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    
018    package org.apache.commons.net.ftp.parser;
019    
020    import java.util.regex.Pattern;
021    
022    import org.apache.commons.net.ftp.Configurable;
023    import org.apache.commons.net.ftp.FTPClientConfig;
024    import 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     */
037    public 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         * <p/>
067         *
068         * @param key    should be a fully qualified classname corresponding to
069         *               a class implementing the FTPFileEntryParser interface<br/>
070         *               OR<br/>
071         *               a string containing (case-insensitively) one of the
072         *               following keywords:
073         *               <ul>
074         *               <li>{@link FTPClientConfig#SYST_UNIX UNIX}</li>
075         *               <li>{@link FTPClientConfig#SYST_NT WINDOWS}</li>
076         *               <li>{@link FTPClientConfig#SYST_OS2 OS/2}</li>
077         *               <li>{@link FTPClientConfig#SYST_OS400 OS/400}</li>
078         *               <li>{@link FTPClientConfig#SYST_AS400 AS/400}</li>
079         *               <li>{@link FTPClientConfig#SYST_VMS VMS}</li>
080         *               <li>{@link FTPClientConfig#SYST_MVS MVS}</li>
081         *               <li>{@link FTPClientConfig#SYST_NETWARE NETWARE}</li>
082         *               <li>{@link FTPClientConfig#SYST_L8 TYPE:L8}</li>
083         *               </ul>
084         * @return the FTPFileEntryParser corresponding to the supplied key.
085         * @throws ParserInitializationException thrown if for any reason the factory cannot resolve
086         *                   the supplied key into an FTPFileEntryParser.
087         * @see FTPFileEntryParser
088         */
089        public FTPFileEntryParser createFileEntryParser(String key)
090        {
091            if (key == null)
092                throw new ParserInitializationException("Parser key cannot be null");
093            return createFileEntryParser(key, null);
094        }
095    
096        // Common method to process both key and config parameters.
097        private FTPFileEntryParser createFileEntryParser(String key, FTPClientConfig config) {
098            FTPFileEntryParser parser = null;
099    
100            // Is the key a possible class name?
101            if (JAVA_QUALIFIED_NAME_PATTERN.matcher(key).matches()) {
102                try
103                {
104                    Class<?> parserClass = Class.forName(key);
105                    try {
106                        parser = (FTPFileEntryParser) parserClass.newInstance();
107                    } catch (ClassCastException e) {
108                        throw new ParserInitializationException(parserClass.getName()
109                            + " does not implement the interface "
110                            + "org.apache.commons.net.ftp.FTPFileEntryParser.", e);
111                    } catch (Exception e) {
112                        throw new ParserInitializationException("Error initializing parser", e);
113                    } catch (ExceptionInInitializerError e) {
114                        throw new ParserInitializationException("Error initializing parser", e);
115                    }
116                } catch (ClassNotFoundException e) {
117                    // OK, assume it is an alias
118                }
119            }
120    
121            if (parser == null) { // Now try for aliases
122                String ukey = key.toUpperCase(java.util.Locale.ENGLISH);
123                if (ukey.indexOf(FTPClientConfig.SYST_UNIX) >= 0)
124                {
125                    parser = new UnixFTPEntryParser(config);
126                }
127                else if (ukey.indexOf(FTPClientConfig.SYST_VMS) >= 0)
128                {
129                    parser = new VMSVersioningFTPEntryParser(config);
130                }
131                else if (ukey.indexOf(FTPClientConfig.SYST_NT) >= 0)
132                {
133                    parser = createNTFTPEntryParser(config);
134                }
135                else if (ukey.indexOf(FTPClientConfig.SYST_OS2) >= 0)
136                {
137                    parser = new OS2FTPEntryParser(config);
138                }
139                else if (ukey.indexOf(FTPClientConfig.SYST_OS400) >= 0 ||
140                        ukey.indexOf(FTPClientConfig.SYST_AS400) >= 0)
141                {
142                    parser = createOS400FTPEntryParser(config);
143                }
144                else if (ukey.indexOf(FTPClientConfig.SYST_MVS) >= 0)
145                {
146                    parser = new MVSFTPEntryParser(); // Does not currently support config parameter
147                }
148                else if (ukey.indexOf(FTPClientConfig.SYST_NETWARE) >= 0)
149                {
150                    parser = new NetwareFTPEntryParser(config);
151                }
152                else if (ukey.indexOf(FTPClientConfig.SYST_L8) >= 0)
153                {
154                    // L8 normally means Unix, but move it to the end for some L8 systems that aren't.
155                    // This check should be last!
156                    parser = new UnixFTPEntryParser(config);
157                }
158                else
159                {
160                    throw new ParserInitializationException("Unknown parser type: " + key);
161                }
162            }
163    
164            if (parser instanceof Configurable) {
165                ((Configurable)parser).configure(config);
166            }
167            return parser;
168        }
169    
170        /**
171         * <p>Implementation extracts a key from the supplied
172         * {@link  FTPClientConfig FTPClientConfig}
173         * parameter and creates an object implementing the
174         * interface FTPFileEntryParser and uses the supplied configuration
175         * to configure it.
176         * </p><p>
177         * Note that this method will generally not be called in scenarios
178         * that call for autodetection of parser type but rather, for situations
179         * where the user knows that the server uses a non-default configuration
180         * and knows what that configuration is.
181         * </p>
182         * @param config  A {@link  FTPClientConfig FTPClientConfig}
183         * used to configure the parser created
184         *
185         * @return the @link  FTPFileEntryParser FTPFileEntryParser} so created.
186         * @exception ParserInitializationException
187         *                   Thrown on any exception in instantiation
188         * @throws NullPointerException if {@code config} is {@code null}
189         * @since 1.4
190         */
191        public FTPFileEntryParser createFileEntryParser(FTPClientConfig config)
192        throws ParserInitializationException
193        {
194            String key = config.getServerSystemKey();
195            return createFileEntryParser(key, config);
196        }
197    
198    
199        public FTPFileEntryParser createUnixFTPEntryParser()
200        {
201            return new UnixFTPEntryParser();
202        }
203    
204        public FTPFileEntryParser createVMSVersioningFTPEntryParser()
205        {
206            return new VMSVersioningFTPEntryParser();
207        }
208    
209        public FTPFileEntryParser createNetwareFTPEntryParser() {
210            return new NetwareFTPEntryParser();
211        }
212    
213        public FTPFileEntryParser createNTFTPEntryParser()
214        {
215            return createNTFTPEntryParser(null);
216        }
217    
218        /**
219         * Creates an NT FTP parser: if the config exists, and the system key equals
220         * {@link FTPClientConfig.SYST_NT} then a plain {@link NTFTPEntryParser} is used,
221         * otherwise a composite of {@link NTFTPEntryParser} and {@link UnixFTPEntryParser} is used.
222         * @param config the config to use, may be {@code null}
223         * @return the parser
224         */
225        private FTPFileEntryParser createNTFTPEntryParser(FTPClientConfig config)
226        {
227            if (config != null && FTPClientConfig.SYST_NT.equals(
228                    config.getServerSystemKey()))
229            {
230                return new NTFTPEntryParser(config);
231            } else {
232                return new CompositeFileEntryParser(new FTPFileEntryParser[]
233                       {
234                           new NTFTPEntryParser(config),
235                           new UnixFTPEntryParser(config)
236                       });
237            }
238        }
239    
240         public FTPFileEntryParser createOS2FTPEntryParser()
241        {
242            return new OS2FTPEntryParser();
243        }
244    
245        public FTPFileEntryParser createOS400FTPEntryParser()
246        {
247            return createOS400FTPEntryParser(null);
248        }
249    
250        /**
251         * Creates an OS400 FTP parser: if the config exists, and the system key equals
252         * {@link FTPClientConfig.SYST_OS400} then a plain {@link OS400FTPEntryParser} is used,
253         * otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
254         * @param config the config to use, may be {@code null}
255         * @return the parser
256         */
257        private FTPFileEntryParser createOS400FTPEntryParser(FTPClientConfig config)
258            {
259            if (config != null &&
260                    FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey()))
261            {
262                return new OS400FTPEntryParser(config);
263            } else {
264                return new CompositeFileEntryParser(new FTPFileEntryParser[]
265                    {
266                        new OS400FTPEntryParser(config),
267                        new UnixFTPEntryParser(config)
268                    });
269            }
270        }
271    
272        public FTPFileEntryParser createMVSEntryParser()
273        {
274            return new MVSFTPEntryParser();
275        }
276    
277    }
278