src/zutil/io/file/FileWatcher.java

@@ -0,0 +1,67 @@
+package zutil.io.file;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Timer;
+import java.util.TimerTask;
+
+import zutil.io.MultiPrintStream;
+
+/**
+ * This class calls a given listener 
+ * when a file is changed
+ * 
+ * @author Ziver
+ *
+ */
+public class FileWatcher extends TimerTask{
+	private FileChangeListener listener;
+	private long lastChanged;
+	private File file;
+	
+	/**
+	 * Creates a watcher for the given file whit the check 
+	 * interval of 1 second
+	 * 
+	 * @param 		file 	is the file to check
+	 * @throws FileNotFoundException 
+	 */
+	public FileWatcher(File file) throws FileNotFoundException{
+		this(file, 1000);
+	}
+	
+	/**
+	 * Creates a watcher for the given file whit the given 
+	 * check interval
+	 * 
+	 * @param 		file 			is the file
+	 * @param 		intervall 		is the interval
+	 * @throws FileNotFoundException 
+	 */
+	public FileWatcher(File file, int intervall) throws FileNotFoundException{
+		if(file==null || !file.exists()) 
+			throw new FileNotFoundException("File not found: "+file);
+		this.file = file;
+		lastChanged = file.lastModified();
+		
+		Timer t = new Timer(true);
+		t.schedule(this, 0, intervall);
+	}
+	
+	public void setListener(FileChangeListener listener){
+		this.listener = listener;
+	}
+
+	@Override
+	public void run() {
+		if (lastChanged != file.lastModified()) {
+			lastChanged = file.lastModified();
+			if(listener != null){
+				listener.fileChangedEvent(file);
+			}
+			else{
+				MultiPrintStream.out.println("File Changed: "+file);
+			}
+		}
+	}
+}