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Java > Open Source Codes > org > joda > time > DateTimeFieldType


1 /*
2  * Copyright 2001-2005 Stephen Colebourne
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.joda.time;
17
18 import java.io.Serializable JavaDoc;
19
20 /**
21  * Identifies a field, such as year or minuteOfHour, in a chronology-neutral way.
22  * <p>
23  * A field type defines the type of the field, such as hourOfDay.
24  * If does not directly enable any calculations, however it does provide a
25  * {@link #getField(Chronology)} method that returns the actual calculation engine
26  * for a particular chronology.
27  * It also provides access to the related {@link DurationFieldType}s.
28  * <p>
29  * Instances of <code>DateTimeFieldType</code> are singletons.
30  * They can be compared using <code>==</code>.
31  * <p>
32  * If required, you can create your own field, for example a quarterOfYear.
33  * You must create a subclass of <code>DateTimeFieldType</code> that defines the field type.
34  * This class returns the actual calculation engine from {@link #getField(Chronology)}.
35  *
36  * @author Stephen Colebourne
37  * @author Brian S O'Neill
38  * @since 1.0
39  */
40 public abstract class DateTimeFieldType implements Serializable JavaDoc {
41
42     /** Serialization version */
43     private static final long serialVersionUID = -42615285973990L;
44
45     /** Ordinal values for standard field types. */
46     static final byte
47         ERA = 1,
48         YEAR_OF_ERA = 2,
49         CENTURY_OF_ERA = 3,
50         YEAR_OF_CENTURY = 4,
51         YEAR = 5,
52         DAY_OF_YEAR = 6,
53         MONTH_OF_YEAR = 7,
54         DAY_OF_MONTH = 8,
55         WEEKYEAR_OF_CENTURY = 9,
56         WEEKYEAR = 10,
57         WEEK_OF_WEEKYEAR = 11,
58         DAY_OF_WEEK = 12,
59         HALFDAY_OF_DAY = 13,
60         HOUR_OF_HALFDAY = 14,
61         CLOCKHOUR_OF_HALFDAY = 15,
62         CLOCKHOUR_OF_DAY = 16,
63         HOUR_OF_DAY = 17,
64         MINUTE_OF_DAY = 18,
65         MINUTE_OF_HOUR = 19,
66         SECOND_OF_DAY = 20,
67         SECOND_OF_MINUTE = 21,
68         MILLIS_OF_DAY = 22,
69         MILLIS_OF_SECOND = 23;
70
71     /** The era field type. */
72     private static final DateTimeFieldType ERA_TYPE = new StandardDateTimeFieldType(
73         "era", ERA, DurationFieldType.eras(), null);
74     /** The yearOfEra field type. */
75     private static final DateTimeFieldType YEAR_OF_ERA_TYPE = new StandardDateTimeFieldType(
76         "yearOfEra", YEAR_OF_ERA, DurationFieldType.years(), DurationFieldType.eras());
77     /** The centuryOfEra field type. */
78     private static final DateTimeFieldType CENTURY_OF_ERA_TYPE = new StandardDateTimeFieldType(
79         "centuryOfEra", CENTURY_OF_ERA, DurationFieldType.centuries(), DurationFieldType.eras());
80     /** The yearOfCentury field type. */
81     private static final DateTimeFieldType YEAR_OF_CENTURY_TYPE = new StandardDateTimeFieldType(
82         "yearOfCentury", YEAR_OF_CENTURY, DurationFieldType.years(), DurationFieldType.centuries());
83     /** The year field type. */
84     private static final DateTimeFieldType YEAR_TYPE = new StandardDateTimeFieldType(
85         "year", YEAR, DurationFieldType.years(), null);
86     /** The dayOfYear field type. */
87     private static final DateTimeFieldType DAY_OF_YEAR_TYPE = new StandardDateTimeFieldType(
88         "dayOfYear", DAY_OF_YEAR, DurationFieldType.days(), DurationFieldType.years());
89     /** The monthOfYear field type. */
90     private static final DateTimeFieldType MONTH_OF_YEAR_TYPE = new StandardDateTimeFieldType(
91         "monthOfYear", MONTH_OF_YEAR, DurationFieldType.months(), DurationFieldType.years());
92     /** The dayOfMonth field type. */
93     private static final DateTimeFieldType DAY_OF_MONTH_TYPE = new StandardDateTimeFieldType(
94         "dayOfMonth", DAY_OF_MONTH, DurationFieldType.days(), DurationFieldType.months());
95     /** The weekyearOfCentury field type. */
96     private static final DateTimeFieldType WEEKYEAR_OF_CENTURY_TYPE = new StandardDateTimeFieldType(
97         "weekyearOfCentury", WEEKYEAR_OF_CENTURY, DurationFieldType.weekyears(), DurationFieldType.centuries());
98     /** The weekyear field type. */
99     private static final DateTimeFieldType WEEKYEAR_TYPE = new StandardDateTimeFieldType(
100         "weekyear", WEEKYEAR, DurationFieldType.weekyears(), null);
101     /** The weekOfWeekyear field type. */
102     private static final DateTimeFieldType WEEK_OF_WEEKYEAR_TYPE = new StandardDateTimeFieldType(
103         "weekOfWeekyear", WEEK_OF_WEEKYEAR, DurationFieldType.weeks(), DurationFieldType.weekyears());
104     /** The dayOfWeek field type. */
105     private static final DateTimeFieldType DAY_OF_WEEK_TYPE = new StandardDateTimeFieldType(
106         "dayOfWeek", DAY_OF_WEEK, DurationFieldType.days(), DurationFieldType.weeks());
107
108     /** The halfday field type. */
109     private static final DateTimeFieldType HALFDAY_OF_DAY_TYPE = new StandardDateTimeFieldType(
110         "halfdayOfDay", HALFDAY_OF_DAY, DurationFieldType.halfdays(), DurationFieldType.days());
111     /** The hourOfHalfday field type. */
112     private static final DateTimeFieldType HOUR_OF_HALFDAY_TYPE = new StandardDateTimeFieldType(
113         "hourOfHalfday", HOUR_OF_HALFDAY, DurationFieldType.hours(), DurationFieldType.halfdays());
114     /** The clockhourOfHalfday field type. */
115     private static final DateTimeFieldType CLOCKHOUR_OF_HALFDAY_TYPE = new StandardDateTimeFieldType(
116         "clockhourOfHalfday", CLOCKHOUR_OF_HALFDAY, DurationFieldType.hours(), DurationFieldType.halfdays());
117     /** The clockhourOfDay field type. */
118     private static final DateTimeFieldType CLOCKHOUR_OF_DAY_TYPE = new StandardDateTimeFieldType(
119         "clockhourOfDay", CLOCKHOUR_OF_DAY, DurationFieldType.hours(), DurationFieldType.days());
120     /** The hourOfDay field type. */
121     private static final DateTimeFieldType HOUR_OF_DAY_TYPE = new StandardDateTimeFieldType(
122         "hourOfDay", HOUR_OF_DAY, DurationFieldType.hours(), DurationFieldType.days());
123     /** The minuteOfDay field type. */
124     private static final DateTimeFieldType MINUTE_OF_DAY_TYPE = new StandardDateTimeFieldType(
125         "minuteOfDay", MINUTE_OF_DAY, DurationFieldType.minutes(), DurationFieldType.days());
126     /** The minuteOfHour field type. */
127     private static final DateTimeFieldType MINUTE_OF_HOUR_TYPE = new StandardDateTimeFieldType(
128         "minuteOfHour", MINUTE_OF_HOUR, DurationFieldType.minutes(), DurationFieldType.hours());
129     /** The secondOfDay field type. */
130     private static final DateTimeFieldType SECOND_OF_DAY_TYPE = new StandardDateTimeFieldType(
131         "secondOfDay", SECOND_OF_DAY, DurationFieldType.seconds(), DurationFieldType.days());
132     /** The secondOfMinute field type. */
133     private static final DateTimeFieldType SECOND_OF_MINUTE_TYPE = new StandardDateTimeFieldType(
134         "secondOfMinute", SECOND_OF_MINUTE, DurationFieldType.seconds(), DurationFieldType.minutes());
135     /** The millisOfDay field type. */
136     private static final DateTimeFieldType MILLIS_OF_DAY_TYPE = new StandardDateTimeFieldType(
137         "millisOfDay", MILLIS_OF_DAY, DurationFieldType.millis(), DurationFieldType.days());
138     /** The millisOfSecond field type. */
139     private static final DateTimeFieldType MILLIS_OF_SECOND_TYPE = new StandardDateTimeFieldType(
140         "millisOfSecond", MILLIS_OF_SECOND, DurationFieldType.millis(), DurationFieldType.seconds());
141
142     /** The name of the field. */
143     private final String JavaDoc iName;
144
145     //-----------------------------------------------------------------------
146 /**
147      * Constructor.
148      *
149      * @param name the name to use
150      */
151     protected DateTimeFieldType(String JavaDoc name) {
152         super();
153         iName = name;
154     }
155
156     //-----------------------------------------------------------------------
157 /**
158      * Get the millis of second field type.
159      *
160      * @return the DateTimeFieldType constant
161      */
162     public static DateTimeFieldType millisOfSecond() {
163         return MILLIS_OF_SECOND_TYPE;
164     }
165
166     /**
167      * Get the millis of day field type.
168      *
169      * @return the DateTimeFieldType constant
170      */
171     public static DateTimeFieldType millisOfDay() {
172         return MILLIS_OF_DAY_TYPE;
173     }
174
175     /**
176      * Get the second of minute field type.
177      *
178      * @return the DateTimeFieldType constant
179      */
180     public static DateTimeFieldType secondOfMinute() {
181         return SECOND_OF_MINUTE_TYPE;
182     }
183
184     /**
185      * Get the second of day field type.
186      *
187      * @return the DateTimeFieldType constant
188      */
189     public static DateTimeFieldType secondOfDay() {
190         return SECOND_OF_DAY_TYPE;
191     }
192
193     /**
194      * Get the minute of hour field type.
195      *
196      * @return the DateTimeFieldType constant
197      */
198     public static DateTimeFieldType minuteOfHour() {
199         return MINUTE_OF_HOUR_TYPE;
200     }
201
202     /**
203      * Get the minute of day field type.
204      *
205      * @return the DateTimeFieldType constant
206      */
207     public static DateTimeFieldType minuteOfDay() {
208         return MINUTE_OF_DAY_TYPE;
209     }
210
211     /**
212      * Get the hour of day (0-23) field type.
213      *
214      * @return the DateTimeFieldType constant
215      */
216     public static DateTimeFieldType hourOfDay() {
217         return HOUR_OF_DAY_TYPE;
218     }
219
220     /**
221      * Get the hour of day (offset to 1-24) field type.
222      *
223      * @return the DateTimeFieldType constant
224      */
225     public static DateTimeFieldType clockhourOfDay() {
226         return CLOCKHOUR_OF_DAY_TYPE;
227     }
228
229     /**
230      * Get the hour of am/pm (0-11) field type.
231      *
232      * @return the DateTimeFieldType constant
233      */
234     public static DateTimeFieldType hourOfHalfday() {
235         return HOUR_OF_HALFDAY_TYPE;
236     }
237
238     /**
239      * Get the hour of am/pm (offset to 1-12) field type.
240      *
241      * @return the DateTimeFieldType constant
242      */
243     public static DateTimeFieldType clockhourOfHalfday() {
244         return CLOCKHOUR_OF_HALFDAY_TYPE;
245     }
246
247     /**
248      * Get the AM(0) PM(1) field type.
249      *
250      * @return the DateTimeFieldType constant
251      */
252     public static DateTimeFieldType halfdayOfDay() {
253         return HALFDAY_OF_DAY_TYPE;
254     }
255
256     //-----------------------------------------------------------------------
257 /**
258      * Get the day of week field type.
259      *
260      * @return the DateTimeFieldType constant
261      */
262     public static DateTimeFieldType dayOfWeek() {
263         return DAY_OF_WEEK_TYPE;
264     }
265
266     /**
267      * Get the day of month field type.
268      *
269      * @return the DateTimeFieldType constant
270      */
271     public static DateTimeFieldType dayOfMonth() {
272         return DAY_OF_MONTH_TYPE;
273     }
274
275     /**
276      * Get the day of year field type.
277      *
278      * @return the DateTimeFieldType constant
279      */
280     public static DateTimeFieldType dayOfYear() {
281         return DAY_OF_YEAR_TYPE;
282     }
283
284     /**
285      * Get the week of a week based year field type.
286      *
287      * @return the DateTimeFieldType constant
288      */
289     public static DateTimeFieldType weekOfWeekyear() {
290         return WEEK_OF_WEEKYEAR_TYPE;
291     }
292
293     /**
294      * Get the year of a week based year field type.
295      *
296      * @return the DateTimeFieldType constant
297      */
298     public static DateTimeFieldType weekyear() {
299         return WEEKYEAR_TYPE;
300     }
301
302     /**
303      * Get the year of a week based year within a century field type.
304      *
305      * @return the DateTimeFieldType constant
306      */
307     public static DateTimeFieldType weekyearOfCentury() {
308         return WEEKYEAR_OF_CENTURY_TYPE;
309     }
310
311     /**
312      * Get the month of year field type.
313      *
314      * @return the DateTimeFieldType constant
315      */
316     public static DateTimeFieldType monthOfYear() {
317         return MONTH_OF_YEAR_TYPE;
318     }
319
320     /**
321      * Get the year field type.
322      *
323      * @return the DateTimeFieldType constant
324      */
325     public static DateTimeFieldType year() {
326         return YEAR_TYPE;
327     }
328
329     /**
330      * Get the year of era field type.
331      *
332      * @return the DateTimeFieldType constant
333      */
334     public static DateTimeFieldType yearOfEra() {
335         return YEAR_OF_ERA_TYPE;
336     }
337
338     /**
339      * Get the year of century field type.
340      *
341      * @return the DateTimeFieldType constant
342      */
343     public static DateTimeFieldType yearOfCentury() {
344         return YEAR_OF_CENTURY_TYPE;
345     }
346
347     /**
348      * Get the century of era field type.
349      *
350      * @return the DateTimeFieldType constant
351      */
352     public static DateTimeFieldType centuryOfEra() {
353         return CENTURY_OF_ERA_TYPE;
354     }
355
356     /**
357      * Get the era field type.
358      *
359      * @return the DateTimeFieldType constant
360      */
361     public static DateTimeFieldType era() {
362         return ERA_TYPE;
363     }
364
365     //-----------------------------------------------------------------------
366 /**
367      * Get the name of the field.
368      * <p>
369      * By convention, names follow a pattern of "dddOfRrr", where "ddd" represents
370      * the (singular) duration unit field name and "Rrr" represents the (singular)
371      * duration range field name. If the range field is not applicable, then
372      * the name of the field is simply the (singular) duration field name.
373      *
374      * @return field name
375      */
376     public String JavaDoc getName() {
377         return iName;
378     }
379
380     /**
381      * Get the duration unit of the field.
382      *
383      * @return duration unit of the field, never null
384      */
385     public abstract DurationFieldType getDurationType();
386
387     /**
388      * Get the duration range of the field.
389      *
390      * @return duration range of the field, null if unbounded
391      */
392     public abstract DurationFieldType getRangeDurationType();
393
394     /**
395      * Gets a suitable field for this type from the given Chronology.
396      *
397      * @param chronology the chronology to use, null means ISOChronology in default zone
398      * @return a suitable field
399      */
400     public abstract DateTimeField getField(Chronology chronology);
401
402     /**
403      * Checks whether this field supported in the given Chronology.
404      *
405      * @param chronology the chronology to use, null means ISOChronology in default zone
406      * @return true if supported
407      */
408     public boolean isSupported(Chronology chronology) {
409         return getField(chronology).isSupported();
410     }
411
412     /**
413      * Get a suitable debug string.
414      *
415      * @return debug string
416      */
417     public String JavaDoc toString() {
418         return getName();
419     }
420
421     private static class StandardDateTimeFieldType extends DateTimeFieldType {
422         /** Serialization version */
423         private static final long serialVersionUID = -9937958251642L;
424
425         /** The ordinal of the standard field type, for switch statements */
426         private final byte iOrdinal;
427
428         /** The unit duration of the field. */
429         private final transient DurationFieldType iUnitType;
430         /** The range duration of the field. */
431         private final transient DurationFieldType iRangeType;
432
433         /**
434          * Constructor.
435          *
436          * @param name the name to use
437          * @param ordinal the byte value for the oridinal index
438          * @param unitType the unit duration type
439          * @param rangeType the range duration type
440          */
441         StandardDateTimeFieldType(String JavaDoc name, byte ordinal,
442                                   DurationFieldType unitType, DurationFieldType rangeType) {
443             super(name);
444             iOrdinal = ordinal;
445             iUnitType = unitType;
446             iRangeType = rangeType;
447         }
448
449         /** @inheritdoc */
450         public DurationFieldType getDurationType() {
451             return iUnitType;
452         }
453
454         /** @inheritdoc */
455         public DurationFieldType getRangeDurationType() {
456             return iRangeType;
457         }
458
459         /** @inheritdoc */
460         public DateTimeField getField(Chronology chronology) {
461             chronology = DateTimeUtils.getChronology(chronology);
462
463             switch (iOrdinal) {
464                 case ERA:
465                     return chronology.era();
466                 case YEAR_OF_ERA:
467                     return chronology.yearOfEra();
468                 case CENTURY_OF_ERA:
469                     return chronology.centuryOfEra();
470                 case YEAR_OF_CENTURY:
471                     return chronology.yearOfCentury();
472                 case YEAR:
473                     return chronology.year();
474                 case DAY_OF_YEAR:
475                     return chronology.dayOfYear();
476                 case MONTH_OF_YEAR:
477                     return chronology.monthOfYear();
478                 case DAY_OF_MONTH:
479                     return chronology.dayOfMonth();
480                 case WEEKYEAR_OF_CENTURY:
481                     return chronology.weekyearOfCentury();
482                 case WEEKYEAR:
483                     return chronology.weekyear();
484                 case WEEK_OF_WEEKYEAR:
485                     return chronology.weekOfWeekyear();
486                 case DAY_OF_WEEK:
487                     return chronology.dayOfWeek();
488                 case HALFDAY_OF_DAY:
489                     return chronology.halfdayOfDay();
490                 case HOUR_OF_HALFDAY:
491                     return chronology.hourOfHalfday();
492                 case CLOCKHOUR_OF_HALFDAY:
493                     return chronology.clockhourOfHalfday();
494                 case CLOCKHOUR_OF_DAY:
495                     return chronology.clockhourOfDay();
496                 case HOUR_OF_DAY:
497                     return chronology.hourOfDay();
498                 case MINUTE_OF_DAY:
499                     return chronology.minuteOfDay();
500                 case MINUTE_OF_HOUR:
501                     return chronology.minuteOfHour();
502                 case SECOND_OF_DAY:
503                     return chronology.secondOfDay();
504                 case SECOND_OF_MINUTE:
505                     return chronology.secondOfMinute();
506                 case MILLIS_OF_DAY:
507                     return chronology.millisOfDay();
508                 case MILLIS_OF_SECOND:
509                     return chronology.millisOfSecond();
510                 default:
511                     // Shouldn't happen.
512 throw new InternalError JavaDoc();
513             }
514         }
515
516         /**
517          * Ensure a singleton is returned.
518          *
519          * @return the singleton type
520          */
521         private Object JavaDoc readResolve() {
522             switch (iOrdinal) {
523                 case ERA:
524                     return ERA_TYPE;
525                 case YEAR_OF_ERA:
526                     return YEAR_OF_ERA_TYPE;
527                 case CENTURY_OF_ERA:
528                     return CENTURY_OF_ERA_TYPE;
529                 case YEAR_OF_CENTURY:
530                     return YEAR_OF_CENTURY_TYPE;
531                 case YEAR:
532                     return YEAR_TYPE;
533                 case DAY_OF_YEAR:
534                     return DAY_OF_YEAR_TYPE;
535                 case MONTH_OF_YEAR:
536                     return MONTH_OF_YEAR_TYPE;
537                 case DAY_OF_MONTH:
538                     return DAY_OF_MONTH_TYPE;
539                 case WEEKYEAR_OF_CENTURY:
540                     return WEEKYEAR_OF_CENTURY_TYPE;
541                 case WEEKYEAR:
542                     return WEEKYEAR_TYPE;
543                 case WEEK_OF_WEEKYEAR:
544                     return WEEK_OF_WEEKYEAR_TYPE;
545                 case DAY_OF_WEEK:
546                     return DAY_OF_WEEK_TYPE;
547                 case HALFDAY_OF_DAY:
548                     return HALFDAY_OF_DAY_TYPE;
549                 case HOUR_OF_HALFDAY:
550                     return HOUR_OF_HALFDAY_TYPE;
551                 case CLOCKHOUR_OF_HALFDAY:
552                     return CLOCKHOUR_OF_HALFDAY_TYPE;
553                 case CLOCKHOUR_OF_DAY:
554                     return CLOCKHOUR_OF_DAY_TYPE;
555                 case HOUR_OF_DAY:
556                     return HOUR_OF_DAY_TYPE;
557                 case MINUTE_OF_DAY:
558                     return MINUTE_OF_DAY_TYPE;
559                 case MINUTE_OF_HOUR:
560                     return MINUTE_OF_HOUR_TYPE;
561                 case SECOND_OF_DAY:
562                     return SECOND_OF_DAY_TYPE;
563                 case SECOND_OF_MINUTE:
564                     return SECOND_OF_MINUTE_TYPE;
565                 case MILLIS_OF_DAY:
566                     return MILLIS_OF_DAY_TYPE;
567                 case MILLIS_OF_SECOND:
568                     return MILLIS_OF_SECOND_TYPE;
569                 default:
570                     // Shouldn't happen.
571 return this;
572             }
573         }
574     }
575
576 }
577
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