1 /*
2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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24 */
25
26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file:
31 *
32 * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
33 *
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions are met:
38 *
39 * * Redistributions of source code must retain the above copyright notice,
40 * this list of conditions and the following disclaimer.
41 *
42 * * Redistributions in binary form must reproduce the above copyright notice,
43 * this list of conditions and the following disclaimer in the documentation
44 * and/or other materials provided with the distribution.
45 *
46 * * Neither the name of JSR-310 nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 package java.time.chrono;
63
64 import static java.time.temporal.ChronoField.EPOCH_DAY;
65 import static java.time.temporal.ChronoField.NANO_OF_DAY;
66 import static java.time.temporal.ChronoUnit.FOREVER;
67 import static java.time.temporal.ChronoUnit.NANOS;
68
69 import java.time.DateTimeException;
70 import java.time.Instant;
71 import java.time.LocalDateTime;
72 import java.time.LocalTime;
73 import java.time.ZoneId;
74 import java.time.ZoneOffset;
75 import java.time.format.DateTimeFormatter;
76 import java.time.temporal.ChronoField;
77 import java.time.temporal.ChronoUnit;
78 import java.time.temporal.Temporal;
79 import java.time.temporal.TemporalAccessor;
80 import java.time.temporal.TemporalAdjuster;
81 import java.time.temporal.TemporalAmount;
82 import java.time.temporal.TemporalField;
83 import java.time.temporal.TemporalQueries;
84 import java.time.temporal.TemporalQuery;
85 import java.time.temporal.TemporalUnit;
86 import java.time.zone.ZoneRules;
87 import java.util.Comparator;
88 import java.util.Objects;
89
90 /**
91 * A date-time without a time-zone in an arbitrary chronology, intended
92 * for advanced globalization use cases.
93 * <p>
94 * <b>Most applications should declare method signatures, fields and variables
95 * as {@link LocalDateTime}, not this interface.</b>
96 * <p>
97 * A {@code ChronoLocalDateTime} is the abstract representation of a local date-time
98 * where the {@code Chronology chronology}, or calendar system, is pluggable.
99 * The date-time is defined in terms of fields expressed by {@link TemporalField},
100 * where most common implementations are defined in {@link ChronoField}.
101 * The chronology defines how the calendar system operates and the meaning of
102 * the standard fields.
103 *
104 * <h3>When to use this interface</h3>
105 * The design of the API encourages the use of {@code LocalDateTime} rather than this
106 * interface, even in the case where the application needs to deal with multiple
107 * calendar systems. The rationale for this is explored in detail in {@link ChronoLocalDate}.
108 * <p>
109 * Ensure that the discussion in {@code ChronoLocalDate} has been read and understood
110 * before using this interface.
111 *
112 * @implSpec
113 * This interface must be implemented with care to ensure other classes operate correctly.
114 * All implementations that can be instantiated must be final, immutable and thread-safe.
115 * Subclasses should be Serializable wherever possible.
116 *
117 * @param <D> the concrete type for the date of this date-time
118 * @since 1.8
119 */
120 public interface ChronoLocalDateTime<D extends ChronoLocalDate>
121 extends Temporal, TemporalAdjuster, Comparable<ChronoLocalDateTime<?>> {
122
123 /**
124 * Gets a comparator that compares {@code ChronoLocalDateTime} in
125 * time-line order ignoring the chronology.
126 * <p>
127 * This comparator differs from the comparison in {@link #compareTo} in that it
128 * only compares the underlying date-time and not the chronology.
129 * This allows dates in different calendar systems to be compared based
130 * on the position of the date-time on the local time-line.
131 * The underlying comparison is equivalent to comparing the epoch-day and nano-of-day.
132 *
133 * @return a comparator that compares in time-line order ignoring the chronology
134 * @see #isAfter
135 * @see #isBefore
136 * @see #isEqual
137 */
138 static Comparator<ChronoLocalDateTime<?>> timeLineOrder() {
139 return AbstractChronology.DATE_TIME_ORDER;
140 }
141
142 //-----------------------------------------------------------------------
143 /**
144 * Obtains an instance of {@code ChronoLocalDateTime} from a temporal object.
145 * <p>
146 * This obtains a local date-time based on the specified temporal.
147 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
148 * which this factory converts to an instance of {@code ChronoLocalDateTime}.
149 * <p>
150 * The conversion extracts and combines the chronology and the date-time
151 * from the temporal object. The behavior is equivalent to using
152 * {@link Chronology#localDateTime(TemporalAccessor)} with the extracted chronology.
153 * Implementations are permitted to perform optimizations such as accessing
154 * those fields that are equivalent to the relevant objects.
155 * <p>
156 * This method matches the signature of the functional interface {@link TemporalQuery}
157 * allowing it to be used as a query via method reference, {@code ChronoLocalDateTime::from}.
158 *
159 * @param temporal the temporal object to convert, not null
160 * @return the date-time, not null
161 * @throws DateTimeException if unable to convert to a {@code ChronoLocalDateTime}
162 * @see Chronology#localDateTime(TemporalAccessor)
163 */
164 static ChronoLocalDateTime<?> from(TemporalAccessor temporal) {
165 if (temporal instanceof ChronoLocalDateTime) {
166 return (ChronoLocalDateTime<?>) temporal;
167 }
168 Objects.requireNonNull(temporal, "temporal");
169 Chronology chrono = temporal.query(TemporalQueries.chronology());
170 if (chrono == null) {
171 throw new DateTimeException("Unable to obtain ChronoLocalDateTime from TemporalAccessor: " + temporal.getClass());
172 }
173 return chrono.localDateTime(temporal);
174 }
175
176 //-----------------------------------------------------------------------
177 /**
178 * Gets the chronology of this date-time.
179 * <p>
180 * The {@code Chronology} represents the calendar system in use.
181 * The era and other fields in {@link ChronoField} are defined by the chronology.
182 *
183 * @return the chronology, not null
184 */
185 default Chronology getChronology() {
186 return toLocalDate().getChronology();
187 }
188
189 /**
190 * Gets the local date part of this date-time.
191 * <p>
192 * This returns a local date with the same year, month and day
193 * as this date-time.
194 *
195 * @return the date part of this date-time, not null
196 */
197 D toLocalDate() ;
198
199 /**
200 * Gets the local time part of this date-time.
201 * <p>
202 * This returns a local time with the same hour, minute, second and
203 * nanosecond as this date-time.
204 *
205 * @return the time part of this date-time, not null
206 */
207 LocalTime toLocalTime();
208
209 /**
210 * Checks if the specified field is supported.
211 * <p>
212 * This checks if the specified field can be queried on this date-time.
213 * If false, then calling the {@link #range(TemporalField) range},
214 * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
215 * methods will throw an exception.
216 * <p>
217 * The set of supported fields is defined by the chronology and normally includes
218 * all {@code ChronoField} date and time fields.
219 * <p>
220 * If the field is not a {@code ChronoField}, then the result of this method
221 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
222 * passing {@code this} as the argument.
223 * Whether the field is supported is determined by the field.
224 *
225 * @param field the field to check, null returns false
226 * @return true if the field can be queried, false if not
227 */
228 @Override
229 boolean isSupported(TemporalField field);
230
231 /**
232 * Checks if the specified unit is supported.
233 * <p>
234 * This checks if the specified unit can be added to or subtracted from this date-time.
235 * If false, then calling the {@link #plus(long, TemporalUnit)} and
236 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
237 * <p>
238 * The set of supported units is defined by the chronology and normally includes
239 * all {@code ChronoUnit} units except {@code FOREVER}.
240 * <p>
241 * If the unit is not a {@code ChronoUnit}, then the result of this method
242 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
243 * passing {@code this} as the argument.
244 * Whether the unit is supported is determined by the unit.
245 *
246 * @param unit the unit to check, null returns false
247 * @return true if the unit can be added/subtracted, false if not
248 */
249 @Override
250 default boolean isSupported(TemporalUnit unit) {
251 if (unit instanceof ChronoUnit) {
252 return unit != FOREVER;
253 }
254 return unit != null && unit.isSupportedBy(this);
255 }
256
257 //-----------------------------------------------------------------------
258 // override for covariant return type
259 /**
260 * {@inheritDoc}
261 * @throws DateTimeException {@inheritDoc}
262 * @throws ArithmeticException {@inheritDoc}
263 */
264 @Override
265 default ChronoLocalDateTime<D> with(TemporalAdjuster adjuster) {
266 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.with(adjuster));
267 }
268
269 /**
270 * {@inheritDoc}
271 * @throws DateTimeException {@inheritDoc}
272 * @throws ArithmeticException {@inheritDoc}
273 */
274 @Override
275 ChronoLocalDateTime<D> with(TemporalField field, long newValue);
276
277 /**
278 * {@inheritDoc}
279 * @throws DateTimeException {@inheritDoc}
280 * @throws ArithmeticException {@inheritDoc}
281 */
282 @Override
283 default ChronoLocalDateTime<D> plus(TemporalAmount amount) {
284 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.plus(amount));
285 }
286
287 /**
288 * {@inheritDoc}
289 * @throws DateTimeException {@inheritDoc}
290 * @throws ArithmeticException {@inheritDoc}
291 */
292 @Override
293 ChronoLocalDateTime<D> plus(long amountToAdd, TemporalUnit unit);
294
295 /**
296 * {@inheritDoc}
297 * @throws DateTimeException {@inheritDoc}
298 * @throws ArithmeticException {@inheritDoc}
299 */
300 @Override
301 default ChronoLocalDateTime<D> minus(TemporalAmount amount) {
302 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amount));
303 }
304
305 /**
306 * {@inheritDoc}
307 * @throws DateTimeException {@inheritDoc}
308 * @throws ArithmeticException {@inheritDoc}
309 */
310 @Override
311 default ChronoLocalDateTime<D> minus(long amountToSubtract, TemporalUnit unit) {
312 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amountToSubtract, unit));
313 }
314
315 //-----------------------------------------------------------------------
316 /**
317 * Queries this date-time using the specified query.
318 * <p>
319 * This queries this date-time using the specified query strategy object.
320 * The {@code TemporalQuery} object defines the logic to be used to
321 * obtain the result. Read the documentation of the query to understand
322 * what the result of this method will be.
323 * <p>
324 * The result of this method is obtained by invoking the
325 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
326 * specified query passing {@code this} as the argument.
327 *
328 * @param <R> the type of the result
329 * @param query the query to invoke, not null
330 * @return the query result, null may be returned (defined by the query)
331 * @throws DateTimeException if unable to query (defined by the query)
332 * @throws ArithmeticException if numeric overflow occurs (defined by the query)
333 */
334 @SuppressWarnings("unchecked")
335 @Override
336 default <R> R query(TemporalQuery<R> query) {
337 if (query == TemporalQueries.zoneId() || query == TemporalQueries.zone() || query == TemporalQueries.offset()) {
338 return null;
339 } else if (query == TemporalQueries.localTime()) {
340 return (R) toLocalTime();
341 } else if (query == TemporalQueries.chronology()) {
342 return (R) getChronology();
343 } else if (query == TemporalQueries.precision()) {
344 return (R) NANOS;
345 }
346 // inline TemporalAccessor.super.query(query) as an optimization
347 // non-JDK classes are not permitted to make this optimization
348 return query.queryFrom(this);
349 }
350
351 /**
352 * Adjusts the specified temporal object to have the same date and time as this object.
353 * <p>
354 * This returns a temporal object of the same observable type as the input
355 * with the date and time changed to be the same as this.
356 * <p>
357 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
358 * twice, passing {@link ChronoField#EPOCH_DAY} and
359 * {@link ChronoField#NANO_OF_DAY} as the fields.
360 * <p>
361 * In most cases, it is clearer to reverse the calling pattern by using
362 * {@link Temporal#with(TemporalAdjuster)}:
363 * <pre>
364 * // these two lines are equivalent, but the second approach is recommended
365 * temporal = thisLocalDateTime.adjustInto(temporal);
366 * temporal = temporal.with(thisLocalDateTime);
367 * </pre>
368 * <p>
369 * This instance is immutable and unaffected by this method call.
370 *
371 * @param temporal the target object to be adjusted, not null
372 * @return the adjusted object, not null
373 * @throws DateTimeException if unable to make the adjustment
374 * @throws ArithmeticException if numeric overflow occurs
375 */
376 @Override
377 default Temporal adjustInto(Temporal temporal) {
378 return temporal
379 .with(EPOCH_DAY, toLocalDate().toEpochDay())
380 .with(NANO_OF_DAY, toLocalTime().toNanoOfDay());
381 }
382
383 /**
384 * Formats this date-time using the specified formatter.
385 * <p>
386 * This date-time will be passed to the formatter to produce a string.
387 * <p>
388 * The default implementation must behave as follows:
389 * <pre>
390 * return formatter.format(this);
391 * </pre>
392 *
393 * @param formatter the formatter to use, not null
394 * @return the formatted date-time string, not null
395 * @throws DateTimeException if an error occurs during printing
396 */
397 default String format(DateTimeFormatter formatter) {
398 Objects.requireNonNull(formatter, "formatter");
399 return formatter.format(this);
400 }
401
402 //-----------------------------------------------------------------------
403 /**
404 * Combines this time with a time-zone to create a {@code ChronoZonedDateTime}.
405 * <p>
406 * This returns a {@code ChronoZonedDateTime} formed from this date-time at the
407 * specified time-zone. The result will match this date-time as closely as possible.
408 * Time-zone rules, such as daylight savings, mean that not every local date-time
409 * is valid for the specified zone, thus the local date-time may be adjusted.
410 * <p>
411 * The local date-time is resolved to a single instant on the time-line.
412 * This is achieved by finding a valid offset from UTC/Greenwich for the local
413 * date-time as defined by the {@link ZoneRules rules} of the zone ID.
414 *<p>
415 * In most cases, there is only one valid offset for a local date-time.
416 * In the case of an overlap, where clocks are set back, there are two valid offsets.
417 * This method uses the earlier offset typically corresponding to "summer".
418 * <p>
419 * In the case of a gap, where clocks jump forward, there is no valid offset.
420 * Instead, the local date-time is adjusted to be later by the length of the gap.
421 * For a typical one hour daylight savings change, the local date-time will be
422 * moved one hour later into the offset typically corresponding to "summer".
423 * <p>
424 * To obtain the later offset during an overlap, call
425 * {@link ChronoZonedDateTime#withLaterOffsetAtOverlap()} on the result of this method.
426 *
427 * @param zone the time-zone to use, not null
428 * @return the zoned date-time formed from this date-time, not null
429 */
430 ChronoZonedDateTime<D> atZone(ZoneId zone);
431
432 //-----------------------------------------------------------------------
433 /**
434 * Converts this date-time to an {@code Instant}.
435 * <p>
436 * This combines this local date-time and the specified offset to form
437 * an {@code Instant}.
438 * <p>
439 * This default implementation calculates from the epoch-day of the date and the
440 * second-of-day of the time.
441 *
442 * @param offset the offset to use for the conversion, not null
443 * @return an {@code Instant} representing the same instant, not null
444 */
445 default Instant toInstant(ZoneOffset offset) {
446 return Instant.ofEpochSecond(toEpochSecond(offset), toLocalTime().getNano());
447 }
448
449 /**
450 * Converts this date-time to the number of seconds from the epoch
451 * of 1970-01-01T00:00:00Z.
452 * <p>
453 * This combines this local date-time and the specified offset to calculate the
454 * epoch-second value, which is the number of elapsed seconds from 1970-01-01T00:00:00Z.
455 * Instants on the time-line after the epoch are positive, earlier are negative.
456 * <p>
457 * This default implementation calculates from the epoch-day of the date and the
458 * second-of-day of the time.
459 *
460 * @param offset the offset to use for the conversion, not null
461 * @return the number of seconds from the epoch of 1970-01-01T00:00:00Z
462 */
463 default long toEpochSecond(ZoneOffset offset) {
464 Objects.requireNonNull(offset, "offset");
465 long epochDay = toLocalDate().toEpochDay();
466 long secs = epochDay * 86400 + toLocalTime().toSecondOfDay();
467 secs -= offset.getTotalSeconds();
468 return secs;
469 }
470
471 //-----------------------------------------------------------------------
472 /**
473 * Compares this date-time to another date-time, including the chronology.
474 * <p>
475 * The comparison is based first on the underlying time-line date-time, then
476 * on the chronology.
477 * It is "consistent with equals", as defined by {@link Comparable}.
478 * <p>
479 * For example, the following is the comparator order:
480 * <ol>
481 * <li>{@code 2012-12-03T12:00 (ISO)}</li>
482 * <li>{@code 2012-12-04T12:00 (ISO)}</li>
483 * <li>{@code 2555-12-04T12:00 (ThaiBuddhist)}</li>
484 * <li>{@code 2012-12-05T12:00 (ISO)}</li>
485 * </ol>
486 * Values #2 and #3 represent the same date-time on the time-line.
487 * When two values represent the same date-time, the chronology ID is compared to distinguish them.
488 * This step is needed to make the ordering "consistent with equals".
489 * <p>
490 * If all the date-time objects being compared are in the same chronology, then the
491 * additional chronology stage is not required and only the local date-time is used.
492 * <p>
493 * This default implementation performs the comparison defined above.
494 *
495 * @param other the other date-time to compare to, not null
496 * @return the comparator value, negative if less, positive if greater
497 */
498 @Override
499 default int compareTo(ChronoLocalDateTime<?> other) {
500 int cmp = toLocalDate().compareTo(other.toLocalDate());
501 if (cmp == 0) {
502 cmp = toLocalTime().compareTo(other.toLocalTime());
503 if (cmp == 0) {
504 cmp = getChronology().compareTo(other.getChronology());
505 }
506 }
507 return cmp;
508 }
509
510 /**
511 * Checks if this date-time is after the specified date-time ignoring the chronology.
512 * <p>
513 * This method differs from the comparison in {@link #compareTo} in that it
514 * only compares the underlying date-time and not the chronology.
515 * This allows dates in different calendar systems to be compared based
516 * on the time-line position.
517 * <p>
518 * This default implementation performs the comparison based on the epoch-day
519 * and nano-of-day.
520 *
521 * @param other the other date-time to compare to, not null
522 * @return true if this is after the specified date-time
523 */
524 default boolean isAfter(ChronoLocalDateTime<?> other) {
525 long thisEpDay = this.toLocalDate().toEpochDay();
526 long otherEpDay = other.toLocalDate().toEpochDay();
527 return thisEpDay > otherEpDay ||
528 (thisEpDay == otherEpDay && this.toLocalTime().toNanoOfDay() > other.toLocalTime().toNanoOfDay());
529 }
530
531 /**
532 * Checks if this date-time is before the specified date-time ignoring the chronology.
533 * <p>
534 * This method differs from the comparison in {@link #compareTo} in that it
535 * only compares the underlying date-time and not the chronology.
536 * This allows dates in different calendar systems to be compared based
537 * on the time-line position.
538 * <p>
539 * This default implementation performs the comparison based on the epoch-day
540 * and nano-of-day.
541 *
542 * @param other the other date-time to compare to, not null
543 * @return true if this is before the specified date-time
544 */
545 default boolean isBefore(ChronoLocalDateTime<?> other) {
546 long thisEpDay = this.toLocalDate().toEpochDay();
547 long otherEpDay = other.toLocalDate().toEpochDay();
548 return thisEpDay < otherEpDay ||
549 (thisEpDay == otherEpDay && this.toLocalTime().toNanoOfDay() < other.toLocalTime().toNanoOfDay());
550 }
551
552 /**
553 * Checks if this date-time is equal to the specified date-time ignoring the chronology.
554 * <p>
555 * This method differs from the comparison in {@link #compareTo} in that it
556 * only compares the underlying date and time and not the chronology.
557 * This allows date-times in different calendar systems to be compared based
558 * on the time-line position.
559 * <p>
560 * This default implementation performs the comparison based on the epoch-day
561 * and nano-of-day.
562 *
563 * @param other the other date-time to compare to, not null
564 * @return true if the underlying date-time is equal to the specified date-time on the timeline
565 */
566 default boolean isEqual(ChronoLocalDateTime<?> other) {
567 // Do the time check first, it is cheaper than computing EPOCH day.
568 return this.toLocalTime().toNanoOfDay() == other.toLocalTime().toNanoOfDay() &&
569 this.toLocalDate().toEpochDay() == other.toLocalDate().toEpochDay();
570 }
571
572 /**
573 * Checks if this date-time is equal to another date-time, including the chronology.
574 * <p>
575 * Compares this date-time with another ensuring that the date-time and chronology are the same.
576 *
577 * @param obj the object to check, null returns false
578 * @return true if this is equal to the other date
579 */
580 @Override
581 boolean equals(Object obj);
582
583 /**
584 * A hash code for this date-time.
585 *
586 * @return a suitable hash code
587 */
588 @Override
589 int hashCode();
590
591 //-----------------------------------------------------------------------
592 /**
593 * Outputs this date-time as a {@code String}.
594 * <p>
595 * The output will include the full local date-time.
596 *
597 * @return a string representation of this date-time, not null
598 */
599 @Override
600 String toString();
601
602 }