让我使用非常有用的 Apache FtpServer 为您编写一个基本示例：
FtpServerFactory serverFactory = new FtpServerFactory();ListenerFactory factory = new ListenerFactory();factory.setPort(1234);// set the port of the listener (choose your desired port, not 1234)serverFactory.addListener("default", factory.createListener());PropertiesUserManagerFactory userManagerFactory = new PropertiesUserManagerFactory();userManagerFactory.setFile(new File("/home/blablah/myusers.properties"));//choose any. We're telling the FTP-server where to read its user listuserManagerFactory.setPasswordEncryptor(new PasswordEncryptor(){//We store clear-text passwords in this example @Override public String encrypt(String password) { return password; } @Override public boolean matches(String passwordToCheck, String storedPassword) { return passwordToCheck.equals(storedPassword); } }); //Let's add a user, since our myusers.properties file is empty on our first test run baseUser user = new baseUser(); user.setName("test"); user.setPassword("test"); user.setHomeDirectory("/home/blablah"); List<Authority> authorities = new ArrayList<Authority>(); authorities.add(new WritePermission()); user.setAuthorities(authorities); UserManager um = userManagerFactory.createUserManager(); try { um.save(user);//Save the user to the user list on the filesystem } catch (FtpException e1) { //Deal with exception as you need } serverFactory.setUserManager(um); Map<String, Ftplet> m = new HashMap<String, Ftplet>(); m.put("miaFtplet", new Ftplet() { @Override public void init(FtpletContext ftpletContext) throws FtpException { //System.out.println("init"); //System.out.println("Thread #" + Thread.currentThread().getId()); } @Override public void destroy() { //System.out.println("destroy"); //System.out.println("Thread #" + Thread.currentThread().getId()); } @Override public FtpletResult beforeCommand(FtpSession session, FtpRequest request) throws FtpException, IOException { //System.out.println("beforeCommand " + session.getUserArgument() + " : " + session.toString() + " | " + request.getArgument() + " : " + request.getCommand() + " : " + request.getRequestLine()); //System.out.println("Thread #" + Thread.currentThread().getId()); //do something return FtpletResult.DEFAULT;//...or return accordingly } @Override public FtpletResult afterCommand(FtpSession session, FtpRequest request, FtpReply reply) throws FtpException, IOException { //System.out.println("afterCommand " + session.getUserArgument() + " : " + session.toString() + " | " + request.getArgument() + " : " + request.getCommand() + " : " + request.getRequestLine() + " | " + reply.getMessage() + " : " + reply.toString()); //System.out.println("Thread #" + Thread.currentThread().getId()); //do something return FtpletResult.DEFAULT;//...or return accordingly } @Override public FtpletResult onConnect(FtpSession session) throws FtpException, IOException { //System.out.println("onConnect " + session.getUserArgument() + " : " + session.toString()); //System.out.println("Thread #" + Thread.currentThread().getId()); //do something return FtpletResult.DEFAULT;//...or return accordingly } @Override public FtpletResult onDisconnect(FtpSession session) throws FtpException, IOException { //System.out.println("onDisconnect " + session.getUserArgument() + " : " + session.toString()); //System.out.println("Thread #" + Thread.currentThread().getId()); //do something return FtpletResult.DEFAULT;//...or return accordingly } }); serverFactory.setFtplets(m); //Map<String, Ftplet> mappa = serverFactory.getFtplets(); //System.out.println(mappa.size()); //System.out.println("Thread #" + Thread.currentThread().getId()); //System.out.println(mappa.toString()); FtpServer server = serverFactory.createServer(); try { server.start();//Your FTP server starts listening for incoming FTP-connections, using the configuration options previously set } catch (FtpException ex) { //Deal with exception as you need }请注意，在服务器端，您不必手动处理连接，登录等：Ftplet会为您完成此操作。
不过，您可以在匿名内部Ftplet类的覆盖方法中添加自定义的预处理过程（使用实例化时）
new Ftplet(){ ... }。
