Move connection establishing logic into its own handler.
[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.concurrent.TimeUnit.SECONDS;
22
23 import java.io.BufferedReader;
24 import java.io.Closeable;
25 import java.io.EOFException;
26 import java.io.IOException;
27 import java.io.InputStream;
28 import java.io.InputStreamReader;
29 import java.io.OutputStream;
30 import java.io.UnsupportedEncodingException;
31 import java.net.InetAddress;
32 import java.net.Socket;
33 import java.net.UnknownHostException;
34 import java.util.ArrayList;
35 import java.util.List;
36 import java.util.Map;
37 import java.util.Set;
38 import java.util.concurrent.TimeUnit;
39 import java.util.concurrent.atomic.AtomicBoolean;
40
41 import javax.net.SocketFactory;
42
43 import net.pterodactylus.irc.connection.ConnectionEstablishHandler;
44 import net.pterodactylus.irc.event.ChannelJoined;
45 import net.pterodactylus.irc.event.ChannelLeft;
46 import net.pterodactylus.irc.event.ChannelMessageReceived;
47 import net.pterodactylus.irc.event.ChannelNicknames;
48 import net.pterodactylus.irc.event.ChannelNotJoined;
49 import net.pterodactylus.irc.event.ChannelNotJoined.Reason;
50 import net.pterodactylus.irc.event.ChannelNoticeReceived;
51 import net.pterodactylus.irc.event.ChannelTopic;
52 import net.pterodactylus.irc.event.ClientQuit;
53 import net.pterodactylus.irc.event.ConnectionClosed;
54 import net.pterodactylus.irc.event.ConnectionEstablished;
55 import net.pterodactylus.irc.event.ConnectionFailed;
56 import net.pterodactylus.irc.event.DccAcceptReceived;
57 import net.pterodactylus.irc.event.DccSendReceived;
58 import net.pterodactylus.irc.event.KickedFromChannel;
59 import net.pterodactylus.irc.event.MotdReceived;
60 import net.pterodactylus.irc.event.NicknameChanged;
61 import net.pterodactylus.irc.event.NicknameInUseReceived;
62 import net.pterodactylus.irc.event.NoNicknameGivenReceived;
63 import net.pterodactylus.irc.event.PrivateMessageReceived;
64 import net.pterodactylus.irc.event.PrivateNoticeReceived;
65 import net.pterodactylus.irc.event.ReplyReceived;
66 import net.pterodactylus.irc.event.UnknownReplyReceived;
67 import net.pterodactylus.irc.util.RandomNickname;
68 import net.pterodactylus.xdcc.util.io.BandwidthCountingInputStream;
69 import net.pterodactylus.xdcc.util.io.BandwidthCountingOutputStream;
70
71 import com.google.common.base.Optional;
72 import com.google.common.collect.Maps;
73 import com.google.common.collect.Sets;
74 import com.google.common.eventbus.EventBus;
75 import com.google.common.eventbus.Subscribe;
76 import com.google.common.io.Closeables;
77 import com.google.common.primitives.Ints;
78 import com.google.common.primitives.Longs;
79 import com.google.common.util.concurrent.AbstractExecutionThreadService;
80 import com.google.common.util.concurrent.Service;
81 import org.apache.log4j.Logger;
82
83 /**
84  * A connection to an IRC server.
85  *
86  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
87  */
88 public class Connection extends AbstractExecutionThreadService implements Service {
89
90         /* The logger. */
91         private static final Logger logger = Logger.getLogger(Connection.class.getName());
92
93         /** The event bus. */
94         private final EventBus eventBus;
95
96         /** The socket factory. */
97         private final SocketFactory socketFactory;
98
99         /** The hostname to connect to. */
100         private final String hostname;
101
102         /** The port to connect to. */
103         private final int port;
104
105         /** The nickname chooser. */
106         private NicknameChooser nicknameChooser = new NicknameChooser() {
107
108                 @Override
109                 public String getNickname() {
110                         return RandomNickname.get();
111                 }
112         };
113
114         /** The nickname. */
115         private String nickname = null;
116
117         /** The username. */
118         private Optional<String> username = Optional.absent();
119
120         /** The real name. */
121         private Optional<String> realName = Optional.absent();
122
123         /** The optional password for the connection. */
124         private Optional<String> password = Optional.absent();
125
126         /** The connection handler. */
127         private ConnectionHandler connectionHandler;
128
129         /** Whether the connection has already been established. */
130         private final AtomicBoolean established = new AtomicBoolean();
131
132         /**
133          * Creates a new connection.
134          *
135          * @param eventBus
136          *              The event bus
137          * @param socketFactory
138          *              The socket factory
139          * @param hostname
140          *              The hostname of the IRC server
141          * @param port
142          *              The port number of the IRC server
143          */
144         public Connection(EventBus eventBus, SocketFactory socketFactory, String hostname, int port) {
145                 this.eventBus = eventBus;
146                 this.socketFactory = socketFactory;
147                 this.hostname = hostname;
148                 this.port = port;
149         }
150
151         //
152         // ACCESSORS
153         //
154
155         /**
156          * Returns the hostname of the remote end of the connection.
157          *
158          * @return The remote’s hostname
159          */
160         public String hostname() {
161                 return hostname;
162         }
163
164         /**
165          * Returns the port number of the remote end of the connection.
166          *
167          * @return The remote’s port number
168          */
169         public int port() {
170                 return port;
171         }
172
173         /**
174          * Returns whether this connection has already been established.
175          *
176          * @return {@code true} as long as this connection is established, {@code
177          *         false} otherwise
178          */
179         public boolean established() {
180                 return established.get();
181         }
182
183         /**
184          * Returns the nickname that is currently in use by this connection. The
185          * nickname is only available once the connection has been {@link #start()}ed.
186          *
187          * @return The current nickname
188          */
189         public String nickname() {
190                 return nickname;
191         }
192
193         //
194         // MUTATORS
195         //
196
197         /**
198          * Sets the nickname chooser. The nickname chooser is only used during the
199          * creation of the connection.
200          *
201          * @param nicknameChooser
202          *              The nickname chooser
203          * @return This connection
204          */
205         public Connection nicknameChooser(NicknameChooser nicknameChooser) {
206                 this.nicknameChooser = nicknameChooser;
207                 return this;
208         }
209
210         /**
211          * Sets the username to use.
212          *
213          * @param username
214          *              The username to use
215          * @return This connection
216          */
217         public Connection username(String username) {
218                 this.username = Optional.fromNullable(username);
219                 return this;
220         }
221
222         /**
223          * Sets the real name to use.
224          *
225          * @param realName
226          *              The real name to use
227          * @return This connection
228          */
229         public Connection realName(String realName) {
230                 this.realName = Optional.fromNullable(realName);
231                 return this;
232         }
233
234         /**
235          * Sets the optional password for the connection.
236          *
237          * @param password
238          *              The password for the connection
239          * @return This connection
240          */
241         public Connection password(String password) {
242                 this.password = Optional.fromNullable(password);
243                 return this;
244         }
245
246         //
247         // ACTIONS
248         //
249
250         /**
251          * Returns the current rate of the connection’s incoming side.
252          *
253          * @return The current input rate (in bytes per second)
254          */
255         public long getInputRate() {
256                 return (connectionHandler != null) ? connectionHandler.getInputRate() : 0;
257         }
258
259         /**
260          * Returns the current rate of the connection’s outgoing side.
261          *
262          * @return The current output rate (in bytes per second)
263          */
264         public long getOutputRate() {
265                 return (connectionHandler != null) ? connectionHandler.getOutputRate() : 0;
266         }
267
268         /**
269          * Checks whether the given source is the client represented by this
270          * connection.
271          *
272          * @param source
273          *              The source to check
274          * @return {@code true} if this connection represents the given source, {@code
275          *         false} otherwise
276          */
277         public boolean isSource(Source source) {
278                 return source.nick().isPresent() && source.nick().get().equals(nickname);
279         }
280
281         /**
282          * Joins the given channel.
283          *
284          * @param channel
285          *              The channel to join
286          * @throws IOException
287          *              if an I/O error occurs
288          */
289         public void joinChannel(final String channel) throws IOException {
290                 connectionHandler.sendCommand("JOIN", channel);
291         }
292
293         /**
294          * Sends a message to the given recipient, which may be a channel or another
295          * nickname.
296          *
297          * @param recipient
298          *              The recipient of the message
299          * @param message
300          *              The message
301          * @throws IOException
302          *              if an I/O error occurs
303          */
304         public void sendMessage(String recipient, String message) throws IOException {
305                 connectionHandler.sendCommand("PRIVMSG", recipient, message);
306         }
307
308         /**
309          * Sends a DCC RESUME request to the given recipient.
310          *
311          * @param recipient
312          *              The recipient of the request
313          * @param filename
314          *              The name of the file to resume
315          * @param port
316          *              The port number from the original DCC SEND request
317          * @param position
318          *              The position at which to resume the transfer
319          * @throws IOException
320          *              if an I/O error occurs
321          */
322         public void sendDccResume(String recipient, String filename, int port, long position) throws IOException {
323                 connectionHandler.sendCommand("PRIVMSG", recipient, String.format("\u0001DCC RESUME %s %d %d\u0001", filename, port, position));
324         }
325
326         /**
327          * Closes this connection.
328          *
329          * @throws IOException
330          *              if an I/O error occurs
331          */
332         public void close() throws IOException {
333                 if (connectionHandler != null) {
334                         connectionHandler.close();
335                 }
336         }
337
338         //
339         // ABSTRACTEXECUTIONTHREADSERVICE METHODS
340         //
341
342         @Override
343         protected void startUp() throws IllegalStateException {
344                 checkState(username.isPresent(), "username must be set");
345                 checkState(realName.isPresent(), "realName must be set");
346         }
347
348         @Override
349         protected void run() {
350
351                 /* connect to remote socket. */
352                 try {
353                         Socket socket = socketFactory.createSocket(hostname, port);
354                         socket.setSoTimeout((int) TimeUnit.MINUTES.toMillis(3));
355                         connectionHandler = new ConnectionHandler(socket.getInputStream(), socket.getOutputStream());
356
357                         /* register connection. */
358                         if (password.isPresent()) {
359                                 connectionHandler.sendCommand("PASSWORD", password.get());
360                         }
361                         connectionHandler.sendCommand("USER", username.get(), "8", "*", realName.get());
362                         nickname = nicknameChooser.getNickname();
363                         connectionHandler.sendCommand("NICK", nickname);
364
365                 } catch (IOException ioe1) {
366                         eventBus.post(new ConnectionFailed(this, ioe1));
367                         return;
368                 }
369
370                 eventBus.register(this);
371                 /* now read replies and react. */
372                 try {
373                         /* some status variables. */
374                         int oldConnectionStatus = 0;
375                         int connectionStatus = 0;
376                         boolean connected = true;
377                         StringBuilder motd = new StringBuilder();
378                         Set<Nickname> nicks = Sets.newHashSet();
379
380                         /* server modes. */
381                         Map<String, String> nickPrefixes = Maps.newHashMap();
382                         Set<Character> channelTypes = Sets.newHashSet();
383
384                         ConnectionEstablishHandler connectionEstablishHandler = new ConnectionEstablishHandler(eventBus, this);
385
386                         while (connected) {
387                                 Reply reply = connectionHandler.readReply();
388                                 eventBus.post(new ReplyReceived(this, reply));
389                                 logger.trace(String.format("<< %s", reply));
390                                 String command = reply.command();
391                                 List<String> parameters = reply.parameters();
392
393                                 /* most common events. */
394                                 if (command.equalsIgnoreCase("PRIVMSG")) {
395                                         String recipient = parameters.get(0);
396                                         String message = parameters.get(1);
397                                         if (message.startsWith("\u0001") && message.endsWith("\u0001")) {
398                                                 /* CTCP! */
399                                                 handleCtcp(reply.source().get(), message);
400                                         } else if (!channelTypes.contains(recipient.charAt(0))) {
401                                                 eventBus.post(new PrivateMessageReceived(this, reply.source().get(), message));
402                                         } else {
403                                                 eventBus.post(new ChannelMessageReceived(this, recipient, reply.source().get(), message));
404                                         }
405
406                                 } else if (command.equalsIgnoreCase("NOTICE")) {
407                                         String recipient = parameters.get(0);
408                                         String message = parameters.get(1);
409                                         if (message.startsWith("\u0001") && message.endsWith("\u0001")) {
410                                                 /* CTCP! */
411                                                 handleCtcp(reply.source().get(), message);
412                                         } else if (!channelTypes.contains(recipient.charAt(0))) {
413                                                 eventBus.post(new PrivateNoticeReceived(this, reply));
414                                         } else {
415                                                 eventBus.post(new ChannelNoticeReceived(this, reply.source().get(), recipient, message));
416                                         }
417
418                                 /* 43x replies are for nick change errors. */
419                                 } else if (command.equals("431")) {
420                                         eventBus.post(new NoNicknameGivenReceived(this, reply));
421                                 } else if (command.equals("433")) {
422                                         if (connectionStatus == 0) {
423                                                 nickname = nicknameChooser.getNickname();
424                                                 connectionHandler.sendCommand("NICK", nickname);
425                                         } else {
426                                                 eventBus.post(new NicknameInUseReceived(this, reply));
427                                         }
428
429                                 /* client stuff. */
430                                 } else if (command.equalsIgnoreCase("NICK")) {
431                                         eventBus.post(new NicknameChanged(this, reply.source().get(), parameters.get(0)));
432
433                                 /* channel stuff. */
434                                 } else if (command.equalsIgnoreCase("JOIN")) {
435                                         eventBus.post(new ChannelJoined(this, parameters.get(0), reply.source().get()));
436                                 } else if (command.equals("331")) {
437                                         /* no topic is set. */
438                                 } else if (command.equals("332")) {
439                                         eventBus.post(new ChannelTopic(this, parameters.get(1), parameters.get(2)));
440                                 } else if (command.equals("353")) {
441                                         for (String nickname : parameters.get(3).split(" ")) {
442                                                 if (nickPrefixes.containsKey(nickname.substring(0, 1))) {
443                                                         nicks.add(new Nickname(nickname.substring(1), nickname.substring(0, 1)));
444                                                 } else {
445                                                         nicks.add(new Nickname(nickname, ""));
446                                                 }
447                                         }
448                                 } else if (command.equals("366")) {
449                                         eventBus.post(new ChannelNicknames(this, parameters.get(1), nicks));
450                                         nicks.clear();
451                                 } else if (command.equalsIgnoreCase("PART")) {
452                                         eventBus.post(new ChannelLeft(this, parameters.get(0), reply.source().get(), getOptional(parameters, 1)));
453                                 } else if (command.equalsIgnoreCase("QUIT")) {
454                                         eventBus.post(new ClientQuit(this, reply.source().get(), parameters.get(0)));
455
456                                 /* common channel join errors. */
457                                 } else if (command.equals("474")) {
458                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.banned));
459                                 } else if (command.equals("473")) {
460                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.inviteOnly));
461                                 } else if (command.equals("475")) {
462                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.badChannelKey));
463                                 } else if (command.equals("477")) {
464                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.registeredNicknamesOnly));
465
466                                 /* basic connection housekeeping. */
467                                 } else if (command.equalsIgnoreCase("PING")) {
468                                         connectionHandler.sendCommand("PONG", getOptional(parameters, 0), getOptional(parameters, 1));
469
470                                 } else if (connectionEstablishHandler.willHandle(reply)) {
471                                         connectionEstablishHandler.handleReply(reply);
472
473                                 /* 005 originally was a bounce message, now used to transmit useful information about the server. */
474                                 } else if (command.equals("005")) {
475                                         for (String parameter : parameters) {
476                                                 if (parameter.startsWith("PREFIX=")) {
477                                                         int openParen = parameter.indexOf('(');
478                                                         int closeParen = parameter.indexOf(')');
479                                                         if ((openParen != -1) && (closeParen != -1)) {
480                                                                 for (int modeCharacterIndex = 1; modeCharacterIndex < (closeParen - openParen); ++modeCharacterIndex) {
481                                                                         char modeCharacter = parameter.charAt(openParen + modeCharacterIndex);
482                                                                         char modeSymbol = parameter.charAt(closeParen + modeCharacterIndex);
483                                                                         nickPrefixes.put(String.valueOf(modeSymbol), String.valueOf(modeCharacter));
484                                                                 }
485                                                                 logger.debug(String.format("Parsed Prefixes: %s", nickPrefixes));
486                                                         }
487                                                 } else if (parameter.startsWith("CHANTYPES=")) {
488                                                         for (int typeIndex = 10; typeIndex < parameter.length(); ++typeIndex) {
489                                                                 channelTypes.add(parameter.charAt(typeIndex));
490                                                         }
491                                                         logger.debug(String.format("Parsed Channel Types: %s", channelTypes));
492                                                 }
493                                         }
494
495                                 /* 375, 372, and 376 handle the server’s MOTD. */
496                                 } else if (command.equals("375")) {
497                                         /* MOTD starts. */
498                                         motd.append(parameters.get(1)).append('\n');
499                                 } else if (command.equals("372")) {
500                                         motd.append(parameters.get(1)).append('\n');
501                                 } else if (command.equals("376")) {
502                                         motd.append(parameters.get(1)).append('\n');
503                                         eventBus.post(new MotdReceived(this, motd.toString()));
504                                         motd.setLength(0);
505
506                                 } else if (command.equalsIgnoreCase("KICK")) {
507                                         eventBus.post(new KickedFromChannel(this, parameters.get(0), reply.source().get(), parameters.get(1), getOptional(parameters, 2)));
508
509                                 /* okay, everything else. */
510                                 } else {
511                                         eventBus.post(new UnknownReplyReceived(this, reply));
512                                 }
513                         }
514                         eventBus.post(new ConnectionClosed(this));
515                 } catch (IOException ioe1) {
516                         logger.warn("I/O error", ioe1);
517                         eventBus.post(new ConnectionClosed(this, ioe1));
518                 } catch (RuntimeException re1) {
519                         logger.error("Runtime error", re1);
520                         eventBus.post(new ConnectionClosed(this, re1));
521                 } finally {
522                         established.set(false);
523                         eventBus.unregister(this);
524                         logger.info("Closing Connection.");
525                         try {
526                                 Closeables.close(connectionHandler, true);
527                         } catch (IOException ioe1) {
528                                 /* will not be thrown. */
529                         }
530                 }
531
532         }
533
534         @Subscribe
535         public void connectionEstablished(ConnectionEstablished connectionEstablished) {
536                 if (connectionEstablished.connection() == this) {
537                         established.set(true);
538                 }
539         }
540
541         //
542         // PRIVATE METHODS
543         //
544
545         /**
546          * Handles a CTCP message.
547          *
548          * @param client
549          *              The client sending the message
550          * @param message
551          *              The message
552          */
553         private void handleCtcp(Source client, String message) {
554                 String[] messageWords = message.substring(1, message.length() - 1).split(" +");
555                 String ctcpCommand = messageWords[0];
556                 if (ctcpCommand.equalsIgnoreCase("DCC")) {
557                         if (messageWords[1].equalsIgnoreCase("SEND")) {
558                                 Optional<InetAddress> inetAddress = parseInetAddress(messageWords[3]);
559                                 Optional<Integer> port = Optional.fromNullable(Ints.tryParse(messageWords[4]));
560                                 long fileSize = Optional.fromNullable(Longs.tryParse(messageWords[5])).or(-1L);
561                                 if (inetAddress.isPresent() && port.isPresent()) {
562                                         eventBus.post(new DccSendReceived(this, client, messageWords[2], inetAddress.get(), port.get(), fileSize));
563                                 } else {
564                                         logger.warn(String.format("Received malformed DCC SEND: “%s”", message));
565                                 }
566                         } else if (messageWords[1].equalsIgnoreCase("ACCEPT")) {
567                                 Optional<Integer> port = Optional.fromNullable(Ints.tryParse(messageWords[3]));
568                                 long position = (messageWords.length > 4) ? Optional.fromNullable(Longs.tryParse(messageWords[4])).or(-1L) : -1;
569                                 if (port.isPresent()) {
570                                         eventBus.post(new DccAcceptReceived(this, client, messageWords[2], port.get(), position));
571                                 } else {
572                                         logger.warn(String.format("Received malformed DCC ACCEPT: “%s”", message));
573                                 }
574                         }
575                 }
576         }
577
578         /**
579          * Returns an item from the list, or {@link Optional#absent()} if the list is
580          * shorter than required for the given index.
581          *
582          * @param list
583          *              The list to get an item from
584          * @param index
585          *              The index of the item
586          * @param <T>
587          *              The type of the list items
588          * @return This list item wrapped in an {@link Optional}, or {@link
589          *         Optional#absent()} if the list is not long enough
590          */
591         private static <T> Optional<T> getOptional(List<T> list, int index) {
592                 if (index < list.size()) {
593                         return Optional.fromNullable(list.get(index));
594                 }
595                 return Optional.absent();
596         }
597
598         /**
599          * Parses the given {@code ip} and returns an {@link InetAddress} from it.
600          *
601          * @param ip
602          *              The IP to parse
603          * @return The parsed inet address, or {@link Optional#absent()} if no inet
604          *         address could be parsed
605          */
606         private Optional<InetAddress> parseInetAddress(String ip) {
607                 Long ipNumber = Longs.tryParse(ip);
608                 if (ipNumber == null) {
609                         return Optional.absent();
610                 }
611
612                 StringBuilder hostname = new StringBuilder(15);
613                 hostname.append((ipNumber >>> 24) & 0xff).append('.');
614                 hostname.append((ipNumber >>> 16) & 0xff).append('.');
615                 hostname.append((ipNumber >>> 8) & 0xff).append('.');
616                 hostname.append(ipNumber & 0xff);
617                 try {
618                         return Optional.of(InetAddress.getByName(hostname.toString()));
619                 } catch (UnknownHostException uhe1) {
620                         return Optional.absent();
621                 }
622         }
623
624         /** Handles input and output for the connection. */
625         private class ConnectionHandler implements Closeable {
626
627                 /** The output stream of the connection. */
628                 private final BandwidthCountingOutputStream outputStream;
629
630                 /** The input stream. */
631                 private final BandwidthCountingInputStream inputStream;
632
633                 /** The input stream of the connection. */
634                 private final BufferedReader inputStreamReader;
635
636                 /**
637                  * Creates a new connection handler for the given input stream and output
638                  * stream.
639                  *
640                  * @param inputStream
641                  *              The input stream of the connection
642                  * @param outputStream
643                  *              The output stream of the connection
644                  * @throws UnsupportedEncodingException
645                  *              if the encoding (currently “UTF-8”) is not valid
646                  */
647                 private ConnectionHandler(InputStream inputStream, OutputStream outputStream) throws UnsupportedEncodingException {
648                         this.outputStream = new BandwidthCountingOutputStream(outputStream, 5, SECONDS);
649                         this.inputStream = new BandwidthCountingInputStream(inputStream, 5, SECONDS);
650                         inputStreamReader = new BufferedReader(new InputStreamReader(this.inputStream, "UTF-8"));
651                 }
652
653                 //
654                 // ACTIONS
655                 //
656
657                 /**
658                  * Returns the current rate of the connection’s incoming side.
659                  *
660                  * @return The current input rate (in bytes per second)
661                  */
662                 public long getInputRate() {
663                         return inputStream.getCurrentRate();
664                 }
665
666                 /**
667                  * Returns the current rate of the connection’s outgoing side.
668                  *
669                  * @return The current output rate (in bytes per second)
670                  */
671                 public long getOutputRate() {
672                         return outputStream.getCurrentRate();
673                 }
674
675                 /**
676                  * Sends a command with the given parameters, skipping all {@link
677                  * Optional#absent()} optionals.
678                  *
679                  * @param command
680                  *              The command to send
681                  * @param parameters
682                  *              The parameters
683                  * @throws IOException
684                  *              if an I/O error occurs
685                  */
686                 public void sendCommand(String command, Optional<String>... parameters) throws IOException {
687                         List<String> setParameters = new ArrayList<String>();
688                         for (Optional<String> maybeSetParameter : parameters) {
689                                 if (maybeSetParameter.isPresent()) {
690                                         setParameters.add(maybeSetParameter.get());
691                                 }
692                         }
693                         sendCommand(command, setParameters.toArray(new String[setParameters.size()]));
694                 }
695
696                 /**
697                  * Sends a command with the given parameters.
698                  *
699                  * @param command
700                  *              The command to send
701                  * @param parameters
702                  *              The parameters of the command
703                  * @throws IOException
704                  *              if an I/O error occurs
705                  * @throws IllegalArgumentException
706                  *              if any parameter but that last contains a space character
707                  */
708                 public void sendCommand(String command, String... parameters) throws IOException, IllegalArgumentException {
709                         StringBuilder commandBuilder = new StringBuilder();
710
711                         commandBuilder.append(command);
712                         for (int parameterIndex = 0; parameterIndex < parameters.length; ++parameterIndex) {
713                                 String parameter = parameters[parameterIndex];
714                                 /* space is only allowed in the last parameter. */
715                                 commandBuilder.append(' ');
716                                 if (parameter.contains(" ")) {
717                                         if (parameterIndex == (parameters.length - 1)) {
718                                                 commandBuilder.append(':');
719                                         } else {
720                                                 throw new IllegalArgumentException(String.format("parameter “%s” must not contain space!", parameter));
721                                         }
722                                 }
723                                 commandBuilder.append(parameter);
724                         }
725
726                         logger.trace(String.format(">> %s", commandBuilder));
727                         outputStream.write((commandBuilder.toString() + "\r\n").getBytes("UTF-8"));
728                         outputStream.flush();
729                 }
730
731                 /**
732                  * Reads a line of reply from the connection.
733                  *
734                  * @return The reply
735                  * @throws IOException
736                  *              if an I/O error occurs
737                  * @throws EOFException
738                  *              if EOF was reached
739                  */
740                 public Reply readReply() throws IOException, EOFException {
741                         String line = inputStreamReader.readLine();
742                         if (line == null) {
743                                 throw new EOFException();
744                         }
745
746                         return Reply.parseLine(line);
747                 }
748
749                 //
750                 // CLOSEABLE METHODS
751                 //
752
753                 @Override
754                 public void close() throws IOException {
755                         Closeables.close(outputStream, true);
756                         Closeables.close(inputStreamReader, true);
757                         Closeables.close(inputStream, true);
758                 }
759
760         }
761
762 }