1 /*
2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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.NANOS_PER_SECOND;
65 import static java.time.LocalTime.SECONDS_PER_DAY;
66 import static java.time.LocalTime.SECONDS_PER_HOUR;
67 import static java.time.LocalTime.SECONDS_PER_MINUTE;
68 import static java.time.temporal.ChronoField.INSTANT_SECONDS;
69 import static java.time.temporal.ChronoField.MICRO_OF_SECOND;
70 import static java.time.temporal.ChronoField.MILLI_OF_SECOND;
71 import static java.time.temporal.ChronoField.NANO_OF_SECOND;
72 import static java.time.temporal.ChronoUnit.DAYS;
73 import static java.time.temporal.ChronoUnit.NANOS;
74
75 import java.io.DataInput;
76 import java.io.DataOutput;
77 import java.io.IOException;
78 import java.io.InvalidObjectException;
79 import java.io.ObjectStreamException;
80 import java.io.Serializable;
81 import java.time.format.DateTimeFormatter;
82 import java.time.format.DateTimeParseException;
83 import java.time.temporal.ChronoField;
84 import java.time.temporal.ChronoUnit;
85 import java.time.temporal.Temporal;
86 import java.time.temporal.TemporalAccessor;
87 import java.time.temporal.TemporalAdjuster;
88 import java.time.temporal.TemporalAmount;
89 import java.time.temporal.TemporalField;
90 import java.time.temporal.TemporalQuery;
91 import java.time.temporal.TemporalUnit;
92 import java.time.temporal.UnsupportedTemporalTypeException;
93 import java.time.temporal.ValueRange;
94 import java.util.Objects;
95
96 /**
97 * An instantaneous point on the time-line.
98 * <p>
99 * This class models a single instantaneous point on the time-line.
100 * This might be used to record event time-stamps in the application.
101 * <p>
102 * For practicality, the instant is stored with some constraints.
103 * The measurable time-line is restricted to the number of seconds that can be held
104 * in a {@code long}. This is greater than the current estimated age of the universe.
105 * The instant is stored to nanosecond resolution.
106 * <p>
107 * The range of an instant requires the storage of a number larger than a {@code long}.
108 * To achieve this, the class stores a {@code long} representing epoch-seconds and an
109 * {@code int} representing nanosecond-of-second, which will always be between 0 and 999,999,999.
110 * The epoch-seconds are measured from the standard Java epoch of {@code 1970-01-01T00:00:00Z}
111 * where instants after the epoch have positive values, and earlier instants have negative values.
112 * For both the epoch-second and nanosecond parts, a larger value is always later on the time-line
113 * than a smaller value.
114 *
115 * <h3>Time-scale</h3>
116 * <p>
117 * The length of the solar day is the standard way that humans measure time.
118 * This has traditionally been subdivided into 24 hours of 60 minutes of 60 seconds,
119 * forming a 86400 second day.
120 * <p>
121 * Modern timekeeping is based on atomic clocks which precisely define an SI second
122 * relative to the transitions of a Caesium atom. The length of an SI second was defined
123 * to be very close to the 86400th fraction of a day.
124 * <p>
125 * Unfortunately, as the Earth rotates the length of the day varies.
126 * In addition, over time the average length of the day is getting longer as the Earth slows.
127 * As a result, the length of a solar day in 2012 is slightly longer than 86400 SI seconds.
128 * The actual length of any given day and the amount by which the Earth is slowing
129 * are not predictable and can only be determined by measurement.
130 * The UT1 time-scale captures the accurate length of day, but is only available some
131 * time after the day has completed.
132 * <p>
133 * The UTC time-scale is a standard approach to bundle up all the additional fractions
134 * of a second from UT1 into whole seconds, known as <i>leap-seconds</i>.
135 * A leap-second may be added or removed depending on the Earth's rotational changes.
136 * As such, UTC permits a day to have 86399 SI seconds or 86401 SI seconds where
137 * necessary in order to keep the day aligned with the Sun.
138 * <p>
139 * The modern UTC time-scale was introduced in 1972, introducing the concept of whole leap-seconds.
140 * Between 1958 and 1972, the definition of UTC was complex, with minor sub-second leaps and
141 * alterations to the length of the notional second. As of 2012, discussions are underway
142 * to change the definition of UTC again, with the potential to remove leap seconds or
143 * introduce other changes.
144 * <p>
145 * Given the complexity of accurate timekeeping described above, this Java API defines
146 * its own time-scale, the <i>Java Time-Scale</i>.
147 * <p>
148 * The Java Time-Scale divides each calendar day into exactly 86400
149 * subdivisions, known as seconds. These seconds may differ from the
150 * SI second. It closely matches the de facto international civil time
151 * scale, the definition of which changes from time to time.
152 * <p>
153 * The Java Time-Scale has slightly different definitions for different
154 * segments of the time-line, each based on the consensus international
155 * time scale that is used as the basis for civil time. Whenever the
156 * internationally-agreed time scale is modified or replaced, a new
157 * segment of the Java Time-Scale must be defined for it. Each segment
158 * must meet these requirements:
159 * <p><ul>
160 * <li>the Java Time-Scale shall closely match the underlying international
161 * civil time scale;</li>
162 * <li>the Java Time-Scale shall exactly match the international civil
163 * time scale at noon each day;</li>
164 * <li>the Java Time-Scale shall have a precisely-defined relationship to
165 * the international civil time scale.</li>
166 * </ul><p>
167 * There are currently, as of 2013, two segments in the Java time-scale.
168 * <p>
169 * For the segment from 1972-11-03 (exact boundary discussed below) until
170 * further notice, the consensus international time scale is UTC (with
171 * leap seconds). In this segment, the Java Time-Scale is identical to
172 * <a href="http://www.cl.cam.ac.uk/~mgk25/time/utc-sls/">UTC-SLS</a>.
173 * This is identical to UTC on days that do not have a leap second.
174 * On days that do have a leap second, the leap second is spread equally
175 * over the last 1000 seconds of the day, maintaining the appearance of
176 * exactly 86400 seconds per day.
177 * <p>
178 * For the segment prior to 1972-11-03, extending back arbitrarily far,
179 * the consensus international time scale is defined to be UT1, applied
180 * proleptically, which is equivalent to the (mean) solar time on the
181 * prime meridian (Greenwich). In this segment, the Java Time-Scale is
182 * identical to the consensus international time scale. The exact
183 * boundary between the two segments is the instant where UT1 = UTC
184 * between 1972-11-03T00:00 and 1972-11-04T12:00.
185 * <p>
186 * Implementations of the Java time-scale using the JSR-310 API are not
187 * required to provide any clock that is sub-second accurate, or that
188 * progresses monotonically or smoothly. Implementations are therefore
189 * not required to actually perform the UTC-SLS slew or to otherwise be
190 * aware of leap seconds. JSR-310 does, however, require that
191 * implementations must document the approach they use when defining a
192 * clock representing the current instant.
193 * See {@link Clock} for details on the available clocks.
194 * <p>
195 * The Java time-scale is used for all date-time classes.
196 * This includes {@code Instant}, {@code LocalDate}, {@code LocalTime}, {@code OffsetDateTime},
197 * {@code ZonedDateTime} and {@code Duration}.
198 *
199 * @implSpec
200 * This class is immutable and thread-safe.
201 *
202 * @since 1.8
203 */
204 public final class Instant
205 implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable {
206
207 /**
208 * Constant for the 1970-01-01T00:00:00Z epoch instant.
209 */
210 public static final Instant EPOCH = new Instant(0, 0);
211 /**
212 * The minimum supported epoch second.
213 */
214 private static final long MIN_SECOND = -31557014167219200L;
215 /**
216 * The maximum supported epoch second.
217 */
218 private static final long MAX_SECOND = 31556889864403199L;
219 /**
220 * The minimum supported {@code Instant}, '-1000000000-01-01T00:00Z'.
221 * This could be used by an application as a "far past" instant.
222 * <p>
223 * This is one year earlier than the minimum {@code LocalDateTime}.
224 * This provides sufficient values to handle the range of {@code ZoneOffset}
225 * which affect the instant in addition to the local date-time.
226 * The value is also chosen such that the value of the year fits in
227 * an {@code int}.
228 */
229 public static final Instant MIN = Instant.ofEpochSecond(MIN_SECOND, 0);
230 /**
231 * The maximum supported {@code Instant}, '1000000000-12-31T23:59:59.999999999Z'.
232 * This could be used by an application as a "far future" instant.
233 * <p>
234 * This is one year later than the maximum {@code LocalDateTime}.
235 * This provides sufficient values to handle the range of {@code ZoneOffset}
236 * which affect the instant in addition to the local date-time.
237 * The value is also chosen such that the value of the year fits in
238 * an {@code int}.
239 */
240 public static final Instant MAX = Instant.ofEpochSecond(MAX_SECOND, 999_999_999);
241
242 /**
243 * Serialization version.
244 */
245 private static final long serialVersionUID = -665713676816604388L;
246
247 /**
248 * The number of seconds from the epoch of 1970-01-01T00:00:00Z.
249 */
250 private final long seconds;
251 /**
252 * The number of nanoseconds, later along the time-line, from the seconds field.
253 * This is always positive, and never exceeds 999,999,999.
254 */
255 private final int nanos;
256
257 //-----------------------------------------------------------------------
258 /**
259 * Obtains the current instant from the system clock.
260 * <p>
261 * This will query the {@link Clock#systemUTC() system UTC clock} to
262 * obtain the current instant.
263 * <p>
264 * Using this method will prevent the ability to use an alternate time-source for
265 * testing because the clock is effectively hard-coded.
266 *
267 * @return the current instant using the system clock, not null
268 */
269 public static Instant now() {
270 return Clock.systemUTC().instant();
271 }
272
273 /**
274 * Obtains the current instant from the specified clock.
275 * <p>
276 * This will query the specified clock to obtain the current time.
277 * <p>
278 * Using this method allows the use of an alternate clock for testing.
279 * The alternate clock may be introduced using {@link Clock dependency injection}.
280 *
281 * @param clock the clock to use, not null
282 * @return the current instant, not null
283 */
284 public static Instant now(Clock clock) {
285 Objects.requireNonNull(clock, "clock");
286 return clock.instant();
287 }
288
289 //-----------------------------------------------------------------------
290 /**
291 * Obtains an instance of {@code Instant} using seconds from the
292 * epoch of 1970-01-01T00:00:00Z.
293 * <p>
294 * The nanosecond field is set to zero.
295 *
296 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
297 * @return an instant, not null
298 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
299 */
300 public static Instant ofEpochSecond(long epochSecond) {
301 return create(epochSecond, 0);
302 }
303
304 /**
305 * Obtains an instance of {@code Instant} using seconds from the
306 * epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.
307 * <p>
308 * This method allows an arbitrary number of nanoseconds to be passed in.
309 * The factory will alter the values of the second and nanosecond in order
310 * to ensure that the stored nanosecond is in the range 0 to 999,999,999.
311 * For example, the following will result in the exactly the same instant:
312 * <pre>
313 * Instant.ofEpochSecond(3, 1);
314 * Instant.ofEpochSecond(4, -999_999_999);
315 * Instant.ofEpochSecond(2, 1000_000_001);
316 * </pre>
317 *
318 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
319 * @param nanoAdjustment the nanosecond adjustment to the number of seconds, positive or negative
320 * @return an instant, not null
321 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
322 * @throws ArithmeticException if numeric overflow occurs
323 */
324 public static Instant ofEpochSecond(long epochSecond, long nanoAdjustment) {
325 long secs = Math.addExact(epochSecond, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND));
326 int nos = (int)Math.floorMod(nanoAdjustment, NANOS_PER_SECOND);
327 return create(secs, nos);
328 }
329
330 /**
331 * Obtains an instance of {@code Instant} using milliseconds from the
332 * epoch of 1970-01-01T00:00:00Z.
333 * <p>
334 * The seconds and nanoseconds are extracted from the specified milliseconds.
335 *
336 * @param epochMilli the number of milliseconds from 1970-01-01T00:00:00Z
337 * @return an instant, not null
338 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
339 */
340 public static Instant ofEpochMilli(long epochMilli) {
341 long secs = Math.floorDiv(epochMilli, 1000);
342 int mos = (int)Math.floorMod(epochMilli, 1000);
343 return create(secs, mos * 1000_000);
344 }
345
346 //-----------------------------------------------------------------------
347 /**
348 * Obtains an instance of {@code Instant} from a temporal object.
349 * <p>
350 * This obtains an instant based on the specified temporal.
351 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
352 * which this factory converts to an instance of {@code Instant}.
353 * <p>
354 * The conversion extracts the {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS}
355 * and {@link ChronoField#NANO_OF_SECOND NANO_OF_SECOND} fields.
356 * <p>
357 * This method matches the signature of the functional interface {@link TemporalQuery}
358 * allowing it to be used as a query via method reference, {@code Instant::from}.
359 *
360 * @param temporal the temporal object to convert, not null
361 * @return the instant, not null
362 * @throws DateTimeException if unable to convert to an {@code Instant}
363 */
364 public static Instant from(TemporalAccessor temporal) {
365 long instantSecs = temporal.getLong(INSTANT_SECONDS);
366 int nanoOfSecond = temporal.get(NANO_OF_SECOND);
367 return Instant.ofEpochSecond(instantSecs, nanoOfSecond);
368 }
369
370 //-----------------------------------------------------------------------
371 /**
372 * Obtains an instance of {@code Instant} from a text string such as
373 * {@code 2007-12-03T10:15:30:00}.
374 * <p>
375 * The string must represent a valid instant in UTC and is parsed using
376 * {@link DateTimeFormatter#ISO_INSTANT}.
377 *
378 * @param text the text to parse, not null
379 * @return the parsed instant, not null
380 * @throws DateTimeParseException if the text cannot be parsed
381 */
382 public static Instant parse(final CharSequence text) {
383 return DateTimeFormatter.ISO_INSTANT.parse(text, Instant::from);
384 }
385
386 //-----------------------------------------------------------------------
387 /**
388 * Obtains an instance of {@code Instant} using seconds and nanoseconds.
389 *
390 * @param seconds the length of the duration in seconds
391 * @param nanoOfSecond the nano-of-second, from 0 to 999,999,999
392 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
393 */
394 private static Instant create(long seconds, int nanoOfSecond) {
395 if ((seconds | nanoOfSecond) == 0) {
396 return EPOCH;
397 }
398 if (seconds < MIN_SECOND || seconds > MAX_SECOND) {
399 throw new DateTimeException("Instant exceeds minimum or maximum instant");
400 }
401 return new Instant(seconds, nanoOfSecond);
402 }
403
404 /**
405 * Constructs an instance of {@code Instant} using seconds from the epoch of
406 * 1970-01-01T00:00:00Z and nanosecond fraction of second.
407 *
408 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
409 * @param nanos the nanoseconds within the second, must be positive
410 */
411 private Instant(long epochSecond, int nanos) {
412 super();
413 this.seconds = epochSecond;
414 this.nanos = nanos;
415 }
416
417 //-----------------------------------------------------------------------
418 /**
419 * Checks if the specified field is supported.
420 * <p>
421 * This checks if this instant can be queried for the specified field.
422 * If false, then calling the {@link #range(TemporalField) range},
423 * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
424 * methods will throw an exception.
425 * <p>
426 * If the field is a {@link ChronoField} then the query is implemented here.
427 * The supported fields are:
428 * <ul>
429 * <li>{@code NANO_OF_SECOND}
430 * <li>{@code MICRO_OF_SECOND}
431 * <li>{@code MILLI_OF_SECOND}
432 * <li>{@code INSTANT_SECONDS}
433 * </ul>
434 * All other {@code ChronoField} instances will return false.
435 * <p>
436 * If the field is not a {@code ChronoField}, then the result of this method
437 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
438 * passing {@code this} as the argument.
439 * Whether the field is supported is determined by the field.
440 *
441 * @param field the field to check, null returns false
442 * @return true if the field is supported on this instant, false if not
443 */
444 @Override
445 public boolean isSupported(TemporalField field) {
446 if (field instanceof ChronoField) {
447 return field == INSTANT_SECONDS || field == NANO_OF_SECOND || field == MICRO_OF_SECOND || field == MILLI_OF_SECOND;
448 }
449 return field != null && field.isSupportedBy(this);
450 }
451
452 /**
453 * Checks if the specified unit is supported.
454 * <p>
455 * This checks if the specified unit can be added to, or subtracted from, this date-time.
456 * If false, then calling the {@link #plus(long, TemporalUnit)} and
457 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
458 * <p>
459 * If the unit is a {@link ChronoUnit} then the query is implemented here.
460 * The supported units are:
461 * <ul>
462 * <li>{@code NANOS}
463 * <li>{@code MICROS}
464 * <li>{@code MILLIS}
465 * <li>{@code SECONDS}
466 * <li>{@code MINUTES}
467 * <li>{@code HOURS}
468 * <li>{@code HALF_DAYS}
469 * <li>{@code DAYS}
470 * </ul>
471 * All other {@code ChronoUnit} instances will return false.
472 * <p>
473 * If the unit is not a {@code ChronoUnit}, then the result of this method
474 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
475 * passing {@code this} as the argument.
476 * Whether the unit is supported is determined by the unit.
477 *
478 * @param unit the unit to check, null returns false
479 * @return true if the unit can be added/subtracted, false if not
480 */
481 @Override
482 public boolean isSupported(TemporalUnit unit) {
483 if (unit instanceof ChronoUnit) {
484 return unit.isTimeBased() || unit == DAYS;
485 }
486 return unit != null && unit.isSupportedBy(this);
487 }
488
489 //-----------------------------------------------------------------------
490 /**
491 * Gets the range of valid values for the specified field.
492 * <p>
493 * The range object expresses the minimum and maximum valid values for a field.
494 * This instant is used to enhance the accuracy of the returned range.
495 * If it is not possible to return the range, because the field is not supported
496 * or for some other reason, an exception is thrown.
497 * <p>
498 * If the field is a {@link ChronoField} then the query is implemented here.
499 * The {@link #isSupported(TemporalField) supported fields} will return
500 * appropriate range instances.
501 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
502 * <p>
503 * If the field is not a {@code ChronoField}, then the result of this method
504 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
505 * passing {@code this} as the argument.
506 * Whether the range can be obtained is determined by the field.
507 *
508 * @param field the field to query the range for, not null
509 * @return the range of valid values for the field, not null
510 * @throws DateTimeException if the range for the field cannot be obtained
511 * @throws UnsupportedTemporalTypeException if the field is not supported
512 */
513 @Override // override for Javadoc
514 public ValueRange range(TemporalField field) {
515 return Temporal.super.range(field);
516 }
517
518 /**
519 * Gets the value of the specified field from this instant as an {@code int}.
520 * <p>
521 * This queries this instant for the value for the specified field.
522 * The returned value will always be within the valid range of values for the field.
523 * If it is not possible to return the value, because the field is not supported
524 * or for some other reason, an exception is thrown.
525 * <p>
526 * If the field is a {@link ChronoField} then the query is implemented here.
527 * The {@link #isSupported(TemporalField) supported fields} will return valid
528 * values based on this date-time, except {@code INSTANT_SECONDS} which is too
529 * large to fit in an {@code int} and throws a {@code DateTimeException}.
530 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
531 * <p>
532 * If the field is not a {@code ChronoField}, then the result of this method
533 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
534 * passing {@code this} as the argument. Whether the value can be obtained,
535 * and what the value represents, is determined by the field.
536 *
537 * @param field the field to get, not null
538 * @return the value for the field
539 * @throws DateTimeException if a value for the field cannot be obtained or
540 * the value is outside the range of valid values for the field
541 * @throws UnsupportedTemporalTypeException if the field is not supported or
542 * the range of values exceeds an {@code int}
543 * @throws ArithmeticException if numeric overflow occurs
544 */
545 @Override // override for Javadoc and performance
546 public int get(TemporalField field) {
547 if (field instanceof ChronoField) {
548 switch ((ChronoField) field) {
549 case NANO_OF_SECOND: return nanos;
550 case MICRO_OF_SECOND: return nanos / 1000;
551 case MILLI_OF_SECOND: return nanos / 1000_000;
552 case INSTANT_SECONDS: INSTANT_SECONDS.checkValidIntValue(seconds);
553 }
554 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
555 }
556 return range(field).checkValidIntValue(field.getFrom(this), field);
557 }
558
559 /**
560 * Gets the value of the specified field from this instant as a {@code long}.
561 * <p>
562 * This queries this instant for the value for the specified field.
563 * If it is not possible to return the value, because the field is not supported
564 * or for some other reason, an exception is thrown.
565 * <p>
566 * If the field is a {@link ChronoField} then the query is implemented here.
567 * The {@link #isSupported(TemporalField) supported fields} will return valid
568 * values based on this date-time.
569 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
570 * <p>
571 * If the field is not a {@code ChronoField}, then the result of this method
572 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
573 * passing {@code this} as the argument. Whether the value can be obtained,
574 * and what the value represents, is determined by the field.
575 *
576 * @param field the field to get, not null
577 * @return the value for the field
578 * @throws DateTimeException if a value for the field cannot be obtained
579 * @throws UnsupportedTemporalTypeException if the field is not supported
580 * @throws ArithmeticException if numeric overflow occurs
581 */
582 @Override
583 public long getLong(TemporalField field) {
584 if (field instanceof ChronoField) {
585 switch ((ChronoField) field) {
586 case NANO_OF_SECOND: return nanos;
587 case MICRO_OF_SECOND: return nanos / 1000;
588 case MILLI_OF_SECOND: return nanos / 1000_000;
589 case INSTANT_SECONDS: return seconds;
590 }
591 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
592 }
593 return field.getFrom(this);
594 }
595
596 //-----------------------------------------------------------------------
597 /**
598 * Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
599 * <p>
600 * The epoch second count is a simple incrementing count of seconds where
601 * second 0 is 1970-01-01T00:00:00Z.
602 * The nanosecond part of the day is returned by {@code getNanosOfSecond}.
603 *
604 * @return the seconds from the epoch of 1970-01-01T00:00:00Z
605 */
606 public long getEpochSecond() {
607 return seconds;
608 }
609
610 /**
611 * Gets the number of nanoseconds, later along the time-line, from the start
612 * of the second.
613 * <p>
614 * The nanosecond-of-second value measures the total number of nanoseconds from
615 * the second returned by {@code getEpochSecond}.
616 *
617 * @return the nanoseconds within the second, always positive, never exceeds 999,999,999
618 */
619 public int getNano() {
620 return nanos;
621 }
622
623 //-------------------------------------------------------------------------
624 /**
625 * Returns an adjusted copy of this instant.
626 * <p>
627 * This returns an {@code Instant}, based on this one, with the instant adjusted.
628 * The adjustment takes place using the specified adjuster strategy object.
629 * Read the documentation of the adjuster to understand what adjustment will be made.
630 * <p>
631 * The result of this method is obtained by invoking the
632 * {@link TemporalAdjuster#adjustInto(Temporal)} method on the
633 * specified adjuster passing {@code this} as the argument.
634 * <p>
635 * This instance is immutable and unaffected by this method call.
636 *
637 * @param adjuster the adjuster to use, not null
638 * @return an {@code Instant} based on {@code this} with the adjustment made, not null
639 * @throws DateTimeException if the adjustment cannot be made
640 * @throws ArithmeticException if numeric overflow occurs
641 */
642 @Override
643 public Instant with(TemporalAdjuster adjuster) {
644 return (Instant) adjuster.adjustInto(this);
645 }
646
647 /**
648 * Returns a copy of this instant with the specified field set to a new value.
649 * <p>
650 * This returns an {@code Instant}, based on this one, with the value
651 * for the specified field changed.
652 * If it is not possible to set the value, because the field is not supported or for
653 * some other reason, an exception is thrown.
654 * <p>
655 * If the field is a {@link ChronoField} then the adjustment is implemented here.
656 * The supported fields behave as follows:
657 * <ul>
658 * <li>{@code NANO_OF_SECOND} -
659 * Returns an {@code Instant} with the specified nano-of-second.
660 * The epoch-second will be unchanged.
661 * <li>{@code MICRO_OF_SECOND} -
662 * Returns an {@code Instant} with the nano-of-second replaced by the specified
663 * micro-of-second multiplied by 1,000. The epoch-second will be unchanged.
664 * <li>{@code MILLI_OF_SECOND} -
665 * Returns an {@code Instant} with the nano-of-second replaced by the specified
666 * milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged.
667 * <li>{@code INSTANT_SECONDS} -
668 * Returns an {@code Instant} with the specified epoch-second.
669 * The nano-of-second will be unchanged.
670 * </ul>
671 * <p>
672 * In all cases, if the new value is outside the valid range of values for the field
673 * then a {@code DateTimeException} will be thrown.
674 * <p>
675 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
676 * <p>
677 * If the field is not a {@code ChronoField}, then the result of this method
678 * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
679 * passing {@code this} as the argument. In this case, the field determines
680 * whether and how to adjust the instant.
681 * <p>
682 * This instance is immutable and unaffected by this method call.
683 *
684 * @param field the field to set in the result, not null
685 * @param newValue the new value of the field in the result
686 * @return an {@code Instant} based on {@code this} with the specified field set, not null
687 * @throws DateTimeException if the field cannot be set
688 * @throws UnsupportedTemporalTypeException if the field is not supported
689 * @throws ArithmeticException if numeric overflow occurs
690 */
691 @Override
692 public Instant with(TemporalField field, long newValue) {
693 if (field instanceof ChronoField) {
694 ChronoField f = (ChronoField) field;
695 f.checkValidValue(newValue);
696 switch (f) {
697 case MILLI_OF_SECOND: {
698 int nval = (int) newValue * 1000_000;
699 return (nval != nanos ? create(seconds, nval) : this);
700 }
701 case MICRO_OF_SECOND: {
702 int nval = (int) newValue * 1000;
703 return (nval != nanos ? create(seconds, nval) : this);
704 }
705 case NANO_OF_SECOND: return (newValue != nanos ? create(seconds, (int) newValue) : this);
706 case INSTANT_SECONDS: return (newValue != seconds ? create(newValue, nanos) : this);
707 }
708 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
709 }
710 return field.adjustInto(this, newValue);
711 }
712
713 //-----------------------------------------------------------------------
714 /**
715 * Returns a copy of this {@code Instant} truncated to the specified unit.
716 * <p>
717 * Truncating the instant returns a copy of the original with fields
718 * smaller than the specified unit set to zero.
719 * The fields are calculated on the basis of using a UTC offset as seen
720 * in {@code toString}.
721 * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will
722 * round down to the nearest minute, setting the seconds and nanoseconds to zero.
723 * <p>
724 * The unit must have a {@linkplain TemporalUnit#getDuration() duration}
725 * that divides into the length of a standard day without remainder.
726 * This includes all supplied time units on {@link ChronoUnit} and
727 * {@link ChronoUnit#DAYS DAYS}. Other units throw an exception.
728 * <p>
729 * This instance is immutable and unaffected by this method call.
730 *
731 * @param unit the unit to truncate to, not null
732 * @return an {@code Instant} based on this instant with the time truncated, not null
733 * @throws DateTimeException if the unit is invalid for truncation
734 * @throws UnsupportedTemporalTypeException if the unit is not supported
735 */
736 public Instant truncatedTo(TemporalUnit unit) {
737 if (unit == ChronoUnit.NANOS) {
738 return this;
739 }
740 Duration unitDur = unit.getDuration();
741 if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) {
742 throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
743 }
744 long dur = unitDur.toNanos();
745 if ((LocalTime.NANOS_PER_DAY % dur) != 0) {
746 throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
747 }
748 long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos;
749 long result = (nod / dur) * dur;
750 return plusNanos(result - nod);
751 }
752
753 //-----------------------------------------------------------------------
754 /**
755 * Returns a copy of this instant with the specified amount added.
756 * <p>
757 * This returns an {@code Instant}, based on this one, with the specified amount added.
758 * The amount is typically {@link Duration} but may be any other type implementing
759 * the {@link TemporalAmount} interface.
760 * <p>
761 * The calculation is delegated to the amount object by calling
762 * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free
763 * to implement the addition in any way it wishes, however it typically
764 * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation
765 * of the amount implementation to determine if it can be successfully added.
766 * <p>
767 * This instance is immutable and unaffected by this method call.
768 *
769 * @param amountToAdd the amount to add, not null
770 * @return an {@code Instant} based on this instant with the addition made, not null
771 * @throws DateTimeException if the addition cannot be made
772 * @throws ArithmeticException if numeric overflow occurs
773 */
774 @Override
775 public Instant plus(TemporalAmount amountToAdd) {
776 return (Instant) amountToAdd.addTo(this);
777 }
778
779 /**
780 * Returns a copy of this instant with the specified amount added.
781 * <p>
782 * This returns an {@code Instant}, based on this one, with the amount
783 * in terms of the unit added. If it is not possible to add the amount, because the
784 * unit is not supported or for some other reason, an exception is thrown.
785 * <p>
786 * If the field is a {@link ChronoUnit} then the addition is implemented here.
787 * The supported fields behave as follows:
788 * <ul>
789 * <li>{@code NANOS} -
790 * Returns a {@code Instant} with the specified number of nanoseconds added.
791 * This is equivalent to {@link #plusNanos(long)}.
792 * <li>{@code MICROS} -
793 * Returns a {@code Instant} with the specified number of microseconds added.
794 * This is equivalent to {@link #plusNanos(long)} with the amount
795 * multiplied by 1,000.
796 * <li>{@code MILLIS} -
797 * Returns a {@code Instant} with the specified number of milliseconds added.
798 * This is equivalent to {@link #plusNanos(long)} with the amount
799 * multiplied by 1,000,000.
800 * <li>{@code SECONDS} -
801 * Returns a {@code Instant} with the specified number of seconds added.
802 * This is equivalent to {@link #plusSeconds(long)}.
803 * <li>{@code MINUTES} -
804 * Returns a {@code Instant} with the specified number of minutes added.
805 * This is equivalent to {@link #plusSeconds(long)} with the amount
806 * multiplied by 60.
807 * <li>{@code HOURS} -
808 * Returns a {@code Instant} with the specified number of hours added.
809 * This is equivalent to {@link #plusSeconds(long)} with the amount
810 * multiplied by 3,600.
811 * <li>{@code HALF_DAYS} -
812 * Returns a {@code Instant} with the specified number of half-days added.
813 * This is equivalent to {@link #plusSeconds(long)} with the amount
814 * multiplied by 43,200 (12 hours).
815 * <li>{@code DAYS} -
816 * Returns a {@code Instant} with the specified number of days added.
817 * This is equivalent to {@link #plusSeconds(long)} with the amount
818 * multiplied by 86,400 (24 hours).
819 * </ul>
820 * <p>
821 * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}.
822 * <p>
823 * If the field is not a {@code ChronoUnit}, then the result of this method
824 * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
825 * passing {@code this} as the argument. In this case, the unit determines
826 * whether and how to perform the addition.
827 * <p>
828 * This instance is immutable and unaffected by this method call.
829 *
830 * @param amountToAdd the amount of the unit to add to the result, may be negative
831 * @param unit the unit of the amount to add, not null
832 * @return an {@code Instant} based on this instant with the specified amount added, not null
833 * @throws DateTimeException if the addition cannot be made
834 * @throws UnsupportedTemporalTypeException if the unit is not supported
835 * @throws ArithmeticException if numeric overflow occurs
836 */
837 @Override
838 public Instant plus(long amountToAdd, TemporalUnit unit) {
839 if (unit instanceof ChronoUnit) {
840 switch ((ChronoUnit) unit) {
841 case NANOS: return plusNanos(amountToAdd);
842 case MICROS: return plus(amountToAdd / 1000_000, (amountToAdd % 1000_000) * 1000);
843 case MILLIS: return plusMillis(amountToAdd);
844 case SECONDS: return plusSeconds(amountToAdd);
845 case MINUTES: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_MINUTE));
846 case HOURS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_HOUR));
847 case HALF_DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2));
848 case DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY));
849 }
850 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
851 }
852 return unit.addTo(this, amountToAdd);
853 }
854
855 //-----------------------------------------------------------------------
856 /**
857 * Returns a copy of this instant with the specified duration in seconds added.
858 * <p>
859 * This instance is immutable and unaffected by this method call.
860 *
861 * @param secondsToAdd the seconds to add, positive or negative
862 * @return an {@code Instant} based on this instant with the specified seconds added, not null
863 * @throws DateTimeException if the result exceeds the maximum or minimum instant
864 * @throws ArithmeticException if numeric overflow occurs
865 */
866 public Instant plusSeconds(long secondsToAdd) {
867 return plus(secondsToAdd, 0);
868 }
869
870 /**
871 * Returns a copy of this instant with the specified duration in milliseconds added.
872 * <p>
873 * This instance is immutable and unaffected by this method call.
874 *
875 * @param millisToAdd the milliseconds to add, positive or negative
876 * @return an {@code Instant} based on this instant with the specified milliseconds 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 plusMillis(long millisToAdd) {
881 return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000);
882 }
883
884 /**
885 * Returns a copy of this instant with the specified duration in nanoseconds added.
886 * <p>
887 * This instance is immutable and unaffected by this method call.
888 *
889 * @param nanosToAdd the nanoseconds to add, positive or negative
890 * @return an {@code Instant} based on this instant with the specified nanoseconds added, not null
891 * @throws DateTimeException if the result exceeds the maximum or minimum instant
892 * @throws ArithmeticException if numeric overflow occurs
893 */
894 public Instant plusNanos(long nanosToAdd) {
895 return plus(0, nanosToAdd);
896 }
897
898 /**
899 * Returns a copy of this instant with the specified duration added.
900 * <p>
901 * This instance is immutable and unaffected by this method call.
902 *
903 * @param secondsToAdd the seconds to add, positive or negative
904 * @param nanosToAdd the nanos to add, positive or negative
905 * @return an {@code Instant} based on this instant with the specified seconds added, not null
906 * @throws DateTimeException if the result exceeds the maximum or minimum instant
907 * @throws ArithmeticException if numeric overflow occurs
908 */
909 private Instant plus(long secondsToAdd, long nanosToAdd) {
910 if ((secondsToAdd | nanosToAdd) == 0) {
911 return this;
912 }
913 long epochSec = Math.addExact(seconds, secondsToAdd);
914 epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND);
915 nanosToAdd = nanosToAdd % NANOS_PER_SECOND;
916 long nanoAdjustment = nanos + nanosToAdd; // safe int+NANOS_PER_SECOND
917 return ofEpochSecond(epochSec, nanoAdjustment);
918 }
919
920 //-----------------------------------------------------------------------
921 /**
922 * Returns a copy of this instant with the specified amount subtracted.
923 * <p>
924 * This returns an {@code Instant}, based on this one, with the specified amount subtracted.
925 * The amount is typically {@link Duration} but may be any other type implementing
926 * the {@link TemporalAmount} interface.
927 * <p>
928 * The calculation is delegated to the amount object by calling
929 * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free
930 * to implement the subtraction in any way it wishes, however it typically
931 * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation
932 * of the amount implementation to determine if it can be successfully subtracted.
933 * <p>
934 * This instance is immutable and unaffected by this method call.
935 *
936 * @param amountToSubtract the amount to subtract, not null
937 * @return an {@code Instant} based on this instant with the subtraction made, not null
938 * @throws DateTimeException if the subtraction cannot be made
939 * @throws ArithmeticException if numeric overflow occurs
940 */
941 @Override
942 public Instant minus(TemporalAmount amountToSubtract) {
943 return (Instant) amountToSubtract.subtractFrom(this);
944 }
945
946 /**
947 * Returns a copy of this instant with the specified amount subtracted.
948 * <p>
949 * This returns a {@code Instant}, based on this one, with the amount
950 * in terms of the unit subtracted. If it is not possible to subtract the amount,
951 * because the unit is not supported or for some other reason, an exception is thrown.
952 * <p>
953 * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated.
954 * See that method for a full description of how addition, and thus subtraction, works.
955 * <p>
956 * This instance is immutable and unaffected by this method call.
957 *
958 * @param amountToSubtract the amount of the unit to subtract from the result, may be negative
959 * @param unit the unit of the amount to subtract, not null
960 * @return an {@code Instant} based on this instant with the specified amount subtracted, not null
961 * @throws DateTimeException if the subtraction cannot be made
962 * @throws UnsupportedTemporalTypeException if the unit is not supported
963 * @throws ArithmeticException if numeric overflow occurs
964 */
965 @Override
966 public Instant minus(long amountToSubtract, TemporalUnit unit) {
967 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
968 }
969
970 //-----------------------------------------------------------------------
971 /**
972 * Returns a copy of this instant with the specified duration in seconds subtracted.
973 * <p>
974 * This instance is immutable and unaffected by this method call.
975 *
976 * @param secondsToSubtract the seconds to subtract, positive or negative
977 * @return an {@code Instant} based on this instant with the specified seconds subtracted, not null
978 * @throws DateTimeException if the result exceeds the maximum or minimum instant
979 * @throws ArithmeticException if numeric overflow occurs
980 */
981 public Instant minusSeconds(long secondsToSubtract) {
982 if (secondsToSubtract == Long.MIN_VALUE) {
983 return plusSeconds(Long.MAX_VALUE).plusSeconds(1);
984 }
985 return plusSeconds(-secondsToSubtract);
986 }
987
988 /**
989 * Returns a copy of this instant with the specified duration in milliseconds subtracted.
990 * <p>
991 * This instance is immutable and unaffected by this method call.
992 *
993 * @param millisToSubtract the milliseconds to subtract, positive or negative
994 * @return an {@code Instant} based on this instant with the specified milliseconds 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 minusMillis(long millisToSubtract) {
999 if (millisToSubtract == Long.MIN_VALUE) {
1000 return plusMillis(Long.MAX_VALUE).plusMillis(1);
1001 }
1002 return plusMillis(-millisToSubtract);
1003 }
1004
1005 /**
1006 * Returns a copy of this instant with the specified duration in nanoseconds subtracted.
1007 * <p>
1008 * This instance is immutable and unaffected by this method call.
1009 *
1010 * @param nanosToSubtract the nanoseconds to subtract, positive or negative
1011 * @return an {@code Instant} based on this instant with the specified nanoseconds 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 minusNanos(long nanosToSubtract) {
1016 if (nanosToSubtract == Long.MIN_VALUE) {
1017 return plusNanos(Long.MAX_VALUE).plusNanos(1);
1018 }
1019 return plusNanos(-nanosToSubtract);
1020 }
1021
1022 //-------------------------------------------------------------------------
1023 /**
1024 * Queries this instant using the specified query.
1025 * <p>
1026 * This queries this instant using the specified query strategy object.
1027 * The {@code TemporalQuery} object defines the logic to be used to
1028 * obtain the result. Read the documentation of the query to understand
1029 * what the result of this method will be.
1030 * <p>
1031 * The result of this method is obtained by invoking the
1032 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
1033 * specified query passing {@code this} as the argument.
1034 *
1035 * @param <R> the type of the result
1036 * @param query the query to invoke, not null
1037 * @return the query result, null may be returned (defined by the query)
1038 * @throws DateTimeException if unable to query (defined by the query)
1039 * @throws ArithmeticException if numeric overflow occurs (defined by the query)
1040 */
1041 @SuppressWarnings("unchecked")
1042 @Override
1043 public <R> R query(TemporalQuery<R> query) {
1044 if (query == TemporalQuery.precision()) {
1045 return (R) NANOS;
1046 }
1047 // inline TemporalAccessor.super.query(query) as an optimization
1048 if (query == TemporalQuery.chronology() || query == TemporalQuery.zoneId() ||
1049 query == TemporalQuery.zone() || query == TemporalQuery.offset()) {
1050 return null;
1051 }
1052 return query.queryFrom(this);
1053 }
1054
1055 /**
1056 * Adjusts the specified temporal object to have this instant.
1057 * <p>
1058 * This returns a temporal object of the same observable type as the input
1059 * with the instant changed to be the same as this.
1060 * <p>
1061 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
1062 * twice, passing {@link ChronoField#INSTANT_SECONDS} and
1063 * {@link ChronoField#NANO_OF_SECOND} as the fields.
1064 * <p>
1065 * In most cases, it is clearer to reverse the calling pattern by using
1066 * {@link Temporal#with(TemporalAdjuster)}:
1067 * <pre>
1068 * // these two lines are equivalent, but the second approach is recommended
1069 * temporal = thisInstant.adjustInto(temporal);
1070 * temporal = temporal.with(thisInstant);
1071 * </pre>
1072 * <p>
1073 * This instance is immutable and unaffected by this method call.
1074 *
1075 * @param temporal the target object to be adjusted, not null
1076 * @return the adjusted object, not null
1077 * @throws DateTimeException if unable to make the adjustment
1078 * @throws ArithmeticException if numeric overflow occurs
1079 */
1080 @Override
1081 public Temporal adjustInto(Temporal temporal) {
1082 return temporal.with(INSTANT_SECONDS, seconds).with(NANO_OF_SECOND, nanos);
1083 }
1084
1085 /**
1086 * Calculates the amount of time until another instant in terms of the specified unit.
1087 * <p>
1088 * This calculates the amount of time between two {@code Instant}
1089 * objects in terms of a single {@code TemporalUnit}.
1090 * The start and end points are {@code this} and the specified instant.
1091 * The result will be negative if the end is before the start.
1092 * The calculation returns a whole number, representing the number of
1093 * complete units between the two instants.
1094 * The {@code Temporal} passed to this method must be an {@code Instant}.
1095 * For example, the amount in days between two dates can be calculated
1096 * using {@code startInstant.until(endInstant, SECONDS)}.
1097 * <p>
1098 * There are two equivalent ways of using this method.
1099 * The first is to invoke this method.
1100 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
1101 * <pre>
1102 * // these two lines are equivalent
1103 * amount = start.until(end, SECONDS);
1104 * amount = SECONDS.between(start, end);
1105 * </pre>
1106 * The choice should be made based on which makes the code more readable.
1107 * <p>
1108 * The calculation is implemented in this method for {@link ChronoUnit}.
1109 * The units {@code NANOS}, {@code MICROS}, {@code MILLIS}, {@code SECONDS},
1110 * {@code MINUTES}, {@code HOURS}, {@code HALF_DAYS} and {@code DAYS}
1111 * are supported. Other {@code ChronoUnit} values will throw an exception.
1112 * <p>
1113 * If the unit is not a {@code ChronoUnit}, then the result of this method
1114 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
1115 * passing {@code this} as the first argument and the input temporal as
1116 * the second argument.
1117 * <p>
1118 * This instance is immutable and unaffected by this method call.
1119 *
1120 * @param endInstant the end date, which must be an {@code Instant}, not null
1121 * @param unit the unit to measure the amount in, not null
1122 * @return the amount of time between this instant and the end instant
1123 * @throws DateTimeException if the amount cannot be calculated
1124 * @throws UnsupportedTemporalTypeException if the unit is not supported
1125 * @throws ArithmeticException if numeric overflow occurs
1126 */
1127 @Override
1128 public long until(Temporal endInstant, TemporalUnit unit) {
1129 if (endInstant instanceof Instant == false) {
1130 Objects.requireNonNull(endInstant, "endInstant");
1131 throw new DateTimeException("Unable to calculate amount as objects are of two different types");
1132 }
1133 Instant end = (Instant) endInstant;
1134 if (unit instanceof ChronoUnit) {
1135 ChronoUnit f = (ChronoUnit) unit;
1136 switch (f) {
1137 case NANOS: return nanosUntil(end);
1138 case MICROS: return nanosUntil(end) / 1000;
1139 case MILLIS: return Math.subtractExact(end.toEpochMilli(), toEpochMilli());
1140 case SECONDS: return secondsUntil(end);
1141 case MINUTES: return secondsUntil(end) / SECONDS_PER_MINUTE;
1142 case HOURS: return secondsUntil(end) / SECONDS_PER_HOUR;
1143 case HALF_DAYS: return secondsUntil(end) / (12 * SECONDS_PER_HOUR);
1144 case DAYS: return secondsUntil(end) / (SECONDS_PER_DAY);
1145 }
1146 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
1147 }
1148 return unit.between(this, endInstant);
1149 }
1150
1151 private long nanosUntil(Instant end) {
1152 long secsDiff = Math.subtractExact(end.seconds, seconds);
1153 long totalNanos = Math.multiplyExact(secsDiff, NANOS_PER_SECOND);
1154 return Math.addExact(totalNanos, end.nanos - nanos);
1155 }
1156
1157 private long secondsUntil(Instant end) {
1158 long secsDiff = Math.subtractExact(end.seconds, seconds);
1159 long nanosDiff = end.nanos - nanos;
1160 if (secsDiff > 0 && nanosDiff < 0) {
1161 secsDiff--;
1162 } else if (secsDiff < 0 && nanosDiff > 0) {
1163 secsDiff++;
1164 }
1165 return secsDiff;
1166 }
1167
1168 //-----------------------------------------------------------------------
1169 /**
1170 * Combines this instant with an offset to create an {@code OffsetDateTime}.
1171 * <p>
1172 * This returns an {@code OffsetDateTime} formed from this instant at the
1173 * specified offset from UTC/Greenwich. An exception will be thrown if the
1174 * instant is too large to fit into an offset date-time.
1175 * <p>
1176 * This method is equivalent to
1177 * {@link OffsetDateTime#ofInstant(Instant, ZoneId) OffsetDateTime.ofInstant(this, offset)}.
1178 *
1179 * @param offset the offset to combine with, not null
1180 * @return the offset date-time formed from this instant and the specified offset, not null
1181 * @throws DateTimeException if the result exceeds the supported range
1182 */
1183 public OffsetDateTime atOffset(ZoneOffset offset) {
1184 return OffsetDateTime.ofInstant(this, offset);
1185 }
1186
1187 /**
1188 * Combines this instant with a time-zone to create a {@code ZonedDateTime}.
1189 * <p>
1190 * This returns an {@code ZonedDateTime} formed from this instant at the
1191 * specified time-zone. An exception will be thrown if the instant is too
1192 * large to fit into a zoned date-time.
1193 * <p>
1194 * This method is equivalent to
1195 * {@link ZonedDateTime#ofInstant(Instant, ZoneId) ZonedDateTime.ofInstant(this, zone)}.
1196 *
1197 * @param zone the zone to combine with, not null
1198 * @return the zoned date-time formed from this instant and the specified zone, not null
1199 * @throws DateTimeException if the result exceeds the supported range
1200 */
1201 public ZonedDateTime atZone(ZoneId zone) {
1202 return ZonedDateTime.ofInstant(this, zone);
1203 }
1204
1205 //-----------------------------------------------------------------------
1206 /**
1207 * Converts this instant to the number of milliseconds from the epoch
1208 * of 1970-01-01T00:00:00Z.
1209 * <p>
1210 * If this instant represents a point on the time-line too far in the future
1211 * or past to fit in a {@code long} milliseconds, then an exception is thrown.
1212 * <p>
1213 * If this instant has greater than millisecond precision, then the conversion
1214 * will drop any excess precision information as though the amount in nanoseconds
1215 * was subject to integer division by one million.
1216 *
1217 * @return the number of milliseconds since the epoch of 1970-01-01T00:00:00Z
1218 * @throws ArithmeticException if numeric overflow occurs
1219 */
1220 public long toEpochMilli() {
1221 long millis = Math.multiplyExact(seconds, 1000);
1222 return millis + nanos / 1000_000;
1223 }
1224
1225 //-----------------------------------------------------------------------
1226 /**
1227 * Compares this instant to the specified instant.
1228 * <p>
1229 * The comparison is based on the time-line position of the instants.
1230 * It is "consistent with equals", as defined by {@link Comparable}.
1231 *
1232 * @param otherInstant the other instant to compare to, not null
1233 * @return the comparator value, negative if less, positive if greater
1234 * @throws NullPointerException if otherInstant is null
1235 */
1236 @Override
1237 public int compareTo(Instant otherInstant) {
1238 int cmp = Long.compare(seconds, otherInstant.seconds);
1239 if (cmp != 0) {
1240 return cmp;
1241 }
1242 return nanos - otherInstant.nanos;
1243 }
1244
1245 /**
1246 * Checks if this instant is after the specified instant.
1247 * <p>
1248 * The comparison is based on the time-line position of the instants.
1249 *
1250 * @param otherInstant the other instant to compare to, not null
1251 * @return true if this instant is after the specified instant
1252 * @throws NullPointerException if otherInstant is null
1253 */
1254 public boolean isAfter(Instant otherInstant) {
1255 return compareTo(otherInstant) > 0;
1256 }
1257
1258 /**
1259 * Checks if this instant is before the specified instant.
1260 * <p>
1261 * The comparison is based on the time-line position of the instants.
1262 *
1263 * @param otherInstant the other instant to compare to, not null
1264 * @return true if this instant is before the specified instant
1265 * @throws NullPointerException if otherInstant is null
1266 */
1267 public boolean isBefore(Instant otherInstant) {
1268 return compareTo(otherInstant) < 0;
1269 }
1270
1271 //-----------------------------------------------------------------------
1272 /**
1273 * Checks if this instant is equal to the specified instant.
1274 * <p>
1275 * The comparison is based on the time-line position of the instants.
1276 *
1277 * @param otherInstant the other instant, null returns false
1278 * @return true if the other instant is equal to this one
1279 */
1280 @Override
1281 public boolean equals(Object otherInstant) {
1282 if (this == otherInstant) {
1283 return true;
1284 }
1285 if (otherInstant instanceof Instant) {
1286 Instant other = (Instant) otherInstant;
1287 return this.seconds == other.seconds &&
1288 this.nanos == other.nanos;
1289 }
1290 return false;
1291 }
1292
1293 /**
1294 * Returns a hash code for this instant.
1295 *
1296 * @return a suitable hash code
1297 */
1298 @Override
1299 public int hashCode() {
1300 return ((int) (seconds ^ (seconds >>> 32))) + 51 * nanos;
1301 }
1302
1303 //-----------------------------------------------------------------------
1304 /**
1305 * A string representation of this instant using ISO-8601 representation.
1306 * <p>
1307 * The format used is the same as {@link DateTimeFormatter#ISO_INSTANT}.
1308 *
1309 * @return an ISO-8601 representation of this instant, not null
1310 */
1311 @Override
1312 public String toString() {
1313 return DateTimeFormatter.ISO_INSTANT.format(this);
1314 }
1315
1316 // -----------------------------------------------------------------------
1317 /**
1318 * Writes the object using a
1319 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
1320 * <pre>
1321 * out.writeByte(2); // identifies this as an Instant
1322 * out.writeLong(seconds);
1323 * out.writeInt(nanos);
1324 * </pre>
1325 *
1326 * @return the instance of {@code Ser}, not null
1327 */
1328 private Object writeReplace() {
1329 return new Ser(Ser.INSTANT_TYPE, this);
1330 }
1331
1332 /**
1333 * Defend against malicious streams.
1334 * @return never
1335 * @throws InvalidObjectException always
1336 */
1337 private Object readResolve() throws ObjectStreamException {
1338 throw new InvalidObjectException("Deserialization via serialization delegate");
1339 }
1340
1341 void writeExternal(DataOutput out) throws IOException {
1342 out.writeLong(seconds);
1343 out.writeInt(nanos);
1344 }
1345
1346 static Instant readExternal(DataInput in) throws IOException {
1347 long seconds = in.readLong();
1348 int nanos = in.readInt();
1349 return Instant.ofEpochSecond(seconds, nanos);
1350 }
1351
1352 }