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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;
19  
20  import java.text.DateFormatSymbols;
21  import java.util.Collection;
22  import java.util.Locale;
23  import java.util.Map;
24  import java.util.StringTokenizer;
25  import java.util.TreeMap;
26  
27  /**
28   * <p>
29   * This class implements an alternate means of configuring the
30   * {@link  org.apache.commons.net.ftp.FTPClient  FTPClient} object and
31   * also subordinate objects which it uses.  Any class implementing the
32   * {@link  org.apache.commons.net.ftp.Configurable  Configurable }
33   * interface can be configured by this object.
34   * </p><p>
35   * In particular this class was designed primarily to support configuration
36   * of FTP servers which express file timestamps in formats and languages
37   * other than those for the US locale, which although it is the most common
38   * is not universal.  Unfortunately, nothing in the FTP spec allows this to
39   * be determined in an automated way, so manual configuration such as this
40   * is necessary.
41   * </p><p>
42   * This functionality was designed to allow existing clients to work exactly
43   * as before without requiring use of this component.  This component should
44   * only need to be explicitly invoked by the user of this package for problem
45   * cases that previous implementations could not solve.
46   * </p>
47   * <h3>Examples of use of FTPClientConfig</h3>
48   * Use cases:
49   * You are trying to access a server that
50   * <ul>
51   * <li>lists files with timestamps that use month names in languages other
52   * than English</li>
53   * <li>lists files with timestamps that use date formats other
54   * than the American English "standard" <code>MM dd yyyy</code></li>
55   * <li>is in different timezone and you need accurate timestamps for
56   * dependency checking as in Ant</li>
57   * </ul>
58   * <p>
59   * Unpaged (whole list) access on a UNIX server that uses French month names
60   * but uses the "standard" <code>MMM d yyyy</code> date formatting
61   * <pre>
62   *    FTPClient f=FTPClient();
63   *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
64   *    conf.setServerLanguageCode("fr");
65   *    f.configure(conf);
66   *    f.connect(server);
67   *    f.login(username, password);
68   *    FTPFile[] files = listFiles(directory);
69   * </pre>
70   * <p>
71   * Paged access on a UNIX server that uses Danish month names
72   * and "European" date formatting in Denmark's time zone, when you
73   * are in some other time zone.
74   * <pre>
75   *    FTPClient f=FTPClient();
76   *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
77   *    conf.setServerLanguageCode("da");
78   *    conf.setDefaultDateFormat("d MMM yyyy");
79   *    conf.setRecentDateFormat("d MMM HH:mm");
80   *    conf.setTimeZoneId("Europe/Copenhagen");
81   *    f.configure(conf);
82   *    f.connect(server);
83   *    f.login(username, password);
84   *    FTPListParseEngine engine =
85   *       f.initiateListParsing("com.whatever.YourOwnParser", directory);
86   *
87   *    while (engine.hasNext()) {
88   *       FTPFile[] files = engine.getNext(25);  // "page size" you want
89   *       //do whatever you want with these files, display them, etc.
90   *       //expensive FTPFile objects not created until needed.
91   *    }
92   * </pre>
93   * <p>
94   * Unpaged (whole list) access on a VMS server that uses month names
95   * in a language not {@link #getSupportedLanguageCodes() supported} by the system.
96   * but uses the "standard" <code>MMM d yyyy</code> date formatting
97   * <pre>
98   *    FTPClient f=FTPClient();
99   *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_VMS);
100  *    conf.setShortMonthNames(
101  *        "jan|feb|mar|apr|ma\u00ED|j\u00FAn|j\u00FAl|\u00e1g\u00FA|sep|okt|n\u00F3v|des");
102  *    f.configure(conf);
103  *    f.connect(server);
104  *    f.login(username, password);
105  *    FTPFile[] files = listFiles(directory);
106  * </pre>
107  * <p>
108  * Unpaged (whole list) access on a Windows-NT server in a different time zone.
109  * (Note, since the NT Format uses numeric date formatting, language issues
110  * are irrelevant here).
111  * <pre>
112  *    FTPClient f=FTPClient();
113  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);
114  *    conf.setTimeZoneId("America/Denver");
115  *    f.configure(conf);
116  *    f.connect(server);
117  *    f.login(username, password);
118  *    FTPFile[] files = listFiles(directory);
119  * </pre>
120  * Unpaged (whole list) access on a Windows-NT server in a different time zone
121  * but which has been configured to use a unix-style listing format.
122  * <pre>
123  *    FTPClient f=FTPClient();
124  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
125  *    conf.setTimeZoneId("America/Denver");
126  *    f.configure(conf);
127  *    f.connect(server);
128  *    f.login(username, password);
129  *    FTPFile[] files = listFiles(directory);
130  * </pre>
131  *
132  * @since 1.4
133  * @see org.apache.commons.net.ftp.Configurable
134  * @see org.apache.commons.net.ftp.FTPClient
135  * @see org.apache.commons.net.ftp.parser.FTPTimestampParserImpl#configure(FTPClientConfig)
136  * @see org.apache.commons.net.ftp.parser.ConfigurableFTPFileEntryParserImpl
137  */
138 public class FTPClientConfig
139 {
140 
141     /**
142      * Identifier by which a unix-based ftp server is known throughout
143      * the commons-net ftp system.
144      */
145     public static final String SYST_UNIX  = "UNIX";
146 
147     /**
148      * Identifier for alternate UNIX parser; same as {@link #SYST_UNIX} but leading spaces are
149      * trimmed from file names. This is to maintain backwards compatibility with
150      * the original behaviour of the parser which ignored multiple spaces between the date
151      * and the start of the file name.
152      * @since 3.4
153      */
154     public static final String SYST_UNIX_TRIM_LEADING  = "UNIX_LTRIM";
155 
156     /**
157      * Identifier by which a vms-based ftp server is known throughout
158      * the commons-net ftp system.
159      */
160     public static final String SYST_VMS   = "VMS";
161 
162     /**
163      * Identifier by which a WindowsNT-based ftp server is known throughout
164      * the commons-net ftp system.
165      */
166     public static final String SYST_NT    = "WINDOWS";
167 
168     /**
169      * Identifier by which an OS/2-based ftp server is known throughout
170      * the commons-net ftp system.
171      */
172     public static final String SYST_OS2   = "OS/2";
173 
174     /**
175      * Identifier by which an OS/400-based ftp server is known throughout
176      * the commons-net ftp system.
177      */
178     public static final String SYST_OS400 = "OS/400";
179 
180     /**
181      * Identifier by which an AS/400-based ftp server is known throughout
182      * the commons-net ftp system.
183      */
184     public static final String SYST_AS400 = "AS/400";
185 
186     /**
187      * Identifier by which an MVS-based ftp server is known throughout
188      * the commons-net ftp system.
189      */
190     public static final String SYST_MVS = "MVS";
191 
192     /**
193      * Some servers return an "UNKNOWN Type: L8" message
194      * in response to the SYST command. We set these to be a Unix-type system.
195      * This may happen if the ftpd in question was compiled without system
196      * information.
197      *
198      * NET-230 - Updated to be UPPERCASE so that the check done in
199      * createFileEntryParser will succeed.
200      *
201      * @since 1.5
202      */
203     public static final String SYST_L8 = "TYPE: L8";
204 
205     /**
206      * Identifier by which an Netware-based ftp server is known throughout
207      * the commons-net ftp system.
208      *
209      * @since 1.5
210      */
211     public static final String SYST_NETWARE = "NETWARE";
212 
213     /**
214      * Identifier by which a Mac pre OS-X -based ftp server is known throughout
215      * the commons-net ftp system.
216      *
217      * @since 3.1
218      */
219     // Full string is "MACOS Peter's Server"; the substring below should be enough
220     public static final String SYST_MACOS_PETER  = "MACOS PETER"; // NET-436
221 
222     private final String serverSystemKey;
223     private String defaultDateFormatStr = null;
224     private String recentDateFormatStr = null;
225     private boolean lenientFutureDates = true; // NET-407
226     private String serverLanguageCode = null;
227     private String shortMonthNames = null;
228     private String serverTimeZoneId = null;
229     private boolean saveUnparseableEntries = false;
230 
231 
232     /**
233      * The main constructor for an FTPClientConfig object
234      * @param systemKey key representing system type of the  server being
235      * connected to. See {@link #getServerSystemKey() serverSystemKey}
236      * If set to the empty string, then FTPClient uses the system type returned by the server.
237      * However this is not recommended for general use;
238      * the correct system type should be set if it is known.
239      */
240     public FTPClientConfig(String systemKey) {
241         this.serverSystemKey = systemKey;
242     }
243 
244     /**
245      * Convenience constructor mainly for use in testing.
246      * Constructs a UNIX configuration.
247      */
248     public FTPClientConfig() {
249         this(SYST_UNIX);
250     }
251 
252     /**
253      * Constructor which allows setting of the format string member fields
254      * @param systemKey key representing system type of the  server being
255      * connected to. See
256      *  {@link #getServerSystemKey() serverSystemKey}
257      * @param defaultDateFormatStr See
258      *  {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
259      * @param recentDateFormatStr See
260      *  {@link  #setRecentDateFormatStr(String)  recentDateFormatStr}
261      *  @since 3.6
262      */
263     public FTPClientConfig(String systemKey,
264                            String defaultDateFormatStr,
265                            String recentDateFormatStr)
266     {
267         this(systemKey);
268         this.defaultDateFormatStr = defaultDateFormatStr;
269         this.recentDateFormatStr = recentDateFormatStr;
270     }
271 
272     /**
273      * Constructor which allows setting of most member fields
274      * @param systemKey key representing system type of the  server being
275      * connected to. See
276      *  {@link #getServerSystemKey() serverSystemKey}
277      * @param defaultDateFormatStr See
278      *  {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
279      * @param recentDateFormatStr See
280      *  {@link  #setRecentDateFormatStr(String)  recentDateFormatStr}
281      * @param serverLanguageCode See
282      *  {@link  #setServerLanguageCode(String)  serverLanguageCode}
283      * @param shortMonthNames See
284      *  {@link  #setShortMonthNames(String)  shortMonthNames}
285      * @param serverTimeZoneId See
286      *  {@link  #setServerTimeZoneId(String)  serverTimeZoneId}
287      */
288     public FTPClientConfig(String systemKey,
289                            String defaultDateFormatStr,
290                            String recentDateFormatStr,
291                            String serverLanguageCode,
292                            String shortMonthNames,
293                            String serverTimeZoneId)
294     {
295         this(systemKey);
296         this.defaultDateFormatStr = defaultDateFormatStr;
297         this.recentDateFormatStr = recentDateFormatStr;
298         this.serverLanguageCode = serverLanguageCode;
299         this.shortMonthNames = shortMonthNames;
300         this.serverTimeZoneId = serverTimeZoneId;
301     }
302 
303     /**
304      * Constructor which allows setting of all member fields
305      * @param systemKey key representing system type of the  server being
306      * connected to. See
307      *  {@link #getServerSystemKey() serverSystemKey}
308      * @param defaultDateFormatStr See
309      *  {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
310      * @param recentDateFormatStr See
311      *  {@link  #setRecentDateFormatStr(String)  recentDateFormatStr}
312      * @param serverLanguageCode See
313      *  {@link  #setServerLanguageCode(String)  serverLanguageCode}
314      * @param shortMonthNames See
315      *  {@link  #setShortMonthNames(String)  shortMonthNames}
316      * @param serverTimeZoneId See
317      *  {@link  #setServerTimeZoneId(String)  serverTimeZoneId}
318      * @param lenientFutureDates See
319      * {@link  #setLenientFutureDates(boolean)  lenientFutureDates}
320      * @param saveUnparseableEntries See
321      * {@link  #setUnparseableEntries(boolean)  saveUnparseableEntries}
322      */
323     public FTPClientConfig(String systemKey,
324                            String defaultDateFormatStr,
325                            String recentDateFormatStr,
326                            String serverLanguageCode,
327                            String shortMonthNames,
328                            String serverTimeZoneId,
329                            boolean lenientFutureDates,
330                            boolean saveUnparseableEntries)
331     {
332         this(systemKey);
333         this.defaultDateFormatStr = defaultDateFormatStr;
334         this.lenientFutureDates = lenientFutureDates;
335         this.recentDateFormatStr = recentDateFormatStr;
336         this.saveUnparseableEntries = saveUnparseableEntries;
337         this.serverLanguageCode = serverLanguageCode;
338         this.shortMonthNames = shortMonthNames;
339         this.serverTimeZoneId = serverTimeZoneId;
340     }
341 
342     // Copy constructor, intended for use by FTPClient only
343     FTPClientConfig(String systemKey, FTPClientConfig config) {
344         this.serverSystemKey = systemKey;
345         this.defaultDateFormatStr = config.defaultDateFormatStr;
346         this.lenientFutureDates = config.lenientFutureDates;
347         this.recentDateFormatStr = config.recentDateFormatStr;
348         this.saveUnparseableEntries = config.saveUnparseableEntries;
349         this.serverLanguageCode = config.serverLanguageCode;
350         this.serverTimeZoneId = config.serverTimeZoneId;
351         this.shortMonthNames = config.shortMonthNames;
352     }
353 
354     /**
355      * Copy constructor
356      * @param config source
357      * @since 3.6
358      */
359     public FTPClientConfig(FTPClientConfig config) {
360         this.serverSystemKey = config.serverSystemKey;
361         this.defaultDateFormatStr = config.defaultDateFormatStr;
362         this.lenientFutureDates = config.lenientFutureDates;
363         this.recentDateFormatStr = config.recentDateFormatStr;
364         this.saveUnparseableEntries = config.saveUnparseableEntries;
365         this.serverLanguageCode = config.serverLanguageCode;
366         this.serverTimeZoneId = config.serverTimeZoneId;
367         this.shortMonthNames = config.shortMonthNames;
368     }
369 
370     private static final Map<String, Object> LANGUAGE_CODE_MAP = new TreeMap<String, Object>();
371     static {
372 
373         // if there are other commonly used month name encodings which
374         // correspond to particular locales, please add them here.
375 
376 
377 
378         // many locales code short names for months as all three letters
379         // these we handle simply.
380         LANGUAGE_CODE_MAP.put("en", Locale.ENGLISH);
381         LANGUAGE_CODE_MAP.put("de",Locale.GERMAN);
382         LANGUAGE_CODE_MAP.put("it",Locale.ITALIAN);
383         LANGUAGE_CODE_MAP.put("es", new Locale("es", "", "")); // spanish
384         LANGUAGE_CODE_MAP.put("pt", new Locale("pt", "", "")); // portuguese
385         LANGUAGE_CODE_MAP.put("da", new Locale("da", "", "")); // danish
386         LANGUAGE_CODE_MAP.put("sv", new Locale("sv", "", "")); // swedish
387         LANGUAGE_CODE_MAP.put("no", new Locale("no", "", "")); // norwegian
388         LANGUAGE_CODE_MAP.put("nl", new Locale("nl", "", "")); // dutch
389         LANGUAGE_CODE_MAP.put("ro", new Locale("ro", "", "")); // romanian
390         LANGUAGE_CODE_MAP.put("sq", new Locale("sq", "", "")); // albanian
391         LANGUAGE_CODE_MAP.put("sh", new Locale("sh", "", "")); // serbo-croatian
392         LANGUAGE_CODE_MAP.put("sk", new Locale("sk", "", "")); // slovak
393         LANGUAGE_CODE_MAP.put("sl", new Locale("sl", "", "")); // slovenian
394 
395 
396         // some don't
397         LANGUAGE_CODE_MAP.put("fr",
398                 "jan|f\u00e9v|mar|avr|mai|jun|jui|ao\u00fb|sep|oct|nov|d\u00e9c");  //french
399 
400     }
401 
402     /**
403      * Getter for the serverSystemKey property.  This property
404      * specifies the general type of server to which the client connects.
405      * Should be either one of the <code>FTPClientConfig.SYST_*</code> codes
406      * or else the fully qualified class name of a parser implementing both
407      * the <code>FTPFileEntryParser</code> and <code>Configurable</code>
408      * interfaces.
409      * @return Returns the serverSystemKey property.
410      */
411     public String getServerSystemKey() {
412         return serverSystemKey;
413     }
414 
415     /**
416      * getter for the {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
417      * property.
418      * @return Returns the defaultDateFormatStr property.
419      */
420     public String getDefaultDateFormatStr() {
421         return defaultDateFormatStr;
422     }
423 
424     /**
425      * getter for the {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} property.
426      * @return Returns the recentDateFormatStr property.
427      */
428 
429     public String getRecentDateFormatStr() {
430         return recentDateFormatStr;
431     }
432 
433     /**
434      * getter for the {@link  #setServerTimeZoneId(String)  serverTimeZoneId} property.
435      * @return Returns the serverTimeZoneId property.
436      */
437     public String getServerTimeZoneId() {
438         return serverTimeZoneId;
439     }
440 
441     /**
442      * <p>
443      * getter for the {@link  #setShortMonthNames(String)  shortMonthNames}
444      * property.
445      * </p>
446      * @return Returns the shortMonthNames.
447      */
448     public String getShortMonthNames() {
449         return shortMonthNames;
450     }
451 
452     /**
453      * <p>
454      * getter for the {@link  #setServerLanguageCode(String)  serverLanguageCode} property.
455      * </p>
456      * @return Returns the serverLanguageCode property.
457      */
458     public String getServerLanguageCode() {
459         return serverLanguageCode;
460     }
461 
462     /**
463      * <p>
464      * getter for the {@link  #setLenientFutureDates(boolean)  lenientFutureDates} property.
465      * </p>
466      * @return Returns the lenientFutureDates.
467      * @since 1.5
468      */
469     public boolean isLenientFutureDates() {
470         return lenientFutureDates;
471     }
472     /**
473      * <p>
474      * setter for the defaultDateFormatStr property.  This property
475      * specifies the main date format that will be used by a parser configured
476      * by this configuration to parse file timestamps.  If this is not
477      * specified, such a parser will use as a default value, the most commonly
478      * used format which will be in as used in <code>en_US</code> locales.
479      * </p><p>
480      * This should be in the format described for
481      * <code>java.text.SimpleDateFormat</code>.
482      * property.
483      * </p>
484      * @param defaultDateFormatStr The defaultDateFormatStr to set.
485      */
486     public void setDefaultDateFormatStr(String defaultDateFormatStr) {
487         this.defaultDateFormatStr = defaultDateFormatStr;
488     }
489 
490     /**
491      * <p>
492      * setter for the recentDateFormatStr property.  This property
493      * specifies a secondary date format that will be used by a parser
494      * configured by this configuration to parse file timestamps, typically
495      * those less than a year old.  If this is  not specified, such a parser
496      * will not attempt to parse using an alternate format.
497      * </p>
498      * <p>
499      * This is used primarily in unix-based systems.
500      * </p>
501      * <p>
502      * This should be in the format described for
503      * <code>java.text.SimpleDateFormat</code>.
504      * </p>
505      * @param recentDateFormatStr The recentDateFormatStr to set.
506      */
507     public void setRecentDateFormatStr(String recentDateFormatStr) {
508         this.recentDateFormatStr = recentDateFormatStr;
509     }
510 
511     /**
512      * <p>
513      * setter for the lenientFutureDates property.  This boolean property
514      * (default: false) only has meaning when a
515      * {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} property
516      * has been set.  In that case, if this property is set true, then the
517      * parser, when it encounters a listing parseable with the recent date
518      * format, will only consider a date to belong to the previous year if
519      * it is more than one day in the future.  This will allow all
520      * out-of-synch situations (whether based on "slop" - i.e. servers simply
521      * out of synch with one another or because of time zone differences -
522      * but in the latter case it is highly recommended to use the
523      * {@link  #setServerTimeZoneId(String)  serverTimeZoneId} property
524      * instead) to resolve correctly.
525      * </p><p>
526      * This is used primarily in unix-based systems.
527      * </p>
528      * @param lenientFutureDates set true to compensate for out-of-synch
529      * conditions.
530      */
531     public void setLenientFutureDates(boolean lenientFutureDates) {
532         this.lenientFutureDates = lenientFutureDates;
533     }
534     /**
535      * <p>
536      * setter for the serverTimeZoneId property.  This property
537      * allows a time zone to be specified corresponding to that known to be
538      * used by an FTP server in file listings.  This might be particularly
539      * useful to clients such as Ant that try to use these timestamps for
540      * dependency checking.
541      * </p><p>
542      * This should be one of the identifiers used by
543      * <code>java.util.TimeZone</code> to refer to time zones, for example,
544      * <code>America/Chicago</code> or <code>Asia/Rangoon</code>.
545      * </p>
546      * @param serverTimeZoneId The serverTimeZoneId to set.
547      */
548     public void setServerTimeZoneId(String serverTimeZoneId) {
549         this.serverTimeZoneId = serverTimeZoneId;
550     }
551 
552     /**
553      * <p>
554      * setter for the shortMonthNames property.
555      * This property allows the user to specify a set of month names
556      * used by the server that is different from those that may be
557      * specified using the {@link  #setServerLanguageCode(String)  serverLanguageCode}
558      * property.
559      * </p><p>
560      * This should be a string containing twelve strings each composed of
561      * three characters, delimited by pipe (|) characters.  Currently,
562      * only 8-bit ASCII characters are known to be supported.  For example,
563      * a set of month names used by a hypothetical Icelandic FTP server might
564      * conceivably be specified as
565      * <code>"jan|feb|mar|apr|ma&#xED;|j&#xFA;n|j&#xFA;l|&#xE1;g&#xFA;|sep|okt|n&#xF3;v|des"</code>.
566      * </p>
567      * @param shortMonthNames The value to set to the shortMonthNames property.
568      */
569     public void setShortMonthNames(String shortMonthNames) {
570         this.shortMonthNames = shortMonthNames;
571     }
572 
573     /**
574      * <p>
575      * setter for the serverLanguageCode property.  This property allows
576      * user to specify a
577      * <a href="http://www.ics.uci.edu/pub/ietf/http/related/iso639.txt">
578      * two-letter ISO-639 language code</a> that will be used to
579      * configure the set of month names used by the file timestamp parser.
580      * If neither this nor the {@link #setShortMonthNames(String) shortMonthNames}
581      * is specified, parsing will assume English month names, which may or
582      * may not be significant, depending on whether the date format(s)
583      * specified via {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
584      * and/or {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} are using
585      * numeric or alphabetic month names.
586      * </p>
587      * <p>If the code supplied is not supported here, <code>en_US</code>
588      * month names will be used.  We are supporting here those language
589      * codes which, when a <code> java.util.Locale</code> is constucted
590      * using it, and a <code>java.text.SimpleDateFormat</code> is
591      * constructed using that Locale, the array returned by the
592      * SimpleDateFormat's <code>getShortMonths()</code> method consists
593      * solely of three 8-bit ASCII character strings.  Additionally,
594      * languages which do not meet this requirement are included if a
595      * common alternative set of short month names is known to be used.
596      * This means that users who can tell us of additional such encodings
597      * may get them added to the list of supported languages by contacting
598      * the Apache Commons Net team.
599      * </p>
600      * <p><strong>
601      * Please note that this attribute will NOT be used to determine a
602      * locale-based date format for the language.  </strong>
603      * Experience has shown that many if not most FTP servers outside the
604      * United States employ the standard <code>en_US</code> date format
605      * orderings of <code>MMM d yyyy</code> and <code>MMM d HH:mm</code>
606      * and attempting to deduce this automatically here would cause more
607      * problems than it would solve.  The date format must be changed
608      * via the {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} and/or
609      * {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} parameters.
610      * </p>
611      * @param serverLanguageCode The value to set to the serverLanguageCode property.
612      */
613     public void setServerLanguageCode(String serverLanguageCode) {
614         this.serverLanguageCode = serverLanguageCode;
615     }
616 
617     /**
618      * Looks up the supplied language code in the internally maintained table of
619      * language codes.  Returns a DateFormatSymbols object configured with
620      * short month names corresponding to the code.  If there is no corresponding
621      * entry in the table, the object returned will be that for
622      * <code>Locale.US</code>
623      * @param languageCode See {@link  #setServerLanguageCode(String)  serverLanguageCode}
624      * @return a DateFormatSymbols object configured with short month names
625      * corresponding to the supplied code, or with month names for
626      * <code>Locale.US</code> if there is no corresponding entry in the internal
627      * table.
628      */
629     public static DateFormatSymbols lookupDateFormatSymbols(String languageCode)
630     {
631         Object lang = LANGUAGE_CODE_MAP.get(languageCode);
632         if (lang != null) {
633             if (lang instanceof Locale) {
634                 return new DateFormatSymbols((Locale) lang);
635             } else if (lang instanceof String){
636                 return getDateFormatSymbols((String) lang);
637             }
638         }
639         return new DateFormatSymbols(Locale.US);
640     }
641 
642     /**
643      * Returns a DateFormatSymbols object configured with short month names
644      * as in the supplied string
645      * @param shortmonths This  should be as described in
646      *  {@link  #setShortMonthNames(String)  shortMonthNames}
647      * @return a DateFormatSymbols object configured with short month names
648      * as in the supplied string
649      */
650     public static DateFormatSymbols getDateFormatSymbols(String shortmonths)
651     {
652         String[] months = splitShortMonthString(shortmonths);
653         DateFormatSymbols dfs = new DateFormatSymbols(Locale.US);
654         dfs.setShortMonths(months);
655         return dfs;
656     }
657 
658     private static String[] splitShortMonthString(String shortmonths) {
659         StringTokenizer st = new StringTokenizer(shortmonths, "|");
660         int monthcnt = st.countTokens();
661         if (12 != monthcnt) {
662             throw new IllegalArgumentException(
663                     "expecting a pipe-delimited string containing 12 tokens");
664         }
665         String[] months = new String[13];
666         int pos = 0;
667         while(st.hasMoreTokens()) {
668             months[pos++] = st.nextToken();
669         }
670         months[pos]="";
671         return months;
672     }
673 
674     /**
675      * Returns a Collection of all the language codes currently supported
676      * by this class. See {@link  #setServerLanguageCode(String)  serverLanguageCode}
677      * for a functional descrption of language codes within this system.
678      *
679      * @return a Collection of all the language codes currently supported
680      * by this class
681      */
682     public static Collection<String> getSupportedLanguageCodes() {
683         return LANGUAGE_CODE_MAP.keySet();
684     }
685 
686     /**
687      * Allow list parsing methods to create basic FTPFile entries if parsing fails.
688      * <p>
689      * In this case, the FTPFile will contain only the unparsed entry {@link FTPFile#getRawListing()}
690      * and {@link FTPFile#isValid()} will return {@code false}
691      * @param saveUnparseable if true, then create FTPFile entries if parsing fails
692      * @since 3.4
693      */
694     public void setUnparseableEntries(boolean saveUnparseable) {
695         this.saveUnparseableEntries = saveUnparseable;
696     }
697 
698     /**
699      * @return true if list parsing should return FTPFile entries even for unparseable response lines
700      * <p>
701      * If true, the FTPFile for any unparseable entries will contain only the unparsed entry
702      * {@link FTPFile#getRawListing()} and {@link FTPFile#isValid()} will return {@code false}
703      * @since 3.4
704      */
705     public boolean getUnparseableEntries() {
706         return this.saveUnparseableEntries;
707     }
708 
709 }