    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     * @author Daniel F. Savarese
    119     * @see SMTP
    120     * @see SimpleSMTPHeader
    121     * @see RelayPath
    122     * @see SMTPConnectionClosedException
    123     * @see org.apache.commons.net.MalformedServerReplyException
    124     ***/
    125
    126    public class SMTPClient extends SMTP
    127    {
    128
    129        /**
    130         * Default SMTPClient constructor.  Creates a new SMTPClient instance.
    131         */
    132        public SMTPClient() {  }
    133
    134        /**
    135         * Overloaded constructor that takes an encoding specification
    136         * @param encoding The encoding to use
    137         * @since 2.0
    138         */
    139        public SMTPClient(String encoding) {
    140            super(encoding);
    141        }
    142
    143
    144        /***
    145         * At least one SMTPClient method ({@link #sendMessageData  sendMessageData })
    146         * does not complete the entire sequence of SMTP commands to complete a
    147         * transaction.  These types of commands require some action by the
    148         * programmer after the reception of a positive intermediate command.
    149         * After the programmer's code completes its actions, it must call this
    150         * method to receive the completion reply from the server and verify the
    151         * success of the entire transaction.
    152         * <p>
    153         * For example,
    154         * <pre>
    155         * writer = client.sendMessage();
    156         * if(writer == null) // failure
    157         *   return false;
    158         * header =
    159         *  new SimpleSMTPHeader("foobar@foo.com", "foo@foobar.com", "Re: Foo");
    160         * writer.write(header.toString());
    161         * writer.write("This is just a test");
    162         * writer.close();
    163         * if(!client.completePendingCommand()) // failure
    164         *   return false;
    165         * </pre>
    166         * <p>
    167         * @return True if successfully completed, false if not.
    168         * @exception SMTPConnectionClosedException
    169         *      If the SMTP server prematurely closes the connection as a result
    170         *      of the client being idle or some other reason causing the server
    171         *      to send SMTP reply code 421.  This exception may be caught either
    172         *      as an IOException or independently as itself.
    173         * @exception IOException  If an I/O error occurs while either sending a
    174         *      command to the server or receiving a reply from the server.
    175         ***/
    176        public boolean completePendingCommand() throws IOException
    177        {
    178            return SMTPReply.isPositiveCompletion(getReply());
    179        }
    180
    181
    182        /***
    183         * Login to the SMTP server by sending the HELO command with the
    184         * given hostname as an argument.  Before performing any mail commands,
    185         * you must first login.
    186         * <p>
    187         * @param hostname  The hostname with which to greet the SMTP server.
    188         * @return True if successfully completed, false if not.
    189         * @exception SMTPConnectionClosedException
    190         *      If the SMTP server prematurely closes the connection as a result
    191         *      of the client being idle or some other reason causing the server
    192         *      to send SMTP reply code 421.  This exception may be caught either
    193         *      as an IOException or independently as itself.
    194         * @exception IOException  If an I/O error occurs while either sending a
    195         *      command to the server or receiving a reply from the server.
    196         ***/
    197        public boolean login(String hostname) throws IOException
    198        {
    199            return SMTPReply.isPositiveCompletion(helo(hostname));
    200        }
    201
    202
    203        /***
    204         * Login to the SMTP server by sending the HELO command with the
    205         * client hostname as an argument.  Before performing any mail commands,
    206         * you must first login.
    207         * <p>
    208         * @return True if successfully completed, false if not.
    209         * @exception SMTPConnectionClosedException
    210         *      If the SMTP server prematurely closes the connection as a result
    211         *      of the client being idle or some other reason causing the server
    212         *      to send SMTP reply code 421.  This exception may be caught either
    213         *      as an IOException or independently as itself.
    214         * @exception IOException  If an I/O error occurs while either sending a
    215         *      command to the server or receiving a reply from the server.
    216         ***/
    217        public boolean login() throws IOException
    218        {
    219            String name;
    220            InetAddress host;
    221
    222            host = getLocalAddress();
    223            name = host.getHostName();
    224
    225            if (name == null)
    226                return false;
    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            return new DotTerminatedMessageWriter(_writer);
    366        }
    367
    368
    369        /***
    370         * A convenience method for sending short messages.  This method fetches
    371         * the Writer returned by {@link #sendMessageData  sendMessageData() }
    372         * and writes the specified String to it.  After writing the message,
    373         * this method calls {@link #completePendingCommand completePendingCommand() }
    374         *  to finalize the transaction and returns
    375         * its success or failure.
    376         * <p>
    377         * @param message  The short email message to send.
    378         * @return True if successfully completed, false if not.
    379         * @exception SMTPConnectionClosedException
    380         *      If the SMTP server prematurely closes the connection as a result
    381         *      of the client being idle or some other reason causing the server
    382         *      to send SMTP reply code 421.  This exception may be caught either
    383         *      as an IOException or independently as itself.
    384         * @exception IOException  If an I/O error occurs while either sending a
    385         *      command to the server or receiving a reply from the server.
    386         ***/
    387        public boolean sendShortMessageData(String message) throws IOException
    388        {
    389            Writer writer;
    390
    391            writer = sendMessageData();
    392
    393            if (writer == null)
    394                return false;
    395
    396            writer.write(message);
    397            writer.close();
    398
    399            return completePendingCommand();
    400        }
    401
    402
    403        /***
    404         * A convenience method for a sending short email without having to
    405         * explicitly set the sender and recipient(s).  This method
    406         * sets the sender and recipient using
    407         * {@link #setSender  setSender } and
    408         * {@link #addRecipient  addRecipient }, and then sends the
    409         * message using {@link #sendShortMessageData  sendShortMessageData }.
    410         * <p>
    411         * @param sender  The email address of the sender.
    412         * @param recipient  The email address of the recipient.
    413         * @param message  The short email message to send.
    414         * @return True if successfully completed, false if not.
    415         * @exception SMTPConnectionClosedException
    416         *      If the SMTP server prematurely closes the connection as a result
    417         *      of the client being idle or some other reason causing the server
    418         *      to send SMTP reply code 421.  This exception may be caught either
    419         *      as an IOException or independently as itself.
    420         * @exception IOException  If an I/O error occurs while either sending a
    421         *      command to the server or receiving a reply from the server.
    422         ***/
    423        public boolean sendSimpleMessage(String sender, String recipient,
    424                                         String message)
    425        throws IOException
    426        {
    427            if (!setSender(sender))
    428                return false;
    429
    430            if (!addRecipient(recipient))
    431                return false;
    432
    433            return sendShortMessageData(message);
    434        }
    435
    436
    437
    438        /***
    439         * A convenience method for a sending short email without having to
    440         * explicitly set the sender and recipient(s).  This method
    441         * sets the sender and recipients using
    442         * {@link #setSender  setSender } and
    443         * {@link #addRecipient  addRecipient }, and then sends the
    444         * message using {@link #sendShortMessageData  sendShortMessageData }.
    445         * <p>
    446         * @param sender  The email address of the sender.
    447         * @param recipients  An array of recipient email addresses.
    448         * @param message  The short email message to send.
    449         * @return True if successfully completed, false if not.
    450         * @exception SMTPConnectionClosedException
    451         *      If the SMTP server prematurely closes the connection as a result
    452         *      of the client being idle or some other reason causing the server
    453         *      to send SMTP reply code 421.  This exception may be caught either
    454         *      as an IOException or independently as itself.
    455         * @exception IOException  If an I/O error occurs while either sending a
    456         *      command to the server or receiving a reply from the server.
    457         ***/
    458        public boolean sendSimpleMessage(String sender, String[] recipients,
    459                                         String message)
    460        throws IOException
    461        {
    462            boolean oneSuccess = false;
    463            int count;
    464
    465            if (!setSender(sender))
    466                return false;
    467
    468            for (count = 0; count < recipients.length; count++)
    469            {
    470                if (addRecipient(recipients[count]))
    471                    oneSuccess = true;
    472            }
    473
    474            if (!oneSuccess)
    475                return false;
    476
    477            return sendShortMessageData(message);
    478        }
    479
    480
    481        /***
    482         * Logout of the SMTP server by sending the QUIT command.
    483         * <p>
    484         * @return True if successfully completed, false if not.
    485         * @exception SMTPConnectionClosedException
    486         *      If the SMTP server prematurely closes the connection as a result
    487         *      of the client being idle or some other reason causing the server
    488         *      to send SMTP reply code 421.  This exception may be caught either
    489         *      as an IOException or independently as itself.
    490         * @exception IOException  If an I/O error occurs while either sending a
    491         *      command to the server or receiving a reply from the server.
    492         ***/
    493        public boolean logout() throws IOException
    494        {
    495            return SMTPReply.isPositiveCompletion(quit());
    496        }
    497
    498
    499
    500        /***
    501         * Aborts the current mail transaction, resetting all server stored
    502         * sender, recipient, and mail data, cleaing all buffers and tables.
    503         * <p>
    504         * @return True if successfully completed, false if not.
    505         * @exception SMTPConnectionClosedException
    506         *      If the SMTP server prematurely closes the connection as a result
    507         *      of the client being idle or some other reason causing the server
    508         *      to send SMTP reply code 421.  This exception may be caught either
    509         *      as an IOException or independently as itself.
    510         * @exception IOException  If an I/O error occurs while either sending a
    511         *      command to the server or receiving a reply from the server.
    512         ***/
    513        public boolean reset() throws IOException
    514        {
    515            return SMTPReply.isPositiveCompletion(rset());
    516        }
    517
    518
    519        /***
    520         * Verify that a username or email address is valid, i.e., that mail
    521         * can be delivered to that mailbox on the server.
    522         * <p>
    523         * @param username  The username or email address to validate.
    524         * @return True if the username is valid, false if not.
    525         * @exception SMTPConnectionClosedException
    526         *      If the SMTP server prematurely closes the connection as a result
    527         *      of the client being idle or some other reason causing the server
    528         *      to send SMTP reply code 421.  This exception may be caught either
    529         *      as an IOException or independently as itself.
    530         * @exception IOException  If an I/O error occurs while either sending a
    531         *      command to the server or receiving a reply from the server.
    532         ***/
    533        public boolean verify(String username) throws IOException
    534        {
    535            int result;
    536
    537            result = vrfy(username);
    538
    539            return (result == SMTPReply.ACTION_OK ||
    540                    result == SMTPReply.USER_NOT_LOCAL_WILL_FORWARD);
    541        }
    542
    543
    544        /***
    545         * Fetches the system help information from the server and returns the
    546         * full string.
    547         * <p>
    548         * @return The system help string obtained from the server.  null if the
    549         *       information could not be obtained.
    550         * @exception SMTPConnectionClosedException
    551         *      If the SMTP server prematurely closes the connection as a result
    552         *      of the client being idle or some other reason causing the server
    553         *      to send SMTP reply code 421.  This exception may be caught either
    554         *      as an IOException or independently as itself.
    555         * @exception IOException  If an I/O error occurs while either sending a
    556         *  command to the server or receiving a reply from the server.
    557         ***/
    558        public String listHelp() throws IOException
    559        {
    560            if (SMTPReply.isPositiveCompletion(help()))
    561                return getReplyString();
    562            return null;
    563        }
    564
    565
    566        /***
    567         * Fetches the help information for a given command from the server and
    568         * returns the full string.
    569         * <p>
    570         * @param command The command on which to ask for help.
    571         * @return The command help string obtained from the server.  null if the
    572         *       information could not be obtained.
    573         * @exception SMTPConnectionClosedException
    574         *      If the SMTP server prematurely closes the connection as a result
    575         *      of the client being idle or some other reason causing the server
    576         *      to send SMTP reply code 421.  This exception may be caught either
    577         *      as an IOException or independently as itself.
    578         * @exception IOException  If an I/O error occurs while either sending a
    579         *  command to the server or receiving a reply from the server.
    580         ***/
    581        public String listHelp(String command) throws IOException
    582        {
    583            if (SMTPReply.isPositiveCompletion(help(command)))
    584                return getReplyString();
    585            return null;
    586        }
    587
    588
    589        /***
    590         * Sends a NOOP command to the SMTP server.  This is useful for preventing
    591         * server timeouts.
    592         * <p>
    593         * @return True if successfully completed, false if not.
    594         * @exception SMTPConnectionClosedException
    595         *      If the SMTP server prematurely closes the connection as a result
    596         *      of the client being idle or some other reason causing the server
    597         *      to send SMTP reply code 421.  This exception may be caught either
    598         *      as an IOException or independently as itself.
    599         * @exception IOException  If an I/O error occurs while either sending a
    600         *      command to the server or receiving a reply from the server.
    601         ***/
    602        public boolean sendNoOp() throws IOException
    603        {
    604            return SMTPReply.isPositiveCompletion(noop());
    605        }
    606
    607    }