commandhandler.java

一个用java编写的服务器,对于学习网络编程的人来说是个很好的例子

/*
 * This file is part of the QuickServer library 
 * Copyright (C) 2003-2005 QuickServer.org
 *
 * Use, modification, copying and distribution of this software is subject to
 * the terms and conditions of the GNU Lesser General Public License. 
 * You should have received a copy of the GNU LGP License along with this 
 * library; if not, you can download a copy from <http://www.quickserver.org/>.
 *
 * For questions, suggestions, bug-reports, enhancement-requests etc.
 * visit http://www.quickserver.org
 *
 */

package ftpserver;

import org.quickserver.net.server.ClientCommandHandler;
import org.quickserver.net.server.ClientHandler;

import java.net.*;
import java.io.*;
import java.util.StringTokenizer;
import org.quickserver.util.*;
import java.text.*;
import java.util.Date;
import java.util.logging.*;

/**
 * IMPORTANT NOTE: This example just demonstrates how to use some 
 * of the QuickServer features. This example not built keeping 
 * security in mind. 
 */
public class CommandHandler implements ClientCommandHandler {
	private static Logger logger = 
		Logger.getLogger(CommandHandler.class.getName());

	public void gotConnected(ClientHandler handler)
		throws SocketTimeoutException, IOException {
		handler.sendSystemMsg("Connection opened : "+
			handler.getSocket().getInetAddress(), Level.FINE);

		handler.sendClientMsg("220-     QuickFTPServer v 0.1   ");
		handler.sendClientMsg("220- Developed using QuickServer");
		handler.sendClientMsg("220 ");
		//send feature supported msg
		//handler.sendClientMsg("220 Features: a p .");
	}

	public void lostConnection(ClientHandler handler) throws IOException {
		logger.fine("Connection lost : "+
			handler.getSocket().getInetAddress());
	}
	public void closingConnection(ClientHandler handler) throws IOException {
		logger.fine("Connection closed: " + 
			handler.getSocket().getInetAddress());
	}

	public void handleCommand(ClientHandler handler, String command)
			throws SocketTimeoutException, IOException {
		Data data = (Data)handler.getClientData();
		command = command.trim();
		String ucCommand = command.toUpperCase();
		String args = null;
		String temp = null;
		
		logger.fine("Got command : " + command);

		if(ucCommand.equals("QUIT")) {
			//LOGOUT 
			data.wasQuit = true;
			handler.sendClientMsg("221 Logged out.");
			handler.closeConnection();
			return;
		} else if(ucCommand.endsWith("ABOR")) {
			//ABORT
			data.isStop = true;
			//close data connection
			//handler.sendClientMsg("502 Command not implemented.");
			handler.sendClientMsg("220 OK");
			return;
		} else if(ucCommand.startsWith("STAT")) {
			//STATUS
			handler.sendClientMsg("211- QuickFTPServer");
			handler.sendClientMsg(" Version 0.1 ");
			handler.sendClientMsg(" Connected to " + 
				handler.getSocket().getInetAddress());
			handler.sendClientMsg(" Logged in as "+data.username);
			handler.sendClientMsg(" Cur Dir : "+data.wDir);
			handler.sendClientMsg(" Data connection : "+
				data.isTransferring);
			handler.sendClientMsg("211 End of status");
			return;
		}
		
		///////////// now check if only not processing ///////
		if(data.isProcessing==true) {
			handler.sendClientMsg("503 Bad sequence of commands; another command is being processed.");
			return;
		}
		/////////// ACCESS CONTROL COMMANDS /////////
		if(ucCommand.equals("REIN")) {
			//REINITIALIZE
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("ACCT")) {
			//ACCOUNT
			args = command.substring("ACCT".length()).trim();
			data.account = args;
			handler.sendClientMsg("230 Account OK.");
		} else if(ucCommand.equals("CDUP")) {
			//CHANGE TO PARENT DIRECTORY 
			int i = data.wDir.lastIndexOf("/");
			String temp_wDir = null;
			if(i!=-1) {
				temp_wDir = data.wDir.substring(0,i);
				if(temp_wDir.equals(""))
					temp_wDir = "/";
				else
					temp_wDir += "/"; //end
				temp = MyString.replaceAll(data.root+temp_wDir,"/","\\");
				temp = MyString.replaceAll(temp,"\\\\","\\");
				File file = new File(temp);
				if(	file.canRead() ){
					data.wDir = temp_wDir;
					handler.sendClientMsg("250 Okay");
				} else {
					handler.sendClientMsg("550 No parent dir");
				}
			} else {
				handler.sendClientMsg("550 No parent dir");
			}
		} else if(ucCommand.startsWith("SMNT")) {
			//STRUCTURE MOUNT 
			handler.sendClientMsg("502 Command not implemented.");
		} 
		///////// TRANSFER PARAMETER COMMANDS ////////
		 else if(ucCommand.startsWith("PORT")) {
			/*
            PORT h1,h2,h3,h4,p1,p2
			*/
			args = command.substring("PORT".length()).trim();
			String ipAddr = "";
			int port = 0;
			StringTokenizer st = new StringTokenizer(args,",");
			int p1 = 0;
			int p2 = 0;
			try	{
				ipAddr+=st.nextToken()+".";	
				ipAddr+=st.nextToken()+".";	
				ipAddr+=st.nextToken()+".";	
				ipAddr+=st.nextToken();	
				p1 = Integer.parseInt(st.nextToken());
				p2 = Integer.parseInt(st.nextToken());
				port = p1*256+p2;
				data.ip = ipAddr;
				data.socketPort = port;
				handler.sendClientMsg("200 Command okay.");
			} catch (Exception e)	{
				handler.sendClientMsg("501 Syntax error in parameters or arguments. : PORT "+e);
			}			
		} else if(ucCommand.startsWith("PASV")) {
			/*
			PASSIVE
			This command requests the server-DTP to "listen" on a data
            port (which is not its default data port) and to wait for a
            connection rather than initiate one upon receipt of a
            transfer command.  The response to this command includes the
            host and port address this server is listening on.
			PORT = p1*256+p2
			p1 = PORT / 256
			p2 = PORT - p1*256
			*/
			//227 =127,0,0,1,10,5

			//reset for PORT
			data.ip = null;

			try	{
				InetAddress ipAddr = handler.getSocket().getLocalAddress();
				String ip_port ="";
				StringTokenizer st = 
					new StringTokenizer(ipAddr.getHostAddress(),".");
				while (st.hasMoreTokens()) {
					ip_port+=st.nextToken()+",";
				}
				data.server = new ServerSocket(0,1,ipAddr);
				data.serverPort = data.server.getLocalPort();
				int p1 = data.serverPort / 256;
				int p2 = data.serverPort - p1*256;
				ip_port += p1+","+p2;
				data.startDataServer(data.server,data); //start server
				handler.sendClientMsg("227 ="+ip_port);
			} catch(Exception e){
				handler.sendClientMsg("425 Can't open data port; Error : "+e);
			}
		} else if(ucCommand.startsWith("TYPE")) {
			/*
			REPRESENTATION TYPE 
			             \    /
               A - ASCII |    | N - Non-print
                         |-><-| T - Telnet format effectors
               E - EBCDIC|    | C - Carriage Control (ASA)
                         /    \
               I - Image
               
               L <byte size> - Local byte Byte size
			*/
			args = command.substring("TYPE".length()).trim();
			if(args.equals("A")) {
				data.binary = false;
				data.type = 'A';
				data.typeSub = 'Z';
			} else if(args.equals("A N")) {
				data.binary = false;
				data.type = 'A';
				data.typeSub = 'N';
			} else if(args.equals("I")) {
				data.binary = true;
				data.type = 'I';
				data.typeSub = 'Z';
			} else if(args.equals("L 8")) {
				data.binary = true;
				//data.type = 'A';
				//data.typeSub = 'N';
			} else {
				handler.sendClientMsg("501 Syntax error in parameters.");
				return;
			}
			handler.sendClientMsg("200 Command OK.");
		} else if(ucCommand.startsWith("STRU")) {
			/*
			FILE STRUCTURE
	 		   F - File (no record structure) - default
               R - Record structure
               P - Page structure
			*/
			if(ucCommand.equals("STRU F")) {
				handler.sendClientMsg("200 Command OK.");
			} else {
				//obsolete
				handler.sendClientMsg("504 Command not implemented for that parameter.");
			}
		} else if(ucCommand.startsWith("MODE")) {
			/*
			TRANSFER MODE
			   S - Stream - Default
               B - Block
               C - Compressed
			*/
			if(ucCommand.equals("MODE S")) {
				handler.sendClientMsg("200 Command OK.");
			} else {
				//obsolete
				handler.sendClientMsg("504 Command not implemented for that parameter.");
			}
		}
		/////// FTP SERVICE COMMANDS ///////
		else if(ucCommand.startsWith("RETR")) {
			data.isTransferring = true;
			//RETRIEVE
			args = command.substring("RETR".length()).trim();
			String sfile = "";
			//check if NOT PASSIVE, i.e PORT was set
			if(data.ip!=null) {
				try	{
					data.socket = new Socket(
						InetAddress.getByName(data.ip),	data.socketPort);
				} catch (Exception e)	{
					handler.sendClientMsg("425 Can't open data connection.");
					data.isTransferring = false;
					return;
				}			
			}
			if(data.socket != null) {
				if(args.charAt(0)=='/') {
					sfile = data.root + args;
				} else {
					sfile = data.root + data.wDir + "/" + args;
				}
				temp = MyString.replaceAll(sfile,"/","\\");
				temp = MyString.replaceAll(temp,"\\\\","\\");
				File file = new File(temp);
				if(file.canRead() && file.isFile()) {
					handler.sendClientMsg("150 I see that file.");
					//send file
					try	{
						data.sendFile(temp);
						//close data connection when done
						if(data.ip!=null)
							data.socket.close();
						data.closeDataServer = true;
						if(data.isStop==false)
							handler.sendClientMsg("226 File transferred successfully.");
						else
							handler.sendClientMsg("551 Error sending file : User Aborted");
					} catch (Exception e) {