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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  package org.apache.commons.lang3.time;
18  
19  import java.text.DateFormat;
20  import java.text.FieldPosition;
21  import java.text.Format;
22  import java.text.ParseException;
23  import java.text.ParsePosition;
24  import java.text.SimpleDateFormat;
25  import java.util.Calendar;
26  import java.util.Date;
27  import java.util.GregorianCalendar;
28  import java.util.Locale;
29  import java.util.TimeZone;
30  
31  /**
32   * FastDateFormat is a fast and thread-safe version of
33   * {@link java.text.SimpleDateFormat}.
34   *
35   * <p>To obtain an instance of FastDateFormat, use one of the static factory methods:
36   * {@link #getInstance(String, TimeZone, Locale)}, {@link #getDateInstance(int, TimeZone, Locale)},
37   * {@link #getTimeInstance(int, TimeZone, Locale)}, or {@link #getDateTimeInstance(int, int, TimeZone, Locale)}
38   * </p>
39   *
40   * <p>Since FastDateFormat is thread safe, you can use a static member instance:</p>
41   * <code>
42   *   private static final FastDateFormat DATE_FORMATTER = FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.SHORT);
43   * </code>
44   *
45   * <p>This class can be used as a direct replacement to
46   * {@link SimpleDateFormat} in most formatting and parsing situations.
47   * This class is especially useful in multi-threaded server environments.
48   * {@link SimpleDateFormat} is not thread-safe in any JDK version,
49   * nor will it be as Sun have closed the bug/RFE.
50   * </p>
51   *
52   * <p>All patterns are compatible with
53   * SimpleDateFormat (except time zones and some year patterns - see below).</p>
54   *
55   * <p>Since 3.2, FastDateFormat supports parsing as well as printing.</p>
56   *
57   * <p>Java 1.4 introduced a new pattern letter, {@code 'Z'}, to represent
58   * time zones in RFC822 format (eg. {@code +0800} or {@code -1100}).
59   * This pattern letter can be used here (on all JDK versions).</p>
60   *
61   * <p>In addition, the pattern {@code 'ZZ'} has been made to represent
62   * ISO 8601 extended format time zones (eg. {@code +08:00} or {@code -11:00}).
63   * This introduces a minor incompatibility with Java 1.4, but at a gain of
64   * useful functionality.</p>
65   *
66   * <p>Javadoc cites for the year pattern: <i>For formatting, if the number of
67   * pattern letters is 2, the year is truncated to 2 digits; otherwise it is
68   * interpreted as a number.</i> Starting with Java 1.7 a pattern of 'Y' or
69   * 'YYY' will be formatted as '2003', while it was '03' in former Java
70   * versions. FastDateFormat implements the behavior of Java 7.</p>
71   *
72   * @since 2.0
73   */
74  public class FastDateFormat extends Format implements DateParser, DatePrinter {
75  
76      /**
77       * Required for serialization support.
78       *
79       * @see java.io.Serializable
80       */
81      private static final long serialVersionUID = 2L;
82  
83      /**
84       * FULL locale dependent date or time style.
85       */
86  
87      public static final int FULL = DateFormat.FULL;
88  
89      /**
90       * LONG locale dependent date or time style.
91       */
92      public static final int LONG = DateFormat.LONG;
93  
94      /**
95       * MEDIUM locale dependent date or time style.
96       */
97      public static final int MEDIUM = DateFormat.MEDIUM;
98  
99      /**
100      * SHORT locale dependent date or time style.
101      */
102     public static final int SHORT = DateFormat.SHORT;
103 
104     private static final AbstractFormatCache<FastDateFormat> cache = new AbstractFormatCache<FastDateFormat>() {
105         @Override
106         protected FastDateFormat createInstance(final String pattern, final TimeZone timeZone, final Locale locale) {
107             return new FastDateFormat(pattern, timeZone, locale);
108         }
109     };
110 
111     /**
112      * Gets a date formatter instance using the specified style in the
113      * default time zone and locale.
114      *
115      * @param style  date style: FULL, LONG, MEDIUM, or SHORT
116      * @return a localized standard date formatter
117      * @throws IllegalArgumentException if the Locale has no date
118      *  pattern defined
119      * @since 2.1
120      */
121     public static FastDateFormat getDateInstance(final int style) {
122         return cache.getDateInstance(style, null, null);
123     }
124 
125     /**
126      * Gets a date formatter instance using the specified style and
127      * locale in the default time zone.
128      *
129      * @param style  date style: FULL, LONG, MEDIUM, or SHORT
130      * @param locale  optional locale, overrides system locale
131      * @return a localized standard date formatter
132      * @throws IllegalArgumentException if the Locale has no date
133      *  pattern defined
134      * @since 2.1
135      */
136     public static FastDateFormat getDateInstance(final int style, final Locale locale) {
137         return cache.getDateInstance(style, null, locale);
138     }
139 
140     /**
141      * Gets a date formatter instance using the specified style and
142      * time zone in the default locale.
143      *
144      * @param style  date style: FULL, LONG, MEDIUM, or SHORT
145      * @param timeZone  optional time zone, overrides time zone of
146      *  formatted date
147      * @return a localized standard date formatter
148      * @throws IllegalArgumentException if the Locale has no date
149      *  pattern defined
150      * @since 2.1
151      */
152     public static FastDateFormat getDateInstance(final int style, final TimeZone timeZone) {
153         return cache.getDateInstance(style, timeZone, null);
154     }
155 
156     /**
157      * Gets a date formatter instance using the specified style, time
158      * zone and locale.
159      *
160      * @param style  date style: FULL, LONG, MEDIUM, or SHORT
161      * @param timeZone  optional time zone, overrides time zone of
162      *  formatted date
163      * @param locale  optional locale, overrides system locale
164      * @return a localized standard date formatter
165      * @throws IllegalArgumentException if the Locale has no date
166      *  pattern defined
167      */
168     public static FastDateFormat getDateInstance(final int style, final TimeZone timeZone, final Locale locale) {
169         return cache.getDateInstance(style, timeZone, locale);
170     }
171 
172     /**
173      * Gets a date/time formatter instance using the specified style
174      * in the default time zone and locale.
175      *
176      * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
177      * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
178      * @return a localized standard date/time formatter
179      * @throws IllegalArgumentException if the Locale has no date/time
180      *  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
189      * locale in the default time zone.
190      *
191      * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
192      * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
193      * @param locale  optional locale, overrides system locale
194      * @return a localized standard date/time formatter
195      * @throws IllegalArgumentException if the Locale has no date/time
196      *  pattern defined
197      * @since 2.1
198      */
199     public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final Locale locale) {
200         return cache.getDateTimeInstance(dateStyle, timeStyle, null, locale);
201     }
202 
203     /**
204      * Gets a date/time formatter instance using the specified style and
205      * time zone in the default locale.
206      *
207      * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
208      * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
209      * @param timeZone  optional time zone, overrides time zone of
210      *  formatted date
211      * @return a localized standard date/time formatter
212      * @throws IllegalArgumentException if the Locale has no date/time
213      *  pattern defined
214      * @since 2.1
215      */
216     public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final TimeZone timeZone) {
217         return getDateTimeInstance(dateStyle, timeStyle, timeZone, null);
218     }
219 
220     /**
221      * Gets a date/time formatter instance using the specified style,
222      * time zone and locale.
223      *
224      * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
225      * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
226      * @param timeZone  optional time zone, overrides time zone of
227      *  formatted date
228      * @param locale  optional locale, overrides system locale
229      * @return a localized standard date/time formatter
230      * @throws IllegalArgumentException if the Locale has no date/time
231      *  pattern defined
232      */
233     public static FastDateFormat getDateTimeInstance(
234             final int dateStyle, final int timeStyle, final TimeZone timeZone, final Locale locale) {
235         return cache.getDateTimeInstance(dateStyle, timeStyle, timeZone, locale);
236     }
237 
238     /**
239      * Gets a formatter instance using the default pattern in the
240      * default locale.
241      *
242      * @return a date/time formatter
243      */
244     public static FastDateFormat getInstance() {
245         return cache.getInstance();
246     }
247 
248     /**
249      * Gets a formatter instance using the specified pattern in the
250      * default locale.
251      *
252      * @param pattern  {@link java.text.SimpleDateFormat} compatible
253      *  pattern
254      * @return a pattern based date/time formatter
255      * @throws IllegalArgumentException if pattern is invalid
256      */
257     public static FastDateFormat getInstance(final String pattern) {
258         return cache.getInstance(pattern, null, null);
259     }
260 
261     /**
262      * Gets a formatter instance using the specified pattern and
263      * locale.
264      *
265      * @param pattern  {@link java.text.SimpleDateFormat} compatible
266      *  pattern
267      * @param locale  optional locale, overrides system locale
268      * @return a pattern based date/time formatter
269      * @throws IllegalArgumentException if pattern is invalid
270      */
271     public static FastDateFormat getInstance(final String pattern, final Locale locale) {
272         return cache.getInstance(pattern, null, locale);
273     }
274 
275     /**
276      * Gets a formatter instance using the specified pattern and
277      * time zone.
278      *
279      * @param pattern  {@link java.text.SimpleDateFormat} compatible
280      *  pattern
281      * @param timeZone  optional time zone, overrides time zone of
282      *  formatted date
283      * @return a pattern based date/time formatter
284      * @throws IllegalArgumentException if pattern is invalid
285      */
286     public static FastDateFormat getInstance(final String pattern, final TimeZone timeZone) {
287         return cache.getInstance(pattern, timeZone, null);
288     }
289 
290     /**
291      * Gets a formatter instance using the specified pattern, time zone
292      * and locale.
293      *
294      * @param pattern  {@link java.text.SimpleDateFormat} compatible
295      *  pattern
296      * @param timeZone  optional time zone, overrides time zone of
297      *  formatted date
298      * @param locale  optional locale, overrides system locale
299      * @return a pattern based date/time formatter
300      * @throws IllegalArgumentException if pattern is invalid
301      *  or {@code null}
302      */
303     public static FastDateFormat getInstance(final String pattern, final TimeZone timeZone, final Locale locale) {
304         return cache.getInstance(pattern, timeZone, locale);
305     }
306 
307     /**
308      * Gets a time formatter instance using the specified style in the
309      * default time zone and locale.
310      *
311      * @param style  time style: FULL, LONG, MEDIUM, or SHORT
312      * @return a localized standard time formatter
313      * @throws IllegalArgumentException if the Locale has no time
314      *  pattern defined
315      * @since 2.1
316      */
317     public static FastDateFormat getTimeInstance(final int style) {
318         return cache.getTimeInstance(style, null, null);
319     }
320 
321     /**
322      * Gets a time formatter instance using the specified style and
323      * locale in the default time zone.
324      *
325      * @param style  time style: FULL, LONG, MEDIUM, or SHORT
326      * @param locale  optional locale, overrides system locale
327      * @return a localized standard time formatter
328      * @throws IllegalArgumentException if the Locale has no time
329      *  pattern defined
330      * @since 2.1
331      */
332     public static FastDateFormat getTimeInstance(final int style, final Locale locale) {
333         return cache.getTimeInstance(style, null, locale);
334     }
335 
336     /**
337      * Gets a time formatter instance using the specified style and
338      * time zone in the default locale.
339      *
340      * @param style  time style: FULL, LONG, MEDIUM, or SHORT
341      * @param timeZone  optional time zone, overrides time zone of
342      *  formatted time
343      * @return a localized standard time formatter
344      * @throws IllegalArgumentException if the Locale has no time
345      *  pattern defined
346      * @since 2.1
347      */
348     public static FastDateFormat getTimeInstance(final int style, final TimeZone timeZone) {
349         return cache.getTimeInstance(style, timeZone, null);
350     }
351 
352     /**
353      * Gets a time formatter instance using the specified style, time
354      * zone and locale.
355      *
356      * @param style  time style: FULL, LONG, MEDIUM, or SHORT
357      * @param timeZone  optional time zone, overrides time zone of
358      *  formatted time
359      * @param locale  optional locale, overrides system locale
360      * @return a localized standard time formatter
361      * @throws IllegalArgumentException if the Locale has no time
362      *  pattern defined
363      */
364     public static FastDateFormat getTimeInstance(final int style, final TimeZone timeZone, final Locale locale) {
365         return cache.getTimeInstance(style, timeZone, locale);
366     }
367 
368     /** Our fast printer. */
369     private final FastDatePrinter printer;
370     /** Our fast parser. */
371     private final FastDateParser parser;
372 
373     // Constructor
374     /**
375      * Constructs a new FastDateFormat.
376      *
377      * @param pattern  {@link java.text.SimpleDateFormat} compatible pattern
378      * @param timeZone  non-null time zone to use
379      * @param locale  non-null locale to use
380      * @throws NullPointerException if pattern, timeZone, or locale is null.
381      */
382     protected FastDateFormat(final String pattern, final TimeZone timeZone, final Locale locale) {
383         this(pattern, timeZone, locale, null);
384     }
385 
386     // Constructor
387     /**
388      * Constructs a new FastDateFormat.
389      *
390      * @param pattern  {@link java.text.SimpleDateFormat} compatible pattern
391      * @param timeZone  non-null time zone to use
392      * @param locale  non-null locale to use
393      * @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 - 80 years
394      * @throws NullPointerException if pattern, timeZone, or locale is null.
395      */
396     protected FastDateFormat(final String pattern, final TimeZone timeZone, final Locale locale, final Date centuryStart) {
397         printer = new FastDatePrinter(pattern, timeZone, locale);
398         parser = new FastDateParser(pattern, timeZone, locale, centuryStart);
399     }
400 
401     /**
402      * Performs the formatting by applying the rules to the
403      * specified calendar.
404      *
405      * @param calendar the calendar to format
406      * @param buf  the buffer to format into
407      * @return the specified string buffer
408      * @deprecated Use {@link #format(Calendar, Appendable)}
409      */
410     @Deprecated
411     protected StringBuffer applyRules(final Calendar calendar, final StringBuffer buf) {
412         return printer.applyRules(calendar, buf);
413     }
414 
415     // Basics
416     /**
417      * Compares two objects for equality.
418      *
419      * @param obj  the object to compare to
420      * @return {@code true} if equal
421      */
422     @Override
423     public boolean equals(final Object obj) {
424         if (!(obj instanceof FastDateFormat)) {
425             return false;
426         }
427         final FastDateFormat other = (FastDateFormat) obj;
428         // no need to check parser, as it has same invariants as printer
429         return printer.equals(other.printer);
430     }
431 
432     /**
433      * Formats a {@link Calendar} object.
434      *
435      * @param calendar  the calendar to format
436      * @return the formatted string
437      */
438     @Override
439     public String format(final Calendar calendar) {
440         return printer.format(calendar);
441     }
442 
443     /**
444      * Formats a {@link Calendar} object into the
445      * supplied {@link StringBuffer}.
446      *
447      * @param calendar  the calendar to format
448      * @param buf  the buffer to format into
449      * @return the specified string buffer
450      * @since 3.5
451     */
452     @Override
453     public <B extends Appendable> B format(final Calendar calendar, final B buf) {
454         return printer.format(calendar, buf);
455     }
456 
457     /**
458      * Formats a {@link Calendar} object into the
459      * supplied {@link StringBuffer}.
460      *
461      * @param calendar  the calendar to format
462      * @param buf  the buffer to format into
463      * @return the specified string buffer
464      * @deprecated Use {{@link #format(Calendar, Appendable)}.
465      */
466     @Deprecated
467     @Override
468     public StringBuffer format(final Calendar calendar, final StringBuffer buf) {
469         return printer.format(calendar, buf);
470     }
471 
472     /**
473      * Formats a {@link Date} object using a {@link GregorianCalendar}.
474      *
475      * @param date  the date to format
476      * @return the formatted string
477      */
478     @Override
479     public String format(final Date date) {
480         return printer.format(date);
481     }
482 
483     /**
484      * Formats a {@link Date} object into the
485      * supplied {@link StringBuffer} using a {@link GregorianCalendar}.
486      *
487      * @param date  the date to format
488      * @param buf  the buffer to format into
489      * @return the specified string buffer
490      * @since 3.5
491      */
492     @Override
493     public <B extends Appendable> B format(final Date date, final B buf) {
494         return printer.format(date, buf);
495     }
496 
497     /**
498      * Formats a {@link Date} object into the
499      * supplied {@link StringBuffer} using a {@link GregorianCalendar}.
500      *
501      * @param date  the date to format
502      * @param buf  the buffer to format into
503      * @return the specified string buffer
504      * @deprecated Use {{@link #format(Date, Appendable)}.
505      */
506     @Deprecated
507     @Override
508     public StringBuffer format(final Date date, final StringBuffer buf) {
509         return printer.format(date, buf);
510     }
511 
512     /**
513      * Formats a millisecond {@code long} value.
514      *
515      * @param millis  the millisecond value to format
516      * @return the formatted string
517      * @since 2.1
518      */
519     @Override
520     public String format(final long millis) {
521         return printer.format(millis);
522     }
523 
524     /**
525      * Formats a millisecond {@code long} value into the
526      * supplied {@link StringBuffer}.
527      *
528      * @param millis  the millisecond value to format
529      * @param buf  the buffer to format into
530      * @return the specified string buffer
531      * @since 3.5
532      */
533     @Override
534     public <B extends Appendable> B format(final long millis, final B buf) {
535         return printer.format(millis, buf);
536     }
537 
538     // Parsing
539 
540 
541     /**
542      * Formats a millisecond {@code long} value into the
543      * supplied {@link StringBuffer}.
544      *
545      * @param millis  the millisecond value to format
546      * @param buf  the buffer to format into
547      * @return the specified string buffer
548      * @since 2.1
549      * @deprecated Use {{@link #format(long, Appendable)}.
550      */
551     @Deprecated
552     @Override
553     public StringBuffer format(final long millis, final StringBuffer buf) {
554         return printer.format(millis, buf);
555     }
556 
557     // Format methods
558     /**
559      * Formats a {@link Date}, {@link Calendar} or
560      * {@link Long} (milliseconds) object.
561      * This method is an implementation of {@link Format#format(Object, StringBuffer, FieldPosition)}
562      *
563      * @param obj  the object to format
564      * @param toAppendTo  the buffer to append to
565      * @param pos  the position - ignored
566      * @return the buffer passed in
567      */
568     @Override
569     public StringBuffer format(final Object obj, final StringBuffer toAppendTo, final FieldPosition pos) {
570         return toAppendTo.append(printer.format(obj));
571     }
572 
573     /**
574      * Gets the locale used by this formatter.
575      *
576      * @return the locale
577      */
578     @Override
579     public Locale getLocale() {
580         return printer.getLocale();
581     }
582 
583     /**
584      * Gets an estimate for the maximum string length that the
585      * formatter will produce.
586      *
587      * <p>The actual formatted length will almost always be less than or
588      * equal to this amount.</p>
589      *
590      * @return the maximum formatted length
591      */
592     public int getMaxLengthEstimate() {
593         return printer.getMaxLengthEstimate();
594     }
595 
596     // Accessors
597     /**
598      * Gets the pattern used by this formatter.
599      *
600      * @return the pattern, {@link java.text.SimpleDateFormat} compatible
601      */
602     @Override
603     public String getPattern() {
604         return printer.getPattern();
605     }
606 
607     /**
608      * Gets the time zone used by this formatter.
609      *
610      * <p>This zone is always used for {@link Date} formatting.</p>
611      *
612      * @return the time zone
613      */
614     @Override
615     public TimeZone getTimeZone() {
616         return printer.getTimeZone();
617     }
618 
619     /**
620      * Returns a hash code compatible with equals.
621      *
622      * @return a hash code compatible with equals
623      */
624     @Override
625     public int hashCode() {
626         return printer.hashCode();
627     }
628 
629     /* (non-Javadoc)
630      * @see DateParser#parse(String)
631      */
632     @Override
633     public Date parse(final String source) throws ParseException {
634         return parser.parse(source);
635     }
636 
637     /* (non-Javadoc)
638      * @see DateParser#parse(String, java.text.ParsePosition)
639      */
640     @Override
641     public Date parse(final String source, final ParsePosition pos) {
642         return parser.parse(source, pos);
643     }
644 
645     /*
646      * (non-Javadoc)
647      * @see org.apache.commons.lang3.time.DateParser#parse(String, java.text.ParsePosition, java.util.Calendar)
648      */
649     @Override
650     public boolean parse(final String source, final ParsePosition pos, final Calendar calendar) {
651         return parser.parse(source, pos, calendar);
652     }
653 
654     /* (non-Javadoc)
655      * @see java.text.Format#parseObject(String, java.text.ParsePosition)
656      */
657     @Override
658     public Object parseObject(final String source, final ParsePosition pos) {
659         return parser.parseObject(source, pos);
660     }
661 
662     /**
663      * Gets a debugging string version of this formatter.
664      *
665      * @return a debugging string
666      */
667     @Override
668     public String toString() {
669         return "FastDateFormat[" + printer.getPattern() + "," + printer.getLocale() + "," + printer.getTimeZone().getID() + "]";
670     }
671 }