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.NANOS;
73
74 import java.io.DataInput;
75 import java.io.DataOutput;
76 import java.io.IOException;
77 import java.io.InvalidObjectException;
78 import java.io.ObjectStreamException;
79 import java.io.Serializable;
80 import java.time.format.DateTimeFormatter;
81 import java.time.format.DateTimeParseException;
82 import java.time.temporal.ChronoField;
83 import java.time.temporal.ChronoUnit;
84 import java.time.temporal.Temporal;
85 import java.time.temporal.TemporalAccessor;
86 import java.time.temporal.TemporalAdjuster;
87 import java.time.temporal.TemporalAmount;
88 import java.time.temporal.TemporalField;
89 import java.time.temporal.TemporalQuery;
90 import java.time.temporal.TemporalUnit;
91 import java.time.temporal.UnsupportedTemporalTypeException;
92 import java.time.temporal.ValueRange;
93 import java.util.Objects;
94
95 /**
96 * An instantaneous point on the time-line.
97 * <p>
98 * This class models a single instantaneous point on the time-line.
99 * This might be used to record event time-stamps in the application.
100 * <p>
101 * For practicality, the instant is stored with some constraints.
102 * The measurable time-line is restricted to the number of seconds that can be held
103 * in a {@code long}. This is greater than the current estimated age of the universe.
104 * The instant is stored to nanosecond resolution.
105 * <p>
106 * The range of an instant requires the storage of a number larger than a {@code long}.
107 * To achieve this, the class stores a {@code long} representing epoch-seconds and an
108 * {@code int} representing nanosecond-of-second, which will always be between 0 and 999,999,999.
109 * The epoch-seconds are measured from the standard Java epoch of {@code 1970-01-01T00:00:00Z}
110 * where instants after the epoch have positive values, and earlier instants have negative values.
111 * For both the epoch-second and nanosecond parts, a larger value is always later on the time-line
112 * than a smaller value.
113 *
114 * <h3>Time-scale</h3>
115 * <p>
116 * The length of the solar day is the standard way that humans measure time.
117 * This has traditionally been subdivided into 24 hours of 60 minutes of 60 seconds,
118 * forming a 86400 second day.
119 * <p>
120 * Modern timekeeping is based on atomic clocks which precisely define an SI second
121 * relative to the transitions of a Caesium atom. The length of an SI second was defined
122 * to be very close to the 86400th fraction of a day.
123 * <p>
124 * Unfortunately, as the Earth rotates the length of the day varies.
125 * In addition, over time the average length of the day is getting longer as the Earth slows.
126 * As a result, the length of a solar day in 2012 is slightly longer than 86400 SI seconds.
127 * The actual length of any given day and the amount by which the Earth is slowing
128 * are not predictable and can only be determined by measurement.
129 * The UT1 time-scale captures the accurate length of day, but is only available some
130 * time after the day has completed.
131 * <p>
132 * The UTC time-scale is a standard approach to bundle up all the additional fractions
133 * of a second from UT1 into whole seconds, known as <i>leap-seconds</i>.
134 * A leap-second may be added or removed depending on the Earth's rotational changes.
135 * As such, UTC permits a day to have 86399 SI seconds or 86401 SI seconds where
136 * necessary in order to keep the day aligned with the Sun.
137 * <p>
138 * The modern UTC time-scale was introduced in 1972, introducing the concept of whole leap-seconds.
139 * Between 1958 and 1972, the definition of UTC was complex, with minor sub-second leaps and
140 * alterations to the length of the notional second. As of 2012, discussions are underway
141 * to change the definition of UTC again, with the potential to remove leap seconds or
142 * introduce other changes.
143 * <p>
144 * Given the complexity of accurate timekeeping described above, this Java API defines
145 * its own time-scale with a simplification. The Java time-scale is defined as follows:
146 * <p><ul>
147 * <li>midday will always be exactly as defined by the agreed international civil time</li>
148 * <li>other times during the day will be broadly in line with the agreed international civil time</li>
149 * <li>the day will be divided into exactly 86400 subdivisions, referred to as "seconds"</li>
150 * <li>the Java "second" may differ from an SI second</li>
151 * <li>a well-defined algorithm must be specified to map each second in the accurate agreed
152 * international civil time to each "second" in this time-scale</li>
153 * </ul><p>
154 * Agreed international civil time is the base time-scale agreed by international convention,
155 * which in 2012 is UTC (with leap-seconds).
156 * <p>
157 * In 2012, the definition of the Java time-scale is the same as UTC for all days except
158 * those where a leap-second occurs. On days where a leap-second does occur, the time-scale
159 * effectively eliminates the leap-second, maintaining the fiction of 86400 seconds in the day.
160 * The approved well-defined algorithm to eliminate leap-seconds is specified as
161 * <a href="http://www.cl.cam.ac.uk/~mgk25/time/utc-sls/">UTC-SLS</a>.
162 * <p>
163 * UTC-SLS is a simple algorithm that smoothes the leap-second over the last 1000 seconds of
164 * the day, making each of the last 1000 seconds 1/1000th longer or shorter than an SI second.
165 * Implementations built on an accurate leap-second aware time source should use UTC-SLS.
166 * Use of a different algorithm risks confusion and misinterpretation of instants around a
167 * leap-second and is discouraged.
168 * <p>
169 * The main benefit of always dividing the day into 86400 subdivisions is that it matches the
170 * expectations of most users of the API. The alternative is to force every user to understand
171 * what a leap second is and to force them to have special logic to handle them.
172 * Most applications do not have access to a clock that is accurate enough to record leap-seconds.
173 * Most applications also do not have a problem with a second being a very small amount longer or
174 * shorter than a real SI second during a leap-second.
175 * <p>
176 * One final problem is the definition of the agreed international civil time before the
177 * introduction of modern UTC in 1972. This includes the Java epoch of {@code 1970-01-01}.
178 * It is intended that instants before 1972 be interpreted based on the solar day divided
179 * into 86400 subdivisions, as per the principles of UT1.
180 * <p>
181 * The Java time-scale is used for all date-time classes.
182 * This includes {@code Instant}, {@code LocalDate}, {@code LocalTime}, {@code OffsetDateTime},
183 * {@code ZonedDateTime} and {@code Duration}.
184 *
185 * <h3>Specification for implementors</h3>
186 * This class is immutable and thread-safe.
187 *
188 * @since 1.8
189 */
190 public final class Instant
191 implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable {
192
193 /**
194 * Constant for the 1970-01-01T00:00:00Z epoch instant.
195 */
196 public static final Instant EPOCH = new Instant(0, 0);
197 /**
198 * The minimum supported epoch second.
199 */
200 private static final long MIN_SECOND = -31557014167219200L;
201 /**
202 * The maximum supported epoch second.
203 */
204 private static final long MAX_SECOND = 31556889864403199L;
205 /**
206 * The minimum supported {@code Instant}, '-1000000000-01-01T00:00Z'.
207 * This could be used by an application as a "far past" instant.
208 * <p>
209 * This is one year earlier than the minimum {@code LocalDateTime}.
210 * This provides sufficient values to handle the range of {@code ZoneOffset}
211 * which affect the instant in addition to the local date-time.
212 * The value is also chosen such that the value of the year fits in
213 * an {@code int}.
214 */
215 public static final Instant MIN = Instant.ofEpochSecond(MIN_SECOND, 0);
216 /**
217 * The maximum supported {@code Instant}, '1000000000-12-31T23:59:59.999999999Z'.
218 * This could be used by an application as a "far future" instant.
219 * <p>
220 * This is one year later than the maximum {@code LocalDateTime}.
221 * This provides sufficient values to handle the range of {@code ZoneOffset}
222 * which affect the instant in addition to the local date-time.
223 * The value is also chosen such that the value of the year fits in
224 * an {@code int}.
225 */
226 public static final Instant MAX = Instant.ofEpochSecond(MAX_SECOND, 999_999_999);
227
228 /**
229 * Serialization version.
230 */
231 private static final long serialVersionUID = -665713676816604388L;
232
233 /**
234 * The number of seconds from the epoch of 1970-01-01T00:00:00Z.
235 */
236 private final long seconds;
237 /**
238 * The number of nanoseconds, later along the time-line, from the seconds field.
239 * This is always positive, and never exceeds 999,999,999.
240 */
241 private final int nanos;
242
243 //-----------------------------------------------------------------------
244 /**
245 * Obtains the current instant from the system clock.
246 * <p>
247 * This will query the {@link Clock#systemUTC() system UTC clock} to
248 * obtain the current instant.
249 * <p>
250 * Using this method will prevent the ability to use an alternate time-source for
251 * testing because the clock is effectively hard-coded.
252 *
253 * @return the current instant using the system clock, not null
254 */
255 public static Instant now() {
256 return Clock.systemUTC().instant();
257 }
258
259 /**
260 * Obtains the current instant from the specified clock.
261 * <p>
262 * This will query the specified clock to obtain the current time.
263 * <p>
264 * Using this method allows the use of an alternate clock for testing.
265 * The alternate clock may be introduced using {@link Clock dependency injection}.
266 *
267 * @param clock the clock to use, not null
268 * @return the current instant, not null
269 */
270 public static Instant now(Clock clock) {
271 Objects.requireNonNull(clock, "clock");
272 return clock.instant();
273 }
274
275 //-----------------------------------------------------------------------
276 /**
277 * Obtains an instance of {@code Instant} using seconds from the
278 * epoch of 1970-01-01T00:00:00Z.
279 * <p>
280 * The nanosecond field is set to zero.
281 *
282 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
283 * @return an instant, not null
284 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
285 */
286 public static Instant ofEpochSecond(long epochSecond) {
287 return create(epochSecond, 0);
288 }
289
290 /**
291 * Obtains an instance of {@code Instant} using seconds from the
292 * epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.
293 * <p>
294 * This method allows an arbitrary number of nanoseconds to be passed in.
295 * The factory will alter the values of the second and nanosecond in order
296 * to ensure that the stored nanosecond is in the range 0 to 999,999,999.
297 * For example, the following will result in the exactly the same instant:
298 * <pre>
299 * Instant.ofEpochSecond(3, 1);
300 * Instant.ofEpochSecond(4, -999_999_999);
301 * Instant.ofEpochSecond(2, 1000_000_001);
302 * </pre>
303 *
304 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
305 * @param nanoAdjustment the nanosecond adjustment to the number of seconds, positive or negative
306 * @return an instant, not null
307 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
308 * @throws ArithmeticException if numeric overflow occurs
309 */
310 public static Instant ofEpochSecond(long epochSecond, long nanoAdjustment) {
311 long secs = Math.addExact(epochSecond, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND));
312 int nos = (int)Math.floorMod(nanoAdjustment, NANOS_PER_SECOND);
313 return create(secs, nos);
314 }
315
316 /**
317 * Obtains an instance of {@code Instant} using milliseconds from the
318 * epoch of 1970-01-01T00:00:00Z.
319 * <p>
320 * The seconds and nanoseconds are extracted from the specified milliseconds.
321 *
322 * @param epochMilli the number of milliseconds from 1970-01-01T00:00:00Z
323 * @return an instant, not null
324 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
325 */
326 public static Instant ofEpochMilli(long epochMilli) {
327 long secs = Math.floorDiv(epochMilli, 1000);
328 int mos = (int)Math.floorMod(epochMilli, 1000);
329 return create(secs, mos * 1000_000);
330 }
331
332 //-----------------------------------------------------------------------
333 /**
334 * Obtains an instance of {@code Instant} from a temporal object.
335 * <p>
336 * This obtains an instant based on the specified temporal.
337 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
338 * which this factory converts to an instance of {@code Instant}.
339 * <p>
340 * The conversion extracts the {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS}
341 * and {@link ChronoField#NANO_OF_SECOND NANO_OF_SECOND} fields.
342 * <p>
343 * This method matches the signature of the functional interface {@link TemporalQuery}
344 * allowing it to be used as a query via method reference, {@code Instant::from}.
345 *
346 * @param temporal the temporal object to convert, not null
347 * @return the instant, not null
348 * @throws DateTimeException if unable to convert to an {@code Instant}
349 */
350 public static Instant from(TemporalAccessor temporal) {
351 long instantSecs = temporal.getLong(INSTANT_SECONDS);
352 int nanoOfSecond = temporal.get(NANO_OF_SECOND);
353 return Instant.ofEpochSecond(instantSecs, nanoOfSecond);
354 }
355
356 //-----------------------------------------------------------------------
357 /**
358 * Obtains an instance of {@code Instant} from a text string such as
359 * {@code 2007-12-03T10:15:30:00}.
360 * <p>
361 * The string must represent a valid instant in UTC and is parsed using
362 * {@link DateTimeFormatter#ISO_INSTANT}.
363 *
364 * @param text the text to parse, not null
365 * @return the parsed instant, not null
366 * @throws DateTimeParseException if the text cannot be parsed
367 */
368 public static Instant parse(final CharSequence text) {
369 return DateTimeFormatter.ISO_INSTANT.parse(text, Instant::from);
370 }
371
372 //-----------------------------------------------------------------------
373 /**
374 * Obtains an instance of {@code Instant} using seconds and nanoseconds.
375 *
376 * @param seconds the length of the duration in seconds
377 * @param nanoOfSecond the nano-of-second, from 0 to 999,999,999
378 * @throws DateTimeException if the instant exceeds the maximum or minimum instant
379 */
380 private static Instant create(long seconds, int nanoOfSecond) {
381 if ((seconds | nanoOfSecond) == 0) {
382 return EPOCH;
383 }
384 if (seconds < MIN_SECOND || seconds > MAX_SECOND) {
385 throw new DateTimeException("Instant exceeds minimum or maximum instant");
386 }
387 return new Instant(seconds, nanoOfSecond);
388 }
389
390 /**
391 * Constructs an instance of {@code Instant} using seconds from the epoch of
392 * 1970-01-01T00:00:00Z and nanosecond fraction of second.
393 *
394 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
395 * @param nanos the nanoseconds within the second, must be positive
396 */
397 private Instant(long epochSecond, int nanos) {
398 super();
399 this.seconds = epochSecond;
400 this.nanos = nanos;
401 }
402
403 //-----------------------------------------------------------------------
404 /**
405 * Checks if the specified field is supported.
406 * <p>
407 * This checks if this instant can be queried for the specified field.
408 * If false, then calling the {@link #range(TemporalField) range} and
409 * {@link #get(TemporalField) get} methods will throw an exception.
410 * <p>
411 * If the field is a {@link ChronoField} then the query is implemented here.
412 * The supported fields are:
413 * <ul>
414 * <li>{@code NANO_OF_SECOND}
415 * <li>{@code MICRO_OF_SECOND}
416 * <li>{@code MILLI_OF_SECOND}
417 * <li>{@code INSTANT_SECONDS}
418 * </ul>
419 * All other {@code ChronoField} instances will return false.
420 * <p>
421 * If the field is not a {@code ChronoField}, then the result of this method
422 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
423 * passing {@code this} as the argument.
424 * Whether the field is supported is determined by the field.
425 *
426 * @param field the field to check, null returns false
427 * @return true if the field is supported on this instant, false if not
428 */
429 @Override
430 public boolean isSupported(TemporalField field) {
431 if (field instanceof ChronoField) {
432 return field == INSTANT_SECONDS || field == NANO_OF_SECOND || field == MICRO_OF_SECOND || field == MILLI_OF_SECOND;
433 }
434 return field != null && field.isSupportedBy(this);
435 }
436
437 /**
438 * Gets the range of valid values for the specified field.
439 * <p>
440 * The range object expresses the minimum and maximum valid values for a field.
441 * This instant is used to enhance the accuracy of the returned range.
442 * If it is not possible to return the range, because the field is not supported
443 * or for some other reason, an exception is thrown.
444 * <p>
445 * If the field is a {@link ChronoField} then the query is implemented here.
446 * The {@link #isSupported(TemporalField) supported fields} will return
447 * appropriate range instances.
448 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
449 * <p>
450 * If the field is not a {@code ChronoField}, then the result of this method
451 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
452 * passing {@code this} as the argument.
453 * Whether the range can be obtained is determined by the field.
454 *
455 * @param field the field to query the range for, not null
456 * @return the range of valid values for the field, not null
457 * @throws DateTimeException if the range for the field cannot be obtained
458 * @throws UnsupportedTemporalTypeException if the field is not supported
459 */
460 @Override // override for Javadoc
461 public ValueRange range(TemporalField field) {
462 return Temporal.super.range(field);
463 }
464
465 /**
466 * Gets the value of the specified field from this instant as an {@code int}.
467 * <p>
468 * This queries this instant for the value for the specified field.
469 * The returned value will always be within the valid range of values for the field.
470 * If it is not possible to return the value, because the field is not supported
471 * or for some other reason, an exception is thrown.
472 * <p>
473 * If the field is a {@link ChronoField} then the query is implemented here.
474 * The {@link #isSupported(TemporalField) supported fields} will return valid
475 * values based on this date-time, except {@code INSTANT_SECONDS} which is too
476 * large to fit in an {@code int} and throws a {@code DateTimeException}.
477 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
478 * <p>
479 * If the field is not a {@code ChronoField}, then the result of this method
480 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
481 * passing {@code this} as the argument. Whether the value can be obtained,
482 * and what the value represents, is determined by the field.
483 *
484 * @param field the field to get, not null
485 * @return the value for the field
486 * @throws DateTimeException if a value for the field cannot be obtained or
487 * the value is outside the range of valid values for the field
488 * @throws UnsupportedTemporalTypeException if the field is not supported or
489 * the range of values exceeds an {@code int}
490 * @throws ArithmeticException if numeric overflow occurs
491 */
492 @Override // override for Javadoc and performance
493 public int get(TemporalField field) {
494 if (field instanceof ChronoField) {
495 switch ((ChronoField) field) {
496 case NANO_OF_SECOND: return nanos;
497 case MICRO_OF_SECOND: return nanos / 1000;
498 case MILLI_OF_SECOND: return nanos / 1000_000;
499 case INSTANT_SECONDS: INSTANT_SECONDS.checkValidIntValue(seconds);
500 }
501 throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
502 }
503 return range(field).checkValidIntValue(field.getFrom(this), field);
504 }
505
506 /**
507 * Gets the value of the specified field from this instant as a {@code long}.
508 * <p>
509 * This queries this instant for the value for the specified field.
510 * If it is not possible to return the value, because the field is not supported
511 * or for some other reason, an exception is thrown.
512 * <p>
513 * If the field is a {@link ChronoField} then the query is implemented here.
514 * The {@link #isSupported(TemporalField) supported fields} will return valid
515 * values based on this date-time.
516 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
517 * <p>
518 * If the field is not a {@code ChronoField}, then the result of this method
519 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
520 * passing {@code this} as the argument. Whether the value can be obtained,
521 * and what the value represents, is determined by the field.
522 *
523 * @param field the field to get, not null
524 * @return the value for the field
525 * @throws DateTimeException if a value for the field cannot be obtained
526 * @throws UnsupportedTemporalTypeException if the field is not supported
527 * @throws ArithmeticException if numeric overflow occurs
528 */
529 @Override
530 public long getLong(TemporalField field) {
531 if (field instanceof ChronoField) {
532 switch ((ChronoField) field) {
533 case NANO_OF_SECOND: return nanos;
534 case MICRO_OF_SECOND: return nanos / 1000;
535 case MILLI_OF_SECOND: return nanos / 1000_000;
536 case INSTANT_SECONDS: return seconds;
537 }
538 throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
539 }
540 return field.getFrom(this);
541 }
542
543 //-----------------------------------------------------------------------
544 /**
545 * Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
546 * <p>
547 * The epoch second count is a simple incrementing count of seconds where
548 * second 0 is 1970-01-01T00:00:00Z.
549 * The nanosecond part of the day is returned by {@code getNanosOfSecond}.
550 *
551 * @return the seconds from the epoch of 1970-01-01T00:00:00Z
552 */
553 public long getEpochSecond() {
554 return seconds;
555 }
556
557 /**
558 * Gets the number of nanoseconds, later along the time-line, from the start
559 * of the second.
560 * <p>
561 * The nanosecond-of-second value measures the total number of nanoseconds from
562 * the second returned by {@code getEpochSecond}.
563 *
564 * @return the nanoseconds within the second, always positive, never exceeds 999,999,999
565 */
566 public int getNano() {
567 return nanos;
568 }
569
570 //-------------------------------------------------------------------------
571 /**
572 * Returns an adjusted copy of this instant.
573 * <p>
574 * This returns an {@code Instant}, based on this one, with the instant adjusted.
575 * The adjustment takes place using the specified adjuster strategy object.
576 * Read the documentation of the adjuster to understand what adjustment will be made.
577 * <p>
578 * The result of this method is obtained by invoking the
579 * {@link TemporalAdjuster#adjustInto(Temporal)} method on the
580 * specified adjuster passing {@code this} as the argument.
581 * <p>
582 * This instance is immutable and unaffected by this method call.
583 *
584 * @param adjuster the adjuster to use, not null
585 * @return an {@code Instant} based on {@code this} with the adjustment made, not null
586 * @throws DateTimeException if the adjustment cannot be made
587 * @throws ArithmeticException if numeric overflow occurs
588 */
589 @Override
590 public Instant with(TemporalAdjuster adjuster) {
591 return (Instant) adjuster.adjustInto(this);
592 }
593
594 /**
595 * Returns a copy of this instant with the specified field set to a new value.
596 * <p>
597 * This returns an {@code Instant}, based on this one, with the value
598 * for the specified field changed.
599 * If it is not possible to set the value, because the field is not supported or for
600 * some other reason, an exception is thrown.
601 * <p>
602 * If the field is a {@link ChronoField} then the adjustment is implemented here.
603 * The supported fields behave as follows:
604 * <ul>
605 * <li>{@code NANO_OF_SECOND} -
606 * Returns an {@code Instant} with the specified nano-of-second.
607 * The epoch-second will be unchanged.
608 * <li>{@code MICRO_OF_SECOND} -
609 * Returns an {@code Instant} with the nano-of-second replaced by the specified
610 * micro-of-second multiplied by 1,000. The epoch-second will be unchanged.
611 * <li>{@code MILLI_OF_SECOND} -
612 * Returns an {@code Instant} with the nano-of-second replaced by the specified
613 * milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged.
614 * <li>{@code INSTANT_SECONDS} -
615 * Returns an {@code Instant} with the specified epoch-second.
616 * The nano-of-second will be unchanged.
617 * </ul>
618 * <p>
619 * In all cases, if the new value is outside the valid range of values for the field
620 * then a {@code DateTimeException} will be thrown.
621 * <p>
622 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
623 * <p>
624 * If the field is not a {@code ChronoField}, then the result of this method
625 * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
626 * passing {@code this} as the argument. In this case, the field determines
627 * whether and how to adjust the instant.
628 * <p>
629 * This instance is immutable and unaffected by this method call.
630 *
631 * @param field the field to set in the result, not null
632 * @param newValue the new value of the field in the result
633 * @return an {@code Instant} based on {@code this} with the specified field set, not null
634 * @throws DateTimeException if the field cannot be set
635 * @throws UnsupportedTemporalTypeException if the field is not supported
636 * @throws ArithmeticException if numeric overflow occurs
637 */
638 @Override
639 public Instant with(TemporalField field, long newValue) {
640 if (field instanceof ChronoField) {
641 ChronoField f = (ChronoField) field;
642 f.checkValidValue(newValue);
643 switch (f) {
644 case MILLI_OF_SECOND: {
645 int nval = (int) newValue * 1000_000;
646 return (nval != nanos ? create(seconds, nval) : this);
647 }
648 case MICRO_OF_SECOND: {
649 int nval = (int) newValue * 1000;
650 return (nval != nanos ? create(seconds, nval) : this);
651 }
652 case NANO_OF_SECOND: return (newValue != nanos ? create(seconds, (int) newValue) : this);
653 case INSTANT_SECONDS: return (newValue != seconds ? create(newValue, nanos) : this);
654 }
655 throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
656 }
657 return field.adjustInto(this, newValue);
658 }
659
660 //-----------------------------------------------------------------------
661 /**
662 * Returns a copy of this {@code Instant} truncated to the specified unit.
663 * <p>
664 * Truncating the instant returns a copy of the original with fields
665 * smaller than the specified unit set to zero.
666 * The fields are calculated on the basis of using a UTC offset as seen
667 * in {@code toString}.
668 * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will
669 * round down to the nearest minute, setting the seconds and nanoseconds to zero.
670 * <p>
671 * The unit must have a {@linkplain TemporalUnit#getDuration() duration}
672 * that divides into the length of a standard day without remainder.
673 * This includes all supplied time units on {@link ChronoUnit} and
674 * {@link ChronoUnit#DAYS DAYS}. Other units throw an exception.
675 * <p>
676 * This instance is immutable and unaffected by this method call.
677 *
678 * @param unit the unit to truncate to, not null
679 * @return an {@code Instant} based on this instant with the time truncated, not null
680 * @throws DateTimeException if the unit is invalid for truncation
681 * @throws UnsupportedTemporalTypeException if the unit is not supported
682 */
683 public Instant truncatedTo(TemporalUnit unit) {
684 if (unit == ChronoUnit.NANOS) {
685 return this;
686 }
687 Duration unitDur = unit.getDuration();
688 if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) {
689 throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
690 }
691 long dur = unitDur.toNanos();
692 if ((LocalTime.NANOS_PER_DAY % dur) != 0) {
693 throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
694 }
695 long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos;
696 long result = (nod / dur) * dur;
697 return plusNanos(result - nod);
698 }
699
700 //-----------------------------------------------------------------------
701 /**
702 * Returns a copy of this instant with the specified amount added.
703 * <p>
704 * This returns an {@code Instant}, based on this one, with the specified amount added.
705 * The amount is typically {@link Duration} but may be any other type implementing
706 * the {@link TemporalAmount} interface.
707 * <p>
708 * The calculation is delegated to the amount object by calling
709 * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free
710 * to implement the addition in any way it wishes, however it typically
711 * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation
712 * of the amount implementation to determine if it can be successfully added.
713 * <p>
714 * This instance is immutable and unaffected by this method call.
715 *
716 * @param amountToAdd the amount to add, not null
717 * @return an {@code Instant} based on this instant with the addition made, not null
718 * @throws DateTimeException if the addition cannot be made
719 * @throws ArithmeticException if numeric overflow occurs
720 */
721 @Override
722 public Instant plus(TemporalAmount amountToAdd) {
723 return (Instant) amountToAdd.addTo(this);
724 }
725
726 /**
727 * Returns a copy of this instant with the specified amount added.
728 * <p>
729 * This returns an {@code Instant}, based on this one, with the amount
730 * in terms of the unit added. If it is not possible to add the amount, because the
731 * unit is not supported or for some other reason, an exception is thrown.
732 * <p>
733 * If the field is a {@link ChronoUnit} then the addition is implemented here.
734 * The supported fields behave as follows:
735 * <ul>
736 * <li>{@code NANOS} -
737 * Returns a {@code Instant} with the specified number of nanoseconds added.
738 * This is equivalent to {@link #plusNanos(long)}.
739 * <li>{@code MICROS} -
740 * Returns a {@code Instant} with the specified number of microseconds added.
741 * This is equivalent to {@link #plusNanos(long)} with the amount
742 * multiplied by 1,000.
743 * <li>{@code MILLIS} -
744 * Returns a {@code Instant} with the specified number of milliseconds added.
745 * This is equivalent to {@link #plusNanos(long)} with the amount
746 * multiplied by 1,000,000.
747 * <li>{@code SECONDS} -
748 * Returns a {@code Instant} with the specified number of seconds added.
749 * This is equivalent to {@link #plusSeconds(long)}.
750 * <li>{@code MINUTES} -
751 * Returns a {@code Instant} with the specified number of minutes added.
752 * This is equivalent to {@link #plusSeconds(long)} with the amount
753 * multiplied by 60.
754 * <li>{@code HOURS} -
755 * Returns a {@code Instant} with the specified number of hours added.
756 * This is equivalent to {@link #plusSeconds(long)} with the amount
757 * multiplied by 3,600.
758 * <li>{@code HALF_DAYS} -
759 * Returns a {@code Instant} with the specified number of half-days added.
760 * This is equivalent to {@link #plusSeconds(long)} with the amount
761 * multiplied by 43,200 (12 hours).
762 * <li>{@code DAYS} -
763 * Returns a {@code Instant} with the specified number of days added.
764 * This is equivalent to {@link #plusSeconds(long)} with the amount
765 * multiplied by 86,400 (24 hours).
766 * </ul>
767 * <p>
768 * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}.
769 * <p>
770 * If the field is not a {@code ChronoUnit}, then the result of this method
771 * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
772 * passing {@code this} as the argument. In this case, the unit determines
773 * whether and how to perform the addition.
774 * <p>
775 * This instance is immutable and unaffected by this method call.
776 *
777 * @param amountToAdd the amount of the unit to add to the result, may be negative
778 * @param unit the unit of the amount to add, not null
779 * @return an {@code Instant} based on this instant with the specified amount added, not null
780 * @throws DateTimeException if the addition cannot be made
781 * @throws UnsupportedTemporalTypeException if the unit is not supported
782 * @throws ArithmeticException if numeric overflow occurs
783 */
784 @Override
785 public Instant plus(long amountToAdd, TemporalUnit unit) {
786 if (unit instanceof ChronoUnit) {
787 switch ((ChronoUnit) unit) {
788 case NANOS: return plusNanos(amountToAdd);
789 case MICROS: return plus(amountToAdd / 1000_000, (amountToAdd % 1000_000) * 1000);
790 case MILLIS: return plusMillis(amountToAdd);
791 case SECONDS: return plusSeconds(amountToAdd);
792 case MINUTES: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_MINUTE));
793 case HOURS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_HOUR));
794 case HALF_DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2));
795 case DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY));
796 }
797 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
798 }
799 return unit.addTo(this, amountToAdd);
800 }
801
802 //-----------------------------------------------------------------------
803 /**
804 * Returns a copy of this instant with the specified duration in seconds added.
805 * <p>
806 * This instance is immutable and unaffected by this method call.
807 *
808 * @param secondsToAdd the seconds to add, positive or negative
809 * @return an {@code Instant} based on this instant with the specified seconds added, not null
810 * @throws DateTimeException if the result exceeds the maximum or minimum instant
811 * @throws ArithmeticException if numeric overflow occurs
812 */
813 public Instant plusSeconds(long secondsToAdd) {
814 return plus(secondsToAdd, 0);
815 }
816
817 /**
818 * Returns a copy of this instant with the specified duration in milliseconds added.
819 * <p>
820 * This instance is immutable and unaffected by this method call.
821 *
822 * @param millisToAdd the milliseconds to add, positive or negative
823 * @return an {@code Instant} based on this instant with the specified milliseconds added, not null
824 * @throws DateTimeException if the result exceeds the maximum or minimum instant
825 * @throws ArithmeticException if numeric overflow occurs
826 */
827 public Instant plusMillis(long millisToAdd) {
828 return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000);
829 }
830
831 /**
832 * Returns a copy of this instant with the specified duration in nanoseconds added.
833 * <p>
834 * This instance is immutable and unaffected by this method call.
835 *
836 * @param nanosToAdd the nanoseconds to add, positive or negative
837 * @return an {@code Instant} based on this instant with the specified nanoseconds added, not null
838 * @throws DateTimeException if the result exceeds the maximum or minimum instant
839 * @throws ArithmeticException if numeric overflow occurs
840 */
841 public Instant plusNanos(long nanosToAdd) {
842 return plus(0, nanosToAdd);
843 }
844
845 /**
846 * Returns a copy of this instant with the specified duration added.
847 * <p>
848 * This instance is immutable and unaffected by this method call.
849 *
850 * @param secondsToAdd the seconds to add, positive or negative
851 * @param nanosToAdd the nanos to add, positive or negative
852 * @return an {@code Instant} based on this instant with the specified seconds added, not null
853 * @throws DateTimeException if the result exceeds the maximum or minimum instant
854 * @throws ArithmeticException if numeric overflow occurs
855 */
856 private Instant plus(long secondsToAdd, long nanosToAdd) {
857 if ((secondsToAdd | nanosToAdd) == 0) {
858 return this;
859 }
860 long epochSec = Math.addExact(seconds, secondsToAdd);
861 epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND);
862 nanosToAdd = nanosToAdd % NANOS_PER_SECOND;
863 long nanoAdjustment = nanos + nanosToAdd; // safe int+NANOS_PER_SECOND
864 return ofEpochSecond(epochSec, nanoAdjustment);
865 }
866
867 //-----------------------------------------------------------------------
868 /**
869 * Returns a copy of this instant with the specified amount subtracted.
870 * <p>
871 * This returns an {@code Instant}, based on this one, with the specified amount subtracted.
872 * The amount is typically {@link Duration} but may be any other type implementing
873 * the {@link TemporalAmount} interface.
874 * <p>
875 * The calculation is delegated to the amount object by calling
876 * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free
877 * to implement the subtraction in any way it wishes, however it typically
878 * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation
879 * of the amount implementation to determine if it can be successfully subtracted.
880 * <p>
881 * This instance is immutable and unaffected by this method call.
882 *
883 * @param amountToSubtract the amount to subtract, not null
884 * @return an {@code Instant} based on this instant with the subtraction made, not null
885 * @throws DateTimeException if the subtraction cannot be made
886 * @throws ArithmeticException if numeric overflow occurs
887 */
888 @Override
889 public Instant minus(TemporalAmount amountToSubtract) {
890 return (Instant) amountToSubtract.subtractFrom(this);
891 }
892
893 /**
894 * Returns a copy of this instant with the specified amount subtracted.
895 * <p>
896 * This returns a {@code Instant}, based on this one, with the amount
897 * in terms of the unit subtracted. If it is not possible to subtract the amount,
898 * because the unit is not supported or for some other reason, an exception is thrown.
899 * <p>
900 * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated.
901 * See that method for a full description of how addition, and thus subtraction, works.
902 * <p>
903 * This instance is immutable and unaffected by this method call.
904 *
905 * @param amountToSubtract the amount of the unit to subtract from the result, may be negative
906 * @param unit the unit of the amount to subtract, not null
907 * @return an {@code Instant} based on this instant with the specified amount subtracted, not null
908 * @throws DateTimeException if the subtraction cannot be made
909 * @throws UnsupportedTemporalTypeException if the unit is not supported
910 * @throws ArithmeticException if numeric overflow occurs
911 */
912 @Override
913 public Instant minus(long amountToSubtract, TemporalUnit unit) {
914 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
915 }
916
917 //-----------------------------------------------------------------------
918 /**
919 * Returns a copy of this instant with the specified duration in seconds subtracted.
920 * <p>
921 * This instance is immutable and unaffected by this method call.
922 *
923 * @param secondsToSubtract the seconds to subtract, positive or negative
924 * @return an {@code Instant} based on this instant with the specified seconds subtracted, not null
925 * @throws DateTimeException if the result exceeds the maximum or minimum instant
926 * @throws ArithmeticException if numeric overflow occurs
927 */
928 public Instant minusSeconds(long secondsToSubtract) {
929 if (secondsToSubtract == Long.MIN_VALUE) {
930 return plusSeconds(Long.MAX_VALUE).plusSeconds(1);
931 }
932 return plusSeconds(-secondsToSubtract);
933 }
934
935 /**
936 * Returns a copy of this instant with the specified duration in milliseconds subtracted.
937 * <p>
938 * This instance is immutable and unaffected by this method call.
939 *
940 * @param millisToSubtract the milliseconds to subtract, positive or negative
941 * @return an {@code Instant} based on this instant with the specified milliseconds subtracted, not null
942 * @throws DateTimeException if the result exceeds the maximum or minimum instant
943 * @throws ArithmeticException if numeric overflow occurs
944 */
945 public Instant minusMillis(long millisToSubtract) {
946 if (millisToSubtract == Long.MIN_VALUE) {
947 return plusMillis(Long.MAX_VALUE).plusMillis(1);
948 }
949 return plusMillis(-millisToSubtract);
950 }
951
952 /**
953 * Returns a copy of this instant with the specified duration in nanoseconds subtracted.
954 * <p>
955 * This instance is immutable and unaffected by this method call.
956 *
957 * @param nanosToSubtract the nanoseconds to subtract, positive or negative
958 * @return an {@code Instant} based on this instant with the specified nanoseconds subtracted, not null
959 * @throws DateTimeException if the result exceeds the maximum or minimum instant
960 * @throws ArithmeticException if numeric overflow occurs
961 */
962 public Instant minusNanos(long nanosToSubtract) {
963 if (nanosToSubtract == Long.MIN_VALUE) {
964 return plusNanos(Long.MAX_VALUE).plusNanos(1);
965 }
966 return plusNanos(-nanosToSubtract);
967 }
968
969 //-------------------------------------------------------------------------
970 /**
971 * Queries this instant using the specified query.
972 * <p>
973 * This queries this instant using the specified query strategy object.
974 * The {@code TemporalQuery} object defines the logic to be used to
975 * obtain the result. Read the documentation of the query to understand
976 * what the result of this method will be.
977 * <p>
978 * The result of this method is obtained by invoking the
979 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
980 * specified query passing {@code this} as the argument.
981 *
982 * @param <R> the type of the result
983 * @param query the query to invoke, not null
984 * @return the query result, null may be returned (defined by the query)
985 * @throws DateTimeException if unable to query (defined by the query)
986 * @throws ArithmeticException if numeric overflow occurs (defined by the query)
987 */
988 @SuppressWarnings("unchecked")
989 @Override
990 public <R> R query(TemporalQuery<R> query) {
991 if (query == TemporalQuery.precision()) {
992 return (R) NANOS;
993 }
994 // inline TemporalAccessor.super.query(query) as an optimization
995 if (query == TemporalQuery.chronology() || query == TemporalQuery.zoneId() ||
996 query == TemporalQuery.zone() || query == TemporalQuery.offset()) {
997 return null;
998 }
999 return query.queryFrom(this);
1000 }
1001
1002 /**
1003 * Adjusts the specified temporal object to have this instant.
1004 * <p>
1005 * This returns a temporal object of the same observable type as the input
1006 * with the instant changed to be the same as this.
1007 * <p>
1008 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
1009 * twice, passing {@link ChronoField#INSTANT_SECONDS} and
1010 * {@link ChronoField#NANO_OF_SECOND} as the fields.
1011 * <p>
1012 * In most cases, it is clearer to reverse the calling pattern by using
1013 * {@link Temporal#with(TemporalAdjuster)}:
1014 * <pre>
1015 * // these two lines are equivalent, but the second approach is recommended
1016 * temporal = thisInstant.adjustInto(temporal);
1017 * temporal = temporal.with(thisInstant);
1018 * </pre>
1019 * <p>
1020 * This instance is immutable and unaffected by this method call.
1021 *
1022 * @param temporal the target object to be adjusted, not null
1023 * @return the adjusted object, not null
1024 * @throws DateTimeException if unable to make the adjustment
1025 * @throws ArithmeticException if numeric overflow occurs
1026 */
1027 @Override
1028 public Temporal adjustInto(Temporal temporal) {
1029 return temporal.with(INSTANT_SECONDS, seconds).with(NANO_OF_SECOND, nanos);
1030 }
1031
1032 /**
1033 * Calculates the period between this instant and another instant in
1034 * terms of the specified unit.
1035 * <p>
1036 * This calculates the period between two instants in terms of a single unit.
1037 * The start and end points are {@code this} and the specified instant.
1038 * The result will be negative if the end is before the start.
1039 * The calculation returns a whole number, representing the number of
1040 * complete units between the two instants.
1041 * The {@code Temporal} passed to this method must be an {@code Instant}.
1042 * For example, the period in days between two dates can be calculated
1043 * using {@code startInstant.periodUntil(endInstant, SECONDS)}.
1044 * <p>
1045 * There are two equivalent ways of using this method.
1046 * The first is to invoke this method.
1047 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
1048 * <pre>
1049 * // these two lines are equivalent
1050 * amount = start.periodUntil(end, SECONDS);
1051 * amount = SECONDS.between(start, end);
1052 * </pre>
1053 * The choice should be made based on which makes the code more readable.
1054 * <p>
1055 * The calculation is implemented in this method for {@link ChronoUnit}.
1056 * The units {@code NANOS}, {@code MICROS}, {@code MILLIS}, {@code SECONDS},
1057 * {@code MINUTES}, {@code HOURS}, {@code HALF_DAYS} and {@code DAYS}
1058 * are supported. Other {@code ChronoUnit} values will throw an exception.
1059 * <p>
1060 * If the unit is not a {@code ChronoUnit}, then the result of this method
1061 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
1062 * passing {@code this} as the first argument and the input temporal as
1063 * the second argument.
1064 * <p>
1065 * This instance is immutable and unaffected by this method call.
1066 *
1067 * @param endInstant the end date, which must be a {@code LocalDate}, not null
1068 * @param unit the unit to measure the period in, not null
1069 * @return the amount of the period between this date and the end date
1070 * @throws DateTimeException if the period cannot be calculated
1071 * @throws UnsupportedTemporalTypeException if the unit is not supported
1072 * @throws ArithmeticException if numeric overflow occurs
1073 */
1074 @Override
1075 public long periodUntil(Temporal endInstant, TemporalUnit unit) {
1076 if (endInstant instanceof Instant == false) {
1077 Objects.requireNonNull(endInstant, "endInstant");
1078 throw new DateTimeException("Unable to calculate period between objects of two different types");
1079 }
1080 Instant end = (Instant) endInstant;
1081 if (unit instanceof ChronoUnit) {
1082 ChronoUnit f = (ChronoUnit) unit;
1083 switch (f) {
1084 case NANOS: return nanosUntil(end);
1085 case MICROS: return nanosUntil(end) / 1000;
1086 case MILLIS: return Math.subtractExact(end.toEpochMilli(), toEpochMilli());
1087 case SECONDS: return secondsUntil(end);
1088 case MINUTES: return secondsUntil(end) / SECONDS_PER_MINUTE;
1089 case HOURS: return secondsUntil(end) / SECONDS_PER_HOUR;
1090 case HALF_DAYS: return secondsUntil(end) / (12 * SECONDS_PER_HOUR);
1091 case DAYS: return secondsUntil(end) / (SECONDS_PER_DAY);
1092 }
1093 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
1094 }
1095 return unit.between(this, endInstant);
1096 }
1097
1098 private long nanosUntil(Instant end) {
1099 long secsDiff = Math.subtractExact(end.seconds, seconds);
1100 long totalNanos = Math.multiplyExact(secsDiff, NANOS_PER_SECOND);
1101 return Math.addExact(totalNanos, end.nanos - nanos);
1102 }
1103
1104 private long secondsUntil(Instant end) {
1105 long secsDiff = Math.subtractExact(end.seconds, seconds);
1106 long nanosDiff = end.nanos - nanos;
1107 if (secsDiff > 0 && nanosDiff < 0) {
1108 secsDiff--;
1109 } else if (secsDiff < 0 && nanosDiff > 0) {
1110 secsDiff++;
1111 }
1112 return secsDiff;
1113 }
1114
1115 //-----------------------------------------------------------------------
1116 /**
1117 * Combines this instant with an offset to create an {@code OffsetDateTime}.
1118 * <p>
1119 * This returns an {@code OffsetDateTime} formed from this instant at the
1120 * specified offset from UTC/Greenwich. An exception will be thrown if the
1121 * instant is too large to fit into an offset date-time.
1122 * <p>
1123 * This method is equivalent to
1124 * {@link OffsetDateTime#ofInstant(Instant, ZoneId) OffsetDateTime.ofInstant(this, offset)}.
1125 *
1126 * @param offset the offset to combine with, not null
1127 * @return the offset date-time formed from this instant and the specified offset, not null
1128 * @throws DateTimeException if the result exceeds the supported range
1129 */
1130 public OffsetDateTime atOffset(ZoneOffset offset) {
1131 return OffsetDateTime.ofInstant(this, offset);
1132 }
1133
1134 /**
1135 * Combines this instant with a time-zone to create a {@code ZonedDateTime}.
1136 * <p>
1137 * This returns an {@code ZonedDateTime} formed from this instant at the
1138 * specified time-zone. An exception will be thrown if the instant is too
1139 * large to fit into a zoned date-time.
1140 * <p>
1141 * This method is equivalent to
1142 * {@link ZonedDateTime#ofInstant(Instant, ZoneId) ZonedDateTime.ofInstant(this, zone)}.
1143 *
1144 * @param zone the zone to combine with, not null
1145 * @return the zoned date-time formed from this instant and the specified zone, not null
1146 * @throws DateTimeException if the result exceeds the supported range
1147 */
1148 public ZonedDateTime atZone(ZoneId zone) {
1149 return ZonedDateTime.ofInstant(this, zone);
1150 }
1151
1152 //-----------------------------------------------------------------------
1153 /**
1154 * Converts this instant to the number of milliseconds from the epoch
1155 * of 1970-01-01T00:00:00Z.
1156 * <p>
1157 * If this instant represents a point on the time-line too far in the future
1158 * or past to fit in a {@code long} milliseconds, then an exception is thrown.
1159 * <p>
1160 * If this instant has greater than millisecond precision, then the conversion
1161 * will drop any excess precision information as though the amount in nanoseconds
1162 * was subject to integer division by one million.
1163 *
1164 * @return the number of milliseconds since the epoch of 1970-01-01T00:00:00Z
1165 * @throws ArithmeticException if numeric overflow occurs
1166 */
1167 public long toEpochMilli() {
1168 long millis = Math.multiplyExact(seconds, 1000);
1169 return millis + nanos / 1000_000;
1170 }
1171
1172 //-----------------------------------------------------------------------
1173 /**
1174 * Compares this instant to the specified instant.
1175 * <p>
1176 * The comparison is based on the time-line position of the instants.
1177 * It is "consistent with equals", as defined by {@link Comparable}.
1178 *
1179 * @param otherInstant the other instant to compare to, not null
1180 * @return the comparator value, negative if less, positive if greater
1181 * @throws NullPointerException if otherInstant is null
1182 */
1183 @Override
1184 public int compareTo(Instant otherInstant) {
1185 int cmp = Long.compare(seconds, otherInstant.seconds);
1186 if (cmp != 0) {
1187 return cmp;
1188 }
1189 return nanos - otherInstant.nanos;
1190 }
1191
1192 /**
1193 * Checks if this instant is after the specified instant.
1194 * <p>
1195 * The comparison is based on the time-line position of the instants.
1196 *
1197 * @param otherInstant the other instant to compare to, not null
1198 * @return true if this instant is after the specified instant
1199 * @throws NullPointerException if otherInstant is null
1200 */
1201 public boolean isAfter(Instant otherInstant) {
1202 return compareTo(otherInstant) > 0;
1203 }
1204
1205 /**
1206 * Checks if this instant is before the specified instant.
1207 * <p>
1208 * The comparison is based on the time-line position of the instants.
1209 *
1210 * @param otherInstant the other instant to compare to, not null
1211 * @return true if this instant is before the specified instant
1212 * @throws NullPointerException if otherInstant is null
1213 */
1214 public boolean isBefore(Instant otherInstant) {
1215 return compareTo(otherInstant) < 0;
1216 }
1217
1218 //-----------------------------------------------------------------------
1219 /**
1220 * Checks if this instant is equal to the specified instant.
1221 * <p>
1222 * The comparison is based on the time-line position of the instants.
1223 *
1224 * @param otherInstant the other instant, null returns false
1225 * @return true if the other instant is equal to this one
1226 */
1227 @Override
1228 public boolean equals(Object otherInstant) {
1229 if (this == otherInstant) {
1230 return true;
1231 }
1232 if (otherInstant instanceof Instant) {
1233 Instant other = (Instant) otherInstant;
1234 return this.seconds == other.seconds &&
1235 this.nanos == other.nanos;
1236 }
1237 return false;
1238 }
1239
1240 /**
1241 * Returns a hash code for this instant.
1242 *
1243 * @return a suitable hash code
1244 */
1245 @Override
1246 public int hashCode() {
1247 return ((int) (seconds ^ (seconds >>> 32))) + 51 * nanos;
1248 }
1249
1250 //-----------------------------------------------------------------------
1251 /**
1252 * A string representation of this instant using ISO-8601 representation.
1253 * <p>
1254 * The format used is the same as {@link DateTimeFormatter#ISO_INSTANT}.
1255 *
1256 * @return an ISO-8601 representation of this instant, not null
1257 */
1258 @Override
1259 public String toString() {
1260 return DateTimeFormatter.ISO_INSTANT.format(this);
1261 }
1262
1263 // -----------------------------------------------------------------------
1264 /**
1265 * Writes the object using a
1266 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
1267 * <pre>
1268 * out.writeByte(2); // identifies this as an Instant
1269 * out.writeLong(seconds);
1270 * out.writeInt(nanos);
1271 * </pre>
1272 *
1273 * @return the instance of {@code Ser}, not null
1274 */
1275 private Object writeReplace() {
1276 return new Ser(Ser.INSTANT_TYPE, this);
1277 }
1278
1279 /**
1280 * Defend against malicious streams.
1281 * @return never
1282 * @throws InvalidObjectException always
1283 */
1284 private Object readResolve() throws ObjectStreamException {
1285 throw new InvalidObjectException("Deserialization via serialization delegate");
1286 }
1287
1288 void writeExternal(DataOutput out) throws IOException {
1289 out.writeLong(seconds);
1290 out.writeInt(nanos);
1291 }
1292
1293 static Instant readExternal(DataInput in) throws IOException {
1294 long seconds = in.readLong();
1295 int nanos = in.readInt();
1296 return Instant.ofEpochSecond(seconds, nanos);
1297 }
1298
1299 }