    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.pop3;
    019
    020    import java.io.BufferedReader;
    021    import java.io.BufferedWriter;
    022    import java.io.EOFException;
    023    import java.io.IOException;
    024    import java.io.InputStreamReader;
    025    import java.io.OutputStreamWriter;
    026    import java.util.ArrayList;
    027    import java.util.List;
    028
    029    import org.apache.commons.net.MalformedServerReplyException;
    030    import org.apache.commons.net.ProtocolCommandSupport;
    031    import org.apache.commons.net.SocketClient;
    032    import org.apache.commons.net.io.CRLFLineReader;
    033
    034    /***
    035     * The POP3 class is not meant to be used by itself and is provided
    036     * only so that you may easily implement your own POP3 client if
    037     * you so desire.  If you have no need to perform your own implementation,
    038     * you should use {@link org.apache.commons.net.pop3.POP3Client}.
    039     * <p>
    040     * Rather than list it separately for each method, we mention here that
    041     * every method communicating with the server and throwing an IOException
    042     * can also throw a
    043     * {@link org.apache.commons.net.MalformedServerReplyException}
    044     * , which is a subclass
    045     * of IOException.  A MalformedServerReplyException will be thrown when
    046     * the reply received from the server deviates enough from the protocol
    047     * specification that it cannot be interpreted in a useful manner despite
    048     * attempts to be as lenient as possible.
    049     * <p>
    050     * <p>
    051     * @see POP3Client
    052     * @see org.apache.commons.net.MalformedServerReplyException
    053     ***/
    054
    055    public class POP3 extends SocketClient
    056    {
    057        /*** The default POP3 port.  Set to 110 according to RFC 1288. ***/
    058        public static final int DEFAULT_PORT = 110;
    059        /***
    060         * A constant representing the state where the client is not yet connected
    061         * to a POP3 server.
    062         ***/
    063        public static final int DISCONNECTED_STATE = -1;
    064        /***  A constant representing the POP3 authorization state. ***/
    065        public static final int AUTHORIZATION_STATE = 0;
    066        /***  A constant representing the POP3 transaction state. ***/
    067        public static final int TRANSACTION_STATE = 1;
    068        /***  A constant representing the POP3 update state. ***/
    069        public static final int UPDATE_STATE = 2;
    070
    071        static final String _OK = "+OK";
    072        // The reply indicating intermediate response to a command.
    073        static final String _OK_INT = "+ ";
    074        static final String _ERROR = "-ERR";
    075
    076        // We have to ensure that the protocol communication is in ASCII
    077        // but we use ISO-8859-1 just in case 8-bit characters cross
    078        // the wire.
    079        private static final String __DEFAULT_ENCODING = "ISO-8859-1";
    080
    081        private int __popState;
    082        private BufferedWriter __writer;
    083
    084        BufferedReader _reader;
    085        int _replyCode;
    086        String _lastReplyLine;
    087        List<String> _replyLines;
    088
    089        /**
    090         * A ProtocolCommandSupport object used to manage the registering of
    091         * ProtocolCommandListeners and te firing of ProtocolCommandEvents.
    092         */
    093        protected ProtocolCommandSupport _commandSupport_;
    094
    095        /***
    096         * The default POP3Client constructor.  Initializes the state
    097         * to <code>DISCONNECTED_STATE</code>.
    098         ***/
    099        public POP3()
    100        {
    101            setDefaultPort(DEFAULT_PORT);
    102            __popState = DISCONNECTED_STATE;
    103            _reader = null;
    104            __writer = null;
    105            _replyLines = new ArrayList<String>();
    106            _commandSupport_ = new ProtocolCommandSupport(this);
    107        }
    108
    109        private void __getReply() throws IOException
    110        {
    111            String line;
    112
    113            _replyLines.clear();
    114            line = _reader.readLine();
    115
    116            if (line == null)
    117                throw new EOFException("Connection closed without indication.");
    118
    119            if (line.startsWith(_OK))
    120                _replyCode = POP3Reply.OK;
    121            else if (line.startsWith(_ERROR))
    122                _replyCode = POP3Reply.ERROR;
    123            else if (line.startsWith(_OK_INT))
    124                _replyCode = POP3Reply.OK_INT;
    125            else
    126                throw new
    127                MalformedServerReplyException(
    128                    "Received invalid POP3 protocol response from server." + line);
    129
    130            _replyLines.add(line);
    131            _lastReplyLine = line;
    132
    133            fireReplyReceived(_replyCode, getReplyString());
    134        }
    135
    136
    137        /***
    138         * Performs connection initialization and sets state to
    139         * <code> AUTHORIZATION_STATE </code>.
    140         ***/
    141        @Override
    142        protected void _connectAction_() throws IOException
    143        {
    144            super._connectAction_();
    145            _reader =
    146              new CRLFLineReader(new InputStreamReader(_input_,
    147                                                       __DEFAULT_ENCODING));
    148            __writer =
    149              new BufferedWriter(new OutputStreamWriter(_output_,
    150                                                        __DEFAULT_ENCODING));
    151            __getReply();
    152            setState(AUTHORIZATION_STATE);
    153        }
    154
    155
    156        /**
    157         * Set the internal POP3 state.
    158         * @param state the new state. This must be one of the <code>_STATE</code> constants.
    159         */
    160        public void setState(int state)
    161        {
    162            __popState = state;
    163        }
    164
    165
    166        /***
    167         * Returns the current POP3 client state.
    168         * <p>
    169         * @return The current POP3 client state.
    170         ***/
    171        public int getState()
    172        {
    173            return __popState;
    174        }
    175
    176
    177        /***
    178         * Retrieves the additional lines of a multi-line server reply.
    179         ***/
    180        public void getAdditionalReply() throws IOException
    181        {
    182            String line;
    183
    184            line = _reader.readLine();
    185            while (line != null)
    186            {
    187                _replyLines.add(line);
    188                if (line.equals("."))
    189                    break;
    190                line = _reader.readLine();
    191            }
    192        }
    193
    194
    195        /***
    196         * Disconnects the client from the server, and sets the state to
    197         * <code> DISCONNECTED_STATE </code>.  The reply text information
    198         * from the last issued command is voided to allow garbage collection
    199         * of the memory used to store that information.
    200         * <p>
    201         * @exception IOException  If there is an error in disconnecting.
    202         ***/
    203        @Override
    204        public void disconnect() throws IOException
    205        {
    206            super.disconnect();
    207            _reader = null;
    208            __writer = null;
    209            _lastReplyLine = null;
    210            _replyLines.clear();
    211            setState(DISCONNECTED_STATE);
    212        }
    213
    214
    215        /***
    216         * Sends a command an arguments to the server and returns the reply code.
    217         * <p>
    218         * @param command  The POP3 command to send.
    219         * @param args     The command arguments.
    220         * @return  The server reply code (either POP3Reply.OK, POP3Reply.ERROR or POP3Reply.OK_INT).
    221         ***/
    222        public int sendCommand(String command, String args) throws IOException
    223        {
    224            if (__writer == null) {
    225                throw new IllegalStateException("Socket is not connected");
    226            }
    227            StringBuilder __commandBuffer = new StringBuilder();
    228            __commandBuffer.append(command);
    229
    230            if (args != null)
    231            {
    232                __commandBuffer.append(' ');
    233                __commandBuffer.append(args);
    234            }
    235            __commandBuffer.append(SocketClient.NETASCII_EOL);
    236
    237            String message = __commandBuffer.toString();
    238            __writer.write(message);
    239            __writer.flush();
    240
    241            fireCommandSent(command, message);
    242
    243            __getReply();
    244            return _replyCode;
    245        }
    246
    247        /***
    248         * Sends a command with no arguments to the server and returns the
    249         * reply code.
    250         * <p>
    251         * @param command  The POP3 command to send.
    252         * @return  The server reply code (either POP3Reply.OK, POP3Reply.ERROR or POP3Reply.OK_INT).
    253         ***/
    254        public int sendCommand(String command) throws IOException
    255        {
    256            return sendCommand(command, null);
    257        }
    258
    259        /***
    260         * Sends a command an arguments to the server and returns the reply code.
    261         * <p>
    262         * @param command  The POP3 command to send
    263         *                  (one of the POP3Command constants).
    264         * @param args     The command arguments.
    265         * @return  The server reply code (either POP3Reply.OK, POP3Reply.ERROR or POP3Reply.OK_INT).
    266         ***/
    267        public int sendCommand(int command, String args) throws IOException
    268        {
    269            return sendCommand(POP3Command._commands[command], args);
    270        }
    271
    272        /***
    273         * Sends a command with no arguments to the server and returns the
    274         * reply code.
    275         * <p>
    276         * @param command  The POP3 command to send
    277         *                  (one of the POP3Command constants).
    278         * @return  The server reply code (either POP3Reply.OK, POP3Reply.ERROR or POP3Reply.OK_INT).
    279         ***/
    280        public int sendCommand(int command) throws IOException
    281        {
    282            return sendCommand(POP3Command._commands[command], null);
    283        }
    284
    285
    286        /***
    287         * Returns an array of lines received as a reply to the last command
    288         * sent to the server.  The lines have end of lines truncated.  If
    289         * the reply is a single line, but its format ndicates it should be
    290         * a multiline reply, then you must call
    291         * {@link #getAdditionalReply  getAdditionalReply() } to
    292         * fetch the rest of the reply, and then call <code>getReplyStrings</code>
    293         * again.  You only have to worry about this if you are implementing
    294         * your own client using the {@link #sendCommand  sendCommand } methods.
    295         * <p>
    296         * @return The last server response.
    297         ***/
    298        public String[] getReplyStrings()
    299        {
    300            return _replyLines.toArray(new String[_replyLines.size()]);
    301        }
    302
    303        /***
    304         * Returns the reply to the last command sent to the server.
    305         * The value is a single string containing all the reply lines including
    306         * newlines.  If the reply is a single line, but its format ndicates it
    307         * should be a multiline reply, then you must call
    308         * {@link #getAdditionalReply  getAdditionalReply() } to
    309         * fetch the rest of the reply, and then call <code>getReplyString</code>
    310         * again.  You only have to worry about this if you are implementing
    311         * your own client using the {@link #sendCommand  sendCommand } methods.
    312         * <p>
    313         * @return The last server response.
    314         ***/
    315        public String getReplyString()
    316        {
    317            StringBuilder buffer = new StringBuilder(256);
    318
    319            for (String entry : _replyLines)
    320            {
    321                buffer.append(entry);
    322                buffer.append(SocketClient.NETASCII_EOL);
    323            }
    324
    325            return buffer.toString();
    326        }
    327
    328        /**
    329         * Removes a ProtocolCommandListener.
    330         *
    331         * Delegates this incorrectly named method - removeProtocolCommandistener (note the missing "L")- to
    332         * the correct method {@link SocketClient#removeProtocolCommandListener}
    333         * @param listener The ProtocolCommandListener to remove
    334         */
    335        public void removeProtocolCommandistener(org.apache.commons.net.ProtocolCommandListener listener){
    336            removeProtocolCommandListener(listener);
    337        }
    338
    339        /**
    340         * Provide command support to super-class
    341         */
    342        @Override
    343        protected ProtocolCommandSupport getCommandSupport() {
    344            return _commandSupport_;
    345        }
    346    }
    347