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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   * <p>
72   * Paged access on a UNIX server that uses Danish month names
73   * and "European" date formatting in Denmark's time zone, when you
74   * are in some other time zone.
75   * <pre>
76   *    FTPClient f=FTPClient();
77   *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
78   *    conf.setServerLanguageCode("da");
79   *    conf.setDefaultDateFormat("d MMM yyyy");
80   *    conf.setRecentDateFormat("d MMM HH:mm");
81   *    conf.setTimeZoneId("Europe/Copenhagen");
82   *    f.configure(conf);
83   *    f.connect(server);
84   *    f.login(username, password);
85   *    FTPListParseEngine engine =
86   *       f.initiateListParsing("com.whatever.YourOwnParser", directory);
87   *
88   *    while (engine.hasNext()) {
89   *       FTPFile[] files = engine.getNext(25);  // "page size" you want
90   *       //do whatever you want with these files, display them, etc.
91   *       //expensive FTPFile objects not created until needed.
92   *    }
93   * </pre>
94   * </p> 
95   * <p>
96   * Unpaged (whole list) access on a VMS server that uses month names
97   * in a language not {@link #getSupportedLanguageCodes() supported} by the system.
98   * but uses the "standard" <code>MMM d yyyy</code> date formatting
99   * <pre>
100  *    FTPClient f=FTPClient();
101  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_VMS);
102  *    conf.setShortMonthNames(
103  *        "jan|feb|mar|apr|ma\u00ED|j\u00FAn|j\u00FAl|\u00e1g\u00FA|sep|okt|n\u00F3v|des");
104  *    f.configure(conf);
105  *    f.connect(server);
106  *    f.login(username, password);
107  *    FTPFile[] files = listFiles(directory);
108  * </pre>
109  * </p>
110  * <p>
111  * Unpaged (whole list) access on a Windows-NT server in a different time zone.
112  * (Note, since the NT Format uses numeric date formatting, language issues
113  * are irrelevant here).
114  * <pre>
115  *    FTPClient f=FTPClient();
116  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);
117  *    conf.setTimeZoneId("America/Denver");
118  *    f.configure(conf);
119  *    f.connect(server);
120  *    f.login(username, password);
121  *    FTPFile[] files = listFiles(directory);
122  * </pre>
123  * </p>
124  * Unpaged (whole list) access on a Windows-NT server in a different time zone
125  * but which has been configured to use a unix-style listing format.
126  * <pre>
127  *    FTPClient f=FTPClient();
128  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
129  *    conf.setTimeZoneId("America/Denver");
130  *    f.configure(conf);
131  *    f.connect(server);
132  *    f.login(username, password);
133  *    FTPFile[] files = listFiles(directory);
134  * </pre>
135  * </p>
136  * @since 1.4
137  * @see org.apache.commons.net.ftp.Configurable
138  * @see org.apache.commons.net.ftp.FTPClient
139  * @see org.apache.commons.net.ftp.parser.FTPTimestampParserImpl#configure(FTPClientConfig)
140  * @see org.apache.commons.net.ftp.parser.ConfigurableFTPFileEntryParserImpl
141  */
142 public class FTPClientConfig
143 {
144     
145     /**
146      * Identifier by which a unix-based ftp server is known throughout
147      * the commons-net ftp system.
148      */
149     public static final String SYST_UNIX  = "UNIX";
150 
151     /**
152      * Identifier by which a vms-based ftp server is known throughout
153      * the commons-net ftp system.
154      */
155     public static final String SYST_VMS   = "VMS";
156     
157     /**
158      * Identifier by which a WindowsNT-based ftp server is known throughout
159      * the commons-net ftp system.
160      */
161     public static final String SYST_NT    = "WINDOWS";
162 
163     /**
164      * Identifier by which an OS/2-based ftp server is known throughout
165      * the commons-net ftp system.
166      */
167     public static final String SYST_OS2   = "OS/2";
168 
169     /**
170      * Identifier by which an OS/400-based ftp server is known throughout
171      * the commons-net ftp system.
172      */
173     public static final String SYST_OS400 = "OS/400";
174     
175     /**
176      * Identifier by which an AS/400-based ftp server is known throughout
177      * the commons-net ftp system.
178      */
179     public static final String SYST_AS400 = "AS/400";
180     
181     /**
182      * Identifier by which an MVS-based ftp server is known throughout
183      * the commons-net ftp system.
184      */
185     public static final String SYST_MVS = "MVS";
186 
187     /**
188      * Some servers return an "UNKNOWN Type: L8" message
189      * in response to the SYST command. We set these to be a Unix-type system.
190      * This may happen if the ftpd in question was compiled without system
191      * information.
192      *
193      * NET-230 - Updated to be UPPERCASE so that the check done in
194      * createFileEntryParser will succeed.
195      *
196      * @since 1.5
197      */
198     public static final String SYST_L8 = "TYPE: L8";
199     
200     /**
201      * Identifier by which an Netware-based ftp server is known throughout
202      * the commons-net ftp system.
203      *
204      * @since 1.5
205      */
206     public static final String SYST_NETWARE = "NETWARE";
207     
208     private final String serverSystemKey;
209     private String defaultDateFormatStr = null;
210     private String recentDateFormatStr = null;
211     private boolean lenientFutureDates = false;
212     private String serverLanguageCode = null;
213     private String shortMonthNames = null;
214     private String serverTimeZoneId = null;
215     
216     
217     /**
218      * The main constructor for an FTPClientConfig object
219      * @param systemKey key representing system type of the  server being 
220      * connected to. See {@link #getServerSystemKey() serverSystemKey}
221      */
222     public FTPClientConfig(String systemKey) {
223         this.serverSystemKey = systemKey;
224     }
225 
226     /**
227      * Convenience constructor mainly for use in testing.
228      * Constructs a UNIX configuration. 
229      */
230     public FTPClientConfig() {
231         this(SYST_UNIX);
232     }
233 
234     /**
235      * Constructor which allows setting of all member fields
236      * @param systemKey key representing system type of the  server being 
237      * connected to. See 
238      *  {@link #getServerSystemKey() serverSystemKey}
239      * @param defaultDateFormatStr See 
240      *  {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
241      * @param recentDateFormatStr See
242      *  {@link  #setRecentDateFormatStr(String)  recentDateFormatStr}
243      * @param serverLanguageCode See
244      *  {@link  #setServerLanguageCode(String)  serverLanguageCode}
245      * @param shortMonthNames See
246      *  {@link  #setShortMonthNames(String)  shortMonthNames}
247      * @param serverTimeZoneId See
248      *  {@link  #setServerTimeZoneId(String)  serverTimeZoneId}
249      */
250     public FTPClientConfig(String systemKey,
251                            String defaultDateFormatStr,
252                            String recentDateFormatStr,
253                            String serverLanguageCode,
254                            String shortMonthNames,
255                            String serverTimeZoneId)
256     {
257         this(systemKey);
258         this.defaultDateFormatStr = defaultDateFormatStr;
259         this.recentDateFormatStr = recentDateFormatStr;
260         this.serverLanguageCode = serverLanguageCode;
261         this.shortMonthNames = shortMonthNames;
262         this.serverTimeZoneId = serverTimeZoneId;
263     }
264     
265     private static Map<String, Object> LANGUAGE_CODE_MAP = new TreeMap<String, Object>();
266     static {
267         
268         // if there are other commonly used month name encodings which
269         // correspond to particular locales, please add them here.
270         
271         
272         
273         // many locales code short names for months as all three letters
274         // these we handle simply.
275         LANGUAGE_CODE_MAP.put("en", Locale.ENGLISH);
276         LANGUAGE_CODE_MAP.put("de",Locale.GERMAN);
277         LANGUAGE_CODE_MAP.put("it",Locale.ITALIAN);
278         LANGUAGE_CODE_MAP.put("es", new Locale("es", "", "")); // spanish
279         LANGUAGE_CODE_MAP.put("pt", new Locale("pt", "", "")); // portuguese
280         LANGUAGE_CODE_MAP.put("da", new Locale("da", "", "")); // danish
281         LANGUAGE_CODE_MAP.put("sv", new Locale("sv", "", "")); // swedish
282         LANGUAGE_CODE_MAP.put("no", new Locale("no", "", "")); // norwegian
283         LANGUAGE_CODE_MAP.put("nl", new Locale("nl", "", "")); // dutch
284         LANGUAGE_CODE_MAP.put("ro", new Locale("ro", "", "")); // romanian
285         LANGUAGE_CODE_MAP.put("sq", new Locale("sq", "", "")); // albanian
286         LANGUAGE_CODE_MAP.put("sh", new Locale("sh", "", "")); // serbo-croatian
287         LANGUAGE_CODE_MAP.put("sk", new Locale("sk", "", "")); // slovak
288         LANGUAGE_CODE_MAP.put("sl", new Locale("sl", "", "")); // slovenian
289 
290 
291         // some don't
292         LANGUAGE_CODE_MAP.put("fr",
293                 "jan|f\u00e9v|mar|avr|mai|jun|jui|ao\u00fb|sep|oct|nov|d\u00e9c");  //french
294             
295     }
296     
297     /**
298      * Getter for the serverSystemKey property.  This property
299      * specifies the general type of server to which the client connects.
300      * Should be either one of the <code>FTPClientConfig.SYST_*</code> codes
301      * or else the fully qualified class name of a parser implementing both
302      * the <code>FTPFileEntryParser</code> and <code>Configurable</code>
303      * interfaces.
304      * @return Returns the serverSystemKey property.
305      */
306     public String getServerSystemKey() {
307         return serverSystemKey;
308     }
309     
310     /**
311      * getter for the {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} 
312      * property.  
313      * @return Returns the defaultDateFormatStr property.
314      */
315     public String getDefaultDateFormatStr() {
316         return defaultDateFormatStr;
317     }
318     
319     /**
320      * getter for the {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} property.
321      * @return Returns the recentDateFormatStr property.
322      */
323 
324     public String getRecentDateFormatStr() {
325         return recentDateFormatStr;
326     }
327     
328     /**
329      * getter for the {@link  #setServerTimeZoneId(String)  serverTimeZoneId} property.
330      * @return Returns the serverTimeZoneId property.
331      */
332     public String getServerTimeZoneId() {
333         return serverTimeZoneId;
334     }
335     
336     /**
337      * <p>
338      * getter for the {@link  #setShortMonthNames(String)  shortMonthNames} 
339      * property.  
340      * </p>
341      * @return Returns the shortMonthNames.
342      */
343     public String getShortMonthNames() {
344         return shortMonthNames;
345     }
346     
347     /**
348      * <p>
349      * getter for the {@link  #setServerLanguageCode(String)  serverLanguageCode} property.
350      * </p>  
351      * @return Returns the serverLanguageCode property.
352      */
353     public String getServerLanguageCode() {
354         return serverLanguageCode;
355     }
356     
357     /**
358      * <p>
359      * getter for the {@link  #setLenientFutureDates(boolean)  lenientFutureDates} property.
360      * </p>  
361      * @return Returns the lenientFutureDates.
362      * @since 1.5
363      */
364     public boolean isLenientFutureDates() {
365         return lenientFutureDates;
366     }
367     /**
368      * <p>
369      * setter for the defaultDateFormatStr property.  This property
370      * specifies the main date format that will be used by a parser configured
371      * by this configuration to parse file timestamps.  If this is not
372      * specified, such a parser will use as a default value, the most commonly
373      * used format which will be in as used in <code>en_US</code> locales.
374      * </p><p>
375      * This should be in the format described for 
376      * <code>java.text.SimpleDateFormat</code>. 
377      * property.
378      * </p>
379      * @param defaultDateFormatStr The defaultDateFormatStr to set.
380      */
381     public void setDefaultDateFormatStr(String defaultDateFormatStr) {
382         this.defaultDateFormatStr = defaultDateFormatStr;
383     }
384     
385     /**
386      * <p>
387      * setter for the recentDateFormatStr property.  This property
388      * specifies a secondary date format that will be used by a parser 
389      * configured by this configuration to parse file timestamps, typically 
390      * those less than a year old.  If this is  not specified, such a parser 
391      * will not attempt to parse using an alternate format.
392      * </p>
393      * This is used primarily in unix-based systems.
394      * </p>
395      * This should be in the format described for 
396      * <code>java.text.SimpleDateFormat</code>.
397      * </p>
398      * @param recentDateFormatStr The recentDateFormatStr to set.
399      */
400     public void setRecentDateFormatStr(String recentDateFormatStr) {
401         this.recentDateFormatStr = recentDateFormatStr;
402     }
403     
404     /**
405      * <p>
406      * setter for the lenientFutureDates property.  This boolean property
407      * (default: false) only has meaning when a 
408      * {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} property
409      * has been set.  In that case, if this property is set true, then the
410      * parser, when it encounters a listing parseable with the recent date 
411      * format, will only consider a date to belong to the previous year if
412      * it is more than one day in the future.  This will allow all 
413      * out-of-synch situations (whether based on "slop" - i.e. servers simply 
414      * out of synch with one another or because of time zone differences - 
415      * but in the latter case it is highly recommended to use the 
416      * {@link  #setServerTimeZoneId(String)  serverTimeZoneId} property
417      * instead) to resolve correctly.
418      * </p><p>
419      * This is used primarily in unix-based systems.
420      * </p>
421      * @param lenientFutureDates set true to compensate for out-of-synch 
422      * conditions.
423      */
424     public void setLenientFutureDates(boolean lenientFutureDates) {
425         this.lenientFutureDates = lenientFutureDates;
426     }
427     /**
428      * <p>
429      * setter for the serverTimeZoneId property.  This property
430      * allows a time zone to be specified corresponding to that known to be 
431      * used by an FTP server in file listings.  This might be particularly 
432      * useful to clients such as Ant that try to use these timestamps for 
433      * dependency checking.
434      * </p><p>
435      * This should be one of the identifiers used by 
436      * <code>java.util.TimeZone</code> to refer to time zones, for example, 
437      * <code>America/Chicago</code> or <code>Asia/Rangoon</code>.
438      * </p>
439      * @param serverTimeZoneId The serverTimeZoneId to set.
440      */
441     public void setServerTimeZoneId(String serverTimeZoneId) {
442         this.serverTimeZoneId = serverTimeZoneId;
443     }
444     
445     /**
446      * <p>
447      * setter for the shortMonthNames property.  
448      * This property allows the user to specify a set of month names
449      * used by the server that is different from those that may be 
450      * specified using the {@link  #setServerLanguageCode(String)  serverLanguageCode}
451      * property.
452      * </p><p>
453      * This should be a string containing twelve strings each composed of
454      * three characters, delimited by pipe (|) characters.  Currently, 
455      * only 8-bit ASCII characters are known to be supported.  For example,
456      * a set of month names used by a hypothetical Icelandic FTP server might 
457      * conceivably be specified as 
458      * <code>"jan|feb|mar|apr|ma&#xED;|j&#xFA;n|j&#xFA;l|&#xE1;g&#xFA;|sep|okt|n&#xF3;v|des"</code>.  
459      * </p>
460      * @param shortMonthNames The value to set to the shortMonthNames property.
461      */
462     public void setShortMonthNames(String shortMonthNames) {
463         this.shortMonthNames = shortMonthNames;
464     }
465     
466     /**
467      * <p>
468      * setter for the serverLanguageCode property.  This property allows
469      * user to specify a 
470      * <a href="http://www.ics.uci.edu/pub/ietf/http/related/iso639.txt">
471      * two-letter ISO-639 language code</a> that will be used to 
472      * configure the set of month names used by the file timestamp parser.
473      * If neither this nor the {@link #setShortMonthNames(String) shortMonthNames} 
474      * is specified, parsing will assume English month names, which may or 
475      * may not be significant, depending on whether the date format(s) 
476      * specified via {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} 
477      * and/or {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} are using 
478      * numeric or alphabetic month names.
479      * </p>
480      * <p>If the code supplied is not supported here, <code>en_US</code>
481      * month names will be used.  We are supporting here those language 
482      * codes which, when a <code> java.util.Locale</code> is constucted
483      * using it, and a <code>java.text.SimpleDateFormat</code> is 
484      * constructed using that Locale, the array returned by the 
485      * SimpleDateFormat's <code>getShortMonths()</code> method consists
486      * solely of three 8-bit ASCII character strings.  Additionally, 
487      * languages which do not meet this requirement are included if a 
488      * common alternative set of short month names is known to be used.
489      * This means that users who can tell us of additional such encodings
490      * may get them added to the list of supported languages by contacting
491      * the jakarta-commons-net team.
492      * </p>
493      * <p><strong>
494      * Please note that this attribute will NOT be used to determine a 
495      * locale-based date format for the language.  </strong>  
496      * Experience has shown that many if not most FTP servers outside the
497      * United States employ the standard <code>en_US</code> date format 
498      * orderings of <code>MMM d yyyy</code> and <code>MMM d HH:mm</code> 
499      * and attempting to deduce this automatically here would cause more
500      * problems than it would solve.  The date format must be changed 
501      * via the {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} and/or 
502      * {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} parameters.
503      * </p>
504      * @param serverLanguageCode The value to set to the serverLanguageCode property.  
505      */
506     public void setServerLanguageCode(String serverLanguageCode) {
507         this.serverLanguageCode = serverLanguageCode;
508     }
509     
510     /**
511      * Looks up the supplied language code in the internally maintained table of 
512      * language codes.  Returns a DateFormatSymbols object configured with 
513      * short month names corresponding to the code.  If there is no corresponding
514      * entry in the table, the object returned will be that for 
515      * <code>Locale.US</code> 
516      * @param languageCode See {@link  #setServerLanguageCode(String)  serverLanguageCode}
517      * @return a DateFormatSymbols object configured with short month names 
518      * corresponding to the supplied code, or with month names for  
519      * <code>Locale.US</code> if there is no corresponding entry in the internal
520      * table.
521      */
522     public static DateFormatSymbols lookupDateFormatSymbols(String languageCode) 
523     {
524         Object lang = LANGUAGE_CODE_MAP.get(languageCode);
525         if (lang != null) {
526             if (lang instanceof Locale) {
527                 return new DateFormatSymbols((Locale) lang);
528             } else if (lang instanceof String){
529                 return getDateFormatSymbols((String) lang);
530             }
531         }
532         return new DateFormatSymbols(Locale.US);
533     }
534     
535     /**
536      * Returns a DateFormatSymbols object configured with short month names
537      * as in the supplied string
538      * @param shortmonths This  should be as described in 
539      *  {@link  #setShortMonthNames(String)  shortMonthNames}
540      * @return a DateFormatSymbols object configured with short month names
541      * as in the supplied string
542      */
543     public static DateFormatSymbols getDateFormatSymbols(String shortmonths) 
544     {
545         String[] months = splitShortMonthString(shortmonths);
546         DateFormatSymbols dfs = new DateFormatSymbols(Locale.US);
547         dfs.setShortMonths(months);
548         return dfs;
549     }
550     
551     private static String[] splitShortMonthString(String shortmonths) {
552         StringTokenizer st = new StringTokenizer(shortmonths, "|");
553         int monthcnt = st.countTokens();
554         if (12 != monthcnt) {
555             throw new IllegalArgumentException(
556                     "expecting a pipe-delimited string containing 12 tokens");
557         }
558         String[] months = new String[13];
559         int pos = 0;
560         while(st.hasMoreTokens()) {
561             months[pos++] = st.nextToken();
562         }
563         months[pos]="";
564         return months;
565     }
566 
567     /**
568      * Returns a Collection of all the language codes currently supported
569      * by this class. See {@link  #setServerLanguageCode(String)  serverLanguageCode}  
570      * for a functional descrption of language codes within this system. 
571      *
572      * @return a Collection of all the language codes currently supported
573      * by this class
574      */
575     public static Collection<String> getSupportedLanguageCodes() {
576         return LANGUAGE_CODE_MAP.keySet();
577     }
578     
579     
580 }