public FtpClient() 
{

}

Constructor for the FtpClient object.

 public  void connect(String host,
    String username,
    String password) throws Exception 
{
		InetAddress addr = InetAddress.getByName(host);
		s = new Socket(addr, port);
		out = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
		InputStreamReader isr = new InputStreamReader(s.getInputStream());
		in = new BufferedReader(isr);
		send("USER " + username);
		send("PASS " + password);
}

Connect to server.

 public  void disconnect() 
{
		try {
			send("QUIT");
			getResponse();
		} catch (Exception e) {
			log.error("FTP client - ", e);
		}
		try {
			in.close();
			out.close();
			s.close();
		} catch (Exception e) {
			log.error("FTP client - ", e);
		}
}

Disconnect from the server

 public String get(String file) throws Exception 
{
		send("SYST");
		getResponse();
		send("PWD");
		getResponse();
		send("TYPE I");
		getResponse();
		String data = "";
		if (!passive) {
			dataPort++;
			int upper = getUpper(dataPort);
			int lower = getLower(dataPort);
			String ip = InetAddress.getLocalHost().getHostAddress().replace('.', ',');
			String ports = ip + "," + upper + "," + lower;
			log.info("port:" + ports);
			send("PORT " + ports);
			getResponse();
			dataGrabber grab = new dataGrabber(ip, dataPort);
			while (!grab.isPortCreated()) {
			}
			send("RETR " + file);
			String response = in.readLine();
			log.info(response);
			log.info("" + dataPort);
			data = "FTP client - File Not Found";
			if (!response.startsWith("5")) {
				while (!grab.isDone()) {
				}
				data = grab.getData();
			}
		} else {
			send("PASV");
			String portResp = getResponse();
			while (!portResp.startsWith("227")) {
				portResp = getResponse();
			}
			int start = portResp.indexOf('(');
			int end = portResp.indexOf(')');
			portResp = portResp.substring(start + 1, end);
			int a = portResp.indexOf(',');
			int b = portResp.indexOf(',', a + 1);
			int c = portResp.indexOf(',', b + 1);
			int d = portResp.indexOf(',', c + 1);
			int e = portResp.indexOf(',', d + 1);
			String ip = portResp.substring(0, a) + "." + portResp.substring(a + 1, b) + "."
					+ portResp.substring(b + 1, c) + "." + portResp.substring(c + 1, d);
			int upper = Integer.parseInt(portResp.substring(d + 1, e));
			int lower = Integer.parseInt(portResp.substring(e + 1));
			send("RETR " + file);
			dataGrabber grab = new dataGrabber(ip, getPort(upper, lower));
			getResponse();
			while (!grab.isDone()) {
			}
			data = grab.getData();
		}
		return data;
}

Get a file from the server.

 public static int getLower(int lport) 
{
		return lport % 256;
}

Gets the Lower attribute of the FtpClient class.

 public static int getPort(int upper,
    int lower) 
{
		return upper * 256 + lower;
}

Gets the Port attribute of the FtpClient class.

 public String getResponse() throws IOException 
{
		StringBuffer response = new StringBuffer();
		String line = in.readLine();
		response.append(line);
		log.info("FtpClient.getResponse(): #" + line + "#");
		while (line.charAt(3) == '-') {
			line = in.readLine();
			response.append("\n");
			response.append(line);
			log.info("FtpClient.getResponse(): #" + line + "#");
		}
		log.info("return response");
		return response.toString();
}

Get a file from the server.

 public static int getUpper(int lport) 
{
		return lport / 256;
}

Gets the Upper attribute of the FtpClient class.

 public  void send(String command) throws IOException 
{
		for (int i = 0; i <  command.length(); i++) {
			out.write(command.charAt(i));
		}
		out.write('\r');
		out.write('\n');
		out.flush();
}

Send a command to the server.

 public  void setPassive(boolean flag) 
{
		passive = flag;
}

Set passive mode.