    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.net.ftp.parser;
    019
    020import java.util.regex.Pattern;
    021
    022import org.apache.commons.net.ftp.Configurable;
    023import org.apache.commons.net.ftp.FTPClientConfig;
    024import org.apache.commons.net.ftp.FTPFileEntryParser;
    025
    026
    027/**
    028 * This is the default implementation of the
    029 * FTPFileEntryParserFactory interface.  This is the
    030 * implementation that will be used by
    031 * org.apache.commons.net.ftp.FTPClient.listFiles()
    032 * if no other implementation has been specified.
    033 *
    034 * @see org.apache.commons.net.ftp.FTPClient#listFiles
    035 * @see org.apache.commons.net.ftp.FTPClient#setParserFactory
    036 */
    037public class DefaultFTPFileEntryParserFactory
    038    implements FTPFileEntryParserFactory
    039{
    040
    041    // Match a plain Java Identifier
    042    private static final String JAVA_IDENTIFIER = "\\p{javaJavaIdentifierStart}(\\p{javaJavaIdentifierPart})*";
    043    // Match a qualified name, e.g. a.b.c.Name - but don't allow the default package as that would allow "VMS"/"UNIX" etc.
    044    private static final String JAVA_QUALIFIED_NAME  = "("+JAVA_IDENTIFIER+"\\.)+"+JAVA_IDENTIFIER;
    045    // Create the pattern, as it will be reused many times
    046    private static final Pattern JAVA_QUALIFIED_NAME_PATTERN = Pattern.compile(JAVA_QUALIFIED_NAME);
    047
    048    /**
    049     * This default implementation of the FTPFileEntryParserFactory
    050     * interface works according to the following logic:
    051     * First it attempts to interpret the supplied key as a fully
    052     * qualified classname (default package is not allowed) of a class implementing the
    053     * FTPFileEntryParser interface.  If that succeeds, a parser
    054     * object of this class is instantiated and is returned;
    055     * otherwise it attempts to interpret the key as an identirier
    056     * commonly used by the FTP SYST command to identify systems.
    057     * <p>
    058     * If <code>key</code> is not recognized as a fully qualified
    059     * classname known to the system, this method will then attempt
    060     * to see whether it <b>contains</b> a string identifying one of
    061     * the known parsers.  This comparison is <b>case-insensitive</b>.
    062     * The intent here is where possible, to select as keys strings
    063     * which are returned by the SYST command on the systems which
    064     * the corresponding parser successfully parses.  This enables
    065     * this factory to be used in the auto-detection system.
    066     *
    067     * @param key    should be a fully qualified classname corresponding to
    068     *               a class implementing the FTPFileEntryParser interface<br>
    069     *               OR<br>
    070     *               a string containing (case-insensitively) one of the
    071     *               following keywords:
    072     *               <ul>
    073     *               <li>{@link FTPClientConfig#SYST_UNIX UNIX}</li>
    074     *               <li>{@link FTPClientConfig#SYST_NT WINDOWS}</li>
    075     *               <li>{@link FTPClientConfig#SYST_OS2 OS/2}</li>
    076     *               <li>{@link FTPClientConfig#SYST_OS400 OS/400}</li>
    077     *               <li>{@link FTPClientConfig#SYST_AS400 AS/400}</li>
    078     *               <li>{@link FTPClientConfig#SYST_VMS VMS}</li>
    079     *               <li>{@link FTPClientConfig#SYST_MVS MVS}</li>
    080     *               <li>{@link FTPClientConfig#SYST_NETWARE NETWARE}</li>
    081     *               <li>{@link FTPClientConfig#SYST_L8 TYPE:L8}</li>
    082     *               </ul>
    083     * @return the FTPFileEntryParser corresponding to the supplied key.
    084     * @throws ParserInitializationException thrown if for any reason the factory cannot resolve
    085     *                   the supplied key into an FTPFileEntryParser.
    086     * @see FTPFileEntryParser
    087     */
    088    @Override
    089    public FTPFileEntryParser createFileEntryParser(final String key)
    090    {
    091        if (key == null) {
    092            throw new ParserInitializationException("Parser key cannot be null");
    093        }
    094        return createFileEntryParser(key, null);
    095    }
    096
    097    // Common method to process both key and config parameters.
    098    private FTPFileEntryParser createFileEntryParser(final String key, final FTPClientConfig config) {
    099        FTPFileEntryParser parser = null;
    100
    101        // Is the key a possible class name?
    102        if (JAVA_QUALIFIED_NAME_PATTERN.matcher(key).matches()) {
    103            try
    104            {
    105                final Class<?> parserClass = Class.forName(key);
    106                try {
    107                    parser = (FTPFileEntryParser) parserClass.newInstance();
    108                } catch (final ClassCastException e) {
    109                    throw new ParserInitializationException(parserClass.getName()
    110                        + " does not implement the interface "
    111                        + "org.apache.commons.net.ftp.FTPFileEntryParser.", e);
    112                } catch (final Exception e) {
    113                    throw new ParserInitializationException("Error initializing parser", e);
    114                } catch (final ExceptionInInitializerError e) {
    115                    throw new ParserInitializationException("Error initializing parser", e);
    116                }
    117            } catch (final ClassNotFoundException e) {
    118                // OK, assume it is an alias
    119            }
    120        }
    121
    122        if (parser == null) { // Now try for aliases
    123            final String ukey = key.toUpperCase(java.util.Locale.ENGLISH);
    124            if (ukey.indexOf(FTPClientConfig.SYST_UNIX_TRIM_LEADING) >= 0)
    125            {
    126                parser = new UnixFTPEntryParser(config, true);
    127            }
    128            // must check this after SYST_UNIX_TRIM_LEADING as it is a substring of it
    129            else if (ukey.indexOf(FTPClientConfig.SYST_UNIX) >= 0)
    130            {
    131                parser = new UnixFTPEntryParser(config, false);
    132            }
    133            else if (ukey.indexOf(FTPClientConfig.SYST_VMS) >= 0)
    134            {
    135                parser = new VMSVersioningFTPEntryParser(config);
    136            }
    137            else if (ukey.indexOf(FTPClientConfig.SYST_NT) >= 0)
    138            {
    139                parser = createNTFTPEntryParser(config);
    140            }
    141            else if (ukey.indexOf(FTPClientConfig.SYST_OS2) >= 0)
    142            {
    143                parser = new OS2FTPEntryParser(config);
    144            }
    145            else if (ukey.indexOf(FTPClientConfig.SYST_OS400) >= 0 ||
    146                    ukey.indexOf(FTPClientConfig.SYST_AS400) >= 0)
    147            {
    148                parser = createOS400FTPEntryParser(config);
    149            }
    150            else if (ukey.indexOf(FTPClientConfig.SYST_MVS) >= 0)
    151            {
    152                parser = new MVSFTPEntryParser(); // Does not currently support config parameter
    153            }
    154            else if (ukey.indexOf(FTPClientConfig.SYST_NETWARE) >= 0)
    155            {
    156                parser = new NetwareFTPEntryParser(config);
    157            }
    158            else if (ukey.indexOf(FTPClientConfig.SYST_MACOS_PETER) >= 0)
    159            {
    160                parser = new MacOsPeterFTPEntryParser(config);
    161            }
    162            else if (ukey.indexOf(FTPClientConfig.SYST_L8) >= 0)
    163            {
    164                // L8 normally means Unix, but move it to the end for some L8 systems that aren't.
    165                // This check should be last!
    166                parser = new UnixFTPEntryParser(config);
    167            }
    168            else
    169            {
    170                throw new ParserInitializationException("Unknown parser type: " + key);
    171            }
    172        }
    173
    174        if (parser instanceof Configurable) {
    175            ((Configurable)parser).configure(config);
    176        }
    177        return parser;
    178    }
    179
    180    /**
    181     * <p>Implementation extracts a key from the supplied
    182     * {@link  FTPClientConfig FTPClientConfig}
    183     * parameter and creates an object implementing the
    184     * interface FTPFileEntryParser and uses the supplied configuration
    185     * to configure it.
    186     * </p><p>
    187     * Note that this method will generally not be called in scenarios
    188     * that call for autodetection of parser type but rather, for situations
    189     * where the user knows that the server uses a non-default configuration
    190     * and knows what that configuration is.
    191     * </p>
    192     * @param config  A {@link  FTPClientConfig FTPClientConfig}
    193     * used to configure the parser created
    194     *
    195     * @return the @link  FTPFileEntryParser FTPFileEntryParser} so created.
    196     * @throws ParserInitializationException
    197     *                   Thrown on any exception in instantiation
    198     * @throws NullPointerException if {@code config} is {@code null}
    199     * @since 1.4
    200     */
    201    @Override
    202    public FTPFileEntryParser createFileEntryParser(final FTPClientConfig config)
    203    throws ParserInitializationException
    204    {
    205        final String key = config.getServerSystemKey();
    206        return createFileEntryParser(key, config);
    207    }
    208
    209
    210    public FTPFileEntryParser createUnixFTPEntryParser()
    211    {
    212        return new UnixFTPEntryParser();
    213    }
    214
    215    public FTPFileEntryParser createVMSVersioningFTPEntryParser()
    216    {
    217        return new VMSVersioningFTPEntryParser();
    218    }
    219
    220    public FTPFileEntryParser createNetwareFTPEntryParser() {
    221        return new NetwareFTPEntryParser();
    222    }
    223
    224    public FTPFileEntryParser createNTFTPEntryParser()
    225    {
    226        return createNTFTPEntryParser(null);
    227    }
    228
    229    /**
    230     * Creates an NT FTP parser: if the config exists, and the system key equals
    231     * {@link FTPClientConfig.SYST_NT} then a plain {@link NTFTPEntryParser} is used,
    232     * otherwise a composite of {@link NTFTPEntryParser} and {@link UnixFTPEntryParser} is used.
    233     * @param config the config to use, may be {@code null}
    234     * @return the parser
    235     */
    236    private FTPFileEntryParser createNTFTPEntryParser(final FTPClientConfig config)
    237    {
    238        if (config != null && FTPClientConfig.SYST_NT.equals(
    239                config.getServerSystemKey()))
    240        {
    241            return new NTFTPEntryParser(config);
    242        }
    243        // clone the config as it may be changed by the parsers (NET-602)
    244        final FTPClientConfig config2 =  config != null ? new FTPClientConfig(config) : null;
    245        return new CompositeFileEntryParser(new FTPFileEntryParser[]
    246               {
    247                   new NTFTPEntryParser(config),
    248                   new UnixFTPEntryParser(config2,
    249                           config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey()))
    250               });
    251    }
    252
    253     public FTPFileEntryParser createOS2FTPEntryParser()
    254    {
    255        return new OS2FTPEntryParser();
    256    }
    257
    258    public FTPFileEntryParser createOS400FTPEntryParser()
    259    {
    260        return createOS400FTPEntryParser(null);
    261    }
    262
    263    /**
    264     * Creates an OS400 FTP parser: if the config exists, and the system key equals
    265     * {@link FTPClientConfig.SYST_OS400} then a plain {@link OS400FTPEntryParser} is used,
    266     * otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
    267     * @param config the config to use, may be {@code null}
    268     * @return the parser
    269     */
    270    private FTPFileEntryParser createOS400FTPEntryParser(final FTPClientConfig config)
    271        {
    272        if (config != null &&
    273                FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey()))
    274        {
    275            return new OS400FTPEntryParser(config);
    276        }
    277        // clone the config as it may be changed by the parsers (NET-602)
    278        final FTPClientConfig config2 =  config != null ? new FTPClientConfig(config) : null;
    279        return new CompositeFileEntryParser(new FTPFileEntryParser[]
    280            {
    281                new OS400FTPEntryParser(config),
    282                new UnixFTPEntryParser(config2,
    283                        config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey()))
    284            });
    285    }
    286
    287    public FTPFileEntryParser createMVSEntryParser()
    288    {
    289        return new MVSFTPEntryParser();
    290    }
    291
    292}
    293