1 /*
2 * Copyright (c) 2012, 2024, 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
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
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;
63
64 import static java.time.LocalTime.MICROS_PER_SECOND;
65 import static java.time.LocalTime.MILLIS_PER_SECOND;
66 import static java.time.LocalTime.NANOS_PER_SECOND;
67 import static java.time.LocalTime.SECONDS_PER_DAY;
68 import static java.time.LocalTime.SECONDS_PER_HOUR;
69 import static java.time.LocalTime.SECONDS_PER_MINUTE;
70 import static java.time.temporal.ChronoField.INSTANT_SECONDS;
71 import static java.time.temporal.ChronoField.MICRO_OF_SECOND;
72 import static java.time.temporal.ChronoField.MILLI_OF_SECOND;
73 import static java.time.temporal.ChronoField.NANO_OF_SECOND;
74 import static java.time.temporal.ChronoUnit.DAYS;
75 import static java.time.temporal.ChronoUnit.NANOS;
76
77 import java.io.DataInput;
78 import java.io.DataOutput;
79 import java.io.IOException;
80 import java.io.InvalidObjectException;
81 import java.io.ObjectInputStream;
82 import java.io.Serializable;
83 import java.time.format.DateTimeFormatter;
84 import java.time.format.DateTimeParseException;
85 import java.time.temporal.ChronoField;
86 import java.time.temporal.ChronoUnit;
87 import java.time.temporal.Temporal;
88 import java.time.temporal.TemporalAccessor;
89 import java.time.temporal.TemporalAdjuster;
90 import java.time.temporal.TemporalAmount;
91 import java.time.temporal.TemporalField;
92 import java.time.temporal.TemporalQueries;
93 import java.time.temporal.TemporalQuery;
94 import java.time.temporal.TemporalUnit;
95 import java.time.temporal.UnsupportedTemporalTypeException;
96 import java.time.temporal.ValueRange;
97 import java.util.Objects;
98
99 /**
100 * An instantaneous point on the time-line.
101 * <p>
102 * This class models a single instantaneous point on the time-line.
103 * This might be used to record event time-stamps in the application.
104 * <p>
105 * The range of an instant requires the storage of a number larger than a {@code long}.
106 * To achieve this, the class stores a {@code long} representing epoch-seconds and an
107 * {@code int} representing nanosecond-of-second, which will always be between 0 and 999,999,999.
108 * The epoch-seconds are measured from the standard Java epoch of {@code 1970-01-01T00:00:00Z}
109 * where instants after the epoch have positive values, and earlier instants have negative values.
110 * For both the epoch-second and nanosecond parts, a larger value is always later on the time-line
111 * than a smaller value.
112 *
113 * <h2>Time-scale</h2>
114 * <p>
115 * The length of the solar day is the standard way that humans measure time.
116 * This has traditionally been subdivided into 24 hours of 60 minutes of 60 seconds,
117 * forming a 86400 second day.
118 * <p>
119 * Modern timekeeping is based on atomic clocks which precisely define an SI second
120 * relative to the transitions of a Caesium atom. The length of an SI second was defined
121 * to be very close to the 86400th fraction of a day.
122 * <p>
123 * Unfortunately, as the Earth rotates the length of the day varies.
124 * In addition, over time the average length of the day is getting longer as the Earth slows.
125 * As a result, the length of a solar day in 2012 is slightly longer than 86400 SI seconds.
126 * The actual length of any given day and the amount by which the Earth is slowing
127 * are not predictable and can only be determined by measurement.
128 * The UT1 time-scale captures the accurate length of day, but is only available some
129 * time after the day has completed.
130 * <p>
131 * The UTC time-scale is a standard approach to bundle up all the additional fractions
132 * of a second from UT1 into whole seconds, known as <i>leap-seconds</i>.
133 * A leap-second may be added or removed depending on the Earth's rotational changes.
134 * As such, UTC permits a day to have 86399 SI seconds or 86401 SI seconds where
135 * necessary in order to keep the day aligned with the Sun.
136 * <p>
137 * The modern UTC time-scale was introduced in 1972, introducing the concept of whole leap-seconds.
138 * Between 1958 and 1972, the definition of UTC was complex, with minor sub-second leaps and
139 * alterations to the length of the notional second. As of 2012, discussions are underway
140 * to change the definition of UTC again, with the potential to remove leap seconds or
141 * introduce other changes.
142 * <p>
143 * Given the complexity of accurate timekeeping described above, this Java API defines
144 * its own time-scale, the <i>Java Time-Scale</i>.
145 * <p>
146 * The Java Time-Scale divides each calendar day into exactly 86400
147 * subdivisions, known as seconds. These seconds may differ from the
148 * SI second. It closely matches the de facto international civil time
149 * scale, the definition of which changes from time to time.
150 * <p>
151 * The Java Time-Scale has slightly different definitions for different
152 * segments of the time-line, each based on the consensus international
153 * time scale that is used as the basis for civil time. Whenever the
154 * internationally-agreed time scale is modified or replaced, a new
155 * segment of the Java Time-Scale must be defined for it. Each segment
156 * must meet these requirements:
157 * <ul>
158 * <li>the Java Time-Scale shall closely match the underlying international
159 * civil time scale;</li>
160 * <li>the Java Time-Scale shall exactly match the international civil
161 * time scale at noon each day;</li>
162 * <li>the Java Time-Scale shall have a precisely-defined relationship to
163 * the international civil time scale.</li>
164 * </ul>
165 * There are currently, as of 2013, two segments in the Java time-scale.
166 * <p>
167 * For the segment from 1972-11-03 (exact boundary discussed below) until
168 * further notice, the consensus international time scale is UTC (with
169 * leap seconds). In this segment, the Java Time-Scale is identical to
170 * <a href="http://www.cl.cam.ac.uk/~mgk25/time/utc-sls/">UTC-SLS</a>.
171 * This is identical to UTC on days that do not have a leap second.
172 * On days that do have a leap second, the leap second is spread equally
173 * over the last 1000 seconds of the day, maintaining the appearance of
174 * exactly 86400 seconds per day.
175 * <p>
176 * For the segment prior to 1972-11-03, extending back arbitrarily far,
177 * the consensus international time scale is defined to be UT1, applied
178 * proleptically, which is equivalent to the (mean) solar time on the
179 * prime meridian (Greenwich). In this segment, the Java Time-Scale is
180 * identical to the consensus international time scale. The exact
181 * boundary between the two segments is the instant where UT1 = UTC
182 * between 1972-11-03T00:00 and 1972-11-04T12:00.
183 * <p>
184 * Implementations of the Java time-scale using the JSR-310 API are not
185 * required to provide any clock that is sub-second accurate, or that
186 * progresses monotonically or smoothly. Implementations are therefore
187 * not required to actually perform the UTC-SLS slew or to otherwise be
188 * aware of leap seconds. JSR-310 does, however, require that
189 * implementations must document the approach they use when defining a
190 * clock representing the current instant.
191 * See {@link Clock} for details on the available clocks.
192 * <p>
193 * The Java time-scale is used for all date-time classes.
194 * This includes {@code Instant}, {@code LocalDate}, {@code LocalTime}, {@code OffsetDateTime},
195 * {@code ZonedDateTime} and {@code Duration}.
196 * <p>
197 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
198 * class; programmers should treat instances that are
199 * {@linkplain #equals(Object) equal} as interchangeable and should not
200 * use instances for synchronization, or unpredictable behavior may
201 * occur. For example, in a future release, synchronization may fail.
202 * The {@code equals} method should be used for comparisons.
203 *
204 * @implSpec
205 * This class is immutable and thread-safe.
206 *
207 * @since 1.8
208 */
209 @jdk.internal.ValueBased
210 @jdk.internal.MigratedValueClass
211 public final class Instant
212 implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable {
213
214 /**
215 * Constant for the 1970-01-01T00:00:00Z epoch instant.
216 */
217 public static final Instant EPOCH = new Instant(0, 0);
218 /**
219 * The minimum supported epoch second.
220 */
221 private static final long MIN_SECOND = -31557014167219200L;
222 /**
223 * The maximum supported epoch second.
224 */
225 private static final long MAX_SECOND = 31556889864403199L;
226 /**
227 * The minimum supported {@code Instant}, '-1000000000-01-01T00:00Z'.
228 * This could be used by an application as a "far past" instant.
229 * <p>
230 * This is one year earlier than the minimum {@code LocalDateTime}.
231 * This provides sufficient values to handle the range of {@code ZoneOffset}
232 * which affect the instant in addition to the local date-time.
233 * The value is also chosen such that the value of the year fits in
234 * an {@code int}.
235 */
236 public static final Instant MIN = Instant.ofEpochSecond(MIN_SECOND, 0);
237 /**
238 * The maximum supported {@code Instant}, '1000000000-12-31T23:59:59.999999999Z'.
239 * This could be used by an application as a "far future" instant.
240 * <p>
241 * This is one year later than the maximum {@code LocalDateTime}.
242 * This provides sufficient values to handle the range of {@code ZoneOffset}
243 * which affect the instant in addition to the local date-time.
244 * The value is also chosen such that the value of the year fits in
245 * an {@code int}.
246 */
247 public static final Instant MAX = Instant.ofEpochSecond(MAX_SECOND, 999_999_999);
248
249 /**
250 * Serialization version.
251 */
252 @java.io.Serial
253 private static final long serialVersionUID = -665713676816604388L;
254
255 /**
256 * The number of seconds from the epoch of 1970-01-01T00:00:00Z.
257 */
258 private final long seconds;
259 /**
260 * The number of nanoseconds, later along the time-line, from the seconds field.
261 * This is always positive, and never exceeds 999,999,999.
262 */
263 private final int nanos;
264
265 //-----------------------------------------------------------------------
266 /**
267 * Obtains the current instant from the system clock.
268 * <p>
269 * This will query the {@link Clock#systemUTC() system UTC clock} to
270 * obtain the current instant.
271 * <p>
272 * Using this method will prevent the ability to use an alternate time-source for
273 * testing because the clock is effectively hard-coded.
274 *
275 * @return the current instant using the system clock, not null
276 */
277 public static Instant now() {
278 return Clock.currentInstant();
279 }
280
281 /**
282 * Obtains the current instant from the specified clock.
283 * <p>
284 * This will query the specified clock to obtain the current time.
285 * <p>
286 * Using this method allows the use of an alternate clock for testing.
287 * The alternate clock may be introduced using {@link Clock dependency injection}.
288 *
289 * @param clock the clock to use, not null
290 * @return the current instant, not null
291 */
292 public static Instant now(Clock clock) {
293 Objects.requireNonNull(clock, "clock");
294 return clock.instant();
295 }
296
297 //-----------------------------------------------------------------------
298 /**
299 * Obtains an instance of {@code Instant} using seconds from the
300 * epoch of 1970-01-01T00:00:00Z.
301 * <p>
302 * The nanosecond field is set to zero.
303 *
304 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
305 * @return an instant, not null
306 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
307 */
308 public static Instant ofEpochSecond(long epochSecond) {
309 return create(epochSecond, 0);
310 }
311
312 /**
313 * Obtains an instance of {@code Instant} using seconds from the
314 * epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.
315 * <p>
316 * This method allows an arbitrary number of nanoseconds to be passed in.
317 * The factory will alter the values of the second and nanosecond in order
318 * to ensure that the stored nanosecond is in the range 0 to 999,999,999.
319 * For example, the following will result in exactly the same instant:
320 * <pre>
321 * Instant.ofEpochSecond(3, 1);
322 * Instant.ofEpochSecond(4, -999_999_999);
323 * Instant.ofEpochSecond(2, 1000_000_001);
324 * </pre>
325 *
326 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
327 * @param nanoAdjustment the nanosecond adjustment to the number of seconds, positive or negative
328 * @return an instant, not null
329 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
330 * @throws ArithmeticException if numeric overflow occurs
331 */
332 public static Instant ofEpochSecond(long epochSecond, long nanoAdjustment) {
333 long secs = Math.addExact(epochSecond, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND));
334 int nos = (int)Math.floorMod(nanoAdjustment, NANOS_PER_SECOND);
335 return create(secs, nos);
336 }
337
338 /**
339 * Obtains an instance of {@code Instant} using milliseconds from the
340 * epoch of 1970-01-01T00:00:00Z.
341 * <p>
342 * The seconds and nanoseconds are extracted from the specified milliseconds.
343 *
344 * @param epochMilli the number of milliseconds from 1970-01-01T00:00:00Z
345 * @return an instant, not null
346 */
347 public static Instant ofEpochMilli(long epochMilli) {
348 long secs = Math.floorDiv(epochMilli, 1000);
349 int mos = Math.floorMod(epochMilli, 1000);
350 return create(secs, mos * 1000_000);
351 }
352
353 //-----------------------------------------------------------------------
354 /**
355 * Obtains an instance of {@code Instant} from a temporal object.
356 * <p>
357 * This obtains an instant based on the specified temporal.
358 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
359 * which this factory converts to an instance of {@code Instant}.
360 * <p>
361 * The conversion extracts the {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS}
362 * and {@link ChronoField#NANO_OF_SECOND NANO_OF_SECOND} fields.
363 * <p>
364 * This method matches the signature of the functional interface {@link TemporalQuery}
365 * allowing it to be used as a query via method reference, {@code Instant::from}.
366 *
367 * @param temporal the temporal object to convert, not null
368 * @return the instant, not null
369 * @throws DateTimeException if unable to convert to an {@code Instant}
370 */
371 public static Instant from(TemporalAccessor temporal) {
372 if (temporal instanceof Instant) {
373 return (Instant) temporal;
374 }
375 Objects.requireNonNull(temporal, "temporal");
376 try {
377 long instantSecs = temporal.getLong(INSTANT_SECONDS);
378 int nanoOfSecond = temporal.get(NANO_OF_SECOND);
379 return Instant.ofEpochSecond(instantSecs, nanoOfSecond);
380 } catch (DateTimeException ex) {
381 throw new DateTimeException("Unable to obtain Instant from TemporalAccessor: " +
382 temporal + " of type " + temporal.getClass().getName(), ex);
383 }
384 }
385
386 //-----------------------------------------------------------------------
387 /**
388 * Obtains an instance of {@code Instant} from a text string such as
389 * {@code 2007-12-03T10:15:30.00Z}.
390 * <p>
391 * The string must represent a valid instant in UTC and is parsed using
392 * {@link DateTimeFormatter#ISO_INSTANT}.
393 *
394 * @param text the text to parse, not null
395 * @return the parsed instant, not null
396 * @throws DateTimeParseException if the text cannot be parsed
397 */
398 public static Instant parse(final CharSequence text) {
399 return DateTimeFormatter.ISO_INSTANT.parse(text, Instant::from);
400 }
401
402 //-----------------------------------------------------------------------
403 /**
404 * Obtains an instance of {@code Instant} using seconds and nanoseconds.
405 *
406 * @param seconds the length of the duration in seconds
407 * @param nanoOfSecond the nano-of-second, from 0 to 999,999,999
408 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
409 */
410 private static Instant create(long seconds, int nanoOfSecond) {
411 if ((seconds | nanoOfSecond) == 0) {
412 return EPOCH;
413 }
414 if (seconds < MIN_SECOND || seconds > MAX_SECOND) {
415 throw new DateTimeException("Instant exceeds minimum or maximum instant");
416 }
417 return new Instant(seconds, nanoOfSecond);
418 }
419
420 /**
421 * Constructs an instance of {@code Instant} using seconds from the epoch of
422 * 1970-01-01T00:00:00Z and nanosecond fraction of second.
423 *
424 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
425 * @param nanos the nanoseconds within the second, must be positive
426 */
427 private Instant(long epochSecond, int nanos) {
428 this.seconds = epochSecond;
429 this.nanos = nanos;
430 }
431
432 //-----------------------------------------------------------------------
433 /**
434 * Checks if the specified field is supported.
435 * <p>
436 * This checks if this instant can be queried for the specified field.
437 * If false, then calling the {@link #range(TemporalField) range},
438 * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
439 * methods will throw an exception.
440 * <p>
441 * If the field is a {@link ChronoField} then the query is implemented here.
442 * The supported fields are:
443 * <ul>
444 * <li>{@code NANO_OF_SECOND}
445 * <li>{@code MICRO_OF_SECOND}
446 * <li>{@code MILLI_OF_SECOND}
447 * <li>{@code INSTANT_SECONDS}
448 * </ul>
449 * All other {@code ChronoField} instances will return false.
450 * <p>
451 * If the field is not a {@code ChronoField}, then the result of this method
452 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
453 * passing {@code this} as the argument.
454 * Whether the field is supported is determined by the field.
455 *
456 * @param field the field to check, null returns false
457 * @return true if the field is supported on this instant, false if not
458 */
459 @Override
460 public boolean isSupported(TemporalField field) {
461 if (field instanceof ChronoField) {
462 return field == INSTANT_SECONDS || field == NANO_OF_SECOND || field == MICRO_OF_SECOND || field == MILLI_OF_SECOND;
463 }
464 return field != null && field.isSupportedBy(this);
465 }
466
467 /**
468 * Checks if the specified unit is supported.
469 * <p>
470 * This checks if the specified unit can be added to, or subtracted from, this date-time.
471 * If false, then calling the {@link #plus(long, TemporalUnit)} and
472 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
473 * <p>
474 * If the unit is a {@link ChronoUnit} then the query is implemented here.
475 * The supported units are:
476 * <ul>
477 * <li>{@code NANOS}
478 * <li>{@code MICROS}
479 * <li>{@code MILLIS}
480 * <li>{@code SECONDS}
481 * <li>{@code MINUTES}
482 * <li>{@code HOURS}
483 * <li>{@code HALF_DAYS}
484 * <li>{@code DAYS}
485 * </ul>
486 * All other {@code ChronoUnit} instances will return false.
487 * <p>
488 * If the unit is not a {@code ChronoUnit}, then the result of this method
489 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
490 * passing {@code this} as the argument.
491 * Whether the unit is supported is determined by the unit.
492 *
493 * @param unit the unit to check, null returns false
494 * @return true if the unit can be added/subtracted, false if not
495 */
496 @Override
497 public boolean isSupported(TemporalUnit unit) {
498 if (unit instanceof ChronoUnit) {
499 return unit.isTimeBased() || unit == DAYS;
500 }
501 return unit != null && unit.isSupportedBy(this);
502 }
503
504 //-----------------------------------------------------------------------
505 /**
506 * Gets the range of valid values for the specified field.
507 * <p>
508 * The range object expresses the minimum and maximum valid values for a field.
509 * This instant is used to enhance the accuracy of the returned range.
510 * If it is not possible to return the range, because the field is not supported
511 * or for some other reason, an exception is thrown.
512 * <p>
513 * If the field is a {@link ChronoField} then the query is implemented here.
514 * The {@link #isSupported(TemporalField) supported fields} will return
515 * appropriate range instances.
516 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
517 * <p>
518 * If the field is not a {@code ChronoField}, then the result of this method
519 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
520 * passing {@code this} as the argument.
521 * Whether the range can be obtained is determined by the field.
522 *
523 * @param field the field to query the range for, not null
524 * @return the range of valid values for the field, not null
525 * @throws DateTimeException if the range for the field cannot be obtained
526 * @throws UnsupportedTemporalTypeException if the field is not supported
527 */
528 @Override // override for Javadoc
529 public ValueRange range(TemporalField field) {
530 return Temporal.super.range(field);
531 }
532
533 /**
534 * Gets the value of the specified field from this instant as an {@code int}.
535 * <p>
536 * This queries this instant for the value of the specified field.
537 * The returned value will always be within the valid range of values for the field.
538 * If it is not possible to return the value, because the field is not supported
539 * or for some other reason, an exception is thrown.
540 * <p>
541 * If the field is a {@link ChronoField} then the query is implemented here.
542 * The {@link #isSupported(TemporalField) supported fields} will return valid
543 * values based on this date-time, except {@code INSTANT_SECONDS} which is too
544 * large to fit in an {@code int} and throws a {@code DateTimeException}.
545 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
546 * <p>
547 * If the field is not a {@code ChronoField}, then the result of this method
548 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
549 * passing {@code this} as the argument. Whether the value can be obtained,
550 * and what the value represents, is determined by the field.
551 *
552 * @param field the field to get, not null
553 * @return the value for the field
554 * @throws DateTimeException if a value for the field cannot be obtained or
555 * the value is outside the range of valid values for the field
556 * @throws UnsupportedTemporalTypeException if the field is not supported or
557 * the range of values exceeds an {@code int}
558 * @throws ArithmeticException if numeric overflow occurs
559 */
560 @Override // override for Javadoc and performance
561 public int get(TemporalField field) {
562 if (field instanceof ChronoField chronoField) {
563 return switch (chronoField) {
564 case NANO_OF_SECOND -> nanos;
565 case MICRO_OF_SECOND -> nanos / 1000;
566 case MILLI_OF_SECOND -> nanos / 1000_000;
567 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
568 };
569 }
570 return range(field).checkValidIntValue(field.getFrom(this), field);
571 }
572
573 /**
574 * Gets the value of the specified field from this instant as a {@code long}.
575 * <p>
576 * This queries this instant for the value of the specified field.
577 * If it is not possible to return the value, because the field is not supported
578 * or for some other reason, an exception is thrown.
579 * <p>
580 * If the field is a {@link ChronoField} then the query is implemented here.
581 * The {@link #isSupported(TemporalField) supported fields} will return valid
582 * values based on this date-time.
583 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
584 * <p>
585 * If the field is not a {@code ChronoField}, then the result of this method
586 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
587 * passing {@code this} as the argument. Whether the value can be obtained,
588 * and what the value represents, is determined by the field.
589 *
590 * @param field the field to get, not null
591 * @return the value for the field
592 * @throws DateTimeException if a value for the field cannot be obtained
593 * @throws UnsupportedTemporalTypeException if the field is not supported
594 * @throws ArithmeticException if numeric overflow occurs
595 */
596 @Override
597 public long getLong(TemporalField field) {
598 if (field instanceof ChronoField chronoField) {
599 return switch (chronoField) {
600 case NANO_OF_SECOND -> nanos;
601 case MICRO_OF_SECOND -> nanos / 1000;
602 case MILLI_OF_SECOND -> nanos / 1000_000;
603 case INSTANT_SECONDS -> seconds;
604 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
605 };
606 }
607 return field.getFrom(this);
608 }
609
610 //-----------------------------------------------------------------------
611 /**
612 * Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
613 * <p>
614 * The epoch second count is a simple incrementing count of seconds where
615 * second 0 is 1970-01-01T00:00:00Z.
616 * The nanosecond part is returned by {@link #getNano}.
617 *
618 * @return the seconds from the epoch of 1970-01-01T00:00:00Z
619 */
620 public long getEpochSecond() {
621 return seconds;
622 }
623
624 /**
625 * Gets the number of nanoseconds, later along the time-line, from the start
626 * of the second.
627 * <p>
628 * The nanosecond-of-second value measures the total number of nanoseconds from
629 * the second returned by {@link #getEpochSecond}.
630 *
631 * @return the nanoseconds within the second, always positive, never exceeds 999,999,999
632 */
633 public int getNano() {
634 return nanos;
635 }
636
637 //-------------------------------------------------------------------------
638 /**
639 * Returns an adjusted copy of this instant.
640 * <p>
641 * This returns an {@code Instant}, based on this one, with the instant adjusted.
642 * The adjustment takes place using the specified adjuster strategy object.
643 * Read the documentation of the adjuster to understand what adjustment will be made.
644 * <p>
645 * The result of this method is obtained by invoking the
646 * {@link TemporalAdjuster#adjustInto(Temporal)} method on the
647 * specified adjuster passing {@code this} as the argument.
648 * <p>
649 * This instance is immutable and unaffected by this method call.
650 *
651 * @param adjuster the adjuster to use, not null
652 * @return an {@code Instant} based on {@code this} with the adjustment made, not null
653 * @throws DateTimeException if the adjustment cannot be made
654 * @throws ArithmeticException if numeric overflow occurs
655 */
656 @Override
657 public Instant with(TemporalAdjuster adjuster) {
658 return (Instant) adjuster.adjustInto(this);
659 }
660
661 /**
662 * Returns a copy of this instant with the specified field set to a new value.
663 * <p>
664 * This returns an {@code Instant}, based on this one, with the value
665 * for the specified field changed.
666 * If it is not possible to set the value, because the field is not supported or for
667 * some other reason, an exception is thrown.
668 * <p>
669 * If the field is a {@link ChronoField} then the adjustment is implemented here.
670 * The supported fields behave as follows:
671 * <ul>
672 * <li>{@code NANO_OF_SECOND} -
673 * Returns an {@code Instant} with the specified nano-of-second.
674 * The epoch-second will be unchanged.
675 * <li>{@code MICRO_OF_SECOND} -
676 * Returns an {@code Instant} with the nano-of-second replaced by the specified
677 * micro-of-second multiplied by 1,000. The epoch-second will be unchanged.
678 * <li>{@code MILLI_OF_SECOND} -
679 * Returns an {@code Instant} with the nano-of-second replaced by the specified
680 * milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged.
681 * <li>{@code INSTANT_SECONDS} -
682 * Returns an {@code Instant} with the specified epoch-second.
683 * The nano-of-second will be unchanged.
684 * </ul>
685 * <p>
686 * In all cases, if the new value is outside the valid range of values for the field
687 * then a {@code DateTimeException} will be thrown.
688 * <p>
689 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
690 * <p>
691 * If the field is not a {@code ChronoField}, then the result of this method
692 * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
693 * passing {@code this} as the argument. In this case, the field determines
694 * whether and how to adjust the instant.
695 * <p>
696 * This instance is immutable and unaffected by this method call.
697 *
698 * @param field the field to set in the result, not null
699 * @param newValue the new value of the field in the result
700 * @return an {@code Instant} based on {@code this} with the specified field set, not null
701 * @throws DateTimeException if the field cannot be set
702 * @throws UnsupportedTemporalTypeException if the field is not supported
703 * @throws ArithmeticException if numeric overflow occurs
704 */
705 @Override
706 public Instant with(TemporalField field, long newValue) {
707 if (field instanceof ChronoField chronoField) {
708 chronoField.checkValidValue(newValue);
709 return switch (chronoField) {
710 case MILLI_OF_SECOND -> {
711 int nval = (int) newValue * 1000_000;
712 yield nval != nanos ? create(seconds, nval) : this;
713 }
714 case MICRO_OF_SECOND -> {
715 int nval = (int) newValue * 1000;
716 yield nval != nanos ? create(seconds, nval) : this;
717 }
718 case NANO_OF_SECOND -> newValue != nanos ? create(seconds, (int) newValue) : this;
719 case INSTANT_SECONDS -> newValue != seconds ? create(newValue, nanos) : this;
720 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
721 };
722 }
723 return field.adjustInto(this, newValue);
724 }
725
726 //-----------------------------------------------------------------------
727 /**
728 * Returns a copy of this {@code Instant} truncated to the specified unit.
729 * <p>
730 * Truncating the instant returns a copy of the original with fields
731 * smaller than the specified unit set to zero.
732 * The fields are calculated on the basis of using a UTC offset as seen
733 * in {@code toString}.
734 * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will
735 * round down to the nearest minute, setting the seconds and nanoseconds to zero.
736 * <p>
737 * The unit must have a {@linkplain TemporalUnit#getDuration() duration}
738 * that divides into the length of a standard day without remainder.
739 * This includes all supplied time units on {@link ChronoUnit} and
740 * {@link ChronoUnit#DAYS DAYS}. Other units throw an exception.
741 * <p>
742 * This instance is immutable and unaffected by this method call.
743 *
744 * @param unit the unit to truncate to, not null
745 * @return an {@code Instant} based on this instant with the time truncated, not null
746 * @throws DateTimeException if the unit is invalid for truncation
747 * @throws UnsupportedTemporalTypeException if the unit is not supported
748 */
749 public Instant truncatedTo(TemporalUnit unit) {
750 if (unit == ChronoUnit.NANOS) {
751 return this;
752 }
753 Duration unitDur = unit.getDuration();
754 if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) {
755 throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
756 }
757 long dur = unitDur.toNanos();
758 if ((LocalTime.NANOS_PER_DAY % dur) != 0) {
759 throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
760 }
761 long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos;
762 long result = Math.floorDiv(nod, dur) * dur;
763 return plusNanos(result - nod);
764 }
765
766 //-----------------------------------------------------------------------
767 /**
768 * Returns a copy of this instant with the specified amount added.
769 * <p>
770 * This returns an {@code Instant}, based on this one, with the specified amount added.
771 * The amount is typically {@link Duration} but may be any other type implementing
772 * the {@link TemporalAmount} interface.
773 * <p>
774 * The calculation is delegated to the amount object by calling
775 * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free
776 * to implement the addition in any way it wishes, however it typically
777 * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation
778 * of the amount implementation to determine if it can be successfully added.
779 * <p>
780 * This instance is immutable and unaffected by this method call.
781 *
782 * @param amountToAdd the amount to add, not null
783 * @return an {@code Instant} based on this instant with the addition made, not null
784 * @throws DateTimeException if the addition cannot be made
785 * @throws ArithmeticException if numeric overflow occurs
786 */
787 @Override
788 public Instant plus(TemporalAmount amountToAdd) {
789 return (Instant) amountToAdd.addTo(this);
790 }
791
792 /**
793 * Returns a copy of this instant with the specified amount added.
794 * <p>
795 * This returns an {@code Instant}, based on this one, with the amount
796 * in terms of the unit added. If it is not possible to add the amount, because the
797 * unit is not supported or for some other reason, an exception is thrown.
798 * <p>
799 * If the field is a {@link ChronoUnit} then the addition is implemented here.
800 * The supported fields behave as follows:
801 * <ul>
802 * <li>{@code NANOS} -
803 * Returns an {@code Instant} with the specified number of nanoseconds added.
804 * This is equivalent to {@link #plusNanos(long)}.
805 * <li>{@code MICROS} -
806 * Returns an {@code Instant} with the specified number of microseconds added.
807 * This is equivalent to {@link #plusNanos(long)} with the amount
808 * multiplied by 1,000.
809 * <li>{@code MILLIS} -
810 * Returns an {@code Instant} with the specified number of milliseconds added.
811 * This is equivalent to {@link #plusNanos(long)} with the amount
812 * multiplied by 1,000,000.
813 * <li>{@code SECONDS} -
814 * Returns an {@code Instant} with the specified number of seconds added.
815 * This is equivalent to {@link #plusSeconds(long)}.
816 * <li>{@code MINUTES} -
817 * Returns an {@code Instant} with the specified number of minutes added.
818 * This is equivalent to {@link #plusSeconds(long)} with the amount
819 * multiplied by 60.
820 * <li>{@code HOURS} -
821 * Returns an {@code Instant} with the specified number of hours added.
822 * This is equivalent to {@link #plusSeconds(long)} with the amount
823 * multiplied by 3,600.
824 * <li>{@code HALF_DAYS} -
825 * Returns an {@code Instant} with the specified number of half-days added.
826 * This is equivalent to {@link #plusSeconds(long)} with the amount
827 * multiplied by 43,200 (12 hours).
828 * <li>{@code DAYS} -
829 * Returns an {@code Instant} with the specified number of days added.
830 * This is equivalent to {@link #plusSeconds(long)} with the amount
831 * multiplied by 86,400 (24 hours).
832 * </ul>
833 * <p>
834 * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}.
835 * <p>
836 * If the field is not a {@code ChronoUnit}, then the result of this method
837 * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
838 * passing {@code this} as the argument. In this case, the unit determines
839 * whether and how to perform the addition.
840 * <p>
841 * This instance is immutable and unaffected by this method call.
842 *
843 * @param amountToAdd the amount of the unit to add to the result, may be negative
844 * @param unit the unit of the amount to add, not null
845 * @return an {@code Instant} based on this instant with the specified amount added, not null
846 * @throws DateTimeException if the addition cannot be made
847 * @throws UnsupportedTemporalTypeException if the unit is not supported
848 * @throws ArithmeticException if numeric overflow occurs
849 */
850 @Override
851 public Instant plus(long amountToAdd, TemporalUnit unit) {
852 if (unit instanceof ChronoUnit chronoUnit) {
853 return switch (chronoUnit) {
854 case NANOS -> plusNanos(amountToAdd);
855 case MICROS -> plus(amountToAdd / 1000_000, (amountToAdd % 1000_000) * 1000);
856 case MILLIS -> plusMillis(amountToAdd);
857 case SECONDS -> plusSeconds(amountToAdd);
858 case MINUTES -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_MINUTE));
859 case HOURS -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_HOUR));
860 case HALF_DAYS -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2));
861 case DAYS -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY));
862 default -> throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
863 };
864 }
865 return unit.addTo(this, amountToAdd);
866 }
867
868 //-----------------------------------------------------------------------
869 /**
870 * Returns a copy of this instant with the specified duration in seconds added.
871 * <p>
872 * This instance is immutable and unaffected by this method call.
873 *
874 * @param secondsToAdd the seconds to add, positive or negative
875 * @return an {@code Instant} based on this instant with the specified seconds added, not null
876 * @throws DateTimeException if the result exceeds the maximum or minimum instant
877 * @throws ArithmeticException if numeric overflow occurs
878 */
879 public Instant plusSeconds(long secondsToAdd) {
880 if (secondsToAdd == 0) {
881 return this;
882 }
883 long epochSec = Math.addExact(seconds, secondsToAdd);
884 return create(epochSec, nanos);
885 }
886
887 /**
888 * Returns a copy of this instant with the specified duration in milliseconds added.
889 * <p>
890 * This instance is immutable and unaffected by this method call.
891 *
892 * @param millisToAdd the milliseconds to add, positive or negative
893 * @return an {@code Instant} based on this instant with the specified milliseconds added, not null
894 * @throws DateTimeException if the result exceeds the maximum or minimum instant
895 * @throws ArithmeticException if numeric overflow occurs
896 */
897 public Instant plusMillis(long millisToAdd) {
898 return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000);
899 }
900
901 /**
902 * Returns a copy of this instant with the specified duration in nanoseconds added.
903 * <p>
904 * This instance is immutable and unaffected by this method call.
905 *
906 * @param nanosToAdd the nanoseconds to add, positive or negative
907 * @return an {@code Instant} based on this instant with the specified nanoseconds added, not null
908 * @throws DateTimeException if the result exceeds the maximum or minimum instant
909 * @throws ArithmeticException if numeric overflow occurs
910 */
911 public Instant plusNanos(long nanosToAdd) {
912 return plus(0, nanosToAdd);
913 }
914
915 /**
916 * Returns a copy of this instant with the specified duration added.
917 * <p>
918 * This instance is immutable and unaffected by this method call.
919 *
920 * @param secondsToAdd the seconds to add, positive or negative
921 * @param nanosToAdd the nanos to add, positive or negative
922 * @return an {@code Instant} based on this instant with the specified seconds added, not null
923 * @throws DateTimeException if the result exceeds the maximum or minimum instant
924 * @throws ArithmeticException if numeric overflow occurs
925 */
926 private Instant plus(long secondsToAdd, long nanosToAdd) {
927 if ((secondsToAdd | nanosToAdd) == 0) {
928 return this;
929 }
930 long epochSec = Math.addExact(seconds, secondsToAdd);
931 epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND);
932 nanosToAdd = nanosToAdd % NANOS_PER_SECOND;
933 long nanoAdjustment = nanos + nanosToAdd; // safe int+NANOS_PER_SECOND
934 return ofEpochSecond(epochSec, nanoAdjustment);
935 }
936
937 //-----------------------------------------------------------------------
938 /**
939 * Returns a copy of this instant with the specified amount subtracted.
940 * <p>
941 * This returns an {@code Instant}, based on this one, with the specified amount subtracted.
942 * The amount is typically {@link Duration} but may be any other type implementing
943 * the {@link TemporalAmount} interface.
944 * <p>
945 * The calculation is delegated to the amount object by calling
946 * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free
947 * to implement the subtraction in any way it wishes, however it typically
948 * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation
949 * of the amount implementation to determine if it can be successfully subtracted.
950 * <p>
951 * This instance is immutable and unaffected by this method call.
952 *
953 * @param amountToSubtract the amount to subtract, not null
954 * @return an {@code Instant} based on this instant with the subtraction made, not null
955 * @throws DateTimeException if the subtraction cannot be made
956 * @throws ArithmeticException if numeric overflow occurs
957 */
958 @Override
959 public Instant minus(TemporalAmount amountToSubtract) {
960 return (Instant) amountToSubtract.subtractFrom(this);
961 }
962
963 /**
964 * Returns a copy of this instant with the specified amount subtracted.
965 * <p>
966 * This returns an {@code Instant}, based on this one, with the amount
967 * in terms of the unit subtracted. If it is not possible to subtract the amount,
968 * because the unit is not supported or for some other reason, an exception is thrown.
969 * <p>
970 * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated.
971 * See that method for a full description of how addition, and thus subtraction, works.
972 * <p>
973 * This instance is immutable and unaffected by this method call.
974 *
975 * @param amountToSubtract the amount of the unit to subtract from the result, may be negative
976 * @param unit the unit of the amount to subtract, not null
977 * @return an {@code Instant} based on this instant with the specified amount subtracted, not null
978 * @throws DateTimeException if the subtraction cannot be made
979 * @throws UnsupportedTemporalTypeException if the unit is not supported
980 * @throws ArithmeticException if numeric overflow occurs
981 */
982 @Override
983 public Instant minus(long amountToSubtract, TemporalUnit unit) {
984 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
985 }
986
987 //-----------------------------------------------------------------------
988 /**
989 * Returns a copy of this instant with the specified duration in seconds subtracted.
990 * <p>
991 * This instance is immutable and unaffected by this method call.
992 *
993 * @param secondsToSubtract the seconds to subtract, positive or negative
994 * @return an {@code Instant} based on this instant with the specified seconds subtracted, not null
995 * @throws DateTimeException if the result exceeds the maximum or minimum instant
996 * @throws ArithmeticException if numeric overflow occurs
997 */
998 public Instant minusSeconds(long secondsToSubtract) {
999 if (secondsToSubtract == Long.MIN_VALUE) {
1000 return plusSeconds(Long.MAX_VALUE).plusSeconds(1);
1001 }
1002 return plusSeconds(-secondsToSubtract);
1003 }
1004
1005 /**
1006 * Returns a copy of this instant with the specified duration in milliseconds subtracted.
1007 * <p>
1008 * This instance is immutable and unaffected by this method call.
1009 *
1010 * @param millisToSubtract the milliseconds to subtract, positive or negative
1011 * @return an {@code Instant} based on this instant with the specified milliseconds subtracted, not null
1012 * @throws DateTimeException if the result exceeds the maximum or minimum instant
1013 * @throws ArithmeticException if numeric overflow occurs
1014 */
1015 public Instant minusMillis(long millisToSubtract) {
1016 if (millisToSubtract == Long.MIN_VALUE) {
1017 return plusMillis(Long.MAX_VALUE).plusMillis(1);
1018 }
1019 return plusMillis(-millisToSubtract);
1020 }
1021
1022 /**
1023 * Returns a copy of this instant with the specified duration in nanoseconds subtracted.
1024 * <p>
1025 * This instance is immutable and unaffected by this method call.
1026 *
1027 * @param nanosToSubtract the nanoseconds to subtract, positive or negative
1028 * @return an {@code Instant} based on this instant with the specified nanoseconds subtracted, not null
1029 * @throws DateTimeException if the result exceeds the maximum or minimum instant
1030 * @throws ArithmeticException if numeric overflow occurs
1031 */
1032 public Instant minusNanos(long nanosToSubtract) {
1033 if (nanosToSubtract == Long.MIN_VALUE) {
1034 return plusNanos(Long.MAX_VALUE).plusNanos(1);
1035 }
1036 return plusNanos(-nanosToSubtract);
1037 }
1038
1039 //-------------------------------------------------------------------------
1040 /**
1041 * Queries this instant using the specified query.
1042 * <p>
1043 * This queries this instant using the specified query strategy object.
1044 * The {@code TemporalQuery} object defines the logic to be used to
1045 * obtain the result. Read the documentation of the query to understand
1046 * what the result of this method will be.
1047 * <p>
1048 * The result of this method is obtained by invoking the
1049 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
1050 * specified query passing {@code this} as the argument.
1051 *
1052 * @param <R> the type of the result
1053 * @param query the query to invoke, not null
1054 * @return the query result, null may be returned (defined by the query)
1055 * @throws DateTimeException if unable to query (defined by the query)
1056 * @throws ArithmeticException if numeric overflow occurs (defined by the query)
1057 */
1058 @SuppressWarnings("unchecked")
1059 @Override
1060 public <R> R query(TemporalQuery<R> query) {
1061 if (query == TemporalQueries.precision()) {
1062 return (R) NANOS;
1063 }
1064 // inline TemporalAccessor.super.query(query) as an optimization
1065 if (query == TemporalQueries.chronology() || query == TemporalQueries.zoneId() ||
1066 query == TemporalQueries.zone() || query == TemporalQueries.offset() ||
1067 query == TemporalQueries.localDate() || query == TemporalQueries.localTime()) {
1068 return null;
1069 }
1070 return query.queryFrom(this);
1071 }
1072
1073 /**
1074 * Adjusts the specified temporal object to have this instant.
1075 * <p>
1076 * This returns a temporal object of the same observable type as the input
1077 * with the instant changed to be the same as this.
1078 * <p>
1079 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
1080 * twice, passing {@link ChronoField#INSTANT_SECONDS} and
1081 * {@link ChronoField#NANO_OF_SECOND} as the fields.
1082 * <p>
1083 * In most cases, it is clearer to reverse the calling pattern by using
1084 * {@link Temporal#with(TemporalAdjuster)}:
1085 * <pre>
1086 * // these two lines are equivalent, but the second approach is recommended
1087 * temporal = thisInstant.adjustInto(temporal);
1088 * temporal = temporal.with(thisInstant);
1089 * </pre>
1090 * <p>
1091 * This instance is immutable and unaffected by this method call.
1092 *
1093 * @param temporal the target object to be adjusted, not null
1094 * @return the adjusted object, not null
1095 * @throws DateTimeException if unable to make the adjustment
1096 * @throws ArithmeticException if numeric overflow occurs
1097 */
1098 @Override
1099 public Temporal adjustInto(Temporal temporal) {
1100 return temporal.with(INSTANT_SECONDS, seconds).with(NANO_OF_SECOND, nanos);
1101 }
1102
1103 /**
1104 * Calculates the amount of time until another instant in terms of the specified unit.
1105 * <p>
1106 * This calculates the amount of time between two {@code Instant}
1107 * objects in terms of a single {@code TemporalUnit}.
1108 * The start and end points are {@code this} and the specified instant.
1109 * The result will be negative if the end is before the start.
1110 * The calculation returns a whole number, representing the number of
1111 * complete units between the two instants.
1112 * The {@code Temporal} passed to this method is converted to a
1113 * {@code Instant} using {@link #from(TemporalAccessor)}.
1114 * For example, the amount in seconds between two dates can be calculated
1115 * using {@code startInstant.until(endInstant, SECONDS)}.
1116 * <p>
1117 * There are two equivalent ways of using this method.
1118 * The first is to invoke this method.
1119 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
1120 * <pre>
1121 * // these two lines are equivalent
1122 * amount = start.until(end, SECONDS);
1123 * amount = SECONDS.between(start, end);
1124 * </pre>
1125 * The choice should be made based on which makes the code more readable.
1126 * <p>
1127 * The calculation is implemented in this method for {@link ChronoUnit}.
1128 * The units {@code NANOS}, {@code MICROS}, {@code MILLIS}, {@code SECONDS},
1129 * {@code MINUTES}, {@code HOURS}, {@code HALF_DAYS} and {@code DAYS}
1130 * are supported. Other {@code ChronoUnit} values will throw an exception.
1131 * <p>
1132 * If the unit is not a {@code ChronoUnit}, then the result of this method
1133 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
1134 * passing {@code this} as the first argument and the converted input temporal
1135 * as the second argument.
1136 * <p>
1137 * This instance is immutable and unaffected by this method call.
1138 *
1139 * @param endExclusive the end date, exclusive, which is converted to an {@code Instant}, not null
1140 * @param unit the unit to measure the amount in, not null
1141 * @return the amount of time between this instant and the end instant
1142 * @throws DateTimeException if the amount cannot be calculated, or the end
1143 * temporal cannot be converted to an {@code Instant}
1144 * @throws UnsupportedTemporalTypeException if the unit is not supported
1145 * @throws ArithmeticException if numeric overflow occurs
1146 */
1147 @Override
1148 public long until(Temporal endExclusive, TemporalUnit unit) {
1149 Instant end = Instant.from(endExclusive);
1150 if (unit instanceof ChronoUnit chronoUnit) {
1151 return switch (chronoUnit) {
1152 case NANOS -> nanosUntil(end);
1153 case MICROS -> microsUntil(end);
1154 case MILLIS -> millisUntil(end);
1155 case SECONDS -> secondsUntil(end);
1156 case MINUTES -> secondsUntil(end) / SECONDS_PER_MINUTE;
1157 case HOURS -> secondsUntil(end) / SECONDS_PER_HOUR;
1158 case HALF_DAYS -> secondsUntil(end) / (12 * SECONDS_PER_HOUR);
1159 case DAYS -> secondsUntil(end) / (SECONDS_PER_DAY);
1160 default -> throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
1161 };
1162 }
1163 return unit.between(this, end);
1164 }
1165
1166 /**
1167 * Calculates the {@code Duration} until another {@code Instant}.
1168 * <p>
1169 * The start and end points are {@code this} and the specified instant.
1170 * The result will be negative if the end is before the start. Calling
1171 * this method is equivalent to
1172 * {@link Duration#between(Temporal, Temporal) Duration.between(this,
1173 * endExclusive)}.
1174 * <p>
1175 * This instance is immutable and unaffected by this method call.
1176 *
1177 * @param endExclusive the end {@code Instant}, exclusive, not null
1178 * @return the {@code Duration} from this {@code Instant} until the
1179 * specified {@code endExclusive} {@code Instant}
1180 * @see Duration#between(Temporal, Temporal)
1181 * @since 23
1182 */
1183 public Duration until(Instant endExclusive) {
1184 Objects.requireNonNull(endExclusive, "endExclusive");
1185 long secsDiff = Math.subtractExact(endExclusive.seconds, seconds);
1186 int nanosDiff = endExclusive.nanos - nanos;
1187 return Duration.ofSeconds(secsDiff, nanosDiff);
1188 }
1189
1190 private long nanosUntil(Instant end) {
1191 long secsDiff = Math.subtractExact(end.seconds, seconds);
1192 long totalNanos = Math.multiplyExact(secsDiff, NANOS_PER_SECOND);
1193 return Math.addExact(totalNanos, end.nanos - nanos);
1194 }
1195
1196 private long microsUntil(Instant end) {
1197 long microsDiff = Math.multiplyExact(end.seconds - seconds, MICROS_PER_SECOND);
1198 int nanosDiff = end.nanos - nanos;
1199 if (microsDiff > 0 && nanosDiff < 0) {
1200 return (microsDiff - 1_000_000) + (nanosDiff + 1_000_000_000) / 1_000;
1201 } else if (microsDiff < 0 && nanosDiff > 0) {
1202 return (microsDiff + 1_000_000) + (nanosDiff - 1_000_000_000) / 1_000;
1203 }
1204 return Math.addExact(microsDiff, nanosDiff / 1_000);
1205 }
1206
1207 private long millisUntil(Instant end) {
1208 long millisDiff = Math.multiplyExact(end.seconds - seconds, MILLIS_PER_SECOND);
1209 int nanosDiff = end.nanos - nanos;
1210 if (millisDiff > 0 && nanosDiff < 0) {
1211 return (millisDiff - 1_000) + (nanosDiff + 1_000_000_000) / 1_000_000;
1212 } else if (millisDiff < 0 && nanosDiff > 0) {
1213 return (millisDiff + 1_000) + (nanosDiff - 1_000_000_000) / 1_000_000;
1214 }
1215 return Math.addExact(millisDiff, nanosDiff / 1_000_000);
1216 }
1217
1218 private long secondsUntil(Instant end) {
1219 long secsDiff = Math.subtractExact(end.seconds, seconds);
1220 int nanosDiff = end.nanos - nanos;
1221 if (secsDiff > 0 && nanosDiff < 0) {
1222 secsDiff--;
1223 } else if (secsDiff < 0 && nanosDiff > 0) {
1224 secsDiff++;
1225 }
1226 return secsDiff;
1227 }
1228
1229 //-----------------------------------------------------------------------
1230 /**
1231 * Combines this instant with an offset to create an {@code OffsetDateTime}.
1232 * <p>
1233 * This returns an {@code OffsetDateTime} formed from this instant at the
1234 * specified offset from UTC/Greenwich. An exception will be thrown if the
1235 * instant is too large to fit into an offset date-time.
1236 * <p>
1237 * This method is equivalent to
1238 * {@link OffsetDateTime#ofInstant(Instant, ZoneId) OffsetDateTime.ofInstant(this, offset)}.
1239 *
1240 * @param offset the offset to combine with, not null
1241 * @return the offset date-time formed from this instant and the specified offset, not null
1242 * @throws DateTimeException if the result exceeds the supported range
1243 */
1244 public OffsetDateTime atOffset(ZoneOffset offset) {
1245 return OffsetDateTime.ofInstant(this, offset);
1246 }
1247
1248 /**
1249 * Combines this instant with a time-zone to create a {@code ZonedDateTime}.
1250 * <p>
1251 * This returns an {@code ZonedDateTime} formed from this instant at the
1252 * specified time-zone. An exception will be thrown if the instant is too
1253 * large to fit into a zoned date-time.
1254 * <p>
1255 * This method is equivalent to
1256 * {@link ZonedDateTime#ofInstant(Instant, ZoneId) ZonedDateTime.ofInstant(this, zone)}.
1257 *
1258 * @param zone the zone to combine with, not null
1259 * @return the zoned date-time formed from this instant and the specified zone, not null
1260 * @throws DateTimeException if the result exceeds the supported range
1261 */
1262 public ZonedDateTime atZone(ZoneId zone) {
1263 return ZonedDateTime.ofInstant(this, zone);
1264 }
1265
1266 //-----------------------------------------------------------------------
1267 /**
1268 * Converts this instant to the number of milliseconds from the epoch
1269 * of 1970-01-01T00:00:00Z.
1270 * <p>
1271 * If this instant represents a point on the time-line too far in the future
1272 * or past to fit in a {@code long} milliseconds, then an exception is thrown.
1273 * <p>
1274 * If this instant has greater than millisecond precision, then the conversion
1275 * will drop any excess precision information as though the amount in nanoseconds
1276 * was subject to integer division by one million.
1277 *
1278 * @return the number of milliseconds since the epoch of 1970-01-01T00:00:00Z
1279 * @throws ArithmeticException if numeric overflow occurs
1280 */
1281 public long toEpochMilli() {
1282 if (seconds < 0 && nanos > 0) {
1283 long millis = Math.multiplyExact(seconds+1, 1000);
1284 long adjustment = nanos / 1000_000 - 1000;
1285 return Math.addExact(millis, adjustment);
1286 } else {
1287 long millis = Math.multiplyExact(seconds, 1000);
1288 return Math.addExact(millis, nanos / 1000_000);
1289 }
1290 }
1291
1292 //-----------------------------------------------------------------------
1293 /**
1294 * Compares this instant to the specified instant.
1295 * <p>
1296 * The comparison is based on the time-line position of the instants.
1297 * It is "consistent with equals", as defined by {@link Comparable}.
1298 *
1299 * @param otherInstant the other instant to compare to, not null
1300 * @return the comparator value, that is less than zero if this instant is before {@code otherInstant},
1301 * zero if they are equal, or greater than zero if this instant is after {@code otherInstant}
1302 * @throws NullPointerException if otherInstant is null
1303 * @see #isBefore
1304 * @see #isAfter
1305 */
1306 @Override
1307 public int compareTo(Instant otherInstant) {
1308 int cmp = Long.compare(seconds, otherInstant.seconds);
1309 if (cmp != 0) {
1310 return cmp;
1311 }
1312 return nanos - otherInstant.nanos;
1313 }
1314
1315 /**
1316 * Checks if this instant is after the specified instant.
1317 * <p>
1318 * The comparison is based on the time-line position of the instants.
1319 *
1320 * @param otherInstant the other instant to compare to, not null
1321 * @return true if this instant is after the specified instant
1322 * @throws NullPointerException if otherInstant is null
1323 */
1324 public boolean isAfter(Instant otherInstant) {
1325 return compareTo(otherInstant) > 0;
1326 }
1327
1328 /**
1329 * Checks if this instant is before the specified instant.
1330 * <p>
1331 * The comparison is based on the time-line position of the instants.
1332 *
1333 * @param otherInstant the other instant to compare to, not null
1334 * @return true if this instant is before the specified instant
1335 * @throws NullPointerException if otherInstant is null
1336 */
1337 public boolean isBefore(Instant otherInstant) {
1338 return compareTo(otherInstant) < 0;
1339 }
1340
1341 //-----------------------------------------------------------------------
1342 /**
1343 * Checks if this instant is equal to the specified instant.
1344 * <p>
1345 * The comparison is based on the time-line position of the instants.
1346 *
1347 * @param other the other instant, null returns false
1348 * @return true if the other instant is equal to this one
1349 */
1350 @Override
1351 public boolean equals(Object other) {
1352 if (this == other) {
1353 return true;
1354 }
1355 return (other instanceof Instant otherInstant)
1356 && this.seconds == otherInstant.seconds
1357 && this.nanos == otherInstant.nanos;
1358 }
1359
1360 /**
1361 * Returns a hash code for this instant.
1362 *
1363 * @return a suitable hash code
1364 */
1365 @Override
1366 public int hashCode() {
1367 return ((int) (seconds ^ (seconds >>> 32))) + 51 * nanos;
1368 }
1369
1370 //-----------------------------------------------------------------------
1371 /**
1372 * A string representation of this instant using ISO-8601 representation.
1373 * <p>
1374 * The format used is the same as {@link DateTimeFormatter#ISO_INSTANT}.
1375 *
1376 * @return an ISO-8601 representation of this instant, not null
1377 */
1378 @Override
1379 public String toString() {
1380 return DateTimeFormatter.ISO_INSTANT.format(this);
1381 }
1382
1383 // -----------------------------------------------------------------------
1384 /**
1385 * Writes the object using a
1386 * <a href="{@docRoot}/serialized-form.html#java.time.Ser">dedicated serialized form</a>.
1387 * @serialData
1388 * <pre>
1389 * out.writeByte(2); // identifies an Instant
1390 * out.writeLong(seconds);
1391 * out.writeInt(nanos);
1392 * </pre>
1393 *
1394 * @return the instance of {@code Ser}, not null
1395 */
1396 @java.io.Serial
1397 private Object writeReplace() {
1398 return new Ser(Ser.INSTANT_TYPE, this);
1399 }
1400
1401 /**
1402 * Defend against malicious streams.
1403 *
1404 * @param s the stream to read
1405 * @throws InvalidObjectException always
1406 */
1407 @java.io.Serial
1408 private void readObject(ObjectInputStream s) throws InvalidObjectException {
1409 throw new InvalidObjectException("Deserialization via serialization delegate");
1410 }
1411
1412 void writeExternal(DataOutput out) throws IOException {
1413 out.writeLong(seconds);
1414 out.writeInt(nanos);
1415 }
1416
1417 static Instant readExternal(DataInput in) throws IOException {
1418 long seconds = in.readLong();
1419 int nanos = in.readInt();
1420 return Instant.ofEpochSecond(seconds, nanos);
1421 }
1422
1423 }