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

						data.closeDataServer = true;
						handler.sendClientMsg("551 Error sending file : "+e);
					}
				} else {
					handler.sendClientMsg("451 Sorry, that isn't a data file");
				}
			} else {
				handler.sendClientMsg("425 Sorry no TCP connection was established.");
			}
			data.isTransferring = false;
		} else if(ucCommand.startsWith("STOR")) {
			//STORE 
			args = command.substring("STOR".length()).trim();
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("STOU")) {
			//STORE UNIQUE - The 250 Transfer Started response
			//must include the name generated.
			args = command.substring("STOU".length()).trim();
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("APPE")) {
			//APPEND (with create)
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("ALLO")) {
			//ALLOCATE - obsolete
			handler.sendClientMsg("502 Command not implemented - obsolete.");
		} else if(ucCommand.startsWith("REST")) {
			//RESTART transfer
			//350 ok
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("RNFR")) {
			//RENAME FROM
			data.isRenameFrom = true;
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("RNTO")) {
			//RENAME TO
			if(!data.isRenameFrom) {
				//error should not happen
			}
			data.isRenameFrom = false;
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("DELE")) {
			//DELETE
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("RMD")) {
			//REMOVE DIRECTORY
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("MKD")) {
			//MAKE DIRECTORY
			args = command.substring("MKD".length()).trim();
			temp = MyString.replaceAll(data.root+data.wDir+args,"/","\\");
			temp = MyString.replaceAll(temp,"\\\\","\\");
			File file = new File(temp);
			try	{
				file.mkdir();
				file.canRead();
				temp = file.getAbsolutePath();
				temp = "/"+MyString.replaceAll(temp,data.root,"");
				temp = MyString.replaceAll(temp,"\\","/");
				temp = MyString.replaceAll(temp,"//","/");
				handler.sendClientMsg("257 \""+temp+"\" directory created");
			} catch(Exception e) {
				handler.sendClientMsg("521-Could not create dir \""+args+"\"");
				handler.sendClientMsg("521 Error : "+e);
			}
		} else if(ucCommand.startsWith("CWD")) {
			//CHANGE DIRECTORY
			temp = data.wDir;
			args = command.substring("CWD".length()).trim();
			if(data.wDir.charAt(data.wDir.length()-1)!='/')
				data.wDir += "/";
			if(args.charAt(args.length()-1)!='/')
				args += "/";

			if(args.charAt(0)!='/')
				data.wDir += args;
			else
				data.wDir = args;

			temp = MyString.replaceAll(data.root+data.wDir,"/","\\");
			temp = MyString.replaceAll(temp,"\\\\","\\");
			File file = new File(temp);
			if(file.canRead() && file.isDirectory()) {
				handler.sendClientMsg("250 Directory changed to "+data.wDir);
			} else {
				if(file.canRead())
					handler.sendClientMsg("550 "+data.wDir+": The directory name is invalid.");
				else
					handler.sendClientMsg("550 "+data.wDir+": The system cannot find the file specified .");
				data.wDir = temp;
				logger.logp(Level.FINER, "CommandHandler", "handleCommand",
					"Command=CWD; ERROR : 550 No such directory "+file);
			}
		} else if(ucCommand.startsWith("PWD")) {
			//PRINT WORKING DIRECTORY
			temp = MyString.replaceAll(data.wDir,"\"","\"\"");
			handler.sendClientMsg("257 \""+data.wDir+"\"");
		} else if(ucCommand.startsWith("LIST")) {
			data.isTransferring = true;
			if(ucCommand.equals("LIST")) {
				args = "";
			} else {
				args = command.substring("LIST".length()).trim();
				if(args.equals("-latr")) //not known
					args="";
			}
			temp = MyString.replaceAll(data.root+data.wDir+args,"/","\\");
			temp = MyString.replaceAll(temp,"\\\\","\\");
			File file = new File(temp);
			
			if( file.canRead() ) {
				handler.sendClientMsg("150 Opening data connection for LIST "+data.wDir+args);
				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;
					}			
				}
				String result = winDirList(temp);
				try	{
					data.sendData(result);
					//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) {
					if(data.ip!=null && data.socket!=null)
						data.socket.close();
					data.closeDataServer = true;
					handler.sendClientMsg("551 Error sending LIST : "+e);
				}
			} else {
				handler.sendClientMsg("550 No such directory : "+data.wDir+args);
				logger.logp(Level.FINER, "CommandHandler", "handleCommand",
					"Command=LIST; ERROR : 550 No such directory "+file);
			}
			data.isTransferring = false;
		} else if(ucCommand.startsWith("NLST")) {
			//NAME LIST of directory only
			data.isTransferring = true;
			if(ucCommand.equals("NLST")) {
				args = "";
			} else {
				args = command.substring("NLST".length()).trim();
			}
			temp = MyString.replaceAll(data.root+data.wDir+args,"/","\\");
			temp = MyString.replaceAll(temp,"\\\\","\\");
			File file = new File(temp);
			String result = "";
			if( file.canRead() && file.isDirectory() ) {
				handler.sendClientMsg("150 Opening data connection for LIST "+data.wDir+args);
				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;
					}			
				}
				String list[] = file.list();
				for(int i=0;i<list.length;i++) {
					if(!list[i].equals(".") && !list[i].equals("..") )
						result +=list[i]+"\r\n";
				}
				try	{
					data.sendData(result);
					//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) {
					if(data.ip!=null && data.socket!=null)
						data.socket.close();
					data.closeDataServer = true;
					handler.sendClientMsg("551 Error sending NLST : "+e);
				}
			} else {
				handler.sendClientMsg("550 No such directory : "+data.wDir+args);
				logger.logp(Level.FINER, "CommandHandler", "handleCommand",
					"Command=NLST; ERROR : 550 No such directory "+file);
			}
			data.isTransferring = false;
		} else if(ucCommand.startsWith("SITE")) {
			//SITE PARAMETERS
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("SYST")) {
			//SYSTEM - Assigned Numbers document [4]
			// UNIX Type: L8
			handler.sendClientMsg("215 "+"Windows_NT version 5.0");
		} else if(ucCommand.startsWith("HELP")) {
			//HELP
			//The reply is type 211 or 214.
			handler.sendClientMsg("502 Command not implemented.");
		} else if(ucCommand.startsWith("NOOP")) {
			//NOOP - OK reply
			handler.sendClientMsg("200 OK");
		} else if(ucCommand.startsWith("SIZE")) {
			//SIZE OF FILE
			args = command.substring("SIZE".length()).trim();
			temp = MyString.replaceAll(data.root+data.wDir+args,"/","\\");
			temp = MyString.replaceAll(temp,"\\\\","\\");
			File file = new File(temp);
			if( file.canRead() ) {
				handler.sendClientMsg("213 "+file.length());
			} else {
				handler.sendClientMsg("550 No such file.");
			}
		} else {
			//ERROR
			handler.sendClientMsg("500 Syntax error, command unrecognized.");
		}
	}

	// helper meethods
	private String dirList(String dir) {
		//+FACTS1,FACTS@..,FACTN\tfile_name\r\n
		/*
			FACE = xy
		   >X<
			r -> File
			/ -> Dir
			s ->Size, y=size in bytes
			m ->Modified since 1970
			i ->This file has identifier y. 
			up->Chmode is allowed
		*/
		File file = new File(dir);
		File subFile = null;
		String result = "";
		if( file.canRead() ) {
			String list[] = file.list();
			for(int i=0;i<list.length;i++) {
				//if(list[i].equals(".") || list[i].equals("..") )
				//	continue;
				subFile = new File(dir+File.separator+list[i]);
				result += "+";
				result +="i"+subFile.hashCode()+",";
				result +="s"+subFile.length()+",";
				result +="m"+subFile.lastModified()+",";
				if(subFile.isFile()) {
					result +="r,";
				} else {
					result +="/,";
				}
				result +="\t"+list[i]+"\r\n";
			}
		}
		return result;
	}

	private String winDirList(String dir) {
		File file = new File(dir);
		File subFile = null;
		String result = "";
		if( file.canRead() ) {
			String list[] = file.list();
			for(int i=0;i<list.length;i++) {
				subFile = new File(dir+File.separator+list[i]);
				SimpleDateFormat dformat = 
					new SimpleDateFormat("MM-dd-yy  HH:mm:a ");
				result += dformat.format(new Date(subFile.lastModified()));
				if(subFile.isFile()) {
					//20 field length
					StringBuffer size = new StringBuffer(20);
					size.append(subFile.length());
					while(size.length()<20) {
						size.insert(0," ");
					}
					result += size.toString();
				} else {
					result +="      <DIR>         ";
				}
				result +=" "+list[i]+"\r\n";
			}
		}
		return result;
	}
}