001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.commons.net.smtp;
019    
020    import java.io.IOException;
021    import java.io.Writer;
022    import java.net.InetAddress;
023    
024    import org.apache.commons.net.io.DotTerminatedMessageWriter;
025    
026    /***
027     * SMTPClient encapsulates all the functionality necessary to send files
028     * through an SMTP server.  This class takes care of all
029     * low level details of interacting with an SMTP server and provides
030     * a convenient higher level interface.  As with all classes derived
031     * from {@link org.apache.commons.net.SocketClient},
032     * you must first connect to the server with
033     * {@link org.apache.commons.net.SocketClient#connect  connect }
034     * before doing anything, and finally
035     * {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
036     * after you're completely finished interacting with the server.
037     * Then you need to check the SMTP reply code to see if the connection
038     * was successful.  For example:
039     * <pre>
040     *    try {
041     *      int reply;
042     *      client.connect("mail.foobar.com");
043     *      System.out.print(client.getReplyString());
044     *
045     *      // After connection attempt, you should check the reply code to verify
046     *      // success.
047     *      reply = client.getReplyCode();
048     *
049     *      if(!SMTPReply.isPositiveCompletion(reply)) {
050     *        client.disconnect();
051     *        System.err.println("SMTP server refused connection.");
052     *        System.exit(1);
053     *      }
054     *
055     *      // Do useful stuff here.
056     *      ...
057     *    } catch(IOException e) {
058     *      if(client.isConnected()) {
059     *        try {
060     *          client.disconnect();
061     *        } catch(IOException f) {
062     *          // do nothing
063     *        }
064     *      }
065     *      System.err.println("Could not connect to server.");
066     *      e.printStackTrace();
067     *      System.exit(1);
068     *    }
069     * </pre>
070     * <p>
071     * Immediately after connecting is the only real time you need to check the
072     * reply code (because connect is of type void).  The convention for all the
073     * SMTP command methods in SMTPClient is such that they either return a
074     * boolean value or some other value.
075     * The boolean methods return true on a successful completion reply from
076     * the SMTP server and false on a reply resulting in an error condition or
077     * failure.  The methods returning a value other than boolean return a value
078     * containing the higher level data produced by the SMTP command, or null if a
079     * reply resulted in an error condition or failure.  If you want to access
080     * the exact SMTP reply code causing a success or failure, you must call
081     * {@link org.apache.commons.net.smtp.SMTP#getReplyCode  getReplyCode } after
082     * a success or failure.
083     * <p>
084     * You should keep in mind that the SMTP server may choose to prematurely
085     * close a connection for various reasons.  The SMTPClient class will detect a
086     * premature SMTP server connection closing when it receives a
087     * {@link org.apache.commons.net.smtp.SMTPReply#SERVICE_NOT_AVAILABLE SMTPReply.SERVICE_NOT_AVAILABLE }
088     *  response to a command.
089     * When that occurs, the method encountering that reply will throw
090     * an {@link org.apache.commons.net.smtp.SMTPConnectionClosedException}
091     * .
092     * <code>SMTPConectionClosedException</code>
093     * is a subclass of <code> IOException </code> and therefore need not be
094     * caught separately, but if you are going to catch it separately, its
095     * catch block must appear before the more general <code> IOException </code>
096     * catch block.  When you encounter an
097     * {@link org.apache.commons.net.smtp.SMTPConnectionClosedException}
098     * , you must disconnect the connection with
099     * {@link #disconnect  disconnect() } to properly clean up the
100     * system resources used by SMTPClient.  Before disconnecting, you may check
101     * the last reply code and text with
102     * {@link org.apache.commons.net.smtp.SMTP#getReplyCode  getReplyCode },
103     * {@link org.apache.commons.net.smtp.SMTP#getReplyString  getReplyString },
104     * and
105     * {@link org.apache.commons.net.smtp.SMTP#getReplyStrings getReplyStrings}.
106     * <p>
107     * Rather than list it separately for each method, we mention here that
108     * every method communicating with the server and throwing an IOException
109     * can also throw a
110     * {@link org.apache.commons.net.MalformedServerReplyException}
111     * , which is a subclass
112     * of IOException.  A MalformedServerReplyException will be thrown when
113     * the reply received from the server deviates enough from the protocol
114     * specification that it cannot be interpreted in a useful manner despite
115     * attempts to be as lenient as possible.
116     * <p>
117     * <p>
118     * @see SMTP
119     * @see SimpleSMTPHeader
120     * @see RelayPath
121     * @see SMTPConnectionClosedException
122     * @see org.apache.commons.net.MalformedServerReplyException
123     ***/
124    
125    public class SMTPClient extends SMTP
126    {
127    
128        /**
129         * Default SMTPClient constructor.  Creates a new SMTPClient instance.
130         */
131        public SMTPClient() {  }
132    
133        /**
134         * Overloaded constructor that takes an encoding specification
135         * @param encoding The encoding to use
136         * @since 2.0
137         */
138        public SMTPClient(String encoding) {
139            super(encoding);
140        }
141    
142    
143        /***
144         * At least one SMTPClient method ({@link #sendMessageData  sendMessageData })
145         * does not complete the entire sequence of SMTP commands to complete a
146         * transaction.  These types of commands require some action by the
147         * programmer after the reception of a positive intermediate command.
148         * After the programmer's code completes its actions, it must call this
149         * method to receive the completion reply from the server and verify the
150         * success of the entire transaction.
151         * <p>
152         * For example,
153         * <pre>
154         * writer = client.sendMessage();
155         * if(writer == null) // failure
156         *   return false;
157         * header =
158         *  new SimpleSMTPHeader("foobar@foo.com", "foo@foobar.com", "Re: Foo");
159         * writer.write(header.toString());
160         * writer.write("This is just a test");
161         * writer.close();
162         * if(!client.completePendingCommand()) // failure
163         *   return false;
164         * </pre>
165         * <p>
166         * @return True if successfully completed, false if not.
167         * @exception SMTPConnectionClosedException
168         *      If the SMTP server prematurely closes the connection as a result
169         *      of the client being idle or some other reason causing the server
170         *      to send SMTP reply code 421.  This exception may be caught either
171         *      as an IOException or independently as itself.
172         * @exception IOException  If an I/O error occurs while either sending a
173         *      command to the server or receiving a reply from the server.
174         ***/
175        public boolean completePendingCommand() throws IOException
176        {
177            return SMTPReply.isPositiveCompletion(getReply());
178        }
179    
180    
181        /***
182         * Login to the SMTP server by sending the HELO command with the
183         * given hostname as an argument.  Before performing any mail commands,
184         * you must first login.
185         * <p>
186         * @param hostname  The hostname with which to greet the SMTP server.
187         * @return True if successfully completed, false if not.
188         * @exception SMTPConnectionClosedException
189         *      If the SMTP server prematurely closes the connection as a result
190         *      of the client being idle or some other reason causing the server
191         *      to send SMTP reply code 421.  This exception may be caught either
192         *      as an IOException or independently as itself.
193         * @exception IOException  If an I/O error occurs while either sending a
194         *      command to the server or receiving a reply from the server.
195         ***/
196        public boolean login(String hostname) throws IOException
197        {
198            return SMTPReply.isPositiveCompletion(helo(hostname));
199        }
200    
201    
202        /***
203         * Login to the SMTP server by sending the HELO command with the
204         * client hostname as an argument.  Before performing any mail commands,
205         * you must first login.
206         * <p>
207         * @return True if successfully completed, false if not.
208         * @exception SMTPConnectionClosedException
209         *      If the SMTP server prematurely closes the connection as a result
210         *      of the client being idle or some other reason causing the server
211         *      to send SMTP reply code 421.  This exception may be caught either
212         *      as an IOException or independently as itself.
213         * @exception IOException  If an I/O error occurs while either sending a
214         *      command to the server or receiving a reply from the server.
215         ***/
216        public boolean login() throws IOException
217        {
218            String name;
219            InetAddress host;
220    
221            host = getLocalAddress();
222            name = host.getHostName();
223    
224            if (name == null) {
225                return false;
226            }
227    
228            return SMTPReply.isPositiveCompletion(helo(name));
229        }
230    
231    
232        /***
233         * Set the sender of a message using the SMTP MAIL command, specifying
234         * a reverse relay path.  The sender must be set first before any
235         * recipients may be specified, otherwise the mail server will reject
236         * your commands.
237         * <p>
238         * @param path  The reverse relay path pointing back to the sender.
239         * @return True if successfully completed, false if not.
240         * @exception SMTPConnectionClosedException
241         *      If the SMTP server prematurely closes the connection as a result
242         *      of the client being idle or some other reason causing the server
243         *      to send SMTP reply code 421.  This exception may be caught either
244         *      as an IOException or independently as itself.
245         * @exception IOException  If an I/O error occurs while either sending a
246         *      command to the server or receiving a reply from the server.
247         ***/
248        public boolean setSender(RelayPath path) throws IOException
249        {
250            return SMTPReply.isPositiveCompletion(mail(path.toString()));
251        }
252    
253    
254        /***
255         * Set the sender of a message using the SMTP MAIL command, specifying
256         * the sender's email address. The sender must be set first before any
257         * recipients may be specified, otherwise the mail server will reject
258         * your commands.
259         * <p>
260         * @param address  The sender's email address.
261         * @return True if successfully completed, false if not.
262         * @exception SMTPConnectionClosedException
263         *      If the SMTP server prematurely closes the connection as a result
264         *      of the client being idle or some other reason causing the server
265         *      to send SMTP reply code 421.  This exception may be caught either
266         *      as an IOException or independently as itself.
267         * @exception IOException  If an I/O error occurs while either sending a
268         *      command to the server or receiving a reply from the server.
269         ***/
270        public boolean setSender(String address) throws IOException
271        {
272            return SMTPReply.isPositiveCompletion(mail("<" + address + ">"));
273        }
274    
275    
276        /***
277         * Add a recipient for a message using the SMTP RCPT command, specifying
278         * a forward relay path.  The sender must be set first before any
279         * recipients may be specified, otherwise the mail server will reject
280         * your commands.
281         * <p>
282         * @param path  The forward relay path pointing to the recipient.
283         * @return True if successfully completed, false if not.
284         * @exception SMTPConnectionClosedException
285         *      If the SMTP server prematurely closes the connection as a result
286         *      of the client being idle or some other reason causing the server
287         *      to send SMTP reply code 421.  This exception may be caught either
288         *      as an IOException or independently as itself.
289         * @exception IOException  If an I/O error occurs while either sending a
290         *      command to the server or receiving a reply from the server.
291         ***/
292        public boolean addRecipient(RelayPath path) throws IOException
293        {
294            return SMTPReply.isPositiveCompletion(rcpt(path.toString()));
295        }
296    
297    
298        /***
299         * Add a recipient for a message using the SMTP RCPT command, the
300         * recipient's email address.  The sender must be set first before any
301         * recipients may be specified, otherwise the mail server will reject
302         * your commands.
303         * <p>
304         * @param address  The recipient's email address.
305         * @return True if successfully completed, false if not.
306         * @exception SMTPConnectionClosedException
307         *      If the SMTP server prematurely closes the connection as a result
308         *      of the client being idle or some other reason causing the server
309         *      to send SMTP reply code 421.  This exception may be caught either
310         *      as an IOException or independently as itself.
311         * @exception IOException  If an I/O error occurs while either sending a
312         *      command to the server or receiving a reply from the server.
313         ***/
314        public boolean addRecipient(String address) throws IOException
315        {
316            return SMTPReply.isPositiveCompletion(rcpt("<" + address + ">"));
317        }
318    
319    
320    
321        /***
322         * Send the SMTP DATA command in preparation to send an email message.
323         * This method returns a DotTerminatedMessageWriter instance to which
324         * the message can be written.  Null is returned if the DATA command
325         * fails.
326         * <p>
327         * You must not issue any commands to the SMTP server (i.e., call any
328         * (other methods) until you finish writing to the returned Writer
329         * instance and close it.  The SMTP protocol uses the same stream for
330         * issuing commands as it does for returning results.  Therefore the
331         * returned Writer actually writes directly to the SMTP connection.
332         * After you close the writer, you can execute new commands.  If you
333         * do not follow these requirements your program will not work properly.
334         * <p>
335         * You can use the provided
336         * {@link org.apache.commons.net.smtp.SimpleSMTPHeader}
337         * class to construct a bare minimum header.
338         * To construct more complicated headers you should
339         * refer to RFC 822.  When the Java Mail API is finalized, you will be
340         * able to use it to compose fully compliant Internet text messages.
341         * The DotTerminatedMessageWriter takes care of doubling line-leading
342         * dots and ending the message with a single dot upon closing, so all
343         * you have to worry about is writing the header and the message.
344         * <p>
345         * Upon closing the returned Writer, you need to call
346         * {@link #completePendingCommand  completePendingCommand() }
347         * to finalize the transaction and verify its success or failure from
348         * the server reply.
349         * <p>
350         * @return A DotTerminatedMessageWriter to which the message (including
351         *      header) can be written.  Returns null if the command fails.
352         * @exception SMTPConnectionClosedException
353         *      If the SMTP server prematurely closes the connection as a result
354         *      of the client being idle or some other reason causing the server
355         *      to send SMTP reply code 421.  This exception may be caught either
356         *      as an IOException or independently as itself.
357         * @exception IOException  If an I/O error occurs while either sending a
358         *      command to the server or receiving a reply from the server.
359         ***/
360        public Writer sendMessageData() throws IOException
361        {
362            if (!SMTPReply.isPositiveIntermediate(data())) {
363                return null;
364            }
365    
366            return new DotTerminatedMessageWriter(_writer);
367        }
368    
369    
370        /***
371         * A convenience method for sending short messages.  This method fetches
372         * the Writer returned by {@link #sendMessageData  sendMessageData() }
373         * and writes the specified String to it.  After writing the message,
374         * this method calls {@link #completePendingCommand completePendingCommand() }
375         *  to finalize the transaction and returns
376         * its success or failure.
377         * <p>
378         * @param message  The short email message to send.
379         * @return True if successfully completed, false if not.
380         * @exception SMTPConnectionClosedException
381         *      If the SMTP server prematurely closes the connection as a result
382         *      of the client being idle or some other reason causing the server
383         *      to send SMTP reply code 421.  This exception may be caught either
384         *      as an IOException or independently as itself.
385         * @exception IOException  If an I/O error occurs while either sending a
386         *      command to the server or receiving a reply from the server.
387         ***/
388        public boolean sendShortMessageData(String message) throws IOException
389        {
390            Writer writer;
391    
392            writer = sendMessageData();
393    
394            if (writer == null) {
395                return false;
396            }
397    
398            writer.write(message);
399            writer.close();
400    
401            return completePendingCommand();
402        }
403    
404    
405        /***
406         * A convenience method for a sending short email without having to
407         * explicitly set the sender and recipient(s).  This method
408         * sets the sender and recipient using
409         * {@link #setSender  setSender } and
410         * {@link #addRecipient  addRecipient }, and then sends the
411         * message using {@link #sendShortMessageData  sendShortMessageData }.
412         * <p>
413         * @param sender  The email address of the sender.
414         * @param recipient  The email address of the recipient.
415         * @param message  The short email message to send.
416         * @return True if successfully completed, false if not.
417         * @exception SMTPConnectionClosedException
418         *      If the SMTP server prematurely closes the connection as a result
419         *      of the client being idle or some other reason causing the server
420         *      to send SMTP reply code 421.  This exception may be caught either
421         *      as an IOException or independently as itself.
422         * @exception IOException  If an I/O error occurs while either sending a
423         *      command to the server or receiving a reply from the server.
424         ***/
425        public boolean sendSimpleMessage(String sender, String recipient,
426                                         String message)
427        throws IOException
428        {
429            if (!setSender(sender)) {
430                return false;
431            }
432    
433            if (!addRecipient(recipient)) {
434                return false;
435            }
436    
437            return sendShortMessageData(message);
438        }
439    
440    
441    
442        /***
443         * A convenience method for a sending short email without having to
444         * explicitly set the sender and recipient(s).  This method
445         * sets the sender and recipients using
446         * {@link #setSender  setSender } and
447         * {@link #addRecipient  addRecipient }, and then sends the
448         * message using {@link #sendShortMessageData  sendShortMessageData }.
449         * <p>
450         * @param sender  The email address of the sender.
451         * @param recipients  An array of recipient email addresses.
452         * @param message  The short email message to send.
453         * @return True if successfully completed, false if not.
454         * @exception SMTPConnectionClosedException
455         *      If the SMTP server prematurely closes the connection as a result
456         *      of the client being idle or some other reason causing the server
457         *      to send SMTP reply code 421.  This exception may be caught either
458         *      as an IOException or independently as itself.
459         * @exception IOException  If an I/O error occurs while either sending a
460         *      command to the server or receiving a reply from the server.
461         ***/
462        public boolean sendSimpleMessage(String sender, String[] recipients,
463                                         String message)
464        throws IOException
465        {
466            boolean oneSuccess = false;
467            int count;
468    
469            if (!setSender(sender)) {
470                return false;
471            }
472    
473            for (count = 0; count < recipients.length; count++)
474            {
475                if (addRecipient(recipients[count])) {
476                    oneSuccess = true;
477                }
478            }
479    
480            if (!oneSuccess) {
481                return false;
482            }
483    
484            return sendShortMessageData(message);
485        }
486    
487    
488        /***
489         * Logout of the SMTP server by sending the QUIT command.
490         * <p>
491         * @return True if successfully completed, false if not.
492         * @exception SMTPConnectionClosedException
493         *      If the SMTP server prematurely closes the connection as a result
494         *      of the client being idle or some other reason causing the server
495         *      to send SMTP reply code 421.  This exception may be caught either
496         *      as an IOException or independently as itself.
497         * @exception IOException  If an I/O error occurs while either sending a
498         *      command to the server or receiving a reply from the server.
499         ***/
500        public boolean logout() throws IOException
501        {
502            return SMTPReply.isPositiveCompletion(quit());
503        }
504    
505    
506    
507        /***
508         * Aborts the current mail transaction, resetting all server stored
509         * sender, recipient, and mail data, cleaing all buffers and tables.
510         * <p>
511         * @return True if successfully completed, false if not.
512         * @exception SMTPConnectionClosedException
513         *      If the SMTP server prematurely closes the connection as a result
514         *      of the client being idle or some other reason causing the server
515         *      to send SMTP reply code 421.  This exception may be caught either
516         *      as an IOException or independently as itself.
517         * @exception IOException  If an I/O error occurs while either sending a
518         *      command to the server or receiving a reply from the server.
519         ***/
520        public boolean reset() throws IOException
521        {
522            return SMTPReply.isPositiveCompletion(rset());
523        }
524    
525    
526        /***
527         * Verify that a username or email address is valid, i.e., that mail
528         * can be delivered to that mailbox on the server.
529         * <p>
530         * @param username  The username or email address to validate.
531         * @return True if the username is valid, false if not.
532         * @exception SMTPConnectionClosedException
533         *      If the SMTP server prematurely closes the connection as a result
534         *      of the client being idle or some other reason causing the server
535         *      to send SMTP reply code 421.  This exception may be caught either
536         *      as an IOException or independently as itself.
537         * @exception IOException  If an I/O error occurs while either sending a
538         *      command to the server or receiving a reply from the server.
539         ***/
540        public boolean verify(String username) throws IOException
541        {
542            int result;
543    
544            result = vrfy(username);
545    
546            return (result == SMTPReply.ACTION_OK ||
547                    result == SMTPReply.USER_NOT_LOCAL_WILL_FORWARD);
548        }
549    
550    
551        /***
552         * Fetches the system help information from the server and returns the
553         * full string.
554         * <p>
555         * @return The system help string obtained from the server.  null if the
556         *       information could not be obtained.
557         * @exception SMTPConnectionClosedException
558         *      If the SMTP server prematurely closes the connection as a result
559         *      of the client being idle or some other reason causing the server
560         *      to send SMTP reply code 421.  This exception may be caught either
561         *      as an IOException or independently as itself.
562         * @exception IOException  If an I/O error occurs while either sending a
563         *  command to the server or receiving a reply from the server.
564         ***/
565        public String listHelp() throws IOException
566        {
567            if (SMTPReply.isPositiveCompletion(help())) {
568                return getReplyString();
569            }
570            return null;
571        }
572    
573    
574        /***
575         * Fetches the help information for a given command from the server and
576         * returns the full string.
577         * <p>
578         * @param command The command on which to ask for help.
579         * @return The command help string obtained from the server.  null if the
580         *       information could not be obtained.
581         * @exception SMTPConnectionClosedException
582         *      If the SMTP server prematurely closes the connection as a result
583         *      of the client being idle or some other reason causing the server
584         *      to send SMTP reply code 421.  This exception may be caught either
585         *      as an IOException or independently as itself.
586         * @exception IOException  If an I/O error occurs while either sending a
587         *  command to the server or receiving a reply from the server.
588         ***/
589        public String listHelp(String command) throws IOException
590        {
591            if (SMTPReply.isPositiveCompletion(help(command))) {
592                return getReplyString();
593            }
594            return null;
595        }
596    
597    
598        /***
599         * Sends a NOOP command to the SMTP server.  This is useful for preventing
600         * server timeouts.
601         * <p>
602         * @return True if successfully completed, false if not.
603         * @exception SMTPConnectionClosedException
604         *      If the SMTP server prematurely closes the connection as a result
605         *      of the client being idle or some other reason causing the server
606         *      to send SMTP reply code 421.  This exception may be caught either
607         *      as an IOException or independently as itself.
608         * @exception IOException  If an I/O error occurs while either sending a
609         *      command to the server or receiving a reply from the server.
610         ***/
611        public boolean sendNoOp() throws IOException
612        {
613            return SMTPReply.isPositiveCompletion(noop());
614        }
615    
616    }