* avoid potentially NULL-listFiles() calls

source/net/filebot/Main.java

@@ -92,7 +92,7 @@ public class Main {
 				if (args.clearCache()) {
 					// clear preferences and cache
 					System.out.println("Clear cache and temporary files");
-					for (File folder : getApplicationFolder().getAbsoluteFile().listFiles(FOLDERS)) {
+					for (File folder : getChildren(getApplicationFolder().getAbsoluteFile(), FOLDERS)) {
 						if (matches("cache|temp|grape|reports|logs", folder.getName())) {
 							if (delete(folder)) {
 								System.out.println("* Delete " + folder);

source/net/filebot/cli/CmdlineOperations.java

@@ -150,7 +150,8 @@ public class CmdlineOperations implements CmdlineInterface {
 		return renameAll(renameMap, renameAction, ConflictAction.forName(conflict), null);
 	}
 
-	public List<File> renameSeries(Collection<File> files, RenameAction renameAction, ConflictAction conflictAction, File outputDir, ExpressionFormat format, EpisodeListProvider db, String query, SortOrder sortOrder, ExpressionFilter filter, Locale locale, boolean strict) throws Exception {
+	public List<File> renameSeries(Collection<File> files, RenameAction renameAction, ConflictAction conflictAction, File outputDir, ExpressionFormat format, EpisodeListProvider db, String query, SortOrder sortOrder, ExpressionFilter filter, Locale locale, boolean strict)
+			throws Exception {
 		CLILogger.config(format("Rename episodes using [%s]", db.getName()));
 
 		// ignore sample files
@@ -344,10 +345,10 @@ public class CmdlineOperations implements CmdlineInterface {
 			// collect useful nfo files even if they are not part of the selected fileset
 			Set<File> effectiveNfoFileSet = new TreeSet<File>(nfoFiles);
 			for (File dir : mapByFolder(movieFiles).keySet()) {
-				addAll(effectiveNfoFileSet, dir.listFiles(NFO_FILES));
+				effectiveNfoFileSet.addAll(getChildren(dir, NFO_FILES));
 			}
 			for (File dir : filter(fileset, FOLDERS)) {
-				addAll(effectiveNfoFileSet, dir.listFiles(NFO_FILES));
+				effectiveNfoFileSet.addAll(getChildren(dir, NFO_FILES));
 			}
 
 			for (File nfo : effectiveNfoFileSet) {
@@ -758,7 +759,7 @@ public class CmdlineOperations implements CmdlineInterface {
 		List<File> videoFiles = filter(filter(files, VIDEO_FILES), new FileFilter() {
 
 			// save time on repeating filesystem calls
-			private final Map<File, File[]> cache = new HashMap<File, File[]>();
+			private final Map<File, List<File>> cache = new HashMap<File, List<File>>();
 
 			private final SubtitleNaming naming = getSubtitleNaming(format);
 
@@ -776,9 +777,9 @@ public class CmdlineOperations implements CmdlineInterface {
 
 			@Override
 			public boolean accept(File video) {
-				File[] subtitlesByFolder = cache.get(video.getParentFile());
+				List<File> subtitlesByFolder = cache.get(video.getParentFile());
 				if (subtitlesByFolder == null) {
-					subtitlesByFolder = video.getParentFile().listFiles(SUBTITLE_FILES);
+					subtitlesByFolder = getChildren(video.getParentFile(), SUBTITLE_FILES);
 					cache.put(video.getParentFile(), subtitlesByFolder);
 				}
 

source/net/filebot/cli/FolderWatchService.java

@@ -112,12 +112,9 @@ public abstract class FolderWatchService implements Closeable {
 	}
 
 	private void watchFolderTree(File root) throws IOException {
-		File[] folders = root.listFiles(FOLDERS);
+		for (File it : getChildren(root, FOLDERS)) {
-		if (folders != null) {
-			for (File it : folders) {
 			watchFolderTree(it);
 		}
-		}
 
 		startWatch(root);
 	}

source/net/filebot/format/MediaBindingBean.java

@@ -501,7 +501,7 @@ public class MediaBindingBean {
 		if (hasExtension(mediaFile, "idx")) {
 			return Language.getLanguage(grepLanguageFromSUBIDX(mediaFile));
 		} else if (hasExtension(mediaFile, "sub")) {
-			for (File idx : mediaFile.getParentFile().listFiles(new ExtensionFileFilter("idx"))) {
+			for (File idx : getChildren(mediaFile.getParentFile(), new ExtensionFileFilter("idx"))) {
 				if (isDerived(idx, mediaFile)) {
 					return Language.getLanguage(grepLanguageFromSUBIDX(idx));
 				}
@@ -807,7 +807,7 @@ public class MediaBindingBean {
 
 			// file is a subtitle, or nfo, etc
 			String baseName = stripReleaseInfo(FileUtilities.getName(mediaFile)).toLowerCase();
-			File[] videos = mediaFile.getParentFile().listFiles(VIDEO_FILES);
+			List<File> videos = getChildren(mediaFile.getParentFile(), VIDEO_FILES);
 
 			// find corresponding movie file
 			for (File movieFile : videos) {
@@ -817,15 +817,15 @@ public class MediaBindingBean {
 			}
 
 			// still no good match found -> just take the most probable video from the same folder
-			if (videos.length > 0) {
+			if (videos.size() > 0) {
-				sort(videos, new SimilarityComparator(FileUtilities.getName(mediaFile)) {
+				videos.sort(new SimilarityComparator(FileUtilities.getName(mediaFile)) {
 
 					@Override
 					public int compare(Object o1, Object o2) {
 						return super.compare(FileUtilities.getName((File) o1), FileUtilities.getName((File) o2));
 					}
 				});
-				return videos[0];
+				return videos.get(0);
 			}
 		}
 

source/net/filebot/hash/VerificationUtilities.java

@@ -1,7 +1,5 @@
-
 package net.filebot.hash;
 
-
 import static net.filebot.util.FileUtilities.*;
 
 import java.io.File;
@@ -12,17 +10,13 @@ import java.util.Map.Entry;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-
 public final class VerificationUtilities {
 
 	/**
-	 * A {@link Pattern} that will match checksums enclosed in brackets ("[]" or "()"). A
+	 * A {@link Pattern} that will match checksums enclosed in brackets ("[]" or "()"). A checksum string is a hex number with at least 8 digits. Capturing group 0 will contain the matched checksum string.
-	 * checksum string is a hex number with at least 8 digits. Capturing group 0 will contain
-	 * the matched checksum string.
 	 */
 	public static final Pattern EMBEDDED_CHECKSUM = Pattern.compile("(?<=\\[|\\()(\\p{XDigit}{8})(?=\\]|\\))");
 
-	
 	public static String getEmbeddedChecksum(CharSequence string) {
 		Matcher matcher = EMBEDDED_CHECKSUM.matcher(string);
 		String embeddedChecksum = null;
@@ -35,19 +29,17 @@ public final class VerificationUtilities {
 		return embeddedChecksum;
 	}
 
-	
 	public static String getHashFromVerificationFile(File file, HashType type, int maxDepth) throws IOException {
 		return getHashFromVerificationFile(file.getParentFile(), file, type, 0, maxDepth);
 	}
 
-	
 	private static String getHashFromVerificationFile(File folder, File target, HashType type, int depth, int maxDepth) throws IOException {
 		// stop if we reached max depth or the file system root
 		if (folder == null || depth > maxDepth)
 			return null;
 
 		// scan all sfv files in this folder
-		for (File verificationFile : folder.listFiles(type.getFilter())) {
+		for (File verificationFile : getChildren(folder, type.getFilter())) {
 			VerificationFileReader parser = new VerificationFileReader(createTextReader(verificationFile), type.getFormat());
 
 			try {
@@ -69,7 +61,6 @@ public final class VerificationUtilities {
 		return getHashFromVerificationFile(folder.getParentFile(), target, type, depth + 1, maxDepth);
 	}
 
-	
 	public static HashType getHashType(File verificationFile) {
 		for (HashType hashType : HashType.values()) {
 			if (hashType.getFilter().accept(verificationFile))
@@ -79,7 +70,6 @@ public final class VerificationUtilities {
 		return null;
 	}
 
-	
 	public static HashType getHashTypeByExtension(String extension) {
 		for (HashType hashType : HashType.values()) {
 			if (hashType.getFilter().acceptExtension(extension))
@@ -89,7 +79,6 @@ public final class VerificationUtilities {
 		return null;
 	}
 
-	
 	public static String computeHash(File file, HashType type) throws IOException, InterruptedException {
 		Hash hash = type.newHash();
 
@@ -114,7 +103,6 @@ public final class VerificationUtilities {
 		return hash.digest();
 	}
 
-	
 	/**
 	 * Dummy constructor to prevent instantiation.
 	 */

source/net/filebot/media/MediaDetection.java

@@ -1103,7 +1103,7 @@ public class MediaDetection {
 		if (file.isDirectory()) {
 			nfoFiles.addAll(filter(listFiles(file), NFO_FILES));
 		} else if (file.getParentFile().isDirectory()) {
-			addAll(nfoFiles, file.getParentFile().listFiles(NFO_FILES));
+			nfoFiles.addAll(getChildren(file.getParentFile(), NFO_FILES));
 		}
 
 		// parse ids from nfo files
@@ -1135,7 +1135,7 @@ public class MediaDetection {
 			if (!folder.exists())
 				continue;
 
-			for (File nfo : folder.listFiles(NFO_FILES)) {
+			for (File nfo : getChildren(folder, NFO_FILES)) {
 				String text = new String(readFile(nfo), "UTF-8");
 
 				for (int imdbid : grepImdbId(text)) {

source/net/filebot/media/ReleaseInfo.java

@@ -194,24 +194,18 @@ public class ReleaseInfo {
 			volumes.add(new File(System.getProperty("user.home")));
 
 			// Windows / Linux / Mac system roots
-			addAll(volumes, File.listRoots());
+			volumes.addAll(getFileSystemRoots());
 
 			if (File.separator.equals("/")) {
 				// Linux and Mac system root folders
-				for (File root : File.listRoots()) {
+				for (File root : getFileSystemRoots()) {
-					File[] f = root.listFiles(FOLDERS);
+					volumes.addAll(getChildren(root, FOLDERS));
-					if (f != null) {
-						addAll(volumes, f);
-					}
 				}
 
 				// user-specific media roots
 				for (File root : getMediaRoots()) {
 					if (root.isDirectory()) {
-						File[] f = root.listFiles(FOLDERS);
+						volumes.addAll(getChildren(root, FOLDERS));
-						if (f != null) {
-							addAll(volumes, f);
-						}
 					}
 				}
 			}

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

@@ -112,10 +112,10 @@ class MovieHashMatcher implements AutoCompleteMatcher {
 		// collect useful nfo files even if they are not part of the selected fileset
 		Set<File> effectiveNfoFileSet = new TreeSet<File>(nfoFiles);
 		for (File dir : mapByFolder(movieFiles).keySet()) {
-			addAll(effectiveNfoFileSet, dir.listFiles(NFO_FILES));
+			effectiveNfoFileSet.addAll(getChildren(dir, NFO_FILES));
 		}
 		for (File dir : filter(fileset, FOLDERS)) {
-			addAll(effectiveNfoFileSet, dir.listFiles(NFO_FILES));
+			effectiveNfoFileSet.addAll(getChildren(dir, NFO_FILES));
 		}
 
 		for (File nfo : effectiveNfoFileSet) {

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

@@ -198,7 +198,7 @@ class ChecksumTableTransferablePolicy extends BackgroundFileTransferablePolicy<C
 
 				if (seenLevel == null) {
 					// folder we have never encountered before
-					for (File verificationFile : folder.listFiles(MediaTypes.getDefaultFilter("verification"))) {
+					for (File verificationFile : getChildren(folder, MediaTypes.getDefaultFilter("verification"))) {
 						HashType hashType = getHashType(verificationFile);
 						cache.put(verificationFile, importVerificationFile(verificationFile, hashType, verificationFile.getParentFile()));
 						types.put(verificationFile, hashType);

source/net/filebot/ui/transfer/TransferablePolicyFileFilter.java

@@ -1,22 +1,18 @@
-
 package net.filebot.ui.transfer;
 
-
 import java.io.File;
+import java.io.FilenameFilter;
 
 import javax.swing.filechooser.FileFilter;
 
-
+public class TransferablePolicyFileFilter extends FileFilter implements FilenameFilter {
-public class TransferablePolicyFileFilter extends FileFilter {
 
 	private final TransferablePolicy transferablePolicy;
 
-	
 	public TransferablePolicyFileFilter(TransferablePolicy transferablePolicy) {
 		this.transferablePolicy = transferablePolicy;
 	}
 
-
 	@Override
 	public boolean accept(File f) {
 		if (f.isDirectory())
@@ -29,6 +25,10 @@ public class TransferablePolicyFileFilter extends FileFilter {
 		}
 	}
 
+	@Override
+	public boolean accept(File dir, String name) {
+		return accept(new File(dir, name));
+	}
 
 	@Override
 	public String getDescription() {
@@ -38,4 +38,5 @@ public class TransferablePolicyFileFilter extends FileFilter {
 
 		return null;
 	}
+
 }

source/net/filebot/util/FileUtilities.java

@@ -415,12 +415,34 @@ public final class FileUtilities {
 		return f;
 	}
 
-	public static List<File> getChildren(File file) {
+	public static List<File> getFileSystemRoots() {
-		File[] files = file.listFiles();
+		File[] roots = File.listRoots();
+
+		// roots array may be null if folder permissions do not allow listing of files
+		if (roots == null) {
+			roots = new File[0];
+		}
+
+		return asList(roots);
+	}
+
+	public static List<File> getChildren(File folder) {
+		File[] files = folder.listFiles();
 
 		// children array may be null if folder permissions do not allow listing of files
 		if (files == null) {
-			return asList(new File[0]);
+			files = new File[0];
+		}
+
+		return asList(files);
+	}
+
+	public static List<File> getChildren(File folder, FileFilter filter) {
+		File[] files = folder.listFiles(filter);
+
+		// children array may be null if folder permissions do not allow listing of files
+		if (files == null) {
+			files = new File[0];
 		}
 
 		return asList(files);