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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.net.ftp.parser;
19  
20  import java.util.regex.Pattern;
21  
22  import org.apache.commons.net.ftp.Configurable;
23  import org.apache.commons.net.ftp.FTPClientConfig;
24  import org.apache.commons.net.ftp.FTPFileEntryParser;
25  
26  
27  /**
28   * This is the default implementation of the
29   * FTPFileEntryParserFactory interface.  This is the
30   * implementation that will be used by
31   * org.apache.commons.net.ftp.FTPClient.listFiles()
32   * if no other implementation has been specified.
33   *
34   * @see org.apache.commons.net.ftp.FTPClient#listFiles
35   * @see org.apache.commons.net.ftp.FTPClient#setParserFactory
36   */
37  public class DefaultFTPFileEntryParserFactory
38      implements FTPFileEntryParserFactory
39  {
40  
41      // Match a plain Java Identifier
42      private static final String JAVA_IDENTIFIER = "\\p{javaJavaIdentifierStart}(\\p{javaJavaIdentifierPart})*";
43      // Match a qualified name, e.g. a.b.c.Name - but don't allow the default package as that would allow "VMS"/"UNIX" etc.
44      private static final String JAVA_QUALIFIED_NAME  = "("+JAVA_IDENTIFIER+"\\.)+"+JAVA_IDENTIFIER;
45      // Create the pattern, as it will be reused many times
46      private static final Pattern JAVA_QUALIFIED_NAME_PATTERN = Pattern.compile(JAVA_QUALIFIED_NAME);
47  
48      /**
49       * This default implementation of the FTPFileEntryParserFactory
50       * interface works according to the following logic:
51       * First it attempts to interpret the supplied key as a fully
52       * qualified classname (default package is not allowed) of a class implementing the
53       * FTPFileEntryParser interface.  If that succeeds, a parser
54       * object of this class is instantiated and is returned;
55       * otherwise it attempts to interpret the key as an identirier
56       * commonly used by the FTP SYST command to identify systems.
57       * <p>
58       * If <code>key</code> is not recognized as a fully qualified
59       * classname known to the system, this method will then attempt
60       * to see whether it <b>contains</b> a string identifying one of
61       * the known parsers.  This comparison is <b>case-insensitive</b>.
62       * The intent here is where possible, to select as keys strings
63       * which are returned by the SYST command on the systems which
64       * the corresponding parser successfully parses.  This enables
65       * this factory to be used in the auto-detection system.
66       *
67       * @param key    should be a fully qualified classname corresponding to
68       *               a class implementing the FTPFileEntryParser interface<br>
69       *               OR<br>
70       *               a string containing (case-insensitively) one of the
71       *               following keywords:
72       *               <ul>
73       *               <li>{@link FTPClientConfig#SYST_UNIX UNIX}</li>
74       *               <li>{@link FTPClientConfig#SYST_NT WINDOWS}</li>
75       *               <li>{@link FTPClientConfig#SYST_OS2 OS/2}</li>
76       *               <li>{@link FTPClientConfig#SYST_OS400 OS/400}</li>
77       *               <li>{@link FTPClientConfig#SYST_AS400 AS/400}</li>
78       *               <li>{@link FTPClientConfig#SYST_VMS VMS}</li>
79       *               <li>{@link FTPClientConfig#SYST_MVS MVS}</li>
80       *               <li>{@link FTPClientConfig#SYST_NETWARE NETWARE}</li>
81       *               <li>{@link FTPClientConfig#SYST_L8 TYPE:L8}</li>
82       *               </ul>
83       * @return the FTPFileEntryParser corresponding to the supplied key.
84       * @throws ParserInitializationException thrown if for any reason the factory cannot resolve
85       *                   the supplied key into an FTPFileEntryParser.
86       * @see FTPFileEntryParser
87       */
88  //    @Override
89      public FTPFileEntryParser createFileEntryParser(String key)
90      {
91          if (key == null) {
92              throw new ParserInitializationException("Parser key cannot be null");
93          }
94          return createFileEntryParser(key, null);
95      }
96  
97      // Common method to process both key and config parameters.
98      private FTPFileEntryParser createFileEntryParser(String key, FTPClientConfig config) {
99          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