package FtpServer;import java.net.Socket;import java.net.ServerSocket;import java.net.InetAddress;import java.io.InputStream;import java.io.OutputStream;import java.io.FileInputStream;import java.io.IOException;import java.io.File;import java.awt.event.*;import java.net.*;public class FtpServer{	public static final String rootDir = System.getProperty("user.dir") + File.separator  + "ftproot";	//default ftp directory	private final int ftpPort = 21;	private final String username = "test";	private final String password = "test";	public static void main(String[] args)  {    	FtpServer server = new FtpServer();	}	public FtpServer() {		start();	}	public void start() {		System.out.println("My Ftp Sever Starting...");		ServerSocket serverSocket = null;    	try {			serverSocket =  new ServerSocket(ftpPort, 1);    	}    	catch (IOException e) {      		e.printStackTrace();      		System.exit(1);    	}		System.out.println("sever started");		    // Loop waiting for a request		while (true) {			Socket socket = null;			InputStream input = null;			OutputStream output = null;			try {				socket = serverSocket.accept();				System.out.println("receive a new request");				input = socket.getInputStream();				output = socket.getOutputStream();					// create Request object and parse				Request request = new Request(input);					// create Response object				Response response = new Response(output);				response.setRequest(request);				response.setWorkingDir(rootDir);									response.sendEventMsg(Response.WELCOME);		// send welcome massage				request.getMsg();								// get user name				if (request.getRequestType() != Request.LOGIN_USER) {					response.sendEventMsg(Response.ERROR_CMD);					socket.close();					continue;									}				response.sendEventMsg(Response.GET_PSW);		// get user password				request.getMsg();				if (request.getRequestType() != Request.LOGIN_PASS) {					response.sendEventMsg(Response.ERROR_CMD);					socket.close();					continue;									}				if (!request.getUser().equals(username) || !request.getPsw().equals(password)) {	// user password uncorrect					response.sendEventMsg(Response.PSW_ERROR);					socket.close();					continue;									}				response.sendEventMsg(Response.LOGIN_SUCC);	// login								while(request.getRequestType()!=Request.LOGOUT) {					request.getMsg();					response.sendEventMsg(request.getRequestType());	    		}        		// Close the socket        		socket.close();      		}      		catch (Exception e) {        		e.printStackTrace();        		try {        			if (!socket.isClosed()) socket.close();        		}catch (Exception e2) {}        		continue;      		}    	}  	}}