* fix NPE

source/net/sourceforge/filebot/cli/FolderWatchService.java

@@ -1,7 +1,5 @@
-
 package net.sourceforge.filebot.cli;
 
-
 import static java.nio.file.StandardWatchEventKinds.*;
 import static java.util.Collections.*;
 import static net.sourceforge.tuned.FileUtilities.*;
@@ -29,18 +27,17 @@ import java.util.logging.Logger;
 import net.sourceforge.tuned.DefaultThreadFactory;
 import net.sourceforge.tuned.Timer;
 
-
 public abstract class FolderWatchService implements Closeable {
-	
+
 	private final Collection<File> commitSet = new HashSet<File>();
-	
+
 	private final ExecutorService processor = Executors.newSingleThreadExecutor();
 	private final ExecutorService watchers = Executors.newCachedThreadPool(new DefaultThreadFactory("FolderWatchService"));
-	
+
 	private long commitDelay = 500; // 0.5 s
 	private boolean commitPerFolder = true;
 	private final Timer commitTimer = new Timer() {
-		
+
 		@Override
 		public void run() {
 			synchronized (processor) {
@@ -48,37 +45,32 @@ public abstract class FolderWatchService implements Closeable {
 			}
 		}
 	};
-	
+
 	private final boolean watchTree;
-	
-	
+
 	public FolderWatchService(boolean watchTree) {
 		this.watchTree = watchTree;
 	}
-	
-	
+
 	public synchronized void setCommitPerFolder(boolean enabled) {
 		this.commitPerFolder = enabled;
 	}
-	
-	
+
 	public synchronized void setCommitDelay(long commitDelay) {
 		if (commitDelay < 0)
 			throw new IllegalArgumentException("Delay must not be negativ");
-		
+
 		this.commitDelay = commitDelay;
 		resetCommitTimer();
 	}
-	
-	
+
 	public synchronized void resetCommitTimer() {
 		commitTimer.set(commitDelay, TimeUnit.MILLISECONDS, false);
 	}
-	
-	
+
 	public synchronized void commit() {
 		final SortedSet<File> files = new TreeSet<File>();
-		
+
 		synchronized (commitSet) {
 			for (File it : commitSet) {
 				if (it.isFile()) {
@@ -87,16 +79,16 @@ public abstract class FolderWatchService implements Closeable {
 			}
 			commitSet.clear();
 		}
-		
+
 		if (files.isEmpty()) {
 			return;
 		}
-		
+
 		// divide into commit batches per folder if required
 		final Map<File, ? extends Collection<File>> commitBatches = commitPerFolder ? mapByFolder(files) : singletonMap((File) null, files);
-		
+
 		processor.submit(new Runnable() {
-			
+
 			@Override
 			public void run() {
 				synchronized (processor) {
@@ -107,37 +99,36 @@ public abstract class FolderWatchService implements Closeable {
 			}
 		});
 	}
-	
-	
+
 	public abstract void processCommitSet(File[] files, File dir);
-	
-	
+
 	public synchronized void watchFolder(File folder) throws IOException {
 		if (!watchTree) {
 			startWatch(folder);
 			return;
 		}
-		
+
 		watchFolderTree(folder);
 	}
-	
-	
+
 	private void watchFolderTree(File root) throws IOException {
-		for (File it : root.listFiles(FOLDERS)) {
-			watchFolderTree(it);
+		File[] folders = root.listFiles(FOLDERS);
+		if (folders != null) {
+			for (File it : folders) {
+				watchFolderTree(it);
+			}
 		}
-		
+
 		startWatch(root);
 	}
-	
-	
+
 	private synchronized void startWatch(File node) throws IOException {
 		if (!node.isDirectory()) {
 			throw new IllegalArgumentException("Must be a folder: " + node);
 		}
-		
+
 		watchers.submit(new FolderWatcher(node) {
-			
+
 			@Override
 			protected void processEvents(List<WatchEvent<?>> events) {
 				synchronized (commitSet) {
@@ -145,8 +136,7 @@ public abstract class FolderWatchService implements Closeable {
 					super.processEvents(events);
 				}
 			}
-			
-			
+
 			@Override
 			protected void created(File file) {
 				synchronized (commitSet) {
@@ -154,7 +144,7 @@ public abstract class FolderWatchService implements Closeable {
 						commitSet.add(file);
 						return;
 					}
-					
+
 					// start watching newly created folder
 					if (watchTree) {
 						try {
@@ -166,8 +156,7 @@ public abstract class FolderWatchService implements Closeable {
 					}
 				}
 			}
-			
-			
+
 			@Override
 			protected void modified(File file) {
 				synchronized (commitSet) {
@@ -176,8 +165,7 @@ public abstract class FolderWatchService implements Closeable {
 					}
 				}
 			}
-			
-			
+
 			@Override
 			protected void deleted(File file) {
 				synchronized (commitSet) {
@@ -186,29 +174,25 @@ public abstract class FolderWatchService implements Closeable {
 			}
 		});
 	}
-	
-	
+
 	@Override
 	public synchronized void close() throws IOException {
 		commitTimer.cancel();
 		processor.shutdownNow();
 		watchers.shutdownNow();
 	}
-	
-	
+
 	private abstract static class FolderWatcher implements Runnable, Closeable {
-		
+
 		private final Path node;
 		private final WatchService watchService;
-		
-		
+
 		public FolderWatcher(File node) throws IOException {
 			this.node = node.toPath();
 			this.watchService = this.node.getFileSystem().newWatchService();
 			this.node.register(watchService, ENTRY_CREATE, ENTRY_MODIFY, ENTRY_DELETE);
 		}
-		
-		
+
 		@Override
 		public void run() {
 			try {
@@ -219,8 +203,7 @@ public abstract class FolderWatchService implements Closeable {
 				Logger.getLogger(getClass().getName()).log(Level.WARNING, e.getMessage(), e);
 			}
 		}
-		
-		
+
 		public void watch() throws IOException, InterruptedException {
 			try {
 				boolean valid = true;
@@ -233,13 +216,11 @@ public abstract class FolderWatchService implements Closeable {
 				this.close();
 			}
 		}
-		
-		
+
 		public File getAbsoluteFile(WatchEvent event) {
 			return node.resolve(event.context().toString()).toFile();
 		}
-		
-		
+
 		protected void processEvents(List<WatchEvent<?>> list) {
 			for (WatchEvent event : list) {
 				if (event.kind() == ENTRY_CREATE) {
@@ -251,21 +232,17 @@ public abstract class FolderWatchService implements Closeable {
 				}
 			}
 		}
-		
-		
+
 		protected abstract void created(File file);
-		
-		
+
 		protected abstract void modified(File file);
-		
-		
+
 		protected abstract void deleted(File file);
-		
-		
+
 		@Override
 		public void close() throws IOException {
 			watchService.close();
 		}
 	}
-	
+
 }