Source code

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