001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.commons.net.ftp;
019    
020    import java.text.DateFormatSymbols;
021    import java.util.Collection;
022    import java.util.Locale;
023    import java.util.Map;
024    import java.util.StringTokenizer;
025    import java.util.TreeMap;
026    
027    /**
028     * <p>
029     * This class implements an alternate means of configuring the
030     * {@link  org.apache.commons.net.ftp.FTPClient  FTPClient} object and
031     * also subordinate objects which it uses.  Any class implementing the 
032     * {@link  org.apache.commons.net.ftp.Configurable  Configurable } 
033     * interface can be configured by this object. 
034     * </p><p>
035     * In particular this class was designed primarily to support configuration
036     * of FTP servers which express file timestamps in formats and languages 
037     * other than those for the US locale, which although it is the most common
038     * is not universal.  Unfortunately, nothing in the FTP spec allows this to 
039     * be determined in an automated way, so manual configuration such as this
040     * is necessary.
041     * </p><p>
042     * This functionality was designed to allow existing clients to work exactly
043     * as before without requiring use of this component.  This component should
044     * only need to be explicitly invoked by the user of this package for problem
045     * cases that previous implementations could not solve.
046     * </p>
047     * <h3>Examples of use of FTPClientConfig</h3>
048     * Use cases:
049     * You are trying to access a server that 
050     * <ul> 
051     * <li>lists files with timestamps that use month names in languages other 
052     * than English</li>
053     * <li>lists files with timestamps that use date formats other 
054     * than the American English "standard" <code>MM dd yyyy</code></li>
055     * <li>is in different timezone and you need accurate timestamps for 
056     * dependency checking as in Ant</li>
057     * </ul>
058     * <p>
059     * Unpaged (whole list) access on a UNIX server that uses French month names
060     * but uses the "standard" <code>MMM d yyyy</code> date formatting
061     * <pre>
062     *    FTPClient f=FTPClient();
063     *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
064     *    conf.setServerLanguageCode("fr");
065     *    f.configure(conf);
066     *    f.connect(server);
067     *    f.login(username, password);
068     *    FTPFile[] files = listFiles(directory);
069     * </pre>
070     * </p>
071     * <p>
072     * Paged access on a UNIX server that uses Danish month names
073     * and "European" date formatting in Denmark's time zone, when you
074     * are in some other time zone.
075     * <pre>
076     *    FTPClient f=FTPClient();
077     *    FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
078     *    conf.setServerLanguageCode("da");
079     *    conf.setDefaultDateFormat("d MMM yyyy");
080     *    conf.setRecentDateFormat("d MMM HH:mm");
081     *    conf.setTimeZoneId("Europe/Copenhagen");
082     *    f.configure(conf);
083     *    f.connect(server);
084     *    f.login(username, password);
085     *    FTPListParseEngine engine =
086     *       f.initiateListParsing("com.whatever.YourOwnParser", directory);
087     *
088     *    while (engine.hasNext()) {
089     *       FTPFile[] files = engine.getNext(25);  // "page size" you want
090     *       //do whatever you want with these files, display them, etc.
091     *       //expensive FTPFile objects not created until needed.
092     *    }
093     * </pre>
094     * </p> 
095     * <p>
096     * Unpaged (whole list) access on a VMS server that uses month names
097     * in a language not {@link #getSupportedLanguageCodes() supported} by the system.
098     * but uses the "standard" <code>MMM d yyyy</code> date formatting
099     * <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 final 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 Apache 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    }