id, so multiple application instances may run at the same time without the risk of interference.
-	 * created lazily (e.g. when a file is created). The name of the directory will start with
-	 * the given name (lower-case) and contain a unique id, so multiple application instances
-	 * may run at the same time without the risk of interference.
 	 * 
-	 * @param name case-insensitive name of a temporary folder (e.g. application name)
+	 * @param name
+	 *            case-insensitive name of a temporary folder (e.g. application name)
 	 * @return temporary folder for this name
 	 */
 	public static TemporaryFolder getFolder(String name) {
@@ -44,7 +40,6 @@ public final class TemporaryFolder {
 		}
 	}
 
-
 	/**
 	 * Delete all temporary folders on shutdown
 	 */
@@ -64,18 +59,18 @@ public final class TemporaryFolder {
 
 	private final File root;
 
-
 	private TemporaryFolder(File root) {
 		this.root = root;
 	}
 
-
 	/**
 	 * Create an empty file in this temporary folder.
 	 * 
-	 * @param name name of the file
+	 * @param name
+	 *            name of the file
 	 * @return newly created file
-	 * @throws IOException if an I/O error occurred
+	 * @throws IOException
+	 *             if an I/O error occurred
 	 */
 	public File createFile(String name) throws IOException {
 
@@ -86,32 +81,28 @@ public final class TemporaryFolder {
 		return file;
 	}
 
-
 	/**
-	 * Creates an empty file in this temporary folder, using the given prefix and suffix to
+	 * Creates an empty file in this temporary folder, using the given prefix and suffix to generate its name.
-	 * generate its name.
 	 * 
-	 * @param prefix The prefix string to be used in generating the file's name; must be at
+	 * @param prefix
-	 *            least three characters long
+	 *            The prefix string to be used in generating the file's name; must be at least three characters long
-	 * @param suffix The suffix string to be used in generating the file's name; may be null,
+	 * @param suffix
-	 *            in which case the suffix ".tmp" will be used
+	 *            The suffix string to be used in generating the file's name; may be null, in which case the suffix ".tmp" will be used
 	 * @return An abstract pathname denoting a newly-created empty file
-	 * @throws IOException If a file could not be created
+	 * @throws IOException
+	 *             If a file could not be created
 	 * @see File#createTempFile(String, String)
 	 */
 	public File createFile(String prefix, String suffix) throws IOException {
 		return File.createTempFile(prefix, suffix, getFolder());
 	}
 
-
 	public boolean deleteFile(String name) {
 		return new File(getFolder(), name).delete();
 	}
 
-
 	/**
-	 * Retrieve the {@link File} object for this {@link TemporaryFolder}. The actual directory
+	 * Retrieve the {@link File} object for this {@link TemporaryFolder}. The actual directory for the {@link TemporaryFolder} instance will be created by this method.
-	 * for the {@link TemporaryFolder} instance will be created by this method.
 	 * 
 	 * @return the {@link File} object for this {@link TemporaryFolder}
 	 */
@@ -123,12 +114,10 @@ public final class TemporaryFolder {
 		return root;
 	}
 
-
 	public TemporaryFolder subFolder(String name) {
 		return new TemporaryFolder(new File(getFolder(), name));
 	}
 
-
 	public List<File> list(boolean recursive) {
 		List<File> list = new ArrayList<File>();
 
@@ -137,10 +126,9 @@ public final class TemporaryFolder {
 		return list;
 	}
 
-
 	private void list(File file, List<File> list, boolean recursive) {
 		if (file.isDirectory()) {
-			for (File entry : file.listFiles()) {
+			for (File entry : getChildren(file)) {
 				if (entry.isDirectory()) {
 					if (recursive) {
 						list(entry, list, recursive);
@@ -152,20 +140,19 @@ public final class TemporaryFolder {
 		}
 	}
 
-
 	public void delete() {
 		delete(root);
 	}
 
-
 	/**
 	 * Delete files/folders recursively
 	 * 
-	 * @param file file/folder that will be deleted
+	 * @param file
+	 *            file/folder that will be deleted
 	 */
 	private void delete(File file) {
 		if (file.isDirectory()) {
-			for (File entry : file.listFiles()) {
+			for (File entry : getChildren(file)) {
 				delete(entry);
 			}
 		}