1 /*
2 * Copyright (c) 2012, 2021, 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 public final class Instant
211 implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable {
212
213 /**
214 * Constant for the 1970-01-01T00:00:00Z epoch instant.
215 */
216 public static final Instant EPOCH = new Instant(0, 0);
217 /**
218 * The minimum supported epoch second.
219 */
220 private static final long MIN_SECOND = -31557014167219200L;
221 /**
222 * The maximum supported epoch second.
223 */
224 private static final long MAX_SECOND = 31556889864403199L;
225 /**
226 * The minimum supported {@code Instant}, '-1000000000-01-01T00:00Z'.
227 * This could be used by an application as a "far past" instant.
228 * <p>
229 * This is one year earlier than the minimum {@code LocalDateTime}.
230 * This provides sufficient values to handle the range of {@code ZoneOffset}
231 * which affect the instant in addition to the local date-time.
232 * The value is also chosen such that the value of the year fits in
233 * an {@code int}.
234 */
235 public static final Instant MIN = Instant.ofEpochSecond(MIN_SECOND, 0);
236 /**
237 * The maximum supported {@code Instant}, '1000000000-12-31T23:59:59.999999999Z'.
238 * This could be used by an application as a "far future" instant.
239 * <p>
240 * This is one year later than the maximum {@code LocalDateTime}.
241 * This provides sufficient values to handle the range of {@code ZoneOffset}
242 * which affect the instant in addition to the local date-time.
243 * The value is also chosen such that the value of the year fits in
244 * an {@code int}.
245 */
246 public static final Instant MAX = Instant.ofEpochSecond(MAX_SECOND, 999_999_999);
247
248 /**
249 * Serialization version.
250 */
251 @java.io.Serial
252 private static final long serialVersionUID = -665713676816604388L;
253
254 /**
255 * The number of seconds from the epoch of 1970-01-01T00:00:00Z.
256 */
257 private final long seconds;
258 /**
259 * The number of nanoseconds, later along the time-line, from the seconds field.
260 * This is always positive, and never exceeds 999,999,999.
261 */
262 private final int nanos;
263
264 //-----------------------------------------------------------------------
265 /**
266 * Obtains the current instant from the system clock.
267 * <p>
268 * This will query the {@link Clock#systemUTC() system UTC clock} to
269 * obtain the current instant.
270 * <p>
271 * Using this method will prevent the ability to use an alternate time-source for
272 * testing because the clock is effectively hard-coded.
273 *
274 * @return the current instant using the system clock, not null
275 */
276 public static Instant now() {
277 return Clock.currentInstant();
278 }
279
280 /**
281 * Obtains the current instant from the specified clock.
282 * <p>
283 * This will query the specified clock to obtain the current time.
284 * <p>
285 * Using this method allows the use of an alternate clock for testing.
286 * The alternate clock may be introduced using {@link Clock dependency injection}.
287 *
288 * @param clock the clock to use, not null
289 * @return the current instant, not null
290 */
291 public static Instant now(Clock clock) {
292 Objects.requireNonNull(clock, "clock");
293 return clock.instant();
294 }
295
296 //-----------------------------------------------------------------------
297 /**
298 * Obtains an instance of {@code Instant} using seconds from the
299 * epoch of 1970-01-01T00:00:00Z.
300 * <p>
301 * The nanosecond field is set to zero.
302 *
303 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
304 * @return an instant, not null
305 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
306 */
307 public static Instant ofEpochSecond(long epochSecond) {
308 return create(epochSecond, 0);
309 }
310
311 /**
312 * Obtains an instance of {@code Instant} using seconds from the
313 * epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.
314 * <p>
315 * This method allows an arbitrary number of nanoseconds to be passed in.
316 * The factory will alter the values of the second and nanosecond in order
317 * to ensure that the stored nanosecond is in the range 0 to 999,999,999.
318 * For example, the following will result in exactly the same instant:
319 * <pre>
320 * Instant.ofEpochSecond(3, 1);
321 * Instant.ofEpochSecond(4, -999_999_999);
322 * Instant.ofEpochSecond(2, 1000_000_001);
323 * </pre>
324 *
325 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
326 * @param nanoAdjustment the nanosecond adjustment to the number of seconds, positive or negative
327 * @return an instant, not null
328 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
329 * @throws ArithmeticException if numeric overflow occurs
330 */
331 public static Instant ofEpochSecond(long epochSecond, long nanoAdjustment) {
332 long secs = Math.addExact(epochSecond, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND));
333 int nos = (int)Math.floorMod(nanoAdjustment, NANOS_PER_SECOND);
334 return create(secs, nos);
335 }
336
337 /**
338 * Obtains an instance of {@code Instant} using milliseconds from the
339 * epoch of 1970-01-01T00:00:00Z.
340 * <p>
341 * The seconds and nanoseconds are extracted from the specified milliseconds.
342 *
343 * @param epochMilli the number of milliseconds from 1970-01-01T00:00:00Z
344 * @return an instant, not null
345 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
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 super();
429 this.seconds = epochSecond;
430 this.nanos = nanos;
431 }
432
433 //-----------------------------------------------------------------------
434 /**
435 * Checks if the specified field is supported.
436 * <p>
437 * This checks if this instant can be queried for the specified field.
438 * If false, then calling the {@link #range(TemporalField) range},
439 * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
440 * methods will throw an exception.
441 * <p>
442 * If the field is a {@link ChronoField} then the query is implemented here.
443 * The supported fields are:
444 * <ul>
445 * <li>{@code NANO_OF_SECOND}
446 * <li>{@code MICRO_OF_SECOND}
447 * <li>{@code MILLI_OF_SECOND}
448 * <li>{@code INSTANT_SECONDS}
449 * </ul>
450 * All other {@code ChronoField} instances will return false.
451 * <p>
452 * If the field is not a {@code ChronoField}, then the result of this method
453 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
454 * passing {@code this} as the argument.
455 * Whether the field is supported is determined by the field.
456 *
457 * @param field the field to check, null returns false
458 * @return true if the field is supported on this instant, false if not
459 */
460 @Override
461 public boolean isSupported(TemporalField field) {
462 if (field instanceof ChronoField) {
463 return field == INSTANT_SECONDS || field == NANO_OF_SECOND || field == MICRO_OF_SECOND || field == MILLI_OF_SECOND;
464 }
465 return field != null && field.isSupportedBy(this);
466 }
467
468 /**
469 * Checks if the specified unit is supported.
470 * <p>
471 * This checks if the specified unit can be added to, or subtracted from, this date-time.
472 * If false, then calling the {@link #plus(long, TemporalUnit)} and
473 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
474 * <p>
475 * If the unit is a {@link ChronoUnit} then the query is implemented here.
476 * The supported units are:
477 * <ul>
478 * <li>{@code NANOS}
479 * <li>{@code MICROS}
480 * <li>{@code MILLIS}
481 * <li>{@code SECONDS}
482 * <li>{@code MINUTES}
483 * <li>{@code HOURS}
484 * <li>{@code HALF_DAYS}
485 * <li>{@code DAYS}
486 * </ul>
487 * All other {@code ChronoUnit} instances will return false.
488 * <p>
489 * If the unit is not a {@code ChronoUnit}, then the result of this method
490 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
491 * passing {@code this} as the argument.
492 * Whether the unit is supported is determined by the unit.
493 *
494 * @param unit the unit to check, null returns false
495 * @return true if the unit can be added/subtracted, false if not
496 */
497 @Override
498 public boolean isSupported(TemporalUnit unit) {
499 if (unit instanceof ChronoUnit) {
500 return unit.isTimeBased() || unit == DAYS;
501 }
502 return unit != null && unit.isSupportedBy(this);
503 }
504
505 //-----------------------------------------------------------------------
506 /**
507 * Gets the range of valid values for the specified field.
508 * <p>
509 * The range object expresses the minimum and maximum valid values for a field.
510 * This instant is used to enhance the accuracy of the returned range.
511 * If it is not possible to return the range, because the field is not supported
512 * or for some other reason, an exception is thrown.
513 * <p>
514 * If the field is a {@link ChronoField} then the query is implemented here.
515 * The {@link #isSupported(TemporalField) supported fields} will return
516 * appropriate range instances.
517 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
518 * <p>
519 * If the field is not a {@code ChronoField}, then the result of this method
520 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
521 * passing {@code this} as the argument.
522 * Whether the range can be obtained is determined by the field.
523 *
524 * @param field the field to query the range for, not null
525 * @return the range of valid values for the field, not null
526 * @throws DateTimeException if the range for the field cannot be obtained
527 * @throws UnsupportedTemporalTypeException if the field is not supported
528 */
529 @Override // override for Javadoc
530 public ValueRange range(TemporalField field) {
531 return Temporal.super.range(field);
532 }
533
534 /**
535 * Gets the value of the specified field from this instant as an {@code int}.
536 * <p>
537 * This queries this instant for the value of the specified field.
538 * The returned value will always be within the valid range of values for the field.
539 * If it is not possible to return the value, because the field is not supported
540 * or for some other reason, an exception is thrown.
541 * <p>
542 * If the field is a {@link ChronoField} then the query is implemented here.
543 * The {@link #isSupported(TemporalField) supported fields} will return valid
544 * values based on this date-time, except {@code INSTANT_SECONDS} which is too
545 * large to fit in an {@code int} and throws a {@code DateTimeException}.
546 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
547 * <p>
548 * If the field is not a {@code ChronoField}, then the result of this method
549 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
550 * passing {@code this} as the argument. Whether the value can be obtained,
551 * and what the value represents, is determined by the field.
552 *
553 * @param field the field to get, not null
554 * @return the value for the field
555 * @throws DateTimeException if a value for the field cannot be obtained or
556 * the value is outside the range of valid values for the field
557 * @throws UnsupportedTemporalTypeException if the field is not supported or
558 * the range of values exceeds an {@code int}
559 * @throws ArithmeticException if numeric overflow occurs
560 */
561 @Override // override for Javadoc and performance
562 public int get(TemporalField field) {
563 if (field instanceof ChronoField chronoField) {
564 return switch (chronoField) {
565 case NANO_OF_SECOND -> nanos;
566 case MICRO_OF_SECOND -> nanos / 1000;
567 case MILLI_OF_SECOND -> nanos / 1000_000;
568 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
569 };
570 }
571 return range(field).checkValidIntValue(field.getFrom(this), field);
572 }
573
574 /**
575 * Gets the value of the specified field from this instant as a {@code long}.
576 * <p>
577 * This queries this instant for the value of the specified field.
578 * If it is not possible to return the value, because the field is not supported
579 * or for some other reason, an exception is thrown.
580 * <p>
581 * If the field is a {@link ChronoField} then the query is implemented here.
582 * The {@link #isSupported(TemporalField) supported fields} will return valid
583 * values based on this date-time.
584 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
585 * <p>
586 * If the field is not a {@code ChronoField}, then the result of this method
587 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
588 * passing {@code this} as the argument. Whether the value can be obtained,
589 * and what the value represents, is determined by the field.
590 *
591 * @param field the field to get, not null
592 * @return the value for the field
593 * @throws DateTimeException if a value for the field cannot be obtained
594 * @throws UnsupportedTemporalTypeException if the field is not supported
595 * @throws ArithmeticException if numeric overflow occurs
596 */
597 @Override
598 public long getLong(TemporalField field) {
599 if (field instanceof ChronoField chronoField) {
600 return switch (chronoField) {
601 case NANO_OF_SECOND -> nanos;
602 case MICRO_OF_SECOND -> nanos / 1000;
603 case MILLI_OF_SECOND -> nanos / 1000_000;
604 case INSTANT_SECONDS -> seconds;
605 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
606 };
607 }
608 return field.getFrom(this);
609 }
610
611 //-----------------------------------------------------------------------
612 /**
613 * Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
614 * <p>
615 * The epoch second count is a simple incrementing count of seconds where
616 * second 0 is 1970-01-01T00:00:00Z.
617 * The nanosecond part is returned by {@link #getNano}.
618 *
619 * @return the seconds from the epoch of 1970-01-01T00:00:00Z
620 */
621 public long getEpochSecond() {
622 return seconds;
623 }
624
625 /**
626 * Gets the number of nanoseconds, later along the time-line, from the start
627 * of the second.
628 * <p>
629 * The nanosecond-of-second value measures the total number of nanoseconds from
630 * the second returned by {@link #getEpochSecond}.
631 *
632 * @return the nanoseconds within the second, always positive, never exceeds 999,999,999
633 */
634 public int getNano() {
635 return nanos;
636 }
637
638 //-------------------------------------------------------------------------
639 /**
640 * Returns an adjusted copy of this instant.
641 * <p>
642 * This returns an {@code Instant}, based on this one, with the instant adjusted.
643 * The adjustment takes place using the specified adjuster strategy object.
644 * Read the documentation of the adjuster to understand what adjustment will be made.
645 * <p>
646 * The result of this method is obtained by invoking the
647 * {@link TemporalAdjuster#adjustInto(Temporal)} method on the
648 * specified adjuster passing {@code this} as the argument.
649 * <p>
650 * This instance is immutable and unaffected by this method call.
651 *
652 * @param adjuster the adjuster to use, not null
653 * @return an {@code Instant} based on {@code this} with the adjustment made, not null
654 * @throws DateTimeException if the adjustment cannot be made
655 * @throws ArithmeticException if numeric overflow occurs
656 */
657 @Override
658 public Instant with(TemporalAdjuster adjuster) {
659 return (Instant) adjuster.adjustInto(this);
660 }
661
662 /**
663 * Returns a copy of this instant with the specified field set to a new value.
664 * <p>
665 * This returns an {@code Instant}, based on this one, with the value
666 * for the specified field changed.
667 * If it is not possible to set the value, because the field is not supported or for
668 * some other reason, an exception is thrown.
669 * <p>
670 * If the field is a {@link ChronoField} then the adjustment is implemented here.
671 * The supported fields behave as follows:
672 * <ul>
673 * <li>{@code NANO_OF_SECOND} -
674 * Returns an {@code Instant} with the specified nano-of-second.
675 * The epoch-second will be unchanged.
676 * <li>{@code MICRO_OF_SECOND} -
677 * Returns an {@code Instant} with the nano-of-second replaced by the specified
678 * micro-of-second multiplied by 1,000. The epoch-second will be unchanged.
679 * <li>{@code MILLI_OF_SECOND} -
680 * Returns an {@code Instant} with the nano-of-second replaced by the specified
681 * milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged.
682 * <li>{@code INSTANT_SECONDS} -
683 * Returns an {@code Instant} with the specified epoch-second.
684 * The nano-of-second will be unchanged.
685 * </ul>
686 * <p>
687 * In all cases, if the new value is outside the valid range of values for the field
688 * then a {@code DateTimeException} will be thrown.
689 * <p>
690 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
691 * <p>
692 * If the field is not a {@code ChronoField}, then the result of this method
693 * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
694 * passing {@code this} as the argument. In this case, the field determines
695 * whether and how to adjust the instant.
696 * <p>
697 * This instance is immutable and unaffected by this method call.
698 *
699 * @param field the field to set in the result, not null
700 * @param newValue the new value of the field in the result
701 * @return an {@code Instant} based on {@code this} with the specified field set, not null
702 * @throws DateTimeException if the field cannot be set
703 * @throws UnsupportedTemporalTypeException if the field is not supported
704 * @throws ArithmeticException if numeric overflow occurs
705 */
706 @Override
707 public Instant with(TemporalField field, long newValue) {
708 if (field instanceof ChronoField chronoField) {
709 chronoField.checkValidValue(newValue);
710 return switch (chronoField) {
711 case MILLI_OF_SECOND -> {
712 int nval = (int) newValue * 1000_000;
713 yield nval != nanos ? create(seconds, nval) : this;
714 }
715 case MICRO_OF_SECOND -> {
716 int nval = (int) newValue * 1000;
717 yield nval != nanos ? create(seconds, nval) : this;
718 }
719 case NANO_OF_SECOND -> newValue != nanos ? create(seconds, (int) newValue) : this;
720 case INSTANT_SECONDS -> newValue != seconds ? create(newValue, nanos) : this;
721 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
722 };
723 }
724 return field.adjustInto(this, newValue);
725 }
726
727 //-----------------------------------------------------------------------
728 /**
729 * Returns a copy of this {@code Instant} truncated to the specified unit.
730 * <p>
731 * Truncating the instant returns a copy of the original with fields
732 * smaller than the specified unit set to zero.
733 * The fields are calculated on the basis of using a UTC offset as seen
734 * in {@code toString}.
735 * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will
736 * round down to the nearest minute, setting the seconds and nanoseconds to zero.
737 * <p>
738 * The unit must have a {@linkplain TemporalUnit#getDuration() duration}
739 * that divides into the length of a standard day without remainder.
740 * This includes all supplied time units on {@link ChronoUnit} and
741 * {@link ChronoUnit#DAYS DAYS}. Other units throw an exception.
742 * <p>
743 * This instance is immutable and unaffected by this method call.
744 *
745 * @param unit the unit to truncate to, not null
746 * @return an {@code Instant} based on this instant with the time truncated, not null
747 * @throws DateTimeException if the unit is invalid for truncation
748 * @throws UnsupportedTemporalTypeException if the unit is not supported
749 */
750 public Instant truncatedTo(TemporalUnit unit) {
751 if (unit == ChronoUnit.NANOS) {
752 return this;
753 }
754 Duration unitDur = unit.getDuration();
755 if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) {
756 throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
757 }
758 long dur = unitDur.toNanos();
759 if ((LocalTime.NANOS_PER_DAY % dur) != 0) {
760 throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
761 }
762 long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos;
763 long result = Math.floorDiv(nod, dur) * dur;
764 return plusNanos(result - nod);
765 }
766
767 //-----------------------------------------------------------------------
768 /**
769 * Returns a copy of this instant with the specified amount added.
770 * <p>
771 * This returns an {@code Instant}, based on this one, with the specified amount added.
772 * The amount is typically {@link Duration} but may be any other type implementing
773 * the {@link TemporalAmount} interface.
774 * <p>
775 * The calculation is delegated to the amount object by calling
776 * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free
777 * to implement the addition in any way it wishes, however it typically
778 * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation
779 * of the amount implementation to determine if it can be successfully added.
780 * <p>
781 * This instance is immutable and unaffected by this method call.
782 *
783 * @param amountToAdd the amount to add, not null
784 * @return an {@code Instant} based on this instant with the addition made, not null
785 * @throws DateTimeException if the addition cannot be made
786 * @throws ArithmeticException if numeric overflow occurs
787 */
788 @Override
789 public Instant plus(TemporalAmount amountToAdd) {
790 return (Instant) amountToAdd.addTo(this);
791 }
792
793 /**
794 * Returns a copy of this instant with the specified amount added.
795 * <p>
796 * This returns an {@code Instant}, based on this one, with the amount
797 * in terms of the unit added. If it is not possible to add the amount, because the
798 * unit is not supported or for some other reason, an exception is thrown.
799 * <p>
800 * If the field is a {@link ChronoUnit} then the addition is implemented here.
801 * The supported fields behave as follows:
802 * <ul>
803 * <li>{@code NANOS} -
804 * Returns an {@code Instant} with the specified number of nanoseconds added.
805 * This is equivalent to {@link #plusNanos(long)}.
806 * <li>{@code MICROS} -
807 * Returns an {@code Instant} with the specified number of microseconds added.
808 * This is equivalent to {@link #plusNanos(long)} with the amount
809 * multiplied by 1,000.
810 * <li>{@code MILLIS} -
811 * Returns an {@code Instant} with the specified number of milliseconds added.
812 * This is equivalent to {@link #plusNanos(long)} with the amount
813 * multiplied by 1,000,000.
814 * <li>{@code SECONDS} -
815 * Returns an {@code Instant} with the specified number of seconds added.
816 * This is equivalent to {@link #plusSeconds(long)}.
817 * <li>{@code MINUTES} -
818 * Returns an {@code Instant} with the specified number of minutes added.
819 * This is equivalent to {@link #plusSeconds(long)} with the amount
820 * multiplied by 60.
821 * <li>{@code HOURS} -
822 * Returns an {@code Instant} with the specified number of hours added.
823 * This is equivalent to {@link #plusSeconds(long)} with the amount
824 * multiplied by 3,600.
825 * <li>{@code HALF_DAYS} -
826 * Returns an {@code Instant} with the specified number of half-days added.
827 * This is equivalent to {@link #plusSeconds(long)} with the amount
828 * multiplied by 43,200 (12 hours).
829 * <li>{@code DAYS} -
830 * Returns an {@code Instant} with the specified number of days added.
831 * This is equivalent to {@link #plusSeconds(long)} with the amount
832 * multiplied by 86,400 (24 hours).
833 * </ul>
834 * <p>
835 * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}.
836 * <p>
837 * If the field is not a {@code ChronoUnit}, then the result of this method
838 * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
839 * passing {@code this} as the argument. In this case, the unit determines
840 * whether and how to perform the addition.
841 * <p>
842 * This instance is immutable and unaffected by this method call.
843 *
844 * @param amountToAdd the amount of the unit to add to the result, may be negative
845 * @param unit the unit of the amount to add, not null
846 * @return an {@code Instant} based on this instant with the specified amount added, not null
847 * @throws DateTimeException if the addition cannot be made
848 * @throws UnsupportedTemporalTypeException if the unit is not supported
849 * @throws ArithmeticException if numeric overflow occurs
850 */
851 @Override
852 public Instant plus(long amountToAdd, TemporalUnit unit) {
853 if (unit instanceof ChronoUnit chronoUnit) {
854 return switch (chronoUnit) {
855 case NANOS -> plusNanos(amountToAdd);
856 case MICROS -> plus(amountToAdd / 1000_000, (amountToAdd % 1000_000) * 1000);
857 case MILLIS -> plusMillis(amountToAdd);
858 case SECONDS -> plusSeconds(amountToAdd);
859 case MINUTES -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_MINUTE));
860 case HOURS -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_HOUR));
861 case HALF_DAYS -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2));
862 case DAYS -> plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY));
863 default -> throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
864 };
865 }
866 return unit.addTo(this, amountToAdd);
867 }
868
869 //-----------------------------------------------------------------------
870 /**
871 * Returns a copy of this instant with the specified duration in seconds added.
872 * <p>
873 * This instance is immutable and unaffected by this method call.
874 *
875 * @param secondsToAdd the seconds to add, positive or negative
876 * @return an {@code Instant} based on this instant with the specified seconds added, not null
877 * @throws DateTimeException if the result exceeds the maximum or minimum instant
878 * @throws ArithmeticException if numeric overflow occurs
879 */
880 public Instant plusSeconds(long secondsToAdd) {
881 if (secondsToAdd == 0) {
882 return this;
883 }
884 long epochSec = Math.addExact(seconds, secondsToAdd);
885 return create(epochSec, nanos);
886 }
887
888 /**
889 * Returns a copy of this instant with the specified duration in milliseconds added.
890 * <p>
891 * This instance is immutable and unaffected by this method call.
892 *
893 * @param millisToAdd the milliseconds to add, positive or negative
894 * @return an {@code Instant} based on this instant with the specified milliseconds added, not null
895 * @throws DateTimeException if the result exceeds the maximum or minimum instant
896 * @throws ArithmeticException if numeric overflow occurs
897 */
898 public Instant plusMillis(long millisToAdd) {
899 return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000);
900 }
901
902 /**
903 * Returns a copy of this instant with the specified duration in nanoseconds added.
904 * <p>
905 * This instance is immutable and unaffected by this method call.
906 *
907 * @param nanosToAdd the nanoseconds to add, positive or negative
908 * @return an {@code Instant} based on this instant with the specified nanoseconds added, not null
909 * @throws DateTimeException if the result exceeds the maximum or minimum instant
910 * @throws ArithmeticException if numeric overflow occurs
911 */
912 public Instant plusNanos(long nanosToAdd) {
913 return plus(0, nanosToAdd);
914 }
915
916 /**
917 * Returns a copy of this instant with the specified duration added.
918 * <p>
919 * This instance is immutable and unaffected by this method call.
920 *
921 * @param secondsToAdd the seconds to add, positive or negative
922 * @param nanosToAdd the nanos to add, positive or negative
923 * @return an {@code Instant} based on this instant with the specified seconds added, not null
924 * @throws DateTimeException if the result exceeds the maximum or minimum instant
925 * @throws ArithmeticException if numeric overflow occurs
926 */
927 private Instant plus(long secondsToAdd, long nanosToAdd) {
928 if ((secondsToAdd | nanosToAdd) == 0) {
929 return this;
930 }
931 long epochSec = Math.addExact(seconds, secondsToAdd);
932 epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND);
933 nanosToAdd = nanosToAdd % NANOS_PER_SECOND;
934 long nanoAdjustment = nanos + nanosToAdd; // safe int+NANOS_PER_SECOND
935 return ofEpochSecond(epochSec, nanoAdjustment);
936 }
937
938 //-----------------------------------------------------------------------
939 /**
940 * Returns a copy of this instant with the specified amount subtracted.
941 * <p>
942 * This returns an {@code Instant}, based on this one, with the specified amount subtracted.
943 * The amount is typically {@link Duration} but may be any other type implementing
944 * the {@link TemporalAmount} interface.
945 * <p>
946 * The calculation is delegated to the amount object by calling
947 * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free
948 * to implement the subtraction in any way it wishes, however it typically
949 * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation
950 * of the amount implementation to determine if it can be successfully subtracted.
951 * <p>
952 * This instance is immutable and unaffected by this method call.
953 *
954 * @param amountToSubtract the amount to subtract, not null
955 * @return an {@code Instant} based on this instant with the subtraction made, not null
956 * @throws DateTimeException if the subtraction cannot be made
957 * @throws ArithmeticException if numeric overflow occurs
958 */
959 @Override
960 public Instant minus(TemporalAmount amountToSubtract) {
961 return (Instant) amountToSubtract.subtractFrom(this);
962 }
963
964 /**
965 * Returns a copy of this instant with the specified amount subtracted.
966 * <p>
967 * This returns an {@code Instant}, based on this one, with the amount
968 * in terms of the unit subtracted. If it is not possible to subtract the amount,
969 * because the unit is not supported or for some other reason, an exception is thrown.
970 * <p>
971 * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated.
972 * See that method for a full description of how addition, and thus subtraction, works.
973 * <p>
974 * This instance is immutable and unaffected by this method call.
975 *
976 * @param amountToSubtract the amount of the unit to subtract from the result, may be negative
977 * @param unit the unit of the amount to subtract, not null
978 * @return an {@code Instant} based on this instant with the specified amount subtracted, not null
979 * @throws DateTimeException if the subtraction cannot be made
980 * @throws UnsupportedTemporalTypeException if the unit is not supported
981 * @throws ArithmeticException if numeric overflow occurs
982 */
983 @Override
984 public Instant minus(long amountToSubtract, TemporalUnit unit) {
985 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
986 }
987
988 //-----------------------------------------------------------------------
989 /**
990 * Returns a copy of this instant with the specified duration in seconds subtracted.
991 * <p>
992 * This instance is immutable and unaffected by this method call.
993 *
994 * @param secondsToSubtract the seconds to subtract, positive or negative
995 * @return an {@code Instant} based on this instant with the specified seconds subtracted, not null
996 * @throws DateTimeException if the result exceeds the maximum or minimum instant
997 * @throws ArithmeticException if numeric overflow occurs
998 */
999 public Instant minusSeconds(long secondsToSubtract) {
1000 if (secondsToSubtract == Long.MIN_VALUE) {
1001 return plusSeconds(Long.MAX_VALUE).plusSeconds(1);
1002 }
1003 return plusSeconds(-secondsToSubtract);
1004 }
1005
1006 /**
1007 * Returns a copy of this instant with the specified duration in milliseconds subtracted.
1008 * <p>
1009 * This instance is immutable and unaffected by this method call.
1010 *
1011 * @param millisToSubtract the milliseconds to subtract, positive or negative
1012 * @return an {@code Instant} based on this instant with the specified milliseconds subtracted, not null
1013 * @throws DateTimeException if the result exceeds the maximum or minimum instant
1014 * @throws ArithmeticException if numeric overflow occurs
1015 */
1016 public Instant minusMillis(long millisToSubtract) {
1017 if (millisToSubtract == Long.MIN_VALUE) {
1018 return plusMillis(Long.MAX_VALUE).plusMillis(1);
1019 }
1020 return plusMillis(-millisToSubtract);
1021 }
1022
1023 /**
1024 * Returns a copy of this instant with the specified duration in nanoseconds subtracted.
1025 * <p>
1026 * This instance is immutable and unaffected by this method call.
1027 *
1028 * @param nanosToSubtract the nanoseconds to subtract, positive or negative
1029 * @return an {@code Instant} based on this instant with the specified nanoseconds subtracted, not null
1030 * @throws DateTimeException if the result exceeds the maximum or minimum instant
1031 * @throws ArithmeticException if numeric overflow occurs
1032 */
1033 public Instant minusNanos(long nanosToSubtract) {
1034 if (nanosToSubtract == Long.MIN_VALUE) {
1035 return plusNanos(Long.MAX_VALUE).plusNanos(1);
1036 }
1037 return plusNanos(-nanosToSubtract);
1038 }
1039
1040 //-------------------------------------------------------------------------
1041 /**
1042 * Queries this instant using the specified query.
1043 * <p>
1044 * This queries this instant using the specified query strategy object.
1045 * The {@code TemporalQuery} object defines the logic to be used to
1046 * obtain the result. Read the documentation of the query to understand
1047 * what the result of this method will be.
1048 * <p>
1049 * The result of this method is obtained by invoking the
1050 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
1051 * specified query passing {@code this} as the argument.
1052 *
1053 * @param <R> the type of the result
1054 * @param query the query to invoke, not null
1055 * @return the query result, null may be returned (defined by the query)
1056 * @throws DateTimeException if unable to query (defined by the query)
1057 * @throws ArithmeticException if numeric overflow occurs (defined by the query)
1058 */
1059 @SuppressWarnings("unchecked")
1060 @Override
1061 public <R> R query(TemporalQuery<R> query) {
1062 if (query == TemporalQueries.precision()) {
1063 return (R) NANOS;
1064 }
1065 // inline TemporalAccessor.super.query(query) as an optimization
1066 if (query == TemporalQueries.chronology() || query == TemporalQueries.zoneId() ||
1067 query == TemporalQueries.zone() || query == TemporalQueries.offset() ||
1068 query == TemporalQueries.localDate() || query == TemporalQueries.localTime()) {
1069 return null;
1070 }
1071 return query.queryFrom(this);
1072 }
1073
1074 /**
1075 * Adjusts the specified temporal object to have this instant.
1076 * <p>
1077 * This returns a temporal object of the same observable type as the input
1078 * with the instant changed to be the same as this.
1079 * <p>
1080 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
1081 * twice, passing {@link ChronoField#INSTANT_SECONDS} and
1082 * {@link ChronoField#NANO_OF_SECOND} as the fields.
1083 * <p>
1084 * In most cases, it is clearer to reverse the calling pattern by using
1085 * {@link Temporal#with(TemporalAdjuster)}:
1086 * <pre>
1087 * // these two lines are equivalent, but the second approach is recommended
1088 * temporal = thisInstant.adjustInto(temporal);
1089 * temporal = temporal.with(thisInstant);
1090 * </pre>
1091 * <p>
1092 * This instance is immutable and unaffected by this method call.
1093 *
1094 * @param temporal the target object to be adjusted, not null
1095 * @return the adjusted object, not null
1096 * @throws DateTimeException if unable to make the adjustment
1097 * @throws ArithmeticException if numeric overflow occurs
1098 */
1099 @Override
1100 public Temporal adjustInto(Temporal temporal) {
1101 return temporal.with(INSTANT_SECONDS, seconds).with(NANO_OF_SECOND, nanos);
1102 }
1103
1104 /**
1105 * Calculates the amount of time until another instant in terms of the specified unit.
1106 * <p>
1107 * This calculates the amount of time between two {@code Instant}
1108 * objects in terms of a single {@code TemporalUnit}.
1109 * The start and end points are {@code this} and the specified instant.
1110 * The result will be negative if the end is before the start.
1111 * The calculation returns a whole number, representing the number of
1112 * complete units between the two instants.
1113 * The {@code Temporal} passed to this method is converted to a
1114 * {@code Instant} using {@link #from(TemporalAccessor)}.
1115 * For example, the amount in seconds between two dates can be calculated
1116 * using {@code startInstant.until(endInstant, SECONDS)}.
1117 * <p>
1118 * There are two equivalent ways of using this method.
1119 * The first is to invoke this method.
1120 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
1121 * <pre>
1122 * // these two lines are equivalent
1123 * amount = start.until(end, SECONDS);
1124 * amount = SECONDS.between(start, end);
1125 * </pre>
1126 * The choice should be made based on which makes the code more readable.
1127 * <p>
1128 * The calculation is implemented in this method for {@link ChronoUnit}.
1129 * The units {@code NANOS}, {@code MICROS}, {@code MILLIS}, {@code SECONDS},
1130 * {@code MINUTES}, {@code HOURS}, {@code HALF_DAYS} and {@code DAYS}
1131 * are supported. Other {@code ChronoUnit} values will throw an exception.
1132 * <p>
1133 * If the unit is not a {@code ChronoUnit}, then the result of this method
1134 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
1135 * passing {@code this} as the first argument and the converted input temporal
1136 * as the second argument.
1137 * <p>
1138 * This instance is immutable and unaffected by this method call.
1139 *
1140 * @param endExclusive the end date, exclusive, which is converted to an {@code Instant}, not null
1141 * @param unit the unit to measure the amount in, not null
1142 * @return the amount of time between this instant and the end instant
1143 * @throws DateTimeException if the amount cannot be calculated, or the end
1144 * temporal cannot be converted to an {@code Instant}
1145 * @throws UnsupportedTemporalTypeException if the unit is not supported
1146 * @throws ArithmeticException if numeric overflow occurs
1147 */
1148 @Override
1149 public long until(Temporal endExclusive, TemporalUnit unit) {
1150 Instant end = Instant.from(endExclusive);
1151 if (unit instanceof ChronoUnit chronoUnit) {
1152 return switch (chronoUnit) {
1153 case NANOS -> nanosUntil(end);
1154 case MICROS -> microsUntil(end);
1155 case MILLIS -> millisUntil(end);
1156 case SECONDS -> secondsUntil(end);
1157 case MINUTES -> secondsUntil(end) / SECONDS_PER_MINUTE;
1158 case HOURS -> secondsUntil(end) / SECONDS_PER_HOUR;
1159 case HALF_DAYS -> secondsUntil(end) / (12 * SECONDS_PER_HOUR);
1160 case DAYS -> secondsUntil(end) / (SECONDS_PER_DAY);
1161 default -> throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
1162 };
1163 }
1164 return unit.between(this, end);
1165 }
1166
1167 private long nanosUntil(Instant end) {
1168 long secsDiff = Math.subtractExact(end.seconds, seconds);
1169 long totalNanos = Math.multiplyExact(secsDiff, NANOS_PER_SECOND);
1170 return Math.addExact(totalNanos, end.nanos - nanos);
1171 }
1172
1173 private long microsUntil(Instant end) {
1174 long secsDiff = Math.subtractExact(end.seconds, seconds);
1175 long totalMicros = Math.multiplyExact(secsDiff, MICROS_PER_SECOND);
1176 return Math.addExact(totalMicros, (end.nanos - nanos) / 1000);
1177 }
1178
1179 private long millisUntil(Instant end) {
1180 long secsDiff = Math.subtractExact(end.seconds, seconds);
1181 long totalMillis = Math.multiplyExact(secsDiff, MILLIS_PER_SECOND);
1182 return Math.addExact(totalMillis, (end.nanos - nanos) / 1000_000);
1183 }
1184
1185 private long secondsUntil(Instant end) {
1186 long secsDiff = Math.subtractExact(end.seconds, seconds);
1187 long nanosDiff = end.nanos - nanos;
1188 if (secsDiff > 0 && nanosDiff < 0) {
1189 secsDiff--;
1190 } else if (secsDiff < 0 && nanosDiff > 0) {
1191 secsDiff++;
1192 }
1193 return secsDiff;
1194 }
1195
1196 //-----------------------------------------------------------------------
1197 /**
1198 * Combines this instant with an offset to create an {@code OffsetDateTime}.
1199 * <p>
1200 * This returns an {@code OffsetDateTime} formed from this instant at the
1201 * specified offset from UTC/Greenwich. An exception will be thrown if the
1202 * instant is too large to fit into an offset date-time.
1203 * <p>
1204 * This method is equivalent to
1205 * {@link OffsetDateTime#ofInstant(Instant, ZoneId) OffsetDateTime.ofInstant(this, offset)}.
1206 *
1207 * @param offset the offset to combine with, not null
1208 * @return the offset date-time formed from this instant and the specified offset, not null
1209 * @throws DateTimeException if the result exceeds the supported range
1210 */
1211 public OffsetDateTime atOffset(ZoneOffset offset) {
1212 return OffsetDateTime.ofInstant(this, offset);
1213 }
1214
1215 /**
1216 * Combines this instant with a time-zone to create a {@code ZonedDateTime}.
1217 * <p>
1218 * This returns an {@code ZonedDateTime} formed from this instant at the
1219 * specified time-zone. An exception will be thrown if the instant is too
1220 * large to fit into a zoned date-time.
1221 * <p>
1222 * This method is equivalent to
1223 * {@link ZonedDateTime#ofInstant(Instant, ZoneId) ZonedDateTime.ofInstant(this, zone)}.
1224 *
1225 * @param zone the zone to combine with, not null
1226 * @return the zoned date-time formed from this instant and the specified zone, not null
1227 * @throws DateTimeException if the result exceeds the supported range
1228 */
1229 public ZonedDateTime atZone(ZoneId zone) {
1230 return ZonedDateTime.ofInstant(this, zone);
1231 }
1232
1233 //-----------------------------------------------------------------------
1234 /**
1235 * Converts this instant to the number of milliseconds from the epoch
1236 * of 1970-01-01T00:00:00Z.
1237 * <p>
1238 * If this instant represents a point on the time-line too far in the future
1239 * or past to fit in a {@code long} milliseconds, then an exception is thrown.
1240 * <p>
1241 * If this instant has greater than millisecond precision, then the conversion
1242 * will drop any excess precision information as though the amount in nanoseconds
1243 * was subject to integer division by one million.
1244 *
1245 * @return the number of milliseconds since the epoch of 1970-01-01T00:00:00Z
1246 * @throws ArithmeticException if numeric overflow occurs
1247 */
1248 public long toEpochMilli() {
1249 if (seconds < 0 && nanos > 0) {
1250 long millis = Math.multiplyExact(seconds+1, 1000);
1251 long adjustment = nanos / 1000_000 - 1000;
1252 return Math.addExact(millis, adjustment);
1253 } else {
1254 long millis = Math.multiplyExact(seconds, 1000);
1255 return Math.addExact(millis, nanos / 1000_000);
1256 }
1257 }
1258
1259 //-----------------------------------------------------------------------
1260 /**
1261 * Compares this instant to the specified instant.
1262 * <p>
1263 * The comparison is based on the time-line position of the instants.
1264 * It is "consistent with equals", as defined by {@link Comparable}.
1265 *
1266 * @param otherInstant the other instant to compare to, not null
1267 * @return the comparator value, negative if less, positive if greater
1268 * @throws NullPointerException if otherInstant is null
1269 */
1270 @Override
1271 public int compareTo(Instant otherInstant) {
1272 int cmp = Long.compare(seconds, otherInstant.seconds);
1273 if (cmp != 0) {
1274 return cmp;
1275 }
1276 return nanos - otherInstant.nanos;
1277 }
1278
1279 /**
1280 * Checks if this instant is after the specified instant.
1281 * <p>
1282 * The comparison is based on the time-line position of the instants.
1283 *
1284 * @param otherInstant the other instant to compare to, not null
1285 * @return true if this instant is after the specified instant
1286 * @throws NullPointerException if otherInstant is null
1287 */
1288 public boolean isAfter(Instant otherInstant) {
1289 return compareTo(otherInstant) > 0;
1290 }
1291
1292 /**
1293 * Checks if this instant is before the specified instant.
1294 * <p>
1295 * The comparison is based on the time-line position of the instants.
1296 *
1297 * @param otherInstant the other instant to compare to, not null
1298 * @return true if this instant is before the specified instant
1299 * @throws NullPointerException if otherInstant is null
1300 */
1301 public boolean isBefore(Instant otherInstant) {
1302 return compareTo(otherInstant) < 0;
1303 }
1304
1305 //-----------------------------------------------------------------------
1306 /**
1307 * Checks if this instant is equal to the specified instant.
1308 * <p>
1309 * The comparison is based on the time-line position of the instants.
1310 *
1311 * @param other the other instant, null returns false
1312 * @return true if the other instant is equal to this one
1313 */
1314 @Override
1315 public boolean equals(Object other) {
1316 if (this == other) {
1317 return true;
1318 }
1319 return (other instanceof Instant otherInstant)
1320 && this.seconds == otherInstant.seconds
1321 && this.nanos == otherInstant.nanos;
1322 }
1323
1324 /**
1325 * Returns a hash code for this instant.
1326 *
1327 * @return a suitable hash code
1328 */
1329 @Override
1330 public int hashCode() {
1331 return ((int) (seconds ^ (seconds >>> 32))) + 51 * nanos;
1332 }
1333
1334 //-----------------------------------------------------------------------
1335 /**
1336 * A string representation of this instant using ISO-8601 representation.
1337 * <p>
1338 * The format used is the same as {@link DateTimeFormatter#ISO_INSTANT}.
1339 *
1340 * @return an ISO-8601 representation of this instant, not null
1341 */
1342 @Override
1343 public String toString() {
1344 return DateTimeFormatter.ISO_INSTANT.format(this);
1345 }
1346
1347 // -----------------------------------------------------------------------
1348 /**
1349 * Writes the object using a
1350 * <a href="{@docRoot}/serialized-form.html#java.time.Ser">dedicated serialized form</a>.
1351 * @serialData
1352 * <pre>
1353 * out.writeByte(2); // identifies an Instant
1354 * out.writeLong(seconds);
1355 * out.writeInt(nanos);
1356 * </pre>
1357 *
1358 * @return the instance of {@code Ser}, not null
1359 */
1360 @java.io.Serial
1361 private Object writeReplace() {
1362 return new Ser(Ser.INSTANT_TYPE, this);
1363 }
1364
1365 /**
1366 * Defend against malicious streams.
1367 *
1368 * @param s the stream to read
1369 * @throws InvalidObjectException always
1370 */
1371 @java.io.Serial
1372 private void readObject(ObjectInputStream s) throws InvalidObjectException {
1373 throw new InvalidObjectException("Deserialization via serialization delegate");
1374 }
1375
1376 void writeExternal(DataOutput out) throws IOException {
1377 out.writeLong(seconds);
1378 out.writeInt(nanos);
1379 }
1380
1381 static Instant readExternal(DataInput in) throws IOException {
1382 long seconds = in.readLong();
1383 int nanos = in.readInt();
1384 return Instant.ofEpochSecond(seconds, nanos);
1385 }
1386
1387 }