    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 * This is the default implementation of the FTPFileEntryParserFactory interface. This is the implementation that will be used by
    028 * org.apache.commons.net.ftp.FTPClient.listFiles() if no other implementation has been specified.
    029 *
    030 * @see org.apache.commons.net.ftp.FTPClient#listFiles
    031 * @see org.apache.commons.net.ftp.FTPClient#setParserFactory
    032 */
    033public class DefaultFTPFileEntryParserFactory implements FTPFileEntryParserFactory {
    034
    035    // Match a plain Java Identifier
    036    private static final String JAVA_IDENTIFIER = "\\p{javaJavaIdentifierStart}(\\p{javaJavaIdentifierPart})*";
    037    // Match a qualified name, e.g. a.b.c.Name - but don't allow the default package as that would allow "VMS"/"UNIX" etc.
    038    private static final String JAVA_QUALIFIED_NAME = "(" + JAVA_IDENTIFIER + "\\.)+" + JAVA_IDENTIFIER;
    039    // Create the pattern, as it will be reused many times
    040    private static final Pattern JAVA_QUALIFIED_NAME_PATTERN = Pattern.compile(JAVA_QUALIFIED_NAME);
    041
    042    /**
    043     * <p>
    044     * Implementation extracts a key from the supplied {@link FTPClientConfig FTPClientConfig} parameter and creates an object implementing the interface
    045     * FTPFileEntryParser and uses the supplied configuration to configure it.
    046     * </p>
    047     * <p>
    048     * Note that this method will generally not be called in scenarios that call for autodetection of parser type but rather, for situations where the user
    049     * knows that the server uses a non-default configuration and knows what that configuration is.
    050     * </p>
    051     *
    052     * @param config A {@link FTPClientConfig FTPClientConfig} used to configure the parser created
    053     *
    054     * @return the @link FTPFileEntryParser FTPFileEntryParser} so created.
    055     * @throws ParserInitializationException Thrown on any exception in instantiation
    056     * @throws NullPointerException          if {@code config} is {@code null}
    057     * @since 1.4
    058     */
    059    @Override
    060    public FTPFileEntryParser createFileEntryParser(final FTPClientConfig config) throws ParserInitializationException {
    061        final String key = config.getServerSystemKey();
    062        return createFileEntryParser(key, config);
    063    }
    064
    065    /**
    066     * This default implementation of the FTPFileEntryParserFactory interface works according to the following logic: First it attempts to interpret the
    067     * supplied key as a fully qualified classname (default package is not allowed) of a class implementing the FTPFileEntryParser interface. If that succeeds,
    068     * a parser object of this class is instantiated and is returned; otherwise it attempts to interpret the key as an identirier commonly used by the FTP SYST
    069     * command to identify systems.
    070     * <p>
    071     * If <code>key</code> is not recognized as a fully qualified classname known to the system, this method will then attempt to see whether it <b>contains</b>
    072     * a string identifying one of the known parsers. This comparison is <b>case-insensitive</b>. The intent here is where possible, to select as keys strings
    073     * which are returned by the SYST command on the systems which the corresponding parser successfully parses. This enables this factory to be used in the
    074     * auto-detection system.
    075     *
    076     * @param key should be a fully qualified classname corresponding to a class implementing the FTPFileEntryParser interface<br>
    077     *            OR<br>
    078     *            a string containing (case-insensitively) one of the following keywords:
    079     *            <ul>
    080     *            <li>{@link FTPClientConfig#SYST_UNIX UNIX}</li>
    081     *            <li>{@link FTPClientConfig#SYST_NT WINDOWS}</li>
    082     *            <li>{@link FTPClientConfig#SYST_OS2 OS/2}</li>
    083     *            <li>{@link FTPClientConfig#SYST_OS400 OS/400}</li>
    084     *            <li>{@link FTPClientConfig#SYST_AS400 AS/400}</li>
    085     *            <li>{@link FTPClientConfig#SYST_VMS VMS}</li>
    086     *            <li>{@link FTPClientConfig#SYST_MVS MVS}</li>
    087     *            <li>{@link FTPClientConfig#SYST_NETWARE NETWARE}</li>
    088     *            <li>{@link FTPClientConfig#SYST_L8 TYPE:L8}</li>
    089     *            </ul>
    090     * @return the FTPFileEntryParser corresponding to the supplied key.
    091     * @throws ParserInitializationException thrown if for any reason the factory cannot resolve the supplied key into an FTPFileEntryParser.
    092     * @see FTPFileEntryParser
    093     */
    094    @Override
    095    public FTPFileEntryParser createFileEntryParser(final String key) {
    096        if (key == null) {
    097            throw new ParserInitializationException("Parser key cannot be null");
    098        }
    099        return createFileEntryParser(key, null);
    100    }
    101
    102    // Common method to process both key and config parameters.
    103    private FTPFileEntryParser createFileEntryParser(final String key, final FTPClientConfig config) {
    104        FTPFileEntryParser parser = null;
    105
    106        // Is the key a possible class name?
    107        if (JAVA_QUALIFIED_NAME_PATTERN.matcher(key).matches()) {
    108            try {
    109                final Class<?> parserClass = Class.forName(key);
    110                try {
    111                    parser = (FTPFileEntryParser) parserClass.newInstance();
    112                } catch (final ClassCastException e) {
    113                    throw new ParserInitializationException(
    114                            parserClass.getName() + " does not implement the interface " + "org.apache.commons.net.ftp.FTPFileEntryParser.", e);
    115                } catch (final Exception | ExceptionInInitializerError e) {
    116                    throw new ParserInitializationException("Error initializing parser", e);
    117                }
    118            } catch (final ClassNotFoundException e) {
    119                // OK, assume it is an alias
    120            }
    121        }
    122
    123        if (parser == null) { // Now try for aliases
    124            final String ukey = key.toUpperCase(java.util.Locale.ENGLISH);
    125            if (ukey.contains(FTPClientConfig.SYST_UNIX_TRIM_LEADING)) {
    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.contains(FTPClientConfig.SYST_UNIX)) {
    130                parser = new UnixFTPEntryParser(config, false);
    131            } else if (ukey.contains(FTPClientConfig.SYST_VMS)) {
    132                parser = new VMSVersioningFTPEntryParser(config);
    133            } else if (ukey.contains(FTPClientConfig.SYST_NT)) {
    134                parser = createNTFTPEntryParser(config);
    135            } else if (ukey.contains(FTPClientConfig.SYST_OS2)) {
    136                parser = new OS2FTPEntryParser(config);
    137            } else if (ukey.contains(FTPClientConfig.SYST_OS400) || ukey.contains(FTPClientConfig.SYST_AS400)) {
    138                parser = createOS400FTPEntryParser(config);
    139            } else if (ukey.contains(FTPClientConfig.SYST_MVS)) {
    140                parser = new MVSFTPEntryParser(); // Does not currently support config parameter
    141            } else if (ukey.contains(FTPClientConfig.SYST_NETWARE)) {
    142                parser = new NetwareFTPEntryParser(config);
    143            } else if (ukey.contains(FTPClientConfig.SYST_MACOS_PETER)) {
    144                parser = new MacOsPeterFTPEntryParser(config);
    145            } else if (ukey.contains(FTPClientConfig.SYST_L8)) {
    146                // L8 normally means Unix, but move it to the end for some L8 systems that aren't.
    147                // This check should be last!
    148                parser = new UnixFTPEntryParser(config);
    149            } else {
    150                throw new ParserInitializationException("Unknown parser type: " + key);
    151            }
    152        }
    153
    154        if (parser instanceof Configurable) {
    155            ((Configurable) parser).configure(config);
    156        }
    157        return parser;
    158    }
    159
    160    public FTPFileEntryParser createMVSEntryParser() {
    161        return new MVSFTPEntryParser();
    162    }
    163
    164    public FTPFileEntryParser createNetwareFTPEntryParser() {
    165        return new NetwareFTPEntryParser();
    166    }
    167
    168    public FTPFileEntryParser createNTFTPEntryParser() {
    169        return createNTFTPEntryParser(null);
    170    }
    171
    172    /**
    173     * Creates an NT FTP parser: if the config exists, and the system key equals {@link FTPClientConfig#SYST_NT} then a plain {@link NTFTPEntryParser} is used,
    174     * otherwise a composite of {@link NTFTPEntryParser} and {@link UnixFTPEntryParser} is used.
    175     *
    176     * @param config the config to use, may be {@code null}
    177     * @return the parser
    178     */
    179    private FTPFileEntryParser createNTFTPEntryParser(final FTPClientConfig config) {
    180        if (config != null && FTPClientConfig.SYST_NT.equals(config.getServerSystemKey())) {
    181            return new NTFTPEntryParser(config);
    182        }
    183        // clone the config as it may be changed by the parsers (NET-602)
    184        final FTPClientConfig config2 = config != null ? new FTPClientConfig(config) : null;
    185        return new CompositeFileEntryParser(new FTPFileEntryParser[] { new NTFTPEntryParser(config),
    186                new UnixFTPEntryParser(config2, config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey())) });
    187    }
    188
    189    public FTPFileEntryParser createOS2FTPEntryParser() {
    190        return new OS2FTPEntryParser();
    191    }
    192
    193    public FTPFileEntryParser createOS400FTPEntryParser() {
    194        return createOS400FTPEntryParser(null);
    195    }
    196
    197    /**
    198     * Creates an OS400 FTP parser: if the config exists, and the system key equals {@link FTPClientConfig#SYST_OS400} then a plain {@link OS400FTPEntryParser}
    199     * is used, otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
    200     *
    201     * @param config the config to use, may be {@code null}
    202     * @return the parser
    203     */
    204    private FTPFileEntryParser createOS400FTPEntryParser(final FTPClientConfig config) {
    205        if (config != null && FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey())) {
    206            return new OS400FTPEntryParser(config);
    207        }
    208        // clone the config as it may be changed by the parsers (NET-602)
    209        final FTPClientConfig config2 = config != null ? new FTPClientConfig(config) : null;
    210        return new CompositeFileEntryParser(new FTPFileEntryParser[] { new OS400FTPEntryParser(config),
    211                new UnixFTPEntryParser(config2, config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey())) });
    212    }
    213
    214    public FTPFileEntryParser createUnixFTPEntryParser() {
    215        return new UnixFTPEntryParser();
    216    }
    217
    218    public FTPFileEntryParser createVMSVersioningFTPEntryParser() {
    219        return new VMSVersioningFTPEntryParser();
    220    }
    221
    222}