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_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(FTPClientConfig config)
203    throws ParserInitializationException
204    {
205        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(FTPClientConfig config)
237    {
238        if (config != null && FTPClientConfig.SYST_NT.equals(
239                config.getServerSystemKey()))
240        {
241            return new NTFTPEntryParser(config);
242        } else {
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
254     public FTPFileEntryParser createOS2FTPEntryParser()
255    {
256        return new OS2FTPEntryParser();
257    }
258
259    public FTPFileEntryParser createOS400FTPEntryParser()
260    {
261        return createOS400FTPEntryParser(null);
262    }
263
264    /**
265     * Creates an OS400 FTP parser: if the config exists, and the system key equals
266     * {@link FTPClientConfig.SYST_OS400} then a plain {@link OS400FTPEntryParser} is used,
267     * otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
268     * @param config the config to use, may be {@code null}
269     * @return the parser
270     */
271    private FTPFileEntryParser createOS400FTPEntryParser(FTPClientConfig config)
272        {
273        if (config != null &&
274                FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey()))
275        {
276            return new OS400FTPEntryParser(config);
277        } else {
278            // clone the config as it may be changed by the parsers (NET-602)
279            final FTPClientConfig config2 =  (config != null) ? new FTPClientConfig(config) : null;
280            return new CompositeFileEntryParser(new FTPFileEntryParser[]
281                {
282                    new OS400FTPEntryParser(config),
283                    new UnixFTPEntryParser(config2,
284                            config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey()))
285                });
286        }
287    }
288
289    public FTPFileEntryParser createMVSEntryParser()
290    {
291        return new MVSFTPEntryParser();
292    }
293
294}
295