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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    *      https://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.lang3.time;
19  
20  import java.text.DateFormat;
21  import java.text.FieldPosition;
22  import java.text.Format;
23  import java.text.ParseException;
24  import java.text.ParsePosition;
25  import java.text.SimpleDateFormat;
26  import java.util.Calendar;
27  import java.util.Date;
28  import java.util.GregorianCalendar;
29  import java.util.Locale;
30  import java.util.TimeZone;
31  
32  /**
33   * FastDateFormat is a fast and thread-safe version of {@link java.text.SimpleDateFormat}.
34   *
35   * <p>
36   * To obtain an instance of FastDateFormat, use one of the static factory methods: {@link #getInstance(String, TimeZone, Locale)},
37   * {@link #getDateInstance(int, TimeZone, Locale)}, {@link #getTimeInstance(int, TimeZone, Locale)}, or {@link #getDateTimeInstance(int, int, TimeZone, Locale)}
38   * </p>
39   *
40   * <p>
41   * Since FastDateFormat is thread safe, you can use a static member instance:
42   * </p>
43   * {@code
44   *   private static final FastDateFormat DATE_FORMATTER = FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.SHORT);
45   * }
46   *
47   * <p>
48   * This class can be used as a direct replacement to {@link SimpleDateFormat} in most formatting and parsing situations. This class is especially useful in
49   * multi-threaded server environments. {@link SimpleDateFormat} is not thread-safe in any JDK version, nor will it be as Sun have closed the bug/RFE.
50   * </p>
51   *
52   * <p>
53   * All patterns are compatible with SimpleDateFormat (except time zones and some year patterns - see below).
54   * </p>
55   *
56   * <p>
57   * Since 3.2, FastDateFormat supports parsing as well as printing.
58   * </p>
59   *
60   * <p>
61   * Java 1.4 introduced a new pattern letter, {@code 'Z'}, to represent time zones in RFC822 format (for example, {@code +0800} or {@code -1100}). This pattern letter can
62   * be used here (on all JDK versions).
63   * </p>
64   *
65   * <p>
66   * In addition, the pattern {@code 'ZZ'} has been made to represent ISO 8601 extended format time zones (for example, {@code +08:00} or {@code -11:00}). This introduces
67   * a minor incompatibility with Java 1.4, but at a gain of useful functionality.
68   * </p>
69   *
70   * <p>
71   * Javadoc cites for the year pattern: <i>For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted
72   * as a number.</i> Starting with Java 1.7 a pattern of 'Y' or 'YYY' will be formatted as '2003', while it was '03' in former Java versions. FastDateFormat
73   * implements the behavior of Java 7.
74   * </p>
75   *
76   * @since 2.0
77   */
78  public class FastDateFormat extends Format implements DateParser, DatePrinter {
79  
80      /**
81       * Required for serialization support.
82       *
83       * @see java.io.Serializable
84       */
85      private static final long serialVersionUID = 2L;
86  
87      /**
88       * FULL locale dependent date or time style.
89       */
90      public static final int FULL = DateFormat.FULL;
91  
92      /**
93       * LONG locale dependent date or time style.
94       */
95      public static final int LONG = DateFormat.LONG;
96  
97      /**
98       * MEDIUM locale dependent date or time style.
99       */
100     public static final int MEDIUM = DateFormat.MEDIUM;
101 
102     /**
103      * SHORT locale dependent date or time style.
104      */
105     public static final int SHORT = DateFormat.SHORT;
106 
107     private static final AbstractFormatCache<FastDateFormat> CACHE = new AbstractFormatCache<FastDateFormat>() {
108 
109         @Override
110         protected FastDateFormat createInstance(final String pattern, final TimeZone timeZone, final Locale locale) {
111             return new FastDateFormat(pattern, timeZone, locale);
112         }
113     };
114 
115     /**
116      * Clears the cache.
117      */
118     static void clear() {
119         AbstractFormatCache.clear();
120         CACHE.clearInstance();
121     }
122 
123     /**
124      * Gets a date formatter instance using the specified style in the default time zone and locale.
125      *
126      * @param style date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
127      * @return a localized standard date formatter.
128      * @throws IllegalArgumentException if the Locale has no date pattern defined.
129      * @since 2.1
130      */
131     public static FastDateFormat getDateInstance(final int style) {
132         return CACHE.getDateInstance(style, null, null);
133     }
134 
135     /**
136      * Gets a date formatter instance using the specified style and locale in the default time zone.
137      *
138      * @param style  date style: {@link #FULL}, LO{@link #FULL},{@link #MEDIUM}, or {@link #SHORT}.
139      * @param locale optional locale, overrides system locale.
140      * @return a localized standard date formatter.
141      * @throws IllegalArgumentException if the Locale has no date pattern defined.
142      * @since 2.1
143      */
144     public static FastDateFormat getDateInstance(final int style, final Locale locale) {
145         return CACHE.getDateInstance(style, null, locale);
146     }
147 
148     /**
149      * Gets a date formatter instance using the specified style and time zone in the default locale.
150      *
151      * @param style    date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
152      * @param timeZone optional time zone, overrides time zone of formatted date.
153      * @return a localized standard date formatter.
154      * @throws IllegalArgumentException if the Locale has no date pattern defined.
155      * @since 2.1
156      */
157     public static FastDateFormat getDateInstance(final int style, final TimeZone timeZone) {
158         return CACHE.getDateInstance(style, timeZone, null);
159     }
160 
161     /**
162      * Gets a date formatter instance using the specified style, time zone and locale.
163      *
164      * @param style    date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
165      * @param timeZone optional time zone, overrides time zone of formatted date.
166      * @param locale   optional locale, overrides system locale.
167      * @return a localized standard date formatter.
168      * @throws IllegalArgumentException if the Locale has no date pattern defined.
169      */
170     public static FastDateFormat getDateInstance(final int style, final TimeZone timeZone, final Locale locale) {
171         return CACHE.getDateInstance(style, timeZone, locale);
172     }
173 
174     /**
175      * Gets a date/time formatter instance using the specified style in the default time zone and locale.
176      *
177      * @param dateStyle date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
178      * @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
179      * @return a localized standard date/time formatter.
180      * @throws IllegalArgumentException if the Locale has no date/time pattern defined.
181      * @since 2.1
182      */
183     public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle) {
184         return CACHE.getDateTimeInstance(dateStyle, timeStyle, null, null);
185     }
186 
187     /**
188      * Gets a date/time formatter instance using the specified style and locale in the default time zone.
189      *
190      * @param dateStyle date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
191      * @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
192      * @param locale    optional locale, overrides system locale.
193      * @return a localized standard date/time formatter.
194      * @throws IllegalArgumentException if the Locale has no date/time pattern defined.
195      * @since 2.1
196      */
197     public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final Locale locale) {
198         return CACHE.getDateTimeInstance(dateStyle, timeStyle, null, locale);
199     }
200 
201     /**
202      * Gets a date/time formatter instance using the specified style and time zone in the default locale.
203      *
204      * @param dateStyle date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
205      * @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
206      * @param timeZone  optional time zone, overrides time zone of formatted date.
207      * @return a localized standard date/time formatter.
208      * @throws IllegalArgumentException if the Locale has no date/time pattern defined.
209      * @since 2.1
210      */
211     public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final TimeZone timeZone) {
212         return getDateTimeInstance(dateStyle, timeStyle, timeZone, null);
213     }
214 
215     /**
216      * Gets a date/time formatter instance using the specified style, time zone and locale.
217      *
218      * @param dateStyle date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
219      * @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
220      * @param timeZone  optional time zone, overrides time zone of formatted date.
221      * @param locale    optional locale, overrides system locale.
222      * @return a localized standard date/time formatter.
223      * @throws IllegalArgumentException if the Locale has no date/time pattern defined.
224      */
225     public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final TimeZone timeZone, final Locale locale) {
226         return CACHE.getDateTimeInstance(dateStyle, timeStyle, timeZone, locale);
227     }
228 
229     /**
230      * Gets a formatter instance using the default pattern in the default locale.
231      *
232      * @return a date/time formatter.
233      */
234     public static FastDateFormat getInstance() {
235         return CACHE.getInstance();
236     }
237 
238     /**
239      * Gets a formatter instance using the specified pattern in the default locale and time zone.
240      *
241      * @param pattern {@link java.text.SimpleDateFormat} compatible pattern.
242      * @return a pattern based date/time formatter.
243      * @throws IllegalArgumentException if pattern is invalid.
244      */
245     public static FastDateFormat getInstance(final String pattern) {
246         return CACHE.getInstance(pattern, null, null);
247     }
248 
249     /**
250      * Gets a formatter instance using the specified pattern and locale using the default time zone.
251      *
252      * @param pattern {@link java.text.SimpleDateFormat} compatible pattern.
253      * @param locale  optional locale, overrides system locale.
254      * @return a pattern based date/time formatter.
255      * @throws IllegalArgumentException if pattern is invalid.
256      */
257     public static FastDateFormat getInstance(final String pattern, final Locale locale) {
258         return CACHE.getInstance(pattern, null, locale);
259     }
260 
261     /**
262      * Gets a formatter instance using the specified pattern and time zone.
263      *
264      * @param pattern  {@link java.text.SimpleDateFormat} compatible pattern.
265      * @param timeZone optional time zone, overrides time zone of formatted date.
266      * @return a pattern based date/time formatter.
267      * @throws IllegalArgumentException if pattern is invalid.
268      */
269     public static FastDateFormat getInstance(final String pattern, final TimeZone timeZone) {
270         return CACHE.getInstance(pattern, timeZone, null);
271     }
272 
273     /**
274      * Gets a formatter instance using the specified pattern, time zone and locale.
275      *
276      * @param pattern  {@link java.text.SimpleDateFormat} compatible pattern.
277      * @param timeZone optional time zone, overrides time zone of formatted date.
278      * @param locale   optional locale, overrides system locale.
279      * @return a pattern based date/time formatter.
280      * @throws IllegalArgumentException if pattern is invalid or {@code null}.
281      */
282     public static FastDateFormat getInstance(final String pattern, final TimeZone timeZone, final Locale locale) {
283         return CACHE.getInstance(pattern, timeZone, locale);
284     }
285 
286     /**
287      * Gets a time formatter instance using the specified style in the default time zone and locale.
288      *
289      * @param style time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
290      * @return a localized standard time formatter.
291      * @throws IllegalArgumentException if the Locale has no time pattern defined.
292      * @since 2.1
293      */
294     public static FastDateFormat getTimeInstance(final int style) {
295         return CACHE.getTimeInstance(style, null, null);
296     }
297 
298     /**
299      * Gets a time formatter instance using the specified style and locale in the default time zone.
300      *
301      * @param style  time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
302      * @param locale optional locale, overrides system locale.
303      * @return a localized standard time formatter.
304      * @throws IllegalArgumentException if the Locale has no time pattern defined.
305      * @since 2.1
306      */
307     public static FastDateFormat getTimeInstance(final int style, final Locale locale) {
308         return CACHE.getTimeInstance(style, null, locale);
309     }
310 
311     /**
312      * Gets a time formatter instance using the specified style and time zone in the default locale.
313      *
314      * @param style    time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
315      * @param timeZone optional time zone, overrides time zone of formatted time.
316      * @return a localized standard time formatter.
317      * @throws IllegalArgumentException if the Locale has no time pattern defined.
318      * @since 2.1
319      */
320     public static FastDateFormat getTimeInstance(final int style, final TimeZone timeZone) {
321         return CACHE.getTimeInstance(style, timeZone, null);
322     }
323 
324     /**
325      * Gets a time formatter instance using the specified style, time zone and locale.
326      *
327      * @param style    time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
328      * @param timeZone optional time zone, overrides time zone of formatted time.
329      * @param locale   optional locale, overrides system locale.
330      * @return a localized standard time formatter.
331      * @throws IllegalArgumentException if the Locale has no time pattern defined.
332      */
333     public static FastDateFormat getTimeInstance(final int style, final TimeZone timeZone, final Locale locale) {
334         return CACHE.getTimeInstance(style, timeZone, locale);
335     }
336 
337     /** Our fast printer. */
338     private final FastDatePrinter printer;
339     /** Our fast parser. */
340     private final FastDateParser parser;
341 
342     // Constructor
343     /**
344      * Constructs a new FastDateFormat.
345      *
346      * @param pattern  {@link java.text.SimpleDateFormat} compatible pattern.
347      * @param timeZone non-null time zone to use.
348      * @param locale   non-null locale to use.
349      * @throws NullPointerException if pattern, timeZone, or locale is null.
350      */
351     protected FastDateFormat(final String pattern, final TimeZone timeZone, final Locale locale) {
352         this(pattern, timeZone, locale, null);
353     }
354 
355     /**
356      * Constructs a new FastDateFormat.
357      *
358      * @param pattern      {@link java.text.SimpleDateFormat} compatible pattern.
359      * @param timeZone     non-null time zone to use.
360      * @param locale       non-null locale to use.
361      * @param centuryStart The start of the 100-year period to use as the "default century" for 2 digit year parsing. If centuryStart is null, defaults to now -
362      *                     80 years.
363      * @throws NullPointerException if pattern, timeZone, or locale is null.
364      */
365     protected FastDateFormat(final String pattern, final TimeZone timeZone, final Locale locale, final Date centuryStart) {
366         printer = new FastDatePrinter(pattern, timeZone, locale);
367         parser = new FastDateParser(pattern, timeZone, locale, centuryStart);
368     }
369 
370     /**
371      * Performs the formatting by applying the rules to the specified calendar.
372      *
373      * @param calendar the calendar to format.
374      * @param buf      the buffer to format into.
375      * @return the specified string buffer.
376      * @deprecated Use {@link #format(Calendar, Appendable)}
377      */
378     @Deprecated
379     protected StringBuffer applyRules(final Calendar calendar, final StringBuffer buf) {
380         return printer.format(calendar, buf);
381     }
382 
383     // Basics
384     /**
385      * Compares two objects for equality.
386      *
387      * @param obj the object to compare to.
388      * @return {@code true} if equal.
389      */
390     @Override
391     public boolean equals(final Object obj) {
392         if (!(obj instanceof FastDateFormat)) {
393             return false;
394         }
395         final FastDateFormat other = (FastDateFormat) obj;
396         // no need to check parser, as it has same invariants as printer
397         return printer.equals(other.printer);
398     }
399 
400     /**
401      * Formats a {@link Calendar} object.
402      *
403      * @param calendar the calendar to format.
404      * @return the formatted string.
405      */
406     @Override
407     public String format(final Calendar calendar) {
408         return printer.format(calendar);
409     }
410 
411     /**
412      * Formats a {@link Calendar} object into the supplied {@link StringBuffer}.
413      *
414      * @param calendar the calendar to format.
415      * @param buf      the buffer to format into.
416      * @return the specified string buffer.
417      * @since 3.5
418      */
419     @Override
420     public <B extends Appendable> B format(final Calendar calendar, final B buf) {
421         return printer.format(calendar, buf);
422     }
423 
424     /**
425      * Formats a {@link Calendar} object into the supplied {@link StringBuffer}.
426      *
427      * @param calendar the calendar to format.
428      * @param buf      the buffer to format into.
429      * @return the specified string buffer.
430      * @deprecated Use {{@link #format(Calendar, Appendable)}.
431      */
432     @Deprecated
433     @Override
434     public StringBuffer format(final Calendar calendar, final StringBuffer buf) {
435         return printer.format(calendar, buf);
436     }
437 
438     /**
439      * Formats a {@link Date} object using a {@link GregorianCalendar}.
440      *
441      * @param date the date to format.
442      * @return the formatted string.
443      */
444     @Override
445     public String format(final Date date) {
446         return printer.format(date);
447     }
448 
449     /**
450      * Formats a {@link Date} object into the supplied {@link StringBuffer} using a {@link GregorianCalendar}.
451      *
452      * @param date the date to format.
453      * @param buf  the buffer to format into.
454      * @return the specified string buffer.
455      * @since 3.5
456      */
457     @Override
458     public <B extends Appendable> B format(final Date date, final B buf) {
459         return printer.format(date, buf);
460     }
461 
462     /**
463      * Formats a {@link Date} object into the supplied {@link StringBuffer} using a {@link GregorianCalendar}.
464      *
465      * @param date the date to format.
466      * @param buf  the buffer to format into.
467      * @return the specified string buffer.
468      * @deprecated Use {{@link #format(Date, Appendable)}.
469      */
470     @Deprecated
471     @Override
472     public StringBuffer format(final Date date, final StringBuffer buf) {
473         return printer.format(date, buf);
474     }
475 
476     /**
477      * Formats a millisecond {@code long} value.
478      *
479      * @param millis the millisecond value to format.
480      * @return the formatted string.
481      * @since 2.1
482      */
483     @Override
484     public String format(final long millis) {
485         return printer.format(millis);
486     }
487 
488     /**
489      * Formats a millisecond {@code long} value into the supplied {@link StringBuffer}.
490      *
491      * @param millis the millisecond value to format.
492      * @param buf    the buffer to format into.
493      * @return the specified string buffer.
494      * @since 3.5
495      */
496     @Override
497     public <B extends Appendable> B format(final long millis, final B buf) {
498         return printer.format(millis, buf);
499     }
500 
501     /**
502      * Formats a millisecond {@code long} value into the supplied {@link StringBuffer}.
503      *
504      * @param millis the millisecond value to format.
505      * @param buf    the buffer to format into.
506      * @return the specified string buffer.
507      * @since 2.1
508      * @deprecated Use {{@link #format(long, Appendable)}.
509      */
510     @Deprecated
511     @Override
512     public StringBuffer format(final long millis, final StringBuffer buf) {
513         return printer.format(millis, buf);
514     }
515 
516     /**
517      * Formats a {@link Date}, {@link Calendar} or {@link Long} (milliseconds) object. This method is an implementation of
518      * {@link Format#format(Object, StringBuffer, FieldPosition)}
519      *
520      * @param obj        the object to format.
521      * @param toAppendTo the buffer to append to.
522      * @param pos        the position, ignored.
523      * @return the given buffer.
524      */
525     @Override
526     public StringBuffer format(final Object obj, final StringBuffer toAppendTo, final FieldPosition pos) {
527         return toAppendTo.append(printer.format(obj));
528     }
529 
530     /**
531      * Gets the locale used by this formatter.
532      *
533      * @return the locale.
534      */
535     @Override
536     public Locale getLocale() {
537         return printer.getLocale();
538     }
539 
540     /**
541      * Gets an estimate for the maximum string length that the formatter will produce.
542      *
543      * <p>
544      * The actual formatted length will almost always be less than or equal to this amount.
545      * </p>
546      *
547      * @return the maximum formatted length.
548      */
549     public int getMaxLengthEstimate() {
550         return printer.getMaxLengthEstimate();
551     }
552 
553     /**
554      * Gets the pattern used by this formatter.
555      *
556      * @return the pattern, {@link java.text.SimpleDateFormat} compatible.
557      */
558     @Override
559     public String getPattern() {
560         return printer.getPattern();
561     }
562 
563     /**
564      * Gets the time zone used by this formatter.
565      *
566      * <p>
567      * This zone is always used for {@link Date} formatting.
568      * </p>
569      *
570      * @return the time zone.
571      */
572     @Override
573     public TimeZone getTimeZone() {
574         return printer.getTimeZone();
575     }
576 
577     /**
578      * Returns a hash code compatible with equals.
579      *
580      * @return a hash code compatible with equals.
581      */
582     @Override
583     public int hashCode() {
584         return printer.hashCode();
585     }
586 
587     /*
588      * (non-Javadoc)
589      *
590      * @see DateParser#parse(String)
591      */
592     @Override
593     public Date parse(final String source) throws ParseException {
594         return parser.parse(source);
595     }
596 
597     /*
598      * (non-Javadoc)
599      *
600      * @see DateParser#parse(String, java.text.ParsePosition)
601      */
602     @Override
603     public Date parse(final String source, final ParsePosition pos) {
604         return parser.parse(source, pos);
605     }
606 
607     /*
608      * (non-Javadoc)
609      *
610      * @see org.apache.commons.lang3.time.DateParser#parse(String, java.text.ParsePosition, java.util.Calendar)
611      */
612     @Override
613     public boolean parse(final String source, final ParsePosition pos, final Calendar calendar) {
614         return parser.parse(source, pos, calendar);
615     }
616 
617     /*
618      * (non-Javadoc)
619      *
620      * @see java.text.Format#parseObject(String, java.text.ParsePosition)
621      */
622     @Override
623     public Object parseObject(final String source, final ParsePosition pos) {
624         return parser.parseObject(source, pos);
625     }
626 
627     /**
628      * Gets a debugging string version of this formatter.
629      *
630      * @return a debug string.
631      */
632     @Override
633     public String toString() {
634         return "FastDateFormat[" + printer.getPattern() + "," + printer.getLocale() + "," + printer.getTimeZone().getID() + "]";
635     }
636 }