Automatic syncing of local and server files via ftp

Uploader.java

package main;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;

public class Uploader{

	private static final int BUFFER_SIZE=4096;
	private static final String ftpUrl="ftp://%s:%s@%s/%s;type=i";
	//FTP credentials
	private static final String host="";
	private static final String user="";
	private static final String pass="";

	//local directory to sync, e.g. "C:\\xampp\\htdocs\\"
	public static final Path localBase=Paths.get("");

	public static void upload(Path f){
		try{
			URL u=new URL(String.format(ftpUrl,user,pass,host,localBase.relativize(f).toString().replace('\\','/')));
			URLConnection conn=u.openConnection();
			OutputStream o=conn.getOutputStream();
			FileInputStream i=new FileInputStream(f.toFile());
			byte[] buffer=new byte[BUFFER_SIZE];
			int bytesRead=-1;
			while((bytesRead=i.read(buffer))!=-1){
				o.write(buffer,0,bytesRead);
			}
			i.close();o.close();
		}catch(IOException e){
			e.printStackTrace();
		}
	}

	public static void delete(Path f){
		FTPClient ftpClient=new FTPClient();
		try{
			ftpClient.connect(host,21);
			if(!FTPReply.isPositiveCompletion(ftpClient.getReplyCode()))return;
			if(!ftpClient.login(user,pass))return;
			ftpClient.deleteFile(localBase.relativize(f).toString().replace('\\','/'));
		}catch(IOException ex){
			ex.printStackTrace();
		}finally{
			try{
				if(ftpClient.isConnected()){
					ftpClient.logout();
					ftpClient.disconnect();
				}
			}catch(IOException ex){
				ex.printStackTrace();
			}
		}
	}
	
	public static String getFTPPath(){
		return String.format(ftpUrl.substring(0,14),user,pass,host);
	}

}

WatchDir.java

package main;

import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
import static java.nio.file.StandardWatchEventKinds.OVERFLOW;
import java.awt.AWTException;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.io.IOException;
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met: -
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer. - Redistributions in binary
 * form must reproduce the above copyright notice, this list of conditions and
 * the following disclaimer in the documentation and/or other materials provided
 * with the distribution. - Neither the name of Oracle nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission. THIS SOFTWARE IS PROVIDED
 * BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.HashMap;
import java.util.Map;

public class WatchDir{
	private final WatchService watcher;
	private final Map<WatchKey,Path> keys;
	private boolean trace=false,please_stop=false;
	private TrayIcon trayIcon;

	@SuppressWarnings("unchecked")
	static <T> WatchEvent<T> cast(WatchEvent<?> event){
		return (WatchEvent<T>)event;
	}

	private void register(Path dir) throws IOException{
		WatchKey key=dir.register(watcher,ENTRY_CREATE,ENTRY_DELETE,ENTRY_MODIFY);
		if(trace){
			Path prev=keys.get(key);
			if(prev==null){
				System.out.format("register: %s\n",dir);
			}else{
				if(!dir.equals(prev)){
					System.out.format("update: %s -> %s\n",prev,dir);
				}
			}
		}
		keys.put(key,dir);
	}

	private void registerAll(final Path start) throws IOException{
		Files.walkFileTree(start,new SimpleFileVisitor<Path>(){
			@Override
			public FileVisitResult preVisitDirectory(Path dir,BasicFileAttributes attrs) throws IOException{
				register(dir);
				return FileVisitResult.CONTINUE;
			}
		});
	}

	WatchDir() throws IOException{
		this.watcher=FileSystems.getDefault().newWatchService();
		this.keys=new HashMap<WatchKey,Path>();
		Image image=Toolkit.getDefaultToolkit().getImage(WatchDir.class.getResource("img/logo.png"));
		image=image.getScaledInstance(30,30,Image.SCALE_DEFAULT);
		PopupMenu popup=new PopupMenu();
		MenuItem item=new MenuItem("Stop");
		item.addActionListener((ActionEvent e)->{
			please_stop=true;
		});
		popup.add(item);
		item=new MenuItem("Open FTP in Explorer");
		item.addActionListener((ActionEvent e)->{
			try{
				Runtime.getRuntime().exec("explorer "+Uploader.getFTPPath());
			}catch(IOException e1){}
		});
		popup.add(item);
		trayIcon=new TrayIcon(image,"FTPSync",popup);
		trayIcon.setImageAutoSize(true);
		try{
			SystemTray.getSystemTray().add(trayIcon);
		}catch(AWTException e1){}
		registerAll(Uploader.localBase);
		this.trace=true;
	}

	private class wThread extends Thread{
		WatchKey key;

		@Override
		public void run(){
			try{
				key=watcher.take();
			}catch(InterruptedException x){
				return;
			}
		}

		public WatchKey joinR(int milis) throws InterruptedException{
			super.join(milis);
			return key;
		}
	}

	@SuppressWarnings("rawtypes")
	void processEvents(){
		WatchEvent<Path> ev,last=null;
		while(!please_stop){
			WatchKey key=null;
			wThread t=new wThread();
			t.start();
			try{
				while((key=t.joinR(500))==null){
					if(please_stop){
						System.exit(0);
					}else{
						last=null;
						Thread.yield();
					}
				}
			}catch(InterruptedException e){}
			Path dir=keys.get(key);
			if(dir==null)
				continue;
			for(WatchEvent<?> event:key.pollEvents()){
				WatchEvent.Kind kind=event.kind();
				if(kind==OVERFLOW)
					continue;
				ev=cast(event);
				if(last!=null&&ev.context().equals(last.context())){
					last=ev;
					continue;
				}else{
					last=ev;
				}
				Path name=ev.context();
				Path child=dir.resolve(name);
				if(kind==ENTRY_MODIFY||kind==ENTRY_CREATE){
					if(!Files.isDirectory(child,NOFOLLOW_LINKS)){
						Uploader.upload(child);
						trayIcon.displayMessage("Synchronisiert",Uploader.localBase.relativize(child).toString(),TrayIcon.MessageType.INFO);
					}else{
						try{
							registerAll(child);
						}catch(IOException e){
							e.printStackTrace();
						}
					}
				}else if(kind==ENTRY_DELETE){
					Uploader.delete(child);
					trayIcon.displayMessage("Synchronisiert",Uploader.localBase.relativize(child).toString(),TrayIcon.MessageType.INFO);
				}
			}
			boolean valid=key.reset();
			if(!valid){
				keys.remove(key);
				if(keys.isEmpty()){
					break;
				}
			}
		}
	}

	public static void main(String[] args) throws IOException{
		new WatchDir().processEvents();
	}
}