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 | ExceptionInInitializerError e) {
113                    throw new ParserInitializationException("Error initializing parser", e);
114                }
115            } catch (final ClassNotFoundException e) {
116                // OK, assume it is an alias
117            }
118        }
119
120        if (parser == null) { // Now try for aliases
121            final String ukey = key.toUpperCase(java.util.Locale.ENGLISH);
122            if (ukey.indexOf(FTPClientConfig.SYST_UNIX_TRIM_LEADING) >= 0)
123            {
124                parser = new UnixFTPEntryParser(config, true);
125            }
126            // must check this after SYST_UNIX_TRIM_LEADING as it is a substring of it
127            else if (ukey.indexOf(FTPClientConfig.SYST_UNIX) >= 0)
128            {
129                parser = new UnixFTPEntryParser(config, false);
130            }
131            else if (ukey.indexOf(FTPClientConfig.SYST_VMS) >= 0)
132            {
133                parser = new VMSVersioningFTPEntryParser(config);
134            }
135            else if (ukey.indexOf(FTPClientConfig.SYST_NT) >= 0)
136            {
137                parser = createNTFTPEntryParser(config);
138            }
139            else if (ukey.indexOf(FTPClientConfig.SYST_OS2) >= 0)
140            {
141                parser = new OS2FTPEntryParser(config);
142            }
143            else if (ukey.indexOf(FTPClientConfig.SYST_OS400) >= 0 ||
144                    ukey.indexOf(FTPClientConfig.SYST_AS400) >= 0)
145            {
146                parser = createOS400FTPEntryParser(config);
147            }
148            else if (ukey.indexOf(FTPClientConfig.SYST_MVS) >= 0)
149            {
150                parser = new MVSFTPEntryParser(); // Does not currently support config parameter
151            }
152            else if (ukey.indexOf(FTPClientConfig.SYST_NETWARE) >= 0)
153            {
154                parser = new NetwareFTPEntryParser(config);
155            }
156            else if (ukey.indexOf(FTPClientConfig.SYST_MACOS_PETER) >= 0)
157            {
158                parser = new MacOsPeterFTPEntryParser(config);
159            }
160            else if (ukey.indexOf(FTPClientConfig.SYST_L8) >= 0)
161            {
162                // L8 normally means Unix, but move it to the end for some L8 systems that aren't.
163                // This check should be last!
164                parser = new UnixFTPEntryParser(config);
165            }
166            else
167            {
168                throw new ParserInitializationException("Unknown parser type: " + key);
169            }
170        }
171
172        if (parser instanceof Configurable) {
173            ((Configurable)parser).configure(config);
174        }
175        return parser;
176    }
177
178    /**
179     * <p>Implementation extracts a key from the supplied
180     * {@link  FTPClientConfig FTPClientConfig}
181     * parameter and creates an object implementing the
182     * interface FTPFileEntryParser and uses the supplied configuration
183     * to configure it.
184     * </p><p>
185     * Note that this method will generally not be called in scenarios
186     * that call for autodetection of parser type but rather, for situations
187     * where the user knows that the server uses a non-default configuration
188     * and knows what that configuration is.
189     * </p>
190     * @param config  A {@link  FTPClientConfig FTPClientConfig}
191     * used to configure the parser created
192     *
193     * @return the @link  FTPFileEntryParser FTPFileEntryParser} so created.
194     * @throws ParserInitializationException
195     *                   Thrown on any exception in instantiation
196     * @throws NullPointerException if {@code config} is {@code null}
197     * @since 1.4
198     */
199    @Override
200    public FTPFileEntryParser createFileEntryParser(final FTPClientConfig config)
201    throws ParserInitializationException
202    {
203        final String key = config.getServerSystemKey();
204        return createFileEntryParser(key, config);
205    }
206
207
208    public FTPFileEntryParser createUnixFTPEntryParser()
209    {
210        return new UnixFTPEntryParser();
211    }
212
213    public FTPFileEntryParser createVMSVersioningFTPEntryParser()
214    {
215        return new VMSVersioningFTPEntryParser();
216    }
217
218    public FTPFileEntryParser createNetwareFTPEntryParser() {
219        return new NetwareFTPEntryParser();
220    }
221
222    public FTPFileEntryParser createNTFTPEntryParser()
223    {
224        return createNTFTPEntryParser(null);
225    }
226
227    /**
228     * Creates an NT FTP parser: if the config exists, and the system key equals
229     * {@link FTPClientConfig#SYST_NT} then a plain {@link NTFTPEntryParser} is used,
230     * otherwise a composite of {@link NTFTPEntryParser} and {@link UnixFTPEntryParser} is used.
231     * @param config the config to use, may be {@code null}
232     * @return the parser
233     */
234    private FTPFileEntryParser createNTFTPEntryParser(final FTPClientConfig config)
235    {
236        if (config != null && FTPClientConfig.SYST_NT.equals(
237                config.getServerSystemKey()))
238        {
239            return new NTFTPEntryParser(config);
240        }
241        // clone the config as it may be changed by the parsers (NET-602)
242        final FTPClientConfig config2 =  config != null ? new FTPClientConfig(config) : null;
243        return new CompositeFileEntryParser(new FTPFileEntryParser[]
244               {
245                   new NTFTPEntryParser(config),
246                   new UnixFTPEntryParser(config2,
247                           config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey()))
248               });
249    }
250
251     public FTPFileEntryParser createOS2FTPEntryParser()
252    {
253        return new OS2FTPEntryParser();
254    }
255
256    public FTPFileEntryParser createOS400FTPEntryParser()
257    {
258        return createOS400FTPEntryParser(null);
259    }
260
261    /**
262     * Creates an OS400 FTP parser: if the config exists, and the system key equals
263     * {@link FTPClientConfig#SYST_OS400} then a plain {@link OS400FTPEntryParser} is used,
264     * otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
265     * @param config the config to use, may be {@code null}
266     * @return the parser
267     */
268    private FTPFileEntryParser createOS400FTPEntryParser(final FTPClientConfig config)
269        {
270        if (config != null &&
271                FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey()))
272        {
273            return new OS400FTPEntryParser(config);
274        }
275        // clone the config as it may be changed by the parsers (NET-602)
276        final FTPClientConfig config2 =  config != null ? new FTPClientConfig(config) : null;
277        return new CompositeFileEntryParser(new FTPFileEntryParser[]
278            {
279                new OS400FTPEntryParser(config),
280                new UnixFTPEntryParser(config2,
281                        config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey()))
282            });
283    }
284
285    public FTPFileEntryParser createMVSEntryParser()
286    {
287        return new MVSFTPEntryParser();
288    }
289
290}
291