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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       * <p/>
67       *
68       * @param key    should be a fully qualified classname corresponding to
69       *               a class implementing the FTPFileEntryParser interface<br/>
70       *               OR<br/>
71       *               a string containing (case-insensitively) one of the
72       *               following keywords:
73       *               <ul>
74       *               <li>{@link FTPClientConfig#SYST_UNIX UNIX}</li>
75       *               <li>{@link FTPClientConfig#SYST_NT WINDOWS}</li>
76       *               <li>{@link FTPClientConfig#SYST_OS2 OS/2}</li>
77       *               <li>{@link FTPClientConfig#SYST_OS400 OS/400}</li>
78       *               <li>{@link FTPClientConfig#SYST_AS400 AS/400}</li>
79       *               <li>{@link FTPClientConfig#SYST_VMS VMS}</li>
80       *               <li>{@link FTPClientConfig#SYST_MVS MVS}</li>
81       *               <li>{@link FTPClientConfig#SYST_NETWARE NETWARE}</li>
82       *               <li>{@link FTPClientConfig#SYST_L8 TYPE:L8}</li>
83       *               </ul>
84       * @return the FTPFileEntryParser corresponding to the supplied key.
85       * @throws ParserInitializationException thrown if for any reason the factory cannot resolve
86       *                   the supplied key into an FTPFileEntryParser.
87       * @see FTPFileEntryParser
88       */
89  //    @Override
90      public FTPFileEntryParser createFileEntryParser(String key)
91      {
92          if (key == null) {
93              throw new ParserInitializationException("Parser key cannot be null");
94          }
95          return createFileEntryParser(key, null);
96      }
97  
98      // Common method to process both key and config parameters.
99      private FTPFileEntryParser createFileEntryParser(String key, FTPClientConfig config) {
100         FTPFileEntryParser parser = null;
101 
102         // Is the key a possible class name?
103         if (JAVA_QUALIFIED_NAME_PATTERN.matcher(key).matches()) {
104             try
105             {
106                 Class<?> parserClass = Class.forName(key);
107                 try {
108                     parser = (FTPFileEntryParser) parserClass.newInstance();
109                 } catch (ClassCastException e) {
110                     throw new ParserInitializationException(parserClass.getName()
111                         + " does not implement the interface "
112                         + "org.apache.commons.net.ftp.FTPFileEntryParser.", e);
113                 } catch (Exception e) {
114                     throw new ParserInitializationException("Error initializing parser", e);
115                 } catch (ExceptionInInitializerError e) {
116                     throw new ParserInitializationException("Error initializing parser", e);
117                 }
118             } catch (ClassNotFoundException e) {
119                 // OK, assume it is an alias
120             }
121         }
122 
123         if (parser == null) { // Now try for aliases
124             String ukey = key.toUpperCase(java.util.Locale.ENGLISH);
125             if (ukey.indexOf(FTPClientConfig.SYST_UNIX) >= 0)
126             {
127                 parser = new UnixFTPEntryParser(config);
128             }
129             else if (ukey.indexOf(FTPClientConfig.SYST_VMS) >= 0)
130             {
131                 parser = new VMSVersioningFTPEntryParser(config);
132             }
133             else if (ukey.indexOf(FTPClientConfig.SYST_NT) >= 0)
134             {
135                 parser = createNTFTPEntryParser(config);
136             }
137             else if (ukey.indexOf(FTPClientConfig.SYST_OS2) >= 0)
138             {
139                 parser = new OS2FTPEntryParser(config);
140             }
141             else if (ukey.indexOf(FTPClientConfig.SYST_OS400) >= 0 ||
142                     ukey.indexOf(FTPClientConfig.SYST_AS400) >= 0)
143             {
144                 parser = createOS400FTPEntryParser(config);
145             }
146             else if (ukey.indexOf(FTPClientConfig.SYST_MVS) >= 0)
147             {
148                 parser = new MVSFTPEntryParser(); // Does not currently support config parameter
149             }
150             else if (ukey.indexOf(FTPClientConfig.SYST_NETWARE) >= 0)
151             {
152                 parser = new NetwareFTPEntryParser(config);
153             }
154             else if (ukey.indexOf(FTPClientConfig.SYST_MACOS_PETER) >= 0)
155             {
156                 parser = new MacOsPeterFTPEntryParser(config);
157             }
158             else if (ukey.indexOf(FTPClientConfig.SYST_L8) >= 0)
159             {
160                 // L8 normally means Unix, but move it to the end for some L8 systems that aren't.
161                 // This check should be last!
162                 parser = new UnixFTPEntryParser(config);
163             }
164             else
165             {
166                 throw new ParserInitializationException("Unknown parser type: " + key);
167             }
168         }
169 
170         if (parser instanceof Configurable) {
171             ((Configurable)parser).configure(config);
172         }
173         return parser;
174     }
175 
176     /**
177      * <p>Implementation extracts a key from the supplied
178      * {@link  FTPClientConfig FTPClientConfig}
179      * parameter and creates an object implementing the
180      * interface FTPFileEntryParser and uses the supplied configuration
181      * to configure it.
182      * </p><p>
183      * Note that this method will generally not be called in scenarios
184      * that call for autodetection of parser type but rather, for situations
185      * where the user knows that the server uses a non-default configuration
186      * and knows what that configuration is.
187      * </p>
188      * @param config  A {@link  FTPClientConfig FTPClientConfig}
189      * used to configure the parser created
190      *
191      * @return the @link  FTPFileEntryParser FTPFileEntryParser} so created.
192      * @exception ParserInitializationException
193      *                   Thrown on any exception in instantiation
194      * @throws NullPointerException if {@code config} is {@code null}
195      * @since 1.4
196      */
197 //    @Override
198     public FTPFileEntryParser createFileEntryParser(FTPClientConfig config)
199     throws ParserInitializationException
200     {
201         String key = config.getServerSystemKey();
202         return createFileEntryParser(key, config);
203     }
204 
205 
206     public FTPFileEntryParser createUnixFTPEntryParser()
207     {
208         return new UnixFTPEntryParser();
209     }
210 
211     public FTPFileEntryParser createVMSVersioningFTPEntryParser()
212     {
213         return new VMSVersioningFTPEntryParser();
214     }
215 
216     public FTPFileEntryParser createNetwareFTPEntryParser() {
217         return new NetwareFTPEntryParser();
218     }
219 
220     public FTPFileEntryParser createNTFTPEntryParser()
221     {
222         return createNTFTPEntryParser(null);
223     }
224 
225     /**
226      * Creates an NT FTP parser: if the config exists, and the system key equals
227      * {@link FTPClientConfig.SYST_NT} then a plain {@link NTFTPEntryParser} is used,
228      * otherwise a composite of {@link NTFTPEntryParser} and {@link UnixFTPEntryParser} is used.
229      * @param config the config to use, may be {@code null}
230      * @return the parser
231      */
232     private FTPFileEntryParser createNTFTPEntryParser(FTPClientConfig config)
233     {
234         if (config != null && FTPClientConfig.SYST_NT.equals(
235                 config.getServerSystemKey()))
236         {
237             return new NTFTPEntryParser(config);
238         } else {
239             return new CompositeFileEntryParser(new FTPFileEntryParser[]
240                    {
241                        new NTFTPEntryParser(config),
242                        new UnixFTPEntryParser(config)
243                    });
244         }
245     }
246 
247      public FTPFileEntryParser createOS2FTPEntryParser()
248     {
249         return new OS2FTPEntryParser();
250     }
251 
252     public FTPFileEntryParser createOS400FTPEntryParser()
253     {
254         return createOS400FTPEntryParser(null);
255     }
256 
257     /**
258      * Creates an OS400 FTP parser: if the config exists, and the system key equals
259      * {@link FTPClientConfig.SYST_OS400} then a plain {@link OS400FTPEntryParser} is used,
260      * otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
261      * @param config the config to use, may be {@code null}
262      * @return the parser
263      */
264     private FTPFileEntryParser createOS400FTPEntryParser(FTPClientConfig config)
265         {
266         if (config != null &&
267                 FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey()))
268         {
269             return new OS400FTPEntryParser(config);
270         } else {
271             return new CompositeFileEntryParser(new FTPFileEntryParser[]
272                 {
273                     new OS400FTPEntryParser(config),
274                     new UnixFTPEntryParser(config)
275                 });
276         }
277     }
278 
279     public FTPFileEntryParser createMVSEntryParser()
280     {
281         return new MVSFTPEntryParser();
282     }
283 
284 }
285