    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 *      https://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
    018package org.apache.commons.net.ftp;
    019
    020import java.io.BufferedReader;
    021import java.io.BufferedWriter;
    022import java.io.IOException;
    023import java.io.InputStreamReader;
    024import java.io.OutputStreamWriter;
    025import java.io.Reader;
    026import java.net.Inet4Address;
    027import java.net.Inet6Address;
    028import java.net.InetAddress;
    029import java.net.SocketException;
    030import java.net.SocketTimeoutException;
    031import java.nio.charset.Charset;
    032import java.nio.charset.StandardCharsets;
    033import java.util.ArrayList;
    034
    035import org.apache.commons.io.Charsets;
    036import org.apache.commons.net.MalformedServerReplyException;
    037import org.apache.commons.net.ProtocolCommandSupport;
    038import org.apache.commons.net.SocketClient;
    039import org.apache.commons.net.io.CRLFLineReader;
    040import org.apache.commons.net.util.NetConstants;
    041
    042/**
    043 * FTP provides the basic the functionality necessary to implement your own FTP client. It extends org.apache.commons.net.SocketClient since extending
    044 * TelnetClient was causing unwanted behavior (like connections that did not time out properly).
    045 * <p>
    046 * To derive the full benefits of the FTP class requires some knowledge of the FTP protocol defined in RFC 959. However, there is no reason why you should have
    047 * to use the FTP class. The {@link org.apache.commons.net.ftp.FTPClient} class, derived from FTP, implements all the functionality required of an FTP client.
    048 * The FTP class is made public to provide access to various FTP constants and to make it easier for adventurous programmers (or those with special needs) to
    049 * interact with the FTP protocol and implement their own clients. A set of methods with names corresponding to the FTP command names are provided to facilitate
    050 * this interaction.
    051 * </p>
    052 * <p>
    053 * You should keep in mind that the FTP server may choose to prematurely close a connection if the client has been idle for longer than a given time period
    054 * (usually 900 seconds). The FTP class will detect a premature FTP server connection closing when it receives a
    055 * {@link org.apache.commons.net.ftp.FTPReply#SERVICE_NOT_AVAILABLE FTPReply.SERVICE_NOT_AVAILABLE} response to a command. When that occurs, the FTP class
    056 * method encountering that reply will throw an {@link org.apache.commons.net.ftp.FTPConnectionClosedException}. {@code FTPConectionClosedException} is a
    057 * subclass of {@code IOException} and therefore need not be caught separately, but if you are going to catch it separately, its catch block must appear
    058 * before the more general {@code IOException} catch block. When you encounter an {@link org.apache.commons.net.ftp.FTPConnectionClosedException} , you
    059 * must disconnect the connection with {@link #disconnect disconnect()} to properly clean up the system resources used by FTP. Before disconnecting, you may
    060 * check the last reply code and text with {@link #getReplyCode getReplyCode}, {@link #getReplyString getReplyString}, and {@link #getReplyStrings
    061 * getReplyStrings}. You may avoid server disconnections while the client is idle by periodically sending NOOP commands to the server.
    062 * </p>
    063 * <p>
    064 * Rather than list it separately for each method, we mention here that every method communicating with the server and throwing an IOException can also throw a
    065 * {@link org.apache.commons.net.MalformedServerReplyException} , which is a subclass of IOException. A MalformedServerReplyException will be thrown when the
    066 * reply received from the server deviates enough from the protocol specification that it cannot be interpreted in a useful manner despite attempts to be as
    067 * lenient as possible.
    068 * </p>
    069 *
    070 * @see FTPClient
    071 * @see FTPConnectionClosedException
    072 * @see org.apache.commons.net.MalformedServerReplyException
    073 */
    074
    075public class FTP extends SocketClient {
    076
    077    /**
    078     * Space character.
    079     */
    080    private static final char SP = ' ';
    081
    082    /** The default FTP data port (20). */
    083    public static final int DEFAULT_DATA_PORT = 20;
    084
    085    /** The default FTP control port (21). */
    086    public static final int DEFAULT_PORT = 21;
    087
    088    /**
    089     * A constant used to indicate the file(s) being transferred should be treated as ASCII. This is the default file type. All constants ending in
    090     * {@code FILE_TYPE} are used to indicate file types.
    091     */
    092    public static final int ASCII_FILE_TYPE = 0;
    093
    094    /**
    095     * A constant used to indicate the file(s) being transferred should be treated as EBCDIC. Note however that there are several EBCDIC formats. All
    096     * constants ending in {@code FILE_TYPE} are used to indicate file types.
    097     */
    098    public static final int EBCDIC_FILE_TYPE = 1;
    099
    100    /**
    101     * A constant used to indicate the file(s) being transferred should be treated as a binary image, i.e., no translations should be performed. All constants
    102     * ending in {@code FILE_TYPE} are used to indicate file types.
    103     */
    104    public static final int BINARY_FILE_TYPE = 2;
    105
    106    /**
    107     * A constant used to indicate the file(s) being transferred should be treated as a local type. All constants ending in {@code FILE_TYPE} are used to
    108     * indicate file types.
    109     */
    110    public static final int LOCAL_FILE_TYPE = 3;
    111
    112    /**
    113     * A constant used for text files to indicate a non-print text format. This is the default format. All constants ending in {@code TEXT_FORMAT} are used
    114     * to indicate text formatting for text transfers (both ASCII and EBCDIC).
    115     */
    116    public static final int NON_PRINT_TEXT_FORMAT = 4;
    117
    118    /**
    119     * A constant used to indicate a text file contains format vertical format control characters. All constants ending in {@code TEXT_FORMAT} are used to
    120     * indicate text formatting for text transfers (both ASCII and EBCDIC).
    121     */
    122    public static final int TELNET_TEXT_FORMAT = 5;
    123
    124    /**
    125     * A constant used to indicate a text file contains ASA vertical format control characters. All constants ending in {@code TEXT_FORMAT} are used to
    126     * indicate text formatting for text transfers (both ASCII and EBCDIC).
    127     */
    128    public static final int CARRIAGE_CONTROL_TEXT_FORMAT = 6;
    129
    130    /**
    131     * A constant used to indicate a file is to be treated as a continuous sequence of bytes. This is the default structure. All constants ending in
    132     * {@code _STRUCTURE} are used to indicate file structure for file transfers.
    133     */
    134    public static final int FILE_STRUCTURE = 7;
    135
    136    /**
    137     * A constant used to indicate a file is to be treated as a sequence of records. All constants ending in {@code _STRUCTURE} are used to indicate file
    138     * structure for file transfers.
    139     */
    140    public static final int RECORD_STRUCTURE = 8;
    141
    142    /**
    143     * A constant used to indicate a file is to be treated as a set of independent indexed pages. All constants ending in {@code _STRUCTURE} are used to
    144     * indicate file structure for file transfers.
    145     */
    146    public static final int PAGE_STRUCTURE = 9;
    147
    148    /**
    149     * A constant used to indicate a file is to be transferred as a stream of bytes. This is the default transfer mode. All constants ending in
    150     * {@code TRANSFER_MODE} are used to indicate file transfer modes.
    151     */
    152    public static final int STREAM_TRANSFER_MODE = 10;
    153
    154    /**
    155     * A constant used to indicate a file is to be transferred as a series of blocks. All constants ending in {@code TRANSFER_MODE} are used to indicate
    156     * file transfer modes.
    157     */
    158    public static final int BLOCK_TRANSFER_MODE = 11;
    159
    160    /**
    161     * A constant used to indicate a file is to be transferred as FTP compressed data. All constants ending in {@code TRANSFER_MODE} are used to indicate
    162     * file transfer modes. Currently unused.
    163     */
    164    public static final int COMPRESSED_TRANSFER_MODE = 12;
    165
    166    /**
    167     * A constant used to indicate a file is to be transferred as FTP (un)compressing data in the "deflate" compression format. All constants ending in
    168     * {@code TRANSFER_MODE} are used to indicate file transfer modes.
    169     *
    170     * See the Internet Draft <a href="https://datatracker.ietf.org/doc/html/draft-preston-ftpext-deflate-04">Deflate transmission mode for FTP</a>
    171     */
    172    public static final int DEFLATE_TRANSFER_MODE = 13;
    173
    174//    /**
    175//     * A constant used to indicate a file is to be transferred as FTP (un)compressing data in the GZIP compression format. All constants ending in
    176//     * {@code TRANSFER_MODE} are used to indicate file transfer modes.
    177//     */
    178//    public static final int GZIP_TRANSFER_MODE = 14;
    179
    180    // We have to ensure that the protocol communication is in ASCII,
    181    // but we use ISO-8859-1 just in case 8-bit characters cross
    182    // the wire.
    183    /**
    184     * The default character encoding used for communicating over an FTP control connection. The default encoding is an ASCII-compatible encoding. Some FTP
    185     * servers expect other encodings. You can change the encoding used by an FTP instance with {@link #setControlEncoding setControlEncoding}.
    186     */
    187    public static final String DEFAULT_CONTROL_ENCODING = StandardCharsets.ISO_8859_1.name();
    188
    189    /** Length of the FTP reply code (3 alphanumerics) */
    190    public static final int REPLY_CODE_LEN = 3;
    191
    192    private static final String MODES = "AEILNTCFRPSBCZ";
    193
    194    /**
    195     * The last FTP reply code.
    196     */
    197    protected int _replyCode;
    198
    199    /**
    200     * The lines of text from the last FTP server response.
    201     */
    202    protected ArrayList<String> _replyLines;
    203
    204    /**
    205     * Whether we've processed the last reply lines.
    206     */
    207    protected boolean _newReplyString;
    208
    209    /**
    210     * The text from the last FTP server response.
    211     */
    212    protected String _replyString;
    213
    214    /**
    215     * The character encoding to be used by the FTP control connection.
    216     */
    217    protected String _controlEncoding;
    218
    219    /**
    220     * A ProtocolCommandSupport object used to manage the registering of ProtocolCommandListeners and the firing of ProtocolCommandEvents.
    221     */
    222    protected ProtocolCommandSupport _commandSupport_;
    223
    224    /**
    225     * This is used to signal whether a block of multiline responses beginning with xxx must be terminated by the same numeric code xxx See section 4.2 of RFC
    226     * 959 for details.
    227     */
    228    protected boolean strictMultilineParsing;
    229
    230    /**
    231     * If this is true, then non-multiline replies must have the format: 3-digit code <space> <text> If false, then the 3-digit code does not have to be
    232     * followed by space See section 4.2 of RFC 959 for details.
    233     */
    234    private boolean strictReplyParsing = true;
    235
    236    /**
    237     * Wraps SocketClient._input_ to facilitate the reading of text from the FTP control connection. Do not access the control connection via
    238     * SocketClient._input_. This member starts with a null value, is initialized in {@link #_connectAction_}, and set to null in {@link #disconnect}.
    239     */
    240    protected BufferedReader _controlInput_;
    241
    242    /**
    243     * Wraps SocketClient._output_ to facilitate the writing of text to the FTP control connection. Do not access the control connection via
    244     * SocketClient._output_. This member starts with a null value, is initialized in {@link #_connectAction_}, and set to null in {@link #disconnect}.
    245     */
    246    protected BufferedWriter _controlOutput_;
    247
    248    /**
    249     * The default FTP constructor. Sets the default port to {@code DEFAULT_PORT} and initializes internal data structures for saving FTP reply
    250     * information.
    251     */
    252    public FTP() {
    253        setDefaultPort(DEFAULT_PORT);
    254        _replyLines = new ArrayList<>();
    255        _newReplyString = false;
    256        _replyString = null;
    257        _controlEncoding = DEFAULT_CONTROL_ENCODING;
    258        _commandSupport_ = new ProtocolCommandSupport(this);
    259    }
    260
    261    /**
    262     * Gets the reply, but don't pass it to command listeners. Used for keep-alive processing only.
    263     *
    264     * @throws IOException on error
    265     * @since 3.0
    266     */
    267    protected void __getReplyNoReport() throws IOException {
    268        getReply(false);
    269    }
    270
    271    /**
    272     * Send a noop and get the reply without reporting to the command listener. Intended for use with keep-alive.
    273     *
    274     * @throws IOException on error
    275     * @since 3.0
    276     */
    277    protected void __noop() throws IOException {
    278        final String msg = buildMessage(FTPCmd.NOOP.getCommand(), null);
    279        send(msg);
    280        __getReplyNoReport(); // This may time out
    281    }
    282
    283    /**
    284     * Initiates control connections and gets initial reply. Initializes {@link #_controlInput_} and {@link #_controlOutput_}.
    285     */
    286    @Override
    287    protected void _connectAction_() throws IOException {
    288        _connectAction_(null);
    289    }
    290
    291    /**
    292     * Initiates control connections and gets initial reply. Initializes {@link #_controlInput_} and {@link #_controlOutput_}.
    293     *
    294     * @param socketIsReader the reader to reuse (if non-null)
    295     * @throws IOException on error
    296     * @since 3.4
    297     */
    298    protected void _connectAction_(final Reader socketIsReader) throws IOException {
    299        super._connectAction_(); // sets up _input_ and _output_
    300        if (socketIsReader == null) {
    301            _controlInput_ = new CRLFLineReader(new InputStreamReader(_input_, getControlEncoding()));
    302        } else {
    303            _controlInput_ = new CRLFLineReader(socketIsReader);
    304        }
    305        _controlOutput_ = new BufferedWriter(new OutputStreamWriter(_output_, getControlEncoding()));
    306        if (connectTimeout > 0) { // NET-385
    307            final int original = _socket_.getSoTimeout();
    308            _socket_.setSoTimeout(connectTimeout);
    309            try {
    310                getReply();
    311                // If we received code 120, we have to fetch completion reply.
    312                if (FTPReply.isPositivePreliminary(_replyCode)) {
    313                    getReply();
    314                }
    315            } catch (final SocketTimeoutException e) {
    316                throw new IOException("Timed out waiting for initial connect reply", e);
    317            } finally {
    318                _socket_.setSoTimeout(original);
    319            }
    320        } else {
    321            getReply();
    322            // If we received code 120, we have to fetch completion reply.
    323            if (FTPReply.isPositivePreliminary(_replyCode)) {
    324                getReply();
    325            }
    326        }
    327    }
    328
    329    /**
    330     * A convenience method to send the FTP ABOR command to the server, receive the reply, and return the reply code.
    331     *
    332     * @return The reply code received from the server.
    333     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    334     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    335     *                                      independently as itself.
    336     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    337     */
    338    public int abor() throws IOException {
    339        return sendCommand(FTPCmd.ABOR);
    340    }
    341
    342    /**
    343     * A convenience method to send the FTP ACCT command to the server, receive the reply, and return the reply code.
    344     *
    345     * @param account The account name to access.
    346     * @return The reply code received from the server.
    347     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    348     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    349     *                                      independently as itself.
    350     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    351     */
    352    public int acct(final String account) throws IOException {
    353        return sendCommand(FTPCmd.ACCT, account);
    354    }
    355
    356    /**
    357     * A convenience method to send the FTP ALLO command to the server, receive the reply, and return the reply code.
    358     *
    359     * @param bytes The number of bytes to allocate.
    360     * @return The reply code received from the server.
    361     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    362     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    363     *                                      independently as itself.
    364     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    365     */
    366    public int allo(final int bytes) throws IOException {
    367        return sendCommand(FTPCmd.ALLO, Integer.toString(bytes));
    368    }
    369
    370    /**
    371     * A convenience method to send the FTP ALLO command to the server, receive the reply, and return the reply code.
    372     *
    373     * @param bytes      The number of bytes to allocate.
    374     * @param recordSize The size of a record.
    375     * @return The reply code received from the server.
    376     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    377     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    378     *                                      independently as itself.
    379     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    380     */
    381    public int allo(final int bytes, final int recordSize) throws IOException {
    382        return sendCommand(FTPCmd.ALLO, Integer.toString(bytes) + " R " + Integer.toString(recordSize));
    383    }
    384
    385    /**
    386     * A convenience method to send the FTP ALLO command to the server, receive the reply, and return the reply code.
    387     *
    388     * @param bytes The number of bytes to allocate.
    389     * @return The reply code received from the server.
    390     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    391     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    392     *                                      independently as itself.
    393     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    394     */
    395    public int allo(final long bytes) throws IOException {
    396        return sendCommand(FTPCmd.ALLO, Long.toString(bytes));
    397    }
    398
    399    /**
    400     * A convenience method to send the FTP ALLO command to the server, receive the reply, and return the reply code.
    401     *
    402     * @param bytes      The number of bytes to allocate.
    403     * @param recordSize The size of a record.
    404     * @return The reply code received from the server.
    405     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    406     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    407     *                                      independently as itself.
    408     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    409     */
    410    public int allo(final long bytes, final int recordSize) throws IOException {
    411        return sendCommand(FTPCmd.ALLO, Long.toString(bytes) + " R " + Integer.toString(recordSize));
    412    }
    413
    414    /**
    415     * A convenience method to send the FTP APPE command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    416     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    417     * for you.
    418     *
    419     * @param path The path to use for the file when stored at the remote end of the transfer.
    420     * @return The reply code received from the server.
    421     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    422     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    423     *                                      independently as itself.
    424     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    425     */
    426    public int appe(final String path) throws IOException {
    427        return sendCommand(FTPCmd.APPE, path);
    428    }
    429
    430    private String buildMessage(final String command, final String args) {
    431        final StringBuilder builder = new StringBuilder(command);
    432        if (args != null) {
    433            builder.append(SP);
    434            builder.append(args);
    435        }
    436        builder.append(NETASCII_EOL);
    437        return builder.toString();
    438    }
    439
    440    /**
    441     * A convenience method to send the FTP CDUP command to the server, receive the reply, and return the reply code.
    442     *
    443     * @return The reply code received from the server.
    444     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    445     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    446     *                                      independently as itself.
    447     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    448     */
    449    public int cdup() throws IOException {
    450        return sendCommand(FTPCmd.CDUP);
    451    }
    452
    453    private int checkMode(final int index) {
    454        if (index >= MODES.length()) {
    455            throw new IllegalArgumentException("Unknown mode");
    456        }
    457        return index;
    458    }
    459
    460    /**
    461     * A convenience method to send the FTP CWD command to the server, receive the reply, and return the reply code.
    462     *
    463     * @param directory The new working directory.
    464     * @return The reply code received from the server.
    465     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    466     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    467     *                                      independently as itself.
    468     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    469     */
    470    public int cwd(final String directory) throws IOException {
    471        return sendCommand(FTPCmd.CWD, directory);
    472    }
    473
    474    /**
    475     * A convenience method to send the FTP DELE command to the server, receive the reply, and return the reply code.
    476     *
    477     * @param path The path to delete.
    478     * @return The reply code received from the server.
    479     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    480     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    481     *                                      independently as itself.
    482     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    483     */
    484    public int dele(final String path) throws IOException {
    485        return sendCommand(FTPCmd.DELE, path);
    486    }
    487
    488    /**
    489     * Closes the control connection to the FTP server and sets to null some internal data so that the memory may be reclaimed by the garbage collector. The
    490     * reply text and code information from the last command is voided so that the memory it used may be reclaimed. Also sets {@link #_controlInput_} and
    491     * {@link #_controlOutput_} to null.
    492     *
    493     * @throws IOException If an error occurs while disconnecting.
    494     */
    495    @Override
    496    public void disconnect() throws IOException {
    497        super.disconnect();
    498        _controlInput_ = null;
    499        _controlOutput_ = null;
    500        _newReplyString = false;
    501        _replyString = null;
    502    }
    503
    504    /**
    505     * A convenience method to send the FTP EPRT command to the server, receive the reply, and return the reply code.
    506     * <p>
    507     * Examples:
    508     * </p>
    509     * <ul>
    510     * <li>EPRT |1|132.235.1.2|6275|</li>
    511     * <li>EPRT |2|1080::8:800:200C:417A|5282|</li>
    512     * </ul>
    513     *
    514     * @see "http://www.faqs.org/rfcs/rfc2428.html"
    515     * @param host The host owning the port.
    516     * @param port The new port.
    517     * @return The reply code received from the server.
    518     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    519     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    520     *                                      independently as itself.
    521     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    522     * @since 2.2
    523     */
    524    public int eprt(final InetAddress host, final int port) throws IOException {
    525        // If IPv6, trim the zone index
    526        String h = host.getHostAddress();
    527        final int num = h.indexOf('%');
    528        if (num > 0) {
    529            h = h.substring(0, num);
    530        }
    531        final StringBuilder builder = new StringBuilder();
    532        builder.append("|");
    533        if (host instanceof Inet4Address) {
    534            builder.append("1");
    535        } else if (host instanceof Inet6Address) {
    536            builder.append("2");
    537        }
    538        builder.append("|");
    539        builder.append(h);
    540        builder.append("|");
    541        builder.append(port);
    542        builder.append("|");
    543        return sendCommand(FTPCmd.EPRT, builder.toString());
    544    }
    545
    546    /**
    547     * A convenience method to send the FTP EPSV command to the server, receive the reply, and return the reply code. Remember, it's up to you to interpret the
    548     * reply string containing the host/port information.
    549     *
    550     * @return The reply code received from the server.
    551     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    552     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    553     *                                      independently as itself.
    554     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    555     * @since 2.2
    556     */
    557    public int epsv() throws IOException {
    558        return sendCommand(FTPCmd.EPSV);
    559    }
    560
    561    /**
    562     * A convenience method to send the FTP FEAT command to the server, receive the reply, and return the reply code.
    563     *
    564     * @return The reply code received by the server
    565     * @throws IOException If an I/O error occurs while either sending the command or receiving the server reply.
    566     * @since 2.2
    567     */
    568    public int feat() throws IOException {
    569        return sendCommand(FTPCmd.FEAT);
    570    }
    571
    572    /**
    573     * Gets protocol command support.
    574     */
    575    @Override
    576    protected ProtocolCommandSupport getCommandSupport() {
    577        return _commandSupport_;
    578    }
    579
    580    /**
    581     * Gets the character encoding used to communicate over the control connection.
    582     *
    583     * @return The character encoding used to communicate over the control connection.
    584     */
    585    public String getControlEncoding() {
    586        return _controlEncoding;
    587    }
    588
    589    /**
    590     * Gets a reply from the FTP server and returns the integer reply code. After calling this method, the actual reply text can be accessed from either
    591     * calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}. Only use this method if you are implementing your own FTP
    592     * client or if you need to fetch a secondary response from the FTP server.
    593     *
    594     * @return The integer value of the reply code of the fetched FTP reply.
    595     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    596     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    597     *                                      independently as itself.
    598     * @throws IOException                  If an I/O error occurs while receiving the server reply.
    599     */
    600    public int getReply() throws IOException {
    601        return getReply(true);
    602    }
    603
    604    /**
    605     * Reads the reply line.
    606     * <p>
    607     * Syntax:
    608     * </p>
    609     *
    610     * <pre>{@code
    611     * error-response = error-code SP *TCHAR CRLF
    612     * error-code     = ("4" / "5") 2DIGIT
    613     * }</pre>
    614     *
    615     * @param reportReply whether to fire a reply received event.
    616     * @return the reply code.
    617     * @throws IOException If an I/O error occurs.
    618     */
    619    private int getReply(final boolean reportReply) throws IOException {
    620        final int length;
    621        _newReplyString = true;
    622        _replyLines.clear();
    623        String line = _controlInput_.readLine();
    624        if (line == null) {
    625            throw new FTPConnectionClosedException("Connection closed without indication.");
    626        }
    627        // In case we run into an anomaly we don't want fatal index exceptions
    628        // to be thrown.
    629        length = line.length();
    630        if (length < REPLY_CODE_LEN) {
    631            throw new MalformedServerReplyException("Truncated server reply: " + line);
    632        }
    633        final String code;
    634        try {
    635            code = line.substring(0, REPLY_CODE_LEN);
    636            _replyCode = Integer.parseInt(code);
    637        } catch (final NumberFormatException e) {
    638            throw new MalformedServerReplyException("Could not parse response code.\nServer Reply: " + line);
    639        }
    640        _replyLines.add(line);
    641        // Check the server reply type
    642        if (length > REPLY_CODE_LEN) {
    643            final char sep = line.charAt(REPLY_CODE_LEN);
    644            // Get extra lines if message continues.
    645            if (sep == '-') {
    646                do {
    647                    line = _controlInput_.readLine();
    648                    if (line == null) {
    649                        throw new FTPConnectionClosedException("Connection closed without indication.");
    650                    }
    651                    _replyLines.add(line);
    652                    // The length() check handles problems that could arise from readLine()
    653                    // returning too soon after encountering a naked CR or some other
    654                    // anomaly.
    655                } while (isStrictMultilineParsing() ? strictCheck(line, code) : lenientCheck(line));
    656            } else if (isStrictReplyParsing() && sep != SP) {
    657                throw new MalformedServerReplyException("Invalid server reply: '" + line + "'");
    658            }
    659        } else if (isStrictReplyParsing()) {
    660            throw new MalformedServerReplyException("Truncated server reply: '" + line + "'");
    661        }
    662        if (reportReply) {
    663            fireReplyReceived(_replyCode, getReplyString());
    664        }
    665        if (_replyCode == FTPReply.SERVICE_NOT_AVAILABLE) {
    666            throw new FTPConnectionClosedException("FTP response 421 received.  Server closed connection.");
    667        }
    668        return _replyCode;
    669    }
    670
    671    /**
    672     * Gets the integer value of the reply code of the last FTP reply. You will usually only use this method after you connect to the FTP server to check
    673     * that the connection was successful since {@code connect} is of type void.
    674     *
    675     * @return The integer value of the reply code of the last FTP reply.
    676     */
    677    public int getReplyCode() {
    678        return _replyCode;
    679    }
    680
    681    /**
    682     * Gets the entire text of the last FTP server response exactly as it was received, including all end of line markers in NETASCII format.
    683     *
    684     * @return The entire text from the last FTP response as a String.
    685     */
    686    public String getReplyString() {
    687        if (!_newReplyString) {
    688            return _replyString;
    689        }
    690        _newReplyString = false;
    691        return _replyString = String.join(NETASCII_EOL, _replyLines);
    692    }
    693
    694    /**
    695     * Gets the nth line of text from the last FTP server response as a string. The end of line markers of each are stripped from the line.
    696     *
    697     * @param index The index of the line to return, 0-based.
    698     * @return The lines of text from the last FTP response as an array.
    699     */
    700    String getReplyString(final int index) {
    701        return _replyLines.get(index);
    702    }
    703
    704    /**
    705     * Gets the lines of text from the last FTP server response as an array of strings, one entry per line. The end of line markers of each are stripped from
    706     * each line.
    707     *
    708     * @return The lines of text from the last FTP response as an array.
    709     */
    710    public String[] getReplyStrings() {
    711        return _replyLines.toArray(NetConstants.EMPTY_STRING_ARRAY);
    712    }
    713
    714    /**
    715     * A convenience method to send the FTP HELP command to the server, receive the reply, and return the reply code.
    716     *
    717     * @return The reply code received from the server.
    718     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    719     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    720     *                                      independently as itself.
    721     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    722     */
    723    public int help() throws IOException {
    724        return sendCommand(FTPCmd.HELP);
    725    }
    726
    727    /**
    728     * A convenience method to send the FTP HELP command to the server, receive the reply, and return the reply code.
    729     *
    730     * @param command The command name on which to request help.
    731     * @return The reply code received from the server.
    732     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    733     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    734     *                                      independently as itself.
    735     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    736     */
    737    public int help(final String command) throws IOException {
    738        return sendCommand(FTPCmd.HELP, command);
    739    }
    740
    741    /**
    742     * Tests whether strict multiline parsing is enabled, as per RFC 959, section 4.2.
    743     *
    744     * @return True if strict, false if lenient
    745     * @since 2.0
    746     */
    747    public boolean isStrictMultilineParsing() {
    748        return strictMultilineParsing;
    749    }
    750
    751    /**
    752     * Tests whether strict non-multiline parsing is enabled, as per RFC 959, section 4.2.
    753     * <p>
    754     * The default is true, which requires the 3-digit code be followed by space and some text.
    755     * If false, only the 3-digit code is required (as was the case for versions up to 3.5).
    756     * </p>
    757     *
    758     * @return True if strict (default), false if additional checks are not made
    759     * @since 3.6
    760     */
    761    public boolean isStrictReplyParsing() {
    762        return strictReplyParsing;
    763    }
    764
    765    // The strict check is too strong a condition because of non-conforming ftp
    766    // servers like ftp.funet.fi which sent 226 as the last line of a
    767    // 426 multi-line reply in response to ls /. We relax the condition to
    768    // test that the line starts with a digit rather than starting with
    769    // the code.
    770    private boolean lenientCheck(final String line) {
    771        return !(line.length() > REPLY_CODE_LEN && line.charAt(REPLY_CODE_LEN) != '-' && Character.isDigit(line.charAt(0)));
    772    }
    773
    774    /**
    775     * A convenience method to send the FTP LIST command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    776     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    777     * for you.
    778     *
    779     * @return The reply code received from the server.
    780     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    781     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    782     *                                      independently as itself.
    783     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    784     */
    785    public int list() throws IOException {
    786        return sendCommand(FTPCmd.LIST);
    787    }
    788
    789    /**
    790     * A convenience method to send the FTP LIST command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    791     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    792     * for you.
    793     *
    794     * @param path The path to list, may be {@code null} in which case the command is sent with no parameters
    795     * @return The reply code received from the server.
    796     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    797     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    798     *                                      independently as itself.
    799     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    800     */
    801    public int list(final String path) throws IOException {
    802        return sendCommand(FTPCmd.LIST, path);
    803    }
    804
    805    /**
    806     * Sends the MDTM command for the given file.
    807     *
    808     * @param file name of file
    809     * @return the status
    810     * @throws IOException on error
    811     * @since 2.0
    812     **/
    813    public int mdtm(final String file) throws IOException {
    814        return sendCommand(FTPCmd.MDTM, file);
    815    }
    816
    817    /**
    818     * A convenience method to send the FTP MFMT command to the server, receive the reply, and return the reply code.
    819     *
    820     * @param path The path for which mtime is to be changed
    821     * @param timeval  Timestamp in {@code yyyyMMDDhhmmss} format
    822     * @return The reply code received from the server.
    823     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    824     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    825     *                                      independently as itself.
    826     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    827     * @since 2.2
    828     * @see <a href="https://tools.ietf.org/html/draft-somers-ftp-mfxx-04">https://tools.ietf.org/html/draft-somers-ftp-mfxx-04</a>
    829     **/
    830    public int mfmt(final String path, final String timeval) throws IOException {
    831        return sendCommand(FTPCmd.MFMT, timeval + SP + path);
    832    }
    833
    834    /**
    835     * A convenience method to send the FTP MKD command to the server, receive the reply, and return the reply code.
    836     *
    837     * @param path The path of the new directory to create.
    838     * @return The reply code received from the server.
    839     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    840     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    841     *                                      independently as itself.
    842     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    843     */
    844    public int mkd(final String path) throws IOException {
    845        return sendCommand(FTPCmd.MKD, path);
    846    }
    847
    848    /**
    849     * A convenience method to send the FTP MLSD command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    850     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    851     * for you.
    852     *
    853     * @return The reply code received from the server.
    854     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    855     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    856     *                                      independently as itself.
    857     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    858     * @since 3.0
    859     */
    860    public int mlsd() throws IOException {
    861        return sendCommand(FTPCmd.MLSD);
    862    }
    863
    864    /**
    865     * A convenience method to send the FTP MLSD command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    866     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    867     * for you.
    868     *
    869     * @param path the path to report on
    870     * @return The reply code received from the server, may be {@code null} in which case the command is sent with no parameters
    871     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    872     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    873     *                                      independently as itself.
    874     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    875     * @since 3.0
    876     */
    877    public int mlsd(final String path) throws IOException {
    878        return sendCommand(FTPCmd.MLSD, path);
    879    }
    880
    881    /**
    882     * A convenience method to send the FTP MLST command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    883     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    884     * for you.
    885     *
    886     * @return The reply code received from the server.
    887     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    888     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    889     *                                      independently as itself.
    890     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    891     * @since 3.0
    892     */
    893    public int mlst() throws IOException {
    894        return sendCommand(FTPCmd.MLST);
    895    }
    896
    897    /**
    898     * A convenience method to send the FTP MLST command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    899     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    900     * for you.
    901     *
    902     * @param path the path to report on
    903     * @return The reply code received from the server, may be {@code null} in which case the command is sent with no parameters
    904     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    905     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    906     *                                      independently as itself.
    907     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    908     * @since 3.0
    909     */
    910    public int mlst(final String path) throws IOException {
    911        return sendCommand(FTPCmd.MLST, path);
    912    }
    913
    914    /**
    915     * A convenience method to send the FTP MODE command to the server, receive the reply, and return the reply code.
    916     *
    917     * @param mode The transfer mode to use (one of the {@code TRANSFER_MODE} constants).
    918     * @return The reply code received from the server.
    919     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    920     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    921     *                                      independently as itself.
    922     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    923     */
    924    public int mode(final int mode) throws IOException {
    925
    926        return sendCommand(FTPCmd.MODE, modeStringAt(mode));
    927    }
    928
    929    private char modeCharAt(final int index) {
    930        return MODES.charAt(checkMode(index));
    931    }
    932
    933    private String modeStringAt(final int index) {
    934        checkMode(index);
    935        return MODES.substring(index, index + 1);
    936    }
    937
    938    /**
    939     * A convenience method to send the FTP NLST command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    940     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    941     * for you.
    942     *
    943     * @return The reply code received from the server.
    944     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    945     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    946     *                                      independently as itself.
    947     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    948     */
    949    public int nlst() throws IOException {
    950        return sendCommand(FTPCmd.NLST);
    951    }
    952
    953    /**
    954     * A convenience method to send the FTP NLST command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    955     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    956     * for you.
    957     *
    958     * @param path The path to list, may be {@code null} in which case the command is sent with no parameters
    959     * @return The reply code received from the server.
    960     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    961     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    962     *                                      independently as itself.
    963     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    964     */
    965    public int nlst(final String path) throws IOException {
    966        return sendCommand(FTPCmd.NLST, path);
    967    }
    968
    969    /**
    970     * A convenience method to send the FTP NOOP command to the server, receive the reply, and return the reply code.
    971     *
    972     * @return The reply code received from the server.
    973     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    974     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    975     *                                      independently as itself.
    976     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    977     */
    978    public int noop() throws IOException {
    979        return sendCommand(FTPCmd.NOOP);
    980    }
    981
    982    /**
    983     * A convenience method to send the FTP OPTS command to the server, receive the reply, and return the reply code.
    984     * <p>
    985     * FTP request Syntax:
    986     * </p>
    987     * <pre>{@code
    988     * opts             = opts-cmd SP command-name [ SP command-options ] CRLF
    989     * opts-cmd         = "opts"
    990     * command-name     = <any FTP command which allows option setting>
    991     * command-options  = <format specified by individual FTP command>
    992     * }</pre>
    993     * @param commandNameOptions The OPTS command name and options.
    994     * @return The reply code received from the server.
    995     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    996     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    997     *                                      independently as itself.
    998     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    999     * @since 3.12.0
    1000     */
    1001    public int opts(final String... commandNameOptions) throws IOException {
    1002        return sendCommand(FTPCmd.OPTS, String.join(" ", commandNameOptions));
    1003    }
    1004
    1005    /**
    1006     * A convenience method to send the FTP OPTS command to the server, receive the reply, and return the reply code.
    1007     * <p>
    1008     * FTP request Syntax:
    1009     * </p>
    1010     * <pre>{@code
    1011     * opts             = opts-cmd SP command-name [ SP command-options ] CRLF
    1012     * opts-cmd         = "opts"
    1013     * command-name     = <any FTP command which allows option setting>
    1014     * command-options  = <format specified by individual FTP command>
    1015     * }</pre>
    1016     * @param commandName The OPTS command name.
    1017     * @param commandOptions The OPTS command options.
    1018     * @return The reply code received from the server.
    1019     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1020     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1021     *                                      independently as itself.
    1022     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1023     * @since 3.12.0
    1024     */
    1025    public int opts(final String commandName, final String commandOptions) throws IOException {
    1026        return opts(commandName + SP + commandOptions);
    1027    }
    1028
    1029    /**
    1030     * A convenience method to send the FTP PASS command to the server, receive the reply, and return the reply code.
    1031     *
    1032     * @param password The plain text password of the user being logged into.
    1033     * @return The reply code received from the server.
    1034     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1035     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1036     *                                      independently as itself.
    1037     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1038     */
    1039    public int pass(final String password) throws IOException {
    1040        return sendCommand(FTPCmd.PASS, password);
    1041    }
    1042
    1043    /**
    1044     * A convenience method to send the FTP PASV command to the server, receive the reply, and return the reply code. Remember, it's up to you to interpret the
    1045     * reply string containing the host/port information.
    1046     *
    1047     * @return The reply code received from the server.
    1048     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1049     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1050     *                                      independently as itself.
    1051     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1052     */
    1053    public int pasv() throws IOException {
    1054        return sendCommand(FTPCmd.PASV);
    1055    }
    1056
    1057    /**
    1058     * A convenience method to send the FTP PORT command to the server, receive the reply, and return the reply code.
    1059     *
    1060     * @param host The host owning the port.
    1061     * @param port The new port.
    1062     * @return The reply code received from the server.
    1063     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1064     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1065     *                                      independently as itself.
    1066     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1067     */
    1068    public int port(final InetAddress host, final int port) throws IOException {
    1069        final StringBuilder info = new StringBuilder(24);
    1070        info.append(host.getHostAddress().replace('.', ','));
    1071        int num = port >>> 8;
    1072        info.append(',');
    1073        info.append(num);
    1074        info.append(',');
    1075        num = port & 0xff;
    1076        info.append(num);
    1077        return sendCommand(FTPCmd.PORT, info.toString());
    1078    }
    1079
    1080    /**
    1081     * A convenience method to send the FTP PWD command to the server, receive the reply, and return the reply code.
    1082     *
    1083     * @return The reply code received from the server.
    1084     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1085     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1086     *                                      independently as itself.
    1087     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1088     */
    1089    public int pwd() throws IOException {
    1090        return sendCommand(FTPCmd.PWD);
    1091    }
    1092
    1093    /**
    1094     * A convenience method to send the FTP QUIT command to the server, receive the reply, and return the reply code.
    1095     *
    1096     * @return The reply code received from the server.
    1097     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1098     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1099     *                                      independently as itself.
    1100     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1101     */
    1102    public int quit() throws IOException {
    1103        return sendCommand(FTPCmd.QUIT);
    1104    }
    1105
    1106    /**
    1107     * A convenience method to send the FTP REIN command to the server, receive the reply, and return the reply code.
    1108     *
    1109     * @return The reply code received from the server.
    1110     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1111     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1112     *                                      independently as itself.
    1113     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1114     */
    1115    public int rein() throws IOException {
    1116        return sendCommand(FTPCmd.REIN);
    1117    }
    1118
    1119    /**
    1120     * A convenience method to send the FTP REST command to the server, receive the reply, and return the reply code.
    1121     *
    1122     * @param marker The marker at which to restart a transfer.
    1123     * @return The reply code received from the server.
    1124     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1125     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1126     *                                      independently as itself.
    1127     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1128     */
    1129    public int rest(final String marker) throws IOException {
    1130        return sendCommand(FTPCmd.REST, marker);
    1131    }
    1132
    1133    /**
    1134     * A convenience method to send the FTP RETR command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    1135     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    1136     * for you.
    1137     *
    1138     * @param path The path of the file to retrieve.
    1139     * @return The reply code received from the server.
    1140     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1141     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1142     *                                      independently as itself.
    1143     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1144     */
    1145    public int retr(final String path) throws IOException {
    1146        return sendCommand(FTPCmd.RETR, path);
    1147    }
    1148
    1149    /**
    1150     * A convenience method to send the FTP RMD command to the server, receive the reply, and return the reply code.
    1151     *
    1152     * @param path The path of the directory to remove.
    1153     * @return The reply code received from the server.
    1154     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1155     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1156     *                                      independently as itself.
    1157     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1158     */
    1159    public int rmd(final String path) throws IOException {
    1160        return sendCommand(FTPCmd.RMD, path);
    1161    }
    1162
    1163    /**
    1164     * A convenience method to send the FTP RNFR command to the server, receive the reply, and return the reply code.
    1165     *
    1166     * @param path The path to rename from.
    1167     * @return The reply code received from the server.
    1168     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1169     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1170     *                                      independently as itself.
    1171     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1172     */
    1173    public int rnfr(final String path) throws IOException {
    1174        return sendCommand(FTPCmd.RNFR, path);
    1175    }
    1176
    1177
    1178    /**
    1179     * A convenience method to send the FTP RNTO command to the server, receive the reply, and return the reply code.
    1180     *
    1181     * @param path The path to rename to
    1182     * @return The reply code received from the server.
    1183     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1184     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1185     *                                      independently as itself.
    1186     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1187     */
    1188    public int rnto(final String path) throws IOException {
    1189        return sendCommand(FTPCmd.RNTO, path);
    1190    }
    1191
    1192    private void send(final String message) throws IOException, FTPConnectionClosedException, SocketException {
    1193        try {
    1194            _controlOutput_.write(message);
    1195            _controlOutput_.flush();
    1196        } catch (final SocketException e) {
    1197            if (!isConnected()) {
    1198                throw new FTPConnectionClosedException("Connection unexpectedly closed.");
    1199            }
    1200            throw e;
    1201        }
    1202    }
    1203
    1204    /**
    1205     * Sends an FTP command to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the
    1206     * actual reply text can be accessed by calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}.
    1207     *
    1208     * @param command The FTPCmd enum corresponding to the FTP command to send.
    1209     * @return The integer value of the FTP reply code returned by the server in response to the command.
    1210     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1211     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1212     *                                      independently as itself.
    1213     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1214     * @since 3.3
    1215     */
    1216    public int sendCommand(final FTPCmd command) throws IOException {
    1217        return sendCommand(command, null);
    1218    }
    1219
    1220    /**
    1221     * Sends an FTP command to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the
    1222     * actual reply text can be accessed by calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}.
    1223     *
    1224     * @param command The FTPCmd enum corresponding to the FTP command to send.
    1225     * @param args    The arguments to the FTP command. If this parameter is set to null, then the command is sent with no argument.
    1226     * @return The integer value of the FTP reply code returned by the server in response to the command.
    1227     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1228     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1229     *                                      independently as itself.
    1230     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1231     * @since 3.3
    1232     */
    1233    public int sendCommand(final FTPCmd command, final String args) throws IOException {
    1234        return sendCommand(command.getCommand(), args);
    1235    }
    1236
    1237    /**
    1238     * Sends an FTP command with no arguments to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed
    1239     * information, the actual reply text can be accessed by calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}.
    1240     *
    1241     * @param command The FTPCommand constant corresponding to the FTP command to send.
    1242     * @return The integer value of the FTP reply code returned by the server in response to the command.
    1243     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1244     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1245     *                                      independently as itself.
    1246     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1247     */
    1248    public int sendCommand(final int command) throws IOException {
    1249        return sendCommand(command, null);
    1250    }
    1251
    1252    /**
    1253     * Sends an FTP command to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the
    1254     * actual reply text can be accessed by calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}.
    1255     *
    1256     * @param command The FTPCommand constant corresponding to the FTP command to send.
    1257     * @param args    The arguments to the FTP command. If this parameter is set to null, then the command is sent with no argument.
    1258     * @return The integer value of the FTP reply code returned by the server in response to the command.
    1259     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1260     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1261     *                                      independently as itself.
    1262     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1263     * @deprecated (3.3) Use {@link #sendCommand(FTPCmd, String)} instead
    1264     */
    1265    @Deprecated
    1266    public int sendCommand(final int command, final String args) throws IOException {
    1267        return sendCommand(FTPCommand.getCommand(command), args);
    1268    }
    1269
    1270    /**
    1271     * Sends an FTP command with no arguments to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed
    1272     * information, the actual reply text can be accessed by calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}.
    1273     *
    1274     * @param command The text representation of the FTP command to send.
    1275     * @return The integer value of the FTP reply code returned by the server in response to the command.
    1276     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1277     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1278     *                                      independently as itself.
    1279     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1280     */
    1281    public int sendCommand(final String command) throws IOException {
    1282        return sendCommand(command, null);
    1283    }
    1284
    1285    /**
    1286     * Sends an FTP command to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the
    1287     * actual reply text can be accessed by calling {@link #getReplyString getReplyString} or {@link #getReplyStrings getReplyStrings}.
    1288     *
    1289     * @param command The text representation of the FTP command to send.
    1290     * @param args    The arguments to the FTP command. If this parameter is set to null, then the command is sent with no argument.
    1291     * @return The integer value of the FTP reply code returned by the server in response to the command.
    1292     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1293     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1294     *                                      independently as itself.
    1295     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1296     */
    1297    public int sendCommand(final String command, final String args) throws IOException {
    1298        if (_controlOutput_ == null) {
    1299            throw new IOException("Connection is not open");
    1300        }
    1301        final String message = buildMessage(command, args);
    1302        send(message);
    1303        fireCommandSent(command, message);
    1304        return getReply();
    1305    }
    1306
    1307    /**
    1308     * Sets the character encoding to be used by the FTP control connection. Some FTP servers require that commands be issued in a non-ASCII encoding like
    1309     * UTF-8 so that file names with multi-byte character representations (e.g, Big 8) can be specified.
    1310     * <p>
    1311     * Please note that this has to be set before the connection is established.
    1312     * </p>
    1313     * @param charset The new character encoding for the control connection.
    1314     * @since 3.12.0
    1315     */
    1316    public void setControlEncoding(final Charset charset) {
    1317        _controlEncoding = Charsets.toCharset(charset).name();
    1318    }
    1319
    1320    /**
    1321     * Sets the character encoding to be used by the FTP control connection. Some FTP servers require that commands be issued in a non-ASCII encoding like
    1322     * UTF-8 so that file names with multi-byte character representations (e.g, Big 8) can be specified.
    1323     * <p>
    1324     * Please note that this has to be set before the connection is established.
    1325     * </p>
    1326     * @param encoding The new character encoding for the control connection.
    1327     */
    1328    public void setControlEncoding(final String encoding) {
    1329        _controlEncoding = encoding;
    1330    }
    1331
    1332    /**
    1333     * Sets strict multiline parsing.
    1334     *
    1335     * @param strictMultilineParsing the setting
    1336     * @since 2.0
    1337     */
    1338    public void setStrictMultilineParsing(final boolean strictMultilineParsing) {
    1339        this.strictMultilineParsing = strictMultilineParsing;
    1340    }
    1341
    1342    /**
    1343     * Sets strict non-multiline parsing.
    1344     * <p>
    1345     * If true, it requires the 3-digit code be followed by space and some text.
    1346     * If false, only the 3-digit code is required (as was the case for versions up to 3.5).
    1347     * </p>
    1348     * <p>
    1349     * <strong>This should not be required by a well-behaved FTP server</strong> <br>
    1350     * </p>
    1351     *
    1352     * @param strictReplyParsing the setting
    1353     * @since 3.6
    1354     */
    1355    public void setStrictReplyParsing(final boolean strictReplyParsing) {
    1356        this.strictReplyParsing = strictReplyParsing;
    1357    }
    1358
    1359    /**
    1360     * A convenience method to send the FTP SITE command to the server, receive the reply, and return the reply code.
    1361     *
    1362     * @param parameters The site parameters to send.
    1363     * @return The reply code received from the server.
    1364     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1365     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1366     *                                      independently as itself.
    1367     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1368     */
    1369    public int site(final String parameters) throws IOException {
    1370        return sendCommand(FTPCmd.SITE, parameters);
    1371    }
    1372
    1373    /**
    1374     * A convenience method to send the FTP SIZE command to the server, receive the reply, and return the reply code.
    1375     *
    1376     * @param parameters The site parameters to send.
    1377     * @return The reply code received from the server.
    1378     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1379     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1380     *                                      independently as itself.
    1381     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1382     * @since 3.7
    1383     */
    1384    public int size(final String parameters) throws IOException {
    1385        return sendCommand(FTPCmd.SIZE, parameters);
    1386    }
    1387
    1388    /**
    1389     * A convenience method to send the FTP SMNT command to the server, receive the reply, and return the reply code.
    1390     *
    1391     * @param dir The directory name.
    1392     * @return The reply code received from the server.
    1393     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1394     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1395     *                                      independently as itself.
    1396     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1397     */
    1398    public int smnt(final String dir) throws IOException {
    1399        return sendCommand(FTPCmd.SMNT, dir);
    1400    }
    1401
    1402    /**
    1403     * A convenience method to send the FTP STAT command to the server, receive the reply, and return the reply code.
    1404     *
    1405     * @return The reply code received from the server.
    1406     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1407     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1408     *                                      independently as itself.
    1409     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1410     */
    1411    public int stat() throws IOException {
    1412        return sendCommand(FTPCmd.STAT);
    1413    }
    1414
    1415    /**
    1416     * A convenience method to send the FTP STAT command to the server, receive the reply, and return the reply code.
    1417     *
    1418     * @param path A path to list.
    1419     * @return The reply code received from the server.
    1420     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1421     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1422     *                                      independently as itself.
    1423     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1424     */
    1425    public int stat(final String path) throws IOException {
    1426        return sendCommand(FTPCmd.STAT, path);
    1427    }
    1428
    1429    /**
    1430     * A convenience method to send the FTP STOR command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    1431     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    1432     * for you.
    1433     *
    1434     * @param path The path to use for the file when stored at the remote end of the transfer.
    1435     * @return The reply code received from the server.
    1436     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1437     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1438     *                                      independently as itself.
    1439     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1440     */
    1441    public int stor(final String path) throws IOException {
    1442        return sendCommand(FTPCmd.STOR, path);
    1443    }
    1444
    1445    /**
    1446     * A convenience method to send the FTP STOU command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    1447     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    1448     * for you.
    1449     *
    1450     * @return The reply code received from the server.
    1451     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1452     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1453     *                                      independently as itself.
    1454     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1455     */
    1456    public int stou() throws IOException {
    1457        return sendCommand(FTPCmd.STOU);
    1458    }
    1459
    1460    /**
    1461     * A convenience method to send the FTP STOU command to the server, receive the reply, and return the reply code. Remember, it is up to you to manage the
    1462     * data connection. If you don't need this low level of access, use {@link org.apache.commons.net.ftp.FTPClient} , which will handle all low level details
    1463     * for you.
    1464     *
    1465     * @param path The base path to use for the file when stored at the remote end of the transfer. Some FTP servers require this.
    1466     * @return The reply code received from the server.
    1467     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1468     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1469     *                                      independently as itself.
    1470     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1471     */
    1472    public int stou(final String path) throws IOException {
    1473        return sendCommand(FTPCmd.STOU, path);
    1474    }
    1475
    1476    // The RFC-compliant multiline termination check
    1477    private boolean strictCheck(final String line, final String code) {
    1478        return !(line.startsWith(code) && line.charAt(REPLY_CODE_LEN) == SP);
    1479    }
    1480
    1481    /**
    1482     * A convenience method to send the FTP STRU command to the server, receive the reply, and return the reply code.
    1483     *
    1484     * @param structure The structure of the file (one of the {@code _STRUCTURE} constants).
    1485     * @return The reply code received from the server.
    1486     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1487     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1488     *                                      independently as itself.
    1489     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1490     */
    1491    public int stru(final int structure) throws IOException {
    1492        return sendCommand(FTPCmd.STRU, modeStringAt(structure));
    1493    }
    1494
    1495    /**
    1496     * A convenience method to send the FTP SYST command to the server, receive the reply, and return the reply code.
    1497     *
    1498     * @return The reply code received from the server.
    1499     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1500     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1501     *                                      independently as itself.
    1502     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1503     */
    1504    public int syst() throws IOException {
    1505        return sendCommand(FTPCmd.SYST);
    1506    }
    1507
    1508    /**
    1509     * A convenience method to send the FTP TYPE command to the server, receive the reply, and return the reply code.
    1510     *
    1511     * @param fileType The type of the file (one of the {@code FILE_TYPE} constants).
    1512     * @return The reply code received from the server.
    1513     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1514     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1515     *                                      independently as itself.
    1516     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1517     */
    1518    public int type(final int fileType) throws IOException {
    1519        return sendCommand(FTPCmd.TYPE, modeStringAt(fileType));
    1520    }
    1521
    1522    /**
    1523     * A convenience method to send the FTP TYPE command for text files to the server, receive the reply, and return the reply code.
    1524     *
    1525     * @param fileType         The type of the file (one of the {@code FILE_TYPE} constants).
    1526     * @param formatOrByteSize The format of the file (one of the {@code _FORMAT} constants). In the case of {@code LOCAL_FILE_TYPE}, the byte size.
    1527     * @return The reply code received from the server.
    1528     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1529     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1530     *                                      independently as itself.
    1531     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1532     */
    1533    public int type(final int fileType, final int formatOrByteSize) throws IOException {
    1534        final StringBuilder arg = new StringBuilder();
    1535        arg.append(modeCharAt(fileType));
    1536        arg.append(SP);
    1537        if (fileType == LOCAL_FILE_TYPE) {
    1538            arg.append(formatOrByteSize);
    1539        } else {
    1540            arg.append(modeCharAt(formatOrByteSize));
    1541        }
    1542        return sendCommand(FTPCmd.TYPE, arg.toString());
    1543    }
    1544
    1545    /**
    1546     * A convenience method to send the FTP USER command to the server, receive the reply, and return the reply code.
    1547     *
    1548     * @param user The user to login under.
    1549     * @return The reply code received from the server.
    1550     * @throws FTPConnectionClosedException If the FTP server prematurely closes the connection as a result of the client being idle or some other reason
    1551     *                                      causing the server to send FTP reply code 421. This exception may be caught either as an IOException or
    1552     *                                      independently as itself.
    1553     * @throws IOException                  If an I/O error occurs while either sending the command or receiving the server reply.
    1554     */
    1555    public int user(final String user) throws IOException {
    1556        return sendCommand(FTPCmd.USER, user);
    1557    }
    1558}