Don’t store connection status anymore.
[xudocci.git] / src / main / java / net / pterodactylus / irc / Connection.java
1 /*
2  * XdccDownloader - Connection.java - Copyright © 2013 David Roden
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 3 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 package net.pterodactylus.irc;
19
20 import static com.google.common.base.Preconditions.checkState;
21 import static java.util.Arrays.asList;
22 import static java.util.concurrent.TimeUnit.SECONDS;
23
24 import java.io.BufferedReader;
25 import java.io.Closeable;
26 import java.io.EOFException;
27 import java.io.IOException;
28 import java.io.InputStream;
29 import java.io.InputStreamReader;
30 import java.io.OutputStream;
31 import java.io.UnsupportedEncodingException;
32 import java.net.InetAddress;
33 import java.net.Socket;
34 import java.net.UnknownHostException;
35 import java.util.ArrayList;
36 import java.util.List;
37 import java.util.Map;
38 import java.util.Set;
39 import java.util.concurrent.TimeUnit;
40 import java.util.concurrent.atomic.AtomicBoolean;
41
42 import javax.net.SocketFactory;
43
44 import net.pterodactylus.irc.connection.ChannelNotJoinedHandler;
45 import net.pterodactylus.irc.connection.ConnectionEstablishHandler;
46 import net.pterodactylus.irc.connection.Handler;
47 import net.pterodactylus.irc.event.ChannelJoined;
48 import net.pterodactylus.irc.event.ChannelLeft;
49 import net.pterodactylus.irc.event.ChannelMessageReceived;
50 import net.pterodactylus.irc.event.ChannelNicknames;
51 import net.pterodactylus.irc.event.ChannelNotJoined;
52 import net.pterodactylus.irc.event.ChannelNotJoined.Reason;
53 import net.pterodactylus.irc.event.ChannelNoticeReceived;
54 import net.pterodactylus.irc.event.ChannelTopic;
55 import net.pterodactylus.irc.event.ClientQuit;
56 import net.pterodactylus.irc.event.ConnectionClosed;
57 import net.pterodactylus.irc.event.ConnectionEstablished;
58 import net.pterodactylus.irc.event.ConnectionFailed;
59 import net.pterodactylus.irc.event.DccAcceptReceived;
60 import net.pterodactylus.irc.event.DccSendReceived;
61 import net.pterodactylus.irc.event.KickedFromChannel;
62 import net.pterodactylus.irc.event.MotdReceived;
63 import net.pterodactylus.irc.event.NicknameChanged;
64 import net.pterodactylus.irc.event.NicknameInUseReceived;
65 import net.pterodactylus.irc.event.NoNicknameGivenReceived;
66 import net.pterodactylus.irc.event.PrivateMessageReceived;
67 import net.pterodactylus.irc.event.PrivateNoticeReceived;
68 import net.pterodactylus.irc.event.ReplyReceived;
69 import net.pterodactylus.irc.event.UnknownReplyReceived;
70 import net.pterodactylus.irc.util.RandomNickname;
71 import net.pterodactylus.xdcc.util.io.BandwidthCountingInputStream;
72 import net.pterodactylus.xdcc.util.io.BandwidthCountingOutputStream;
73
74 import com.google.common.base.Optional;
75 import com.google.common.collect.Maps;
76 import com.google.common.collect.Sets;
77 import com.google.common.eventbus.EventBus;
78 import com.google.common.eventbus.Subscribe;
79 import com.google.common.io.Closeables;
80 import com.google.common.primitives.Ints;
81 import com.google.common.primitives.Longs;
82 import com.google.common.util.concurrent.AbstractExecutionThreadService;
83 import com.google.common.util.concurrent.Service;
84 import org.apache.log4j.Logger;
85
86 /**
87  * A connection to an IRC server.
88  *
89  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
90  */
91 public class Connection extends AbstractExecutionThreadService implements Service {
92
93         /* The logger. */
94         private static final Logger logger = Logger.getLogger(Connection.class.getName());
95
96         /** The event bus. */
97         private final EventBus eventBus;
98
99         /** The socket factory. */
100         private final SocketFactory socketFactory;
101
102         /** The hostname to connect to. */
103         private final String hostname;
104
105         /** The port to connect to. */
106         private final int port;
107
108         /** The nickname chooser. */
109         private NicknameChooser nicknameChooser = new NicknameChooser() {
110
111                 @Override
112                 public String getNickname() {
113                         return RandomNickname.get();
114                 }
115         };
116
117         /** The nickname. */
118         private String nickname = null;
119
120         /** The username. */
121         private Optional<String> username = Optional.absent();
122
123         /** The real name. */
124         private Optional<String> realName = Optional.absent();
125
126         /** The optional password for the connection. */
127         private Optional<String> password = Optional.absent();
128
129         /** The connection handler. */
130         private ConnectionHandler connectionHandler;
131
132         /** Whether the connection has already been established. */
133         private final AtomicBoolean established = new AtomicBoolean();
134
135         /**
136          * Creates a new connection.
137          *
138          * @param eventBus
139          *              The event bus
140          * @param socketFactory
141          *              The socket factory
142          * @param hostname
143          *              The hostname of the IRC server
144          * @param port
145          *              The port number of the IRC server
146          */
147         public Connection(EventBus eventBus, SocketFactory socketFactory, String hostname, int port) {
148                 this.eventBus = eventBus;
149                 this.socketFactory = socketFactory;
150                 this.hostname = hostname;
151                 this.port = port;
152         }
153
154         //
155         // ACCESSORS
156         //
157
158         /**
159          * Returns the hostname of the remote end of the connection.
160          *
161          * @return The remote’s hostname
162          */
163         public String hostname() {
164                 return hostname;
165         }
166
167         /**
168          * Returns the port number of the remote end of the connection.
169          *
170          * @return The remote’s port number
171          */
172         public int port() {
173                 return port;
174         }
175
176         /**
177          * Returns whether this connection has already been established.
178          *
179          * @return {@code true} as long as this connection is established, {@code
180          *         false} otherwise
181          */
182         public boolean established() {
183                 return established.get();
184         }
185
186         /**
187          * Returns the nickname that is currently in use by this connection. The
188          * nickname is only available once the connection has been {@link #start()}ed.
189          *
190          * @return The current nickname
191          */
192         public String nickname() {
193                 return nickname;
194         }
195
196         //
197         // MUTATORS
198         //
199
200         /**
201          * Sets the nickname chooser. The nickname chooser is only used during the
202          * creation of the connection.
203          *
204          * @param nicknameChooser
205          *              The nickname chooser
206          * @return This connection
207          */
208         public Connection nicknameChooser(NicknameChooser nicknameChooser) {
209                 this.nicknameChooser = nicknameChooser;
210                 return this;
211         }
212
213         /**
214          * Sets the username to use.
215          *
216          * @param username
217          *              The username to use
218          * @return This connection
219          */
220         public Connection username(String username) {
221                 this.username = Optional.fromNullable(username);
222                 return this;
223         }
224
225         /**
226          * Sets the real name to use.
227          *
228          * @param realName
229          *              The real name to use
230          * @return This connection
231          */
232         public Connection realName(String realName) {
233                 this.realName = Optional.fromNullable(realName);
234                 return this;
235         }
236
237         /**
238          * Sets the optional password for the connection.
239          *
240          * @param password
241          *              The password for the connection
242          * @return This connection
243          */
244         public Connection password(String password) {
245                 this.password = Optional.fromNullable(password);
246                 return this;
247         }
248
249         //
250         // ACTIONS
251         //
252
253         /**
254          * Returns the current rate of the connection’s incoming side.
255          *
256          * @return The current input rate (in bytes per second)
257          */
258         public long getInputRate() {
259                 return (connectionHandler != null) ? connectionHandler.getInputRate() : 0;
260         }
261
262         /**
263          * Returns the current rate of the connection’s outgoing side.
264          *
265          * @return The current output rate (in bytes per second)
266          */
267         public long getOutputRate() {
268                 return (connectionHandler != null) ? connectionHandler.getOutputRate() : 0;
269         }
270
271         /**
272          * Checks whether the given source is the client represented by this
273          * connection.
274          *
275          * @param source
276          *              The source to check
277          * @return {@code true} if this connection represents the given source, {@code
278          *         false} otherwise
279          */
280         public boolean isSource(Source source) {
281                 return source.nick().isPresent() && source.nick().get().equals(nickname);
282         }
283
284         /**
285          * Joins the given channel.
286          *
287          * @param channel
288          *              The channel to join
289          * @throws IOException
290          *              if an I/O error occurs
291          */
292         public void joinChannel(final String channel) throws IOException {
293                 connectionHandler.sendCommand("JOIN", channel);
294         }
295
296         /**
297          * Sends a message to the given recipient, which may be a channel or another
298          * nickname.
299          *
300          * @param recipient
301          *              The recipient of the message
302          * @param message
303          *              The message
304          * @throws IOException
305          *              if an I/O error occurs
306          */
307         public void sendMessage(String recipient, String message) throws IOException {
308                 connectionHandler.sendCommand("PRIVMSG", recipient, message);
309         }
310
311         /**
312          * Sends a DCC RESUME request to the given recipient.
313          *
314          * @param recipient
315          *              The recipient of the request
316          * @param filename
317          *              The name of the file to resume
318          * @param port
319          *              The port number from the original DCC SEND request
320          * @param position
321          *              The position at which to resume the transfer
322          * @throws IOException
323          *              if an I/O error occurs
324          */
325         public void sendDccResume(String recipient, String filename, int port, long position) throws IOException {
326                 connectionHandler.sendCommand("PRIVMSG", recipient, String.format("\u0001DCC RESUME %s %d %d\u0001", filename, port, position));
327         }
328
329         /**
330          * Closes this connection.
331          *
332          * @throws IOException
333          *              if an I/O error occurs
334          */
335         public void close() throws IOException {
336                 if (connectionHandler != null) {
337                         connectionHandler.close();
338                 }
339         }
340
341         //
342         // ABSTRACTEXECUTIONTHREADSERVICE METHODS
343         //
344
345         @Override
346         protected void startUp() throws IllegalStateException {
347                 checkState(username.isPresent(), "username must be set");
348                 checkState(realName.isPresent(), "realName must be set");
349         }
350
351         @Override
352         protected void run() {
353
354                 /* connect to remote socket. */
355                 try {
356                         Socket socket = socketFactory.createSocket(hostname, port);
357                         socket.setSoTimeout((int) TimeUnit.MINUTES.toMillis(3));
358                         connectionHandler = new ConnectionHandler(socket.getInputStream(), socket.getOutputStream());
359
360                         /* register connection. */
361                         if (password.isPresent()) {
362                                 connectionHandler.sendCommand("PASSWORD", password.get());
363                         }
364                         connectionHandler.sendCommand("USER", username.get(), "8", "*", realName.get());
365                         nickname = nicknameChooser.getNickname();
366                         connectionHandler.sendCommand("NICK", nickname);
367
368                 } catch (IOException ioe1) {
369                         eventBus.post(new ConnectionFailed(this, ioe1));
370                         return;
371                 }
372
373                 eventBus.register(this);
374                 /* now read replies and react. */
375                 try {
376                         /* some status variables. */
377                         boolean connected = true;
378                         StringBuilder motd = new StringBuilder();
379                         Set<Nickname> nicks = Sets.newHashSet();
380
381                         /* server modes. */
382                         Map<String, String> nickPrefixes = Maps.newHashMap();
383                         Set<Character> channelTypes = Sets.newHashSet();
384
385                         List<Handler> handlers = asList(
386                                         new ConnectionEstablishHandler(eventBus, this),
387                                         new ChannelNotJoinedHandler(eventBus, this)
388                         );
389
390                         while (connected) {
391                                 Reply reply = connectionHandler.readReply();
392                                 eventBus.post(new ReplyReceived(this, reply));
393                                 logger.trace(String.format("<< %s", reply));
394                                 String command = reply.command();
395                                 List<String> parameters = reply.parameters();
396
397                                 for (Handler handler : handlers) {
398                                         if (handler.willHandle(reply)) {
399                                                 handler.handleReply(reply);
400                                                 break;
401                                         }
402                                 }
403
404                                 /* most common events. */
405                                 if (command.equalsIgnoreCase("PRIVMSG")) {
406                                         String recipient = parameters.get(0);
407                                         String message = parameters.get(1);
408                                         if (message.startsWith("\u0001") && message.endsWith("\u0001")) {
409                                                 /* CTCP! */
410                                                 handleCtcp(reply.source().get(), message);
411                                         } else if (!channelTypes.contains(recipient.charAt(0))) {
412                                                 eventBus.post(new PrivateMessageReceived(this, reply.source().get(), message));
413                                         } else {
414                                                 eventBus.post(new ChannelMessageReceived(this, recipient, reply.source().get(), message));
415                                         }
416
417                                 } else if (command.equalsIgnoreCase("NOTICE")) {
418                                         String recipient = parameters.get(0);
419                                         String message = parameters.get(1);
420                                         if (message.startsWith("\u0001") && message.endsWith("\u0001")) {
421                                                 /* CTCP! */
422                                                 handleCtcp(reply.source().get(), message);
423                                         } else if (!channelTypes.contains(recipient.charAt(0))) {
424                                                 eventBus.post(new PrivateNoticeReceived(this, reply));
425                                         } else {
426                                                 eventBus.post(new ChannelNoticeReceived(this, reply.source().get(), recipient, message));
427                                         }
428
429                                 /* 43x replies are for nick change errors. */
430                                 } else if (command.equals("431")) {
431                                         eventBus.post(new NoNicknameGivenReceived(this, reply));
432                                 } else if (command.equals("433")) {
433                                         if (!established.get()) {
434                                                 nickname = nicknameChooser.getNickname();
435                                                 connectionHandler.sendCommand("NICK", nickname);
436                                         } else {
437                                                 eventBus.post(new NicknameInUseReceived(this, reply));
438                                         }
439
440                                 /* client stuff. */
441                                 } else if (command.equalsIgnoreCase("NICK")) {
442                                         eventBus.post(new NicknameChanged(this, reply.source().get(), parameters.get(0)));
443
444                                 /* channel stuff. */
445                                 } else if (command.equalsIgnoreCase("JOIN")) {
446                                         eventBus.post(new ChannelJoined(this, parameters.get(0), reply.source().get()));
447                                 } else if (command.equals("331")) {
448                                         /* no topic is set. */
449                                 } else if (command.equals("332")) {
450                                         eventBus.post(new ChannelTopic(this, parameters.get(1), parameters.get(2)));
451                                 } else if (command.equals("353")) {
452                                         for (String nickname : parameters.get(3).split(" ")) {
453                                                 if (nickPrefixes.containsKey(nickname.substring(0, 1))) {
454                                                         nicks.add(new Nickname(nickname.substring(1), nickname.substring(0, 1)));
455                                                 } else {
456                                                         nicks.add(new Nickname(nickname, ""));
457                                                 }
458                                         }
459                                 } else if (command.equals("366")) {
460                                         eventBus.post(new ChannelNicknames(this, parameters.get(1), nicks));
461                                         nicks.clear();
462                                 } else if (command.equalsIgnoreCase("PART")) {
463                                         eventBus.post(new ChannelLeft(this, parameters.get(0), reply.source().get(), getOptional(parameters, 1)));
464                                 } else if (command.equalsIgnoreCase("QUIT")) {
465                                         eventBus.post(new ClientQuit(this, reply.source().get(), parameters.get(0)));
466
467                                 /* basic connection housekeeping. */
468                                 } else if (command.equalsIgnoreCase("PING")) {
469                                         connectionHandler.sendCommand("PONG", getOptional(parameters, 0), getOptional(parameters, 1));
470
471                                 /* 005 originally was a bounce message, now used to transmit useful information about the server. */
472                                 } else if (command.equals("005")) {
473                                         for (String parameter : parameters) {
474                                                 if (parameter.startsWith("PREFIX=")) {
475                                                         int openParen = parameter.indexOf('(');
476                                                         int closeParen = parameter.indexOf(')');
477                                                         if ((openParen != -1) && (closeParen != -1)) {
478                                                                 for (int modeCharacterIndex = 1; modeCharacterIndex < (closeParen - openParen); ++modeCharacterIndex) {
479                                                                         char modeCharacter = parameter.charAt(openParen + modeCharacterIndex);
480                                                                         char modeSymbol = parameter.charAt(closeParen + modeCharacterIndex);
481                                                                         nickPrefixes.put(String.valueOf(modeSymbol), String.valueOf(modeCharacter));
482                                                                 }
483                                                                 logger.debug(String.format("Parsed Prefixes: %s", nickPrefixes));
484                                                         }
485                                                 } else if (parameter.startsWith("CHANTYPES=")) {
486                                                         for (int typeIndex = 10; typeIndex < parameter.length(); ++typeIndex) {
487                                                                 channelTypes.add(parameter.charAt(typeIndex));
488                                                         }
489                                                         logger.debug(String.format("Parsed Channel Types: %s", channelTypes));
490                                                 }
491                                         }
492
493                                 /* 375, 372, and 376 handle the server’s MOTD. */
494                                 } else if (command.equals("375")) {
495                                         /* MOTD starts. */
496                                         motd.append(parameters.get(1)).append('\n');
497                                 } else if (command.equals("372")) {
498                                         motd.append(parameters.get(1)).append('\n');
499                                 } else if (command.equals("376")) {
500                                         motd.append(parameters.get(1)).append('\n');
501                                         eventBus.post(new MotdReceived(this, motd.toString()));
502                                         motd.setLength(0);
503
504                                 } else if (command.equalsIgnoreCase("KICK")) {
505                                         eventBus.post(new KickedFromChannel(this, parameters.get(0), reply.source().get(), parameters.get(1), getOptional(parameters, 2)));
506
507                                 /* okay, everything else. */
508                                 } else {
509                                         eventBus.post(new UnknownReplyReceived(this, reply));
510                                 }
511                         }
512                         eventBus.post(new ConnectionClosed(this));
513                 } catch (IOException ioe1) {
514                         logger.warn("I/O error", ioe1);
515                         eventBus.post(new ConnectionClosed(this, ioe1));
516                 } catch (RuntimeException re1) {
517                         logger.error("Runtime error", re1);
518                         eventBus.post(new ConnectionClosed(this, re1));
519                 } finally {
520                         established.set(false);
521                         eventBus.unregister(this);
522                         logger.info("Closing Connection.");
523                         try {
524                                 Closeables.close(connectionHandler, true);
525                         } catch (IOException ioe1) {
526                                 /* will not be thrown. */
527                         }
528                 }
529
530         }
531
532         @Subscribe
533         public void connectionEstablished(ConnectionEstablished connectionEstablished) {
534                 if (connectionEstablished.connection() == this) {
535                         established.set(true);
536                 }
537         }
538
539         //
540         // PRIVATE METHODS
541         //
542
543         /**
544          * Handles a CTCP message.
545          *
546          * @param client
547          *              The client sending the message
548          * @param message
549          *              The message
550          */
551         private void handleCtcp(Source client, String message) {
552                 String[] messageWords = message.substring(1, message.length() - 1).split(" +");
553                 String ctcpCommand = messageWords[0];
554                 if (ctcpCommand.equalsIgnoreCase("DCC")) {
555                         if (messageWords[1].equalsIgnoreCase("SEND")) {
556                                 Optional<InetAddress> inetAddress = parseInetAddress(messageWords[3]);
557                                 Optional<Integer> port = Optional.fromNullable(Ints.tryParse(messageWords[4]));
558                                 long fileSize = Optional.fromNullable(Longs.tryParse(messageWords[5])).or(-1L);
559                                 if (inetAddress.isPresent() && port.isPresent()) {
560                                         eventBus.post(new DccSendReceived(this, client, messageWords[2], inetAddress.get(), port.get(), fileSize));
561                                 } else {
562                                         logger.warn(String.format("Received malformed DCC SEND: “%s”", message));
563                                 }
564                         } else if (messageWords[1].equalsIgnoreCase("ACCEPT")) {
565                                 Optional<Integer> port = Optional.fromNullable(Ints.tryParse(messageWords[3]));
566                                 long position = (messageWords.length > 4) ? Optional.fromNullable(Longs.tryParse(messageWords[4])).or(-1L) : -1;
567                                 if (port.isPresent()) {
568                                         eventBus.post(new DccAcceptReceived(this, client, messageWords[2], port.get(), position));
569                                 } else {
570                                         logger.warn(String.format("Received malformed DCC ACCEPT: “%s”", message));
571                                 }
572                         }
573                 }
574         }
575
576         /**
577          * Returns an item from the list, or {@link Optional#absent()} if the list is
578          * shorter than required for the given index.
579          *
580          * @param list
581          *              The list to get an item from
582          * @param index
583          *              The index of the item
584          * @param <T>
585          *              The type of the list items
586          * @return This list item wrapped in an {@link Optional}, or {@link
587          *         Optional#absent()} if the list is not long enough
588          */
589         private static <T> Optional<T> getOptional(List<T> list, int index) {
590                 if (index < list.size()) {
591                         return Optional.fromNullable(list.get(index));
592                 }
593                 return Optional.absent();
594         }
595
596         /**
597          * Parses the given {@code ip} and returns an {@link InetAddress} from it.
598          *
599          * @param ip
600          *              The IP to parse
601          * @return The parsed inet address, or {@link Optional#absent()} if no inet
602          *         address could be parsed
603          */
604         private Optional<InetAddress> parseInetAddress(String ip) {
605                 Long ipNumber = Longs.tryParse(ip);
606                 if (ipNumber == null) {
607                         return Optional.absent();
608                 }
609
610                 StringBuilder hostname = new StringBuilder(15);
611                 hostname.append((ipNumber >>> 24) & 0xff).append('.');
612                 hostname.append((ipNumber >>> 16) & 0xff).append('.');
613                 hostname.append((ipNumber >>> 8) & 0xff).append('.');
614                 hostname.append(ipNumber & 0xff);
615                 try {
616                         return Optional.of(InetAddress.getByName(hostname.toString()));
617                 } catch (UnknownHostException uhe1) {
618                         return Optional.absent();
619                 }
620         }
621
622         /** Handles input and output for the connection. */
623         private class ConnectionHandler implements Closeable {
624
625                 /** The output stream of the connection. */
626                 private final BandwidthCountingOutputStream outputStream;
627
628                 /** The input stream. */
629                 private final BandwidthCountingInputStream inputStream;
630
631                 /** The input stream of the connection. */
632                 private final BufferedReader inputStreamReader;
633
634                 /**
635                  * Creates a new connection handler for the given input stream and output
636                  * stream.
637                  *
638                  * @param inputStream
639                  *              The input stream of the connection
640                  * @param outputStream
641                  *              The output stream of the connection
642                  * @throws UnsupportedEncodingException
643                  *              if the encoding (currently “UTF-8”) is not valid
644                  */
645                 private ConnectionHandler(InputStream inputStream, OutputStream outputStream) throws UnsupportedEncodingException {
646                         this.outputStream = new BandwidthCountingOutputStream(outputStream, 5, SECONDS);
647                         this.inputStream = new BandwidthCountingInputStream(inputStream, 5, SECONDS);
648                         inputStreamReader = new BufferedReader(new InputStreamReader(this.inputStream, "UTF-8"));
649                 }
650
651                 //
652                 // ACTIONS
653                 //
654
655                 /**
656                  * Returns the current rate of the connection’s incoming side.
657                  *
658                  * @return The current input rate (in bytes per second)
659                  */
660                 public long getInputRate() {
661                         return inputStream.getCurrentRate();
662                 }
663
664                 /**
665                  * Returns the current rate of the connection’s outgoing side.
666                  *
667                  * @return The current output rate (in bytes per second)
668                  */
669                 public long getOutputRate() {
670                         return outputStream.getCurrentRate();
671                 }
672
673                 /**
674                  * Sends a command with the given parameters, skipping all {@link
675                  * Optional#absent()} optionals.
676                  *
677                  * @param command
678                  *              The command to send
679                  * @param parameters
680                  *              The parameters
681                  * @throws IOException
682                  *              if an I/O error occurs
683                  */
684                 public void sendCommand(String command, Optional<String>... parameters) throws IOException {
685                         List<String> setParameters = new ArrayList<String>();
686                         for (Optional<String> maybeSetParameter : parameters) {
687                                 if (maybeSetParameter.isPresent()) {
688                                         setParameters.add(maybeSetParameter.get());
689                                 }
690                         }
691                         sendCommand(command, setParameters.toArray(new String[setParameters.size()]));
692                 }
693
694                 /**
695                  * Sends a command with the given parameters.
696                  *
697                  * @param command
698                  *              The command to send
699                  * @param parameters
700                  *              The parameters of the command
701                  * @throws IOException
702                  *              if an I/O error occurs
703                  * @throws IllegalArgumentException
704                  *              if any parameter but that last contains a space character
705                  */
706                 public void sendCommand(String command, String... parameters) throws IOException, IllegalArgumentException {
707                         StringBuilder commandBuilder = new StringBuilder();
708
709                         commandBuilder.append(command);
710                         for (int parameterIndex = 0; parameterIndex < parameters.length; ++parameterIndex) {
711                                 String parameter = parameters[parameterIndex];
712                                 /* space is only allowed in the last parameter. */
713                                 commandBuilder.append(' ');
714                                 if (parameter.contains(" ")) {
715                                         if (parameterIndex == (parameters.length - 1)) {
716                                                 commandBuilder.append(':');
717                                         } else {
718                                                 throw new IllegalArgumentException(String.format("parameter “%s” must not contain space!", parameter));
719                                         }
720                                 }
721                                 commandBuilder.append(parameter);
722                         }
723
724                         logger.trace(String.format(">> %s", commandBuilder));
725                         outputStream.write((commandBuilder.toString() + "\r\n").getBytes("UTF-8"));
726                         outputStream.flush();
727                 }
728
729                 /**
730                  * Reads a line of reply from the connection.
731                  *
732                  * @return The reply
733                  * @throws IOException
734                  *              if an I/O error occurs
735                  * @throws EOFException
736                  *              if EOF was reached
737                  */
738                 public Reply readReply() throws IOException, EOFException {
739                         String line = inputStreamReader.readLine();
740                         if (line == null) {
741                                 throw new EOFException();
742                         }
743
744                         return Reply.parseLine(line);
745                 }
746
747                 //
748                 // CLOSEABLE METHODS
749                 //
750
751                 @Override
752                 public void close() throws IOException {
753                         Closeables.close(outputStream, true);
754                         Closeables.close(inputStreamReader, true);
755                         Closeables.close(inputStream, true);
756                 }
757
758         }
759
760 }