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1   /*
2    * Copyright 2005 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.net.ftp;
17  
18  import java.text.DateFormatSymbols;
19  import java.util.Collection;
20  import java.util.Locale;
21  import java.util.Map;
22  import java.util.StringTokenizer;
23  import java.util.TreeMap;
24  
25  /**
26   * <p>
27   * This class implements an alternate means of configuring the
28   * {@link  org.apache.commons.net.ftp.FTPClient  FTPClient} object and
29   * also subordinate objects which it uses.  Any class implementing the 
30   * {@link  org.apache.commons.net.ftp.Configurable  Configurable } 
31   * interface can be configured by this object. 
32   * </p><p>
33   * In particular this class was designed primarily to support configuration
34   * of FTP servers which express file timestamps in formats and languages 
35   * other than those for the US locale, which although it is the most common
36   * is not universal.  Unfortunately, nothing in the FTP spec allows this to 
37   * be determined in an automated way, so manual configuration such as this
38   * is necessary.
39   * </p><p>
40   * This functionality was designed to allow existing clients to work exactly
41   * as before without requiring use of this component.  This component should
42   * only need to be explicitly invoked by the user of this package for problem
43   * cases that previous implementations could not solve.
44   * </p>
45   * <h3>Examples of use of FTPClientConfig</h3>
46   * Use cases:
47   * You are trying to access a server that 
48   * <ul> 
49   * <li>lists files with timestamps that use month names in languages other 
50   * than English</li>
51   * <li>lists files with timestamps that use date formats other 
52   * than the American English "standard" <code>MM dd yyyy</code></li>
53   * <li>is in different timezone and you need accurate timestamps for 
54   * dependency checking as in Ant</li>
55   * </ul>
56   * <p>
57   * Unpaged (whole list) access on a UNIX server that uses French month names
58   * but uses the "standard" <code>MMM d yyyy</code> date formatting
59   * <pre>
60   *    FTPClient f=FTPClient();
61   *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
62   *    conf.setServerLanguageCode("fr");
63   *    f.configure(conf);
64   *    f.connect(server);
65   *    f.login(username, password);
66   *    FTPFile[] files = listFiles(directory);
67   * </pre>
68   * </p>
69   * <p>
70   * Paged access on a UNIX server that uses Danish month names
71   * and "European" date formatting in Denmark's time zone, when you
72   * are in some other time zone.
73   * <pre>
74   *    FTPClient f=FTPClient();
75   *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
76   *    conf.setServerLanguageCode("da");
77   *    conf.setDefaultDateFormat("d MMM yyyy");
78   *    conf.setRecentDateFormat("d MMM HH:mm");
79   *    conf.setTimeZoneId("Europe/Copenhagen");
80   *    f.configure(conf);
81   *    f.connect(server);
82   *    f.login(username, password);
83   *    FTPListParseEngine engine =
84   *       f.initiateListParsing("com.whatever.YourOwnParser", directory);
85   *
86   *    while (engine.hasNext()) {
87   *       FTPFile[] files = engine.getNext(25);  // "page size" you want
88   *       //do whatever you want with these files, display them, etc.
89   *       //expensive FTPFile objects not created until needed.
90   *    }
91   * </pre>
92   * </p> 
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  * <p>
109  * Unpaged (whole list) access on a Windows-NT server in a different time zone.
110  * (Note, since the NT Format uses numeric date formatting, language issues
111  * are irrelevant here).
112  * <pre>
113  *    FTPClient f=FTPClient();
114  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);
115  *    conf.setTimeZoneId("America/Denver");
116  *    f.configure(conf);
117  *    f.connect(server);
118  *    f.login(username, password);
119  *    FTPFile[] files = listFiles(directory);
120  * </pre>
121  * </p>
122  * Unpaged (whole list) access on a Windows-NT server in a different time zone
123  * but which has been configured to use a unix-style listing format.
124  * <pre>
125  *    FTPClient f=FTPClient();
126  *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
127  *    conf.setTimeZoneId("America/Denver");
128  *    f.configure(conf);
129  *    f.connect(server);
130  *    f.login(username, password);
131  *    FTPFile[] files = listFiles(directory);
132  * </pre>
133  * </p>
134  * @since 1.4
135  * @see org.apache.commons.net.ftp.Configurable
136  * @see org.apache.commons.net.ftp.FTPClient
137  * @see org.apache.commons.net.ftp.parser.FTPTimestampParserImpl#configure(FTPClientConfig)
138  * @see org.apache.commons.net.ftp.parser.ConfigurableFTPFileEntryParserImpl
139  */
140 public class FTPClientConfig
141 {
142 	
143     /**
144      * Identifier by which a unix-based ftp server is known throughout
145      * the commons-net ftp system.
146      */
147     public static final String SYST_UNIX  = "UNIX";
148 
149     /**
150      * Identifier by which a vms-based ftp server is known throughout
151      * the commons-net ftp system.
152      */
153     public static final String SYST_VMS   = "VMS";
154     
155     /**
156      * Identifier by which a WindowsNT-based ftp server is known throughout
157      * the commons-net ftp system.
158      */
159     public static final String SYST_NT    = "WINDOWS";
160 
161     /**
162      * Identifier by which an OS/2-based ftp server is known throughout
163      * the commons-net ftp system.
164      */
165     public static final String SYST_OS2   = "OS/2";
166 
167     /**
168      * Identifier by which an OS/400-based ftp server is known throughout
169      * the commons-net ftp system.
170      */
171     public static final String SYST_OS400 = "OS/400";
172     
173     /**
174      * Identifier by which an MVS-based ftp server is known throughout
175      * the commons-net ftp system.
176      */
177     public static final String SYST_MVS = "MVS";
178     
179     private final String serverSystemKey;
180 	private String defaultDateFormatStr = null;
181 	private String recentDateFormatStr = null;
182 	private String serverLanguageCode = null;
183 	private String shortMonthNames = null;
184 	private String serverTimeZoneId = null;
185 	
186 	
187 	/**
188 	 * The main constructor for an FTPClientConfig object
189 	 * @param systemKey key representing system type of the  server being 
190 	 * connected to. See {@link #getServerSystemKey() serverSystemKey}
191 	 */
192 	public FTPClientConfig(String systemKey) {
193 		this.serverSystemKey = systemKey;
194 	}
195 
196 	/**
197 	 * Convenience constructor mainly for use in testing.
198 	 * Constructs a UNIX configuration. 
199 	 */
200 	public FTPClientConfig() {
201 	    this(SYST_UNIX);
202 	}
203 
204 	/**
205 	 * Constructor which allows setting of all member fields
206 	 * @param systemKey key representing system type of the  server being 
207 	 * connected to. See 
208 	 *  {@link #getServerSystemKey() serverSystemKey}
209 	 * @param defaultDateFormatStr See 
210 	 * 	{@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr}
211 	 * @param recentDateFormatStr See
212 	 * 	{@link  #setRecentDateFormatStr(String)  recentDateFormatStr}
213 	 * @param serverLanguageCode See
214 	 * 	{@link  #setServerLanguageCode(String)  serverLanguageCode}
215 	 * @param shortMonthNames See
216 	 * 	{@link  #setShortMonthNames(String)  shortMonthNames}
217 	 * @param serverTimeZoneId See
218 	 * 	{@link  #setServerTimeZoneId(String)  serverTimeZoneId}
219 	 */
220 	public FTPClientConfig(String systemKey,
221 	        			   String defaultDateFormatStr,
222 	        			   String recentDateFormatStr,
223 	        			   String serverLanguageCode,
224 	        			   String shortMonthNames,
225 	        			   String serverTimeZoneId)
226 	{
227 	    this(systemKey);
228 		this.defaultDateFormatStr = defaultDateFormatStr;
229 		this.recentDateFormatStr = recentDateFormatStr;
230 		this.serverLanguageCode = serverLanguageCode;
231 		this.shortMonthNames = shortMonthNames;
232 		this.serverTimeZoneId = serverTimeZoneId;
233 	}
234 	
235 	private static Map LANGUAGE_CODE_MAP = new TreeMap();
236 	static {
237 		
238 		// if there are other commonly used month name encodings which
239 		// correspond to particular locales, please add them here.
240 		
241 		
242 		
243 		// many locales code short names for months as all three letters
244 		// these we handle simply.
245 		LANGUAGE_CODE_MAP.put("en", Locale.ENGLISH);
246 		LANGUAGE_CODE_MAP.put("de",Locale.GERMAN);
247 		LANGUAGE_CODE_MAP.put("it",Locale.ITALIAN);
248 		LANGUAGE_CODE_MAP.put("es", new Locale("es", "", "")); // spanish
249 		LANGUAGE_CODE_MAP.put("pt", new Locale("pt", "", "")); // portuguese
250 		LANGUAGE_CODE_MAP.put("da", new Locale("da", "", "")); // danish
251 		LANGUAGE_CODE_MAP.put("sv", new Locale("sv", "", "")); // swedish
252 		LANGUAGE_CODE_MAP.put("no", new Locale("no", "", "")); // norwegian
253 		LANGUAGE_CODE_MAP.put("nl", new Locale("nl", "", "")); // dutch
254 		LANGUAGE_CODE_MAP.put("ro", new Locale("ro", "", "")); // romanian
255 		LANGUAGE_CODE_MAP.put("sq", new Locale("sq", "", "")); // albanian
256 		LANGUAGE_CODE_MAP.put("sh", new Locale("sh", "", "")); // serbo-croatian
257 		LANGUAGE_CODE_MAP.put("sk", new Locale("sk", "", "")); // slovak		
258 		LANGUAGE_CODE_MAP.put("sl", new Locale("sl", "", "")); // slovenian
259 
260 
261 		// some don't
262 		LANGUAGE_CODE_MAP.put("fr",	
263 		        "jan|f\u00e9v|mar|avr|mai|jun|jui|ao\u00fb|sep|oct|nov|d\u00e9c");  //french
264 			
265 	}
266 	
267 	/**
268 	 * Getter for the serverSystemKey property.  This property
269      * specifies the general type of server to which the client connects.
270      * Should be either one of the <code>FTPClientConfig.SYST_*</code> codes
271      * or else the fully qualified class name of a parser implementing both
272      * the <code>FTPFileEntryParser</code> and <code>Configurable</code>
273      * interfaces.
274 	 * @return Returns the serverSystemKey property.
275 	 */
276 	public String getServerSystemKey() {
277 		return serverSystemKey;
278 	}
279 	
280 	/**
281 	 * getter for the {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} 
282 	 * property.  
283 	 * @return Returns the defaultDateFormatStr property.
284 	 */
285 	public String getDefaultDateFormatStr() {
286 		return defaultDateFormatStr;
287 	}
288 	
289 	/**
290 	 * getter for the {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} property.
291 	 * @return Returns the recentDateFormatStr property.
292 	 */
293 
294 	public String getRecentDateFormatStr() {
295 		return recentDateFormatStr;
296 	}
297 	
298 	/**
299 	 * getter for the {@link  #setServerTimeZoneId(String)  serverTimeZoneId} property.
300 	 * @return Returns the serverTimeZoneId property.
301 	 */
302 	public String getServerTimeZoneId() {
303 		return serverTimeZoneId;
304 	}
305 	
306 	/**
307 	 * <p>
308 	 * getter for the {@link  #setShortMonthNames(String)  shortMonthNames} 
309 	 * property.  
310 	 * </p>
311 	 * @return Returns the shortMonthNames.
312 	 */
313 	public String getShortMonthNames() {
314 		return shortMonthNames;
315 	}
316 	
317 	/**
318 	 * <p>
319 	 * getter for the {@link  #setServerLanguageCode(String)  serverLanguageCode} property.
320 	 * </p>  
321 * 	 * @return Returns the serverLanguageCode property.
322 	 */
323 	public String getServerLanguageCode() {
324 		return serverLanguageCode;
325 	}
326 	
327 	/**
328 	 * <p>
329 	 * setter for the defaultDateFormatStr property.  This property
330 	 * specifies the main date format that will be used by a parser configured
331 	 * by this configuration to parse file timestamps.  If this is not
332 	 * specified, such a parser will use as a default value, the most commonly
333 	 * used format which will be in as used in <code>en_US</code> locales.
334 	 * </p><p>
335 	 * This should be in the format described for 
336 	 * <code>java.text.SimpleDateFormat</code>. 
337 	 * property.
338 	 * </p>
339 	 * @param defaultDateFormatStr The defaultDateFormatStr to set.
340 	 */
341 	public void setDefaultDateFormatStr(String defaultDateFormatStr) {
342 		this.defaultDateFormatStr = defaultDateFormatStr;
343 	}
344 	
345 	/**
346 	 * <p>
347 	 * setter for the recentDateFormatStr property.  This property
348 	 * specifies a secondary date format that will be used by a parser 
349 	 * configured by this configuration to parse file timestamps, typically 
350 	 * those less than a year old.  If this is  not specified, such a parser 
351 	 * will not attempt to parse using an alternate format.
352 	 * </p>
353 	 * This is used primarily in unix-based systems.
354 	 * </p>
355 	 * This should be in the format described for 
356 	 * <code>java.text.SimpleDateFormat</code>.
357 	 * </p>
358 	 * @param recentDateFormatStr The recentDateFormatStr to set.
359 	 */
360 	public void setRecentDateFormatStr(String recentDateFormatStr) {
361 		this.recentDateFormatStr = recentDateFormatStr;
362 	}
363 	
364 	/**
365 	 * <p>
366 	 * setter for the serverTimeZoneId property.  This property
367 	 * allows a time zone to be specified corresponding to that known to be 
368 	 * used by an FTP server in file listings.  This might be particularly 
369 	 * useful to clients such as Ant that try to use these timestamps for 
370 	 * dependency checking.
371 	 * </p><p>
372 	 * This should be one of the identifiers used by 
373 	 * <code>java.util.TimeZone</code> to refer to time zones, for example, 
374 	 * <code>America/Chicago</code> or <code>Asia/Rangoon</code>.
375 	 * </p>
376 	 * @param serverTimeZoneId The serverTimeZoneId to set.
377 	 */
378 	public void setServerTimeZoneId(String serverTimeZoneId) {
379 		this.serverTimeZoneId = serverTimeZoneId;
380 	}
381 	
382 	/**
383 	 * <p>
384 	 * setter for the shortMonthNames property.  
385 	 * This property allows the user to specify a set of month names
386 	 * used by the server that is different from those that may be 
387 	 * specified using the {@link  #setServerLanguageCode(String)  serverLanguageCode}
388 	 * property.
389 	 * </p><p>
390 	 * This should be a string containing twelve strings each composed of
391 	 * three characters, delimited by pipe (|) characters.  Currently, 
392 	 * only 8-bit ASCII characters are known to be supported.  For example,
393 	 * a set of month names used by a hypothetical Icelandic FTP server might 
394 	 * conceivably be specified as 
395 	 * <code>"jan|feb|mar|apr|ma&#xED;|j&#xFA;n|j&#xFA;l|&#xE1;g&#xFA;|sep|okt|n&#xF3;v|des"</code>.  
396 	 * </p>
397 	 * @param shortMonthNames The value to set to the shortMonthNames property.
398 	 */
399 	public void setShortMonthNames(String shortMonthNames) {
400 		this.shortMonthNames = shortMonthNames;
401 	}
402 	
403 	/**
404 	 * <p>
405 	 * setter for the serverLanguageCode property.  This property allows
406 	 * user to specify a 
407 	 * <a href="http://www.ics.uci.edu/pub/ietf/http/related/iso639.txt">
408 	 * two-letter ISO-639 language code</a> that will be used to 
409 	 * configure the set of month names used by the file timestamp parser.
410 	 * If neither this nor the {@link #setShortMonthNames(String) shortMonthNames} 
411 	 * is specified, parsing will assume English month names, which may or 
412 	 * may not be significant, depending on whether the date format(s) 
413 	 * specified via {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} 
414 	 * and/or {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} are using 
415 	 * numeric or alphabetic month names.
416 	 * </p>
417 	 * <p>If the code supplied is not supported here, <code>en_US</code>
418 	 * month names will be used.  We are supporting here those language 
419 	 * codes which, when a <code> java.util.Locale</code> is constucted
420 	 * using it, and a <code>java.text.SimpleDateFormat</code> is 
421 	 * constructed using that Locale, the array returned by the 
422 	 * SimpleDateFormat's <code>getShortMonths()</code> method consists
423 	 * solely of three 8-bit ASCII character strings.  Additionally, 
424 	 * languages which do not meet this requirement are included if a 
425 	 * common alternative set of short month names is known to be used.
426 	 * This means that users who can tell us of additional such encodings
427 	 * may get them added to the list of supported languages by contacting
428 	 * the jakarta-commons-net team.
429 	 * </p>
430 	 * <p><strong>
431 	 * Please note that this attribute will NOT be used to determine a 
432 	 * locale-based date format for the language.  </strong>  
433 	 * Experience has shown that many if not most FTP servers outside the
434 	 * United States employ the standard <code>en_US</code> date format 
435 	 * orderings of <code>MMM d yyyy</code> and <code>MMM d HH:mm</code> 
436 	 * and attempting to deduce this automatically here would cause more
437 	 * problems than it would solve.  The date format must be changed 
438 	 * via the {@link  #setDefaultDateFormatStr(String)  defaultDateFormatStr} and/or 
439 	 * {@link  #setRecentDateFormatStr(String)  recentDateFormatStr} parameters.
440 	 * </p>	  
441 	 * @param serverLanguageCode The value to set to the serverLanguageCode property.  
442 	 */
443 	public void setServerLanguageCode(String serverLanguageCode) {
444 		this.serverLanguageCode = serverLanguageCode;
445 	}
446 	
447 	/**
448 	 * Looks up the supplied language code in the internally maintained table of 
449 	 * language codes.  Returns a DateFormatSymbols object configured with 
450 	 * short month names corresponding to the code.  If there is no corresponding
451 	 * entry in the table, the object returned will be that for 
452 	 * <code>Locale.US</code> 
453 	 * @param languageCode See {@link  #setServerLanguageCode(String)  serverLanguageCode}
454 	 * @return a DateFormatSymbols object configured with short month names 
455 	 * corresponding to the supplied code, or with month names for  
456 	 * <code>Locale.US</code> if there is no corresponding entry in the internal
457 	 * table.
458 	 */
459 	public static DateFormatSymbols lookupDateFormatSymbols(String languageCode) 
460 	{
461 		Object lang = LANGUAGE_CODE_MAP.get(languageCode);
462 		if (lang != null) {
463 			if (lang instanceof Locale) {
464 				return new DateFormatSymbols((Locale) lang);
465 			} else if (lang instanceof String){
466 				return getDateFormatSymbols((String) lang);
467 			}
468 		}
469 		return new DateFormatSymbols(Locale.US);
470 	}
471 	
472 	/**
473 	 * Returns a DateFormatSymbols object configured with short month names
474 	 * as in the supplied string
475 	 * @param shortmonths This  should be as described in 
476 	 *  {@link  #setShortMonthNames(String)  shortMonthNames}
477 	 * @return a DateFormatSymbols object configured with short month names
478 	 * as in the supplied string
479 	 */
480 	public static DateFormatSymbols getDateFormatSymbols(String shortmonths) 
481 	{
482 		String[] months = splitShortMonthString(shortmonths);
483 		DateFormatSymbols dfs = new DateFormatSymbols(Locale.US);
484 		dfs.setShortMonths(months);
485 		return dfs;
486 	}
487 	
488 	private static String[] splitShortMonthString(String shortmonths) {
489 		StringTokenizer st = new StringTokenizer(shortmonths, "|");
490 		int monthcnt = st.countTokens();
491 		if (12 != monthcnt) {
492 			throw new IllegalArgumentException(
493 					"expecting a pipe-delimited string containing 12 tokens");
494 		}
495 		String[] months = new String[13];
496 		int pos = 0;
497 		while(st.hasMoreTokens()) {
498 			months[pos++] = st.nextToken();
499 		}
500 		months[pos]="";
501 		return months;
502 	}
503 
504 	/**
505 	 * Returns a Collection of all the language codes currently supported
506 	 * by this class. See {@link  #setServerLanguageCode(String)  serverLanguageCode}  
507 	 * for a functional descrption of language codes within this system. 
508 	 * 	
509 	 * @return a Collection of all the language codes currently supported
510 	 * by this class
511 	 */
512 	public static Collection getSupportedLanguageCodes() {
513 	    return LANGUAGE_CODE_MAP.keySet();
514 	}
515 	
516 	
517 }