1 /* 2 * Copyright (c) 2012, 2019, 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.ObjectInputStream; 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.TemporalQueries; 91 import java.time.temporal.TemporalQuery; 92 import java.time.temporal.TemporalUnit; 93 import java.time.temporal.UnsupportedTemporalTypeException; 94 import java.time.temporal.ValueRange; 95 import java.util.Objects; 96 97 /** 98 * An instantaneous point on the time-line. 99 * <p> 100 * This class models a single instantaneous point on the time-line. 101 * This might be used to record event time-stamps in the application. 102 * <p> 103 * The range of an instant requires the storage of a number larger than a {@code long}. 104 * To achieve this, the class stores a {@code long} representing epoch-seconds and an 105 * {@code int} representing nanosecond-of-second, which will always be between 0 and 999,999,999. 106 * The epoch-seconds are measured from the standard Java epoch of {@code 1970-01-01T00:00:00Z} 107 * where instants after the epoch have positive values, and earlier instants have negative values. 108 * For both the epoch-second and nanosecond parts, a larger value is always later on the time-line 109 * than a smaller value. 110 * 111 * <h2>Time-scale</h2> 112 * <p> 113 * The length of the solar day is the standard way that humans measure time. 114 * This has traditionally been subdivided into 24 hours of 60 minutes of 60 seconds, 115 * forming a 86400 second day. 116 * <p> 117 * Modern timekeeping is based on atomic clocks which precisely define an SI second 118 * relative to the transitions of a Caesium atom. The length of an SI second was defined 119 * to be very close to the 86400th fraction of a day. 120 * <p> 121 * Unfortunately, as the Earth rotates the length of the day varies. 122 * In addition, over time the average length of the day is getting longer as the Earth slows. 123 * As a result, the length of a solar day in 2012 is slightly longer than 86400 SI seconds. 124 * The actual length of any given day and the amount by which the Earth is slowing 125 * are not predictable and can only be determined by measurement. 126 * The UT1 time-scale captures the accurate length of day, but is only available some 127 * time after the day has completed. 128 * <p> 129 * The UTC time-scale is a standard approach to bundle up all the additional fractions 130 * of a second from UT1 into whole seconds, known as <i>leap-seconds</i>. 131 * A leap-second may be added or removed depending on the Earth's rotational changes. 132 * As such, UTC permits a day to have 86399 SI seconds or 86401 SI seconds where 133 * necessary in order to keep the day aligned with the Sun. 134 * <p> 135 * The modern UTC time-scale was introduced in 1972, introducing the concept of whole leap-seconds. 136 * Between 1958 and 1972, the definition of UTC was complex, with minor sub-second leaps and 137 * alterations to the length of the notional second. As of 2012, discussions are underway 138 * to change the definition of UTC again, with the potential to remove leap seconds or 139 * introduce other changes. 140 * <p> 141 * Given the complexity of accurate timekeeping described above, this Java API defines 142 * its own time-scale, the <i>Java Time-Scale</i>. 143 * <p> 144 * The Java Time-Scale divides each calendar day into exactly 86400 145 * subdivisions, known as seconds. These seconds may differ from the 146 * SI second. It closely matches the de facto international civil time 147 * scale, the definition of which changes from time to time. 148 * <p> 149 * The Java Time-Scale has slightly different definitions for different 150 * segments of the time-line, each based on the consensus international 151 * time scale that is used as the basis for civil time. Whenever the 152 * internationally-agreed time scale is modified or replaced, a new 153 * segment of the Java Time-Scale must be defined for it. Each segment 154 * must meet these requirements: 155 * <ul> 156 * <li>the Java Time-Scale shall closely match the underlying international 157 * civil time scale;</li> 158 * <li>the Java Time-Scale shall exactly match the international civil 159 * time scale at noon each day;</li> 160 * <li>the Java Time-Scale shall have a precisely-defined relationship to 161 * the international civil time scale.</li> 162 * </ul> 163 * There are currently, as of 2013, two segments in the Java time-scale. 164 * <p> 165 * For the segment from 1972-11-03 (exact boundary discussed below) until 166 * further notice, the consensus international time scale is UTC (with 167 * leap seconds). In this segment, the Java Time-Scale is identical to 168 * <a href="http://www.cl.cam.ac.uk/~mgk25/time/utc-sls/">UTC-SLS</a>. 169 * This is identical to UTC on days that do not have a leap second. 170 * On days that do have a leap second, the leap second is spread equally 171 * over the last 1000 seconds of the day, maintaining the appearance of 172 * exactly 86400 seconds per day. 173 * <p> 174 * For the segment prior to 1972-11-03, extending back arbitrarily far, 175 * the consensus international time scale is defined to be UT1, applied 176 * proleptically, which is equivalent to the (mean) solar time on the 177 * prime meridian (Greenwich). In this segment, the Java Time-Scale is 178 * identical to the consensus international time scale. The exact 179 * boundary between the two segments is the instant where UT1 = UTC 180 * between 1972-11-03T00:00 and 1972-11-04T12:00. 181 * <p> 182 * Implementations of the Java time-scale using the JSR-310 API are not 183 * required to provide any clock that is sub-second accurate, or that 184 * progresses monotonically or smoothly. Implementations are therefore 185 * not required to actually perform the UTC-SLS slew or to otherwise be 186 * aware of leap seconds. JSR-310 does, however, require that 187 * implementations must document the approach they use when defining a 188 * clock representing the current instant. 189 * See {@link Clock} for details on the available clocks. 190 * <p> 191 * The Java time-scale is used for all date-time classes. 192 * This includes {@code Instant}, {@code LocalDate}, {@code LocalTime}, {@code OffsetDateTime}, 193 * {@code ZonedDateTime} and {@code Duration}. 194 * 195 * <p> 196 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a> 197 * class; use of identity-sensitive operations (including reference equality 198 * ({@code ==}), identity hash code, or synchronization) on instances of 199 * {@code Instant} may have unpredictable results and should be avoided. 200 * The {@code equals} method should be used for comparisons. 201 * 202 * @implSpec 203 * This class is immutable and thread-safe. 204 * 205 * @since 1.8 206 */ 207 public final class Instant 208 implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable { 209 210 /** 211 * Constant for the 1970-01-01T00:00:00Z epoch instant. 212 */ 213 public static final Instant EPOCH = new Instant(0, 0); 214 /** 215 * The minimum supported epoch second. 216 */ 217 private static final long MIN_SECOND = -31557014167219200L; 218 /** 219 * The maximum supported epoch second. 220 */ 221 private static final long MAX_SECOND = 31556889864403199L; 222 /** 223 * The minimum supported {@code Instant}, '-1000000000-01-01T00:00Z'. 224 * This could be used by an application as a "far past" instant. 225 * <p> 226 * This is one year earlier than the minimum {@code LocalDateTime}. 227 * This provides sufficient values to handle the range of {@code ZoneOffset} 228 * which affect the instant in addition to the local date-time. 229 * The value is also chosen such that the value of the year fits in 230 * an {@code int}. 231 */ 232 public static final Instant MIN = Instant.ofEpochSecond(MIN_SECOND, 0); 233 /** 234 * The maximum supported {@code Instant}, '1000000000-12-31T23:59:59.999999999Z'. 235 * This could be used by an application as a "far future" instant. 236 * <p> 237 * This is one year later than the maximum {@code LocalDateTime}. 238 * This provides sufficient values to handle the range of {@code ZoneOffset} 239 * which affect the instant in addition to the local date-time. 240 * The value is also chosen such that the value of the year fits in 241 * an {@code int}. 242 */ 243 public static final Instant MAX = Instant.ofEpochSecond(MAX_SECOND, 999_999_999); 244 245 /** 246 * Serialization version. 247 */ 248 private static final long serialVersionUID = -665713676816604388L; 249 250 /** 251 * The number of seconds from the epoch of 1970-01-01T00:00:00Z. 252 */ 253 private final long seconds; 254 /** 255 * The number of nanoseconds, later along the time-line, from the seconds field. 256 * This is always positive, and never exceeds 999,999,999. 257 */ 258 private final int nanos; 259 260 //----------------------------------------------------------------------- 261 /** 262 * Obtains the current instant from the system clock. 263 * <p> 264 * This will query the {@link Clock#systemUTC() system UTC clock} to 265 * obtain the current instant. 266 * <p> 267 * Using this method will prevent the ability to use an alternate time-source for 268 * testing because the clock is effectively hard-coded. 269 * 270 * @return the current instant using the system clock, not null 271 */ 272 public static Instant now() { 273 return Clock.systemUTC().instant(); 274 } 275 276 /** 277 * Obtains the current instant from the specified clock. 278 * <p> 279 * This will query the specified clock to obtain the current time. 280 * <p> 281 * Using this method allows the use of an alternate clock for testing. 282 * The alternate clock may be introduced using {@link Clock dependency injection}. 283 * 284 * @param clock the clock to use, not null 285 * @return the current instant, not null 286 */ 287 public static Instant now(Clock clock) { 288 Objects.requireNonNull(clock, "clock"); 289 return clock.instant(); 290 } 291 292 //----------------------------------------------------------------------- 293 /** 294 * Obtains an instance of {@code Instant} using seconds from the 295 * epoch of 1970-01-01T00:00:00Z. 296 * <p> 297 * The nanosecond field is set to zero. 298 * 299 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z 300 * @return an instant, not null 301 * @throws DateTimeException if the instant exceeds the maximum or minimum instant 302 */ 303 public static Instant ofEpochSecond(long epochSecond) { 304 return create(epochSecond, 0); 305 } 306 307 /** 308 * Obtains an instance of {@code Instant} using seconds from the 309 * epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second. 310 * <p> 311 * This method allows an arbitrary number of nanoseconds to be passed in. 312 * The factory will alter the values of the second and nanosecond in order 313 * to ensure that the stored nanosecond is in the range 0 to 999,999,999. 314 * For example, the following will result in exactly the same instant: 315 * <pre> 316 * Instant.ofEpochSecond(3, 1); 317 * Instant.ofEpochSecond(4, -999_999_999); 318 * Instant.ofEpochSecond(2, 1000_000_001); 319 * </pre> 320 * 321 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z 322 * @param nanoAdjustment the nanosecond adjustment to the number of seconds, positive or negative 323 * @return an instant, not null 324 * @throws DateTimeException if the instant exceeds the maximum or minimum instant 325 * @throws ArithmeticException if numeric overflow occurs 326 */ 327 public static Instant ofEpochSecond(long epochSecond, long nanoAdjustment) { 328 long secs = Math.addExact(epochSecond, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND)); 329 int nos = (int)Math.floorMod(nanoAdjustment, NANOS_PER_SECOND); 330 return create(secs, nos); 331 } 332 333 /** 334 * Obtains an instance of {@code Instant} using milliseconds from the 335 * epoch of 1970-01-01T00:00:00Z. 336 * <p> 337 * The seconds and nanoseconds are extracted from the specified milliseconds. 338 * 339 * @param epochMilli the number of milliseconds from 1970-01-01T00:00:00Z 340 * @return an instant, not null 341 * @throws DateTimeException if the instant exceeds the maximum or minimum instant 342 */ 343 public static Instant ofEpochMilli(long epochMilli) { 344 long secs = Math.floorDiv(epochMilli, 1000); 345 int mos = Math.floorMod(epochMilli, 1000); 346 return create(secs, mos * 1000_000); 347 } 348 349 //----------------------------------------------------------------------- 350 /** 351 * Obtains an instance of {@code Instant} from a temporal object. 352 * <p> 353 * This obtains an instant based on the specified temporal. 354 * A {@code TemporalAccessor} represents an arbitrary set of date and time information, 355 * which this factory converts to an instance of {@code Instant}. 356 * <p> 357 * The conversion extracts the {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS} 358 * and {@link ChronoField#NANO_OF_SECOND NANO_OF_SECOND} fields. 359 * <p> 360 * This method matches the signature of the functional interface {@link TemporalQuery} 361 * allowing it to be used as a query via method reference, {@code Instant::from}. 362 * 363 * @param temporal the temporal object to convert, not null 364 * @return the instant, not null 365 * @throws DateTimeException if unable to convert to an {@code Instant} 366 */ 367 public static Instant from(TemporalAccessor temporal) { 368 if (temporal instanceof Instant) { 369 return (Instant) temporal; 370 } 371 Objects.requireNonNull(temporal, "temporal"); 372 try { 373 long instantSecs = temporal.getLong(INSTANT_SECONDS); 374 int nanoOfSecond = temporal.get(NANO_OF_SECOND); 375 return Instant.ofEpochSecond(instantSecs, nanoOfSecond); 376 } catch (DateTimeException ex) { 377 throw new DateTimeException("Unable to obtain Instant from TemporalAccessor: " + 378 temporal + " of type " + temporal.getClass().getName(), ex); 379 } 380 } 381 382 //----------------------------------------------------------------------- 383 /** 384 * Obtains an instance of {@code Instant} from a text string such as 385 * {@code 2007-12-03T10:15:30.00Z}. 386 * <p> 387 * The string must represent a valid instant in UTC and is parsed using 388 * {@link DateTimeFormatter#ISO_INSTANT}. 389 * 390 * @param text the text to parse, not null 391 * @return the parsed instant, not null 392 * @throws DateTimeParseException if the text cannot be parsed 393 */ 394 public static Instant parse(final CharSequence text) { 395 return DateTimeFormatter.ISO_INSTANT.parse(text, Instant::from); 396 } 397 398 //----------------------------------------------------------------------- 399 /** 400 * Obtains an instance of {@code Instant} using seconds and nanoseconds. 401 * 402 * @param seconds the length of the duration in seconds 403 * @param nanoOfSecond the nano-of-second, from 0 to 999,999,999 404 * @throws DateTimeException if the instant exceeds the maximum or minimum instant 405 */ 406 private static Instant create(long seconds, int nanoOfSecond) { 407 if ((seconds | nanoOfSecond) == 0) { 408 return EPOCH; 409 } 410 if (seconds < MIN_SECOND || seconds > MAX_SECOND) { 411 throw new DateTimeException("Instant exceeds minimum or maximum instant"); 412 } 413 return new Instant(seconds, nanoOfSecond); 414 } 415 416 /** 417 * Constructs an instance of {@code Instant} using seconds from the epoch of 418 * 1970-01-01T00:00:00Z and nanosecond fraction of second. 419 * 420 * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z 421 * @param nanos the nanoseconds within the second, must be positive 422 */ 423 private Instant(long epochSecond, int nanos) { 424 super(); 425 this.seconds = epochSecond; 426 this.nanos = nanos; 427 } 428 429 //----------------------------------------------------------------------- 430 /** 431 * Checks if the specified field is supported. 432 * <p> 433 * This checks if this instant can be queried for the specified field. 434 * If false, then calling the {@link #range(TemporalField) range}, 435 * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)} 436 * methods will throw an exception. 437 * <p> 438 * If the field is a {@link ChronoField} then the query is implemented here. 439 * The supported fields are: 440 * <ul> 441 * <li>{@code NANO_OF_SECOND} 442 * <li>{@code MICRO_OF_SECOND} 443 * <li>{@code MILLI_OF_SECOND} 444 * <li>{@code INSTANT_SECONDS} 445 * </ul> 446 * All other {@code ChronoField} instances will return false. 447 * <p> 448 * If the field is not a {@code ChronoField}, then the result of this method 449 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)} 450 * passing {@code this} as the argument. 451 * Whether the field is supported is determined by the field. 452 * 453 * @param field the field to check, null returns false 454 * @return true if the field is supported on this instant, false if not 455 */ 456 @Override 457 public boolean isSupported(TemporalField field) { 458 if (field instanceof ChronoField) { 459 return field == INSTANT_SECONDS || field == NANO_OF_SECOND || field == MICRO_OF_SECOND || field == MILLI_OF_SECOND; 460 } 461 return field != null && field.isSupportedBy(this); 462 } 463 464 /** 465 * Checks if the specified unit is supported. 466 * <p> 467 * This checks if the specified unit can be added to, or subtracted from, this date-time. 468 * If false, then calling the {@link #plus(long, TemporalUnit)} and 469 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception. 470 * <p> 471 * If the unit is a {@link ChronoUnit} then the query is implemented here. 472 * The supported units are: 473 * <ul> 474 * <li>{@code NANOS} 475 * <li>{@code MICROS} 476 * <li>{@code MILLIS} 477 * <li>{@code SECONDS} 478 * <li>{@code MINUTES} 479 * <li>{@code HOURS} 480 * <li>{@code HALF_DAYS} 481 * <li>{@code DAYS} 482 * </ul> 483 * All other {@code ChronoUnit} instances will return false. 484 * <p> 485 * If the unit is not a {@code ChronoUnit}, then the result of this method 486 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)} 487 * passing {@code this} as the argument. 488 * Whether the unit is supported is determined by the unit. 489 * 490 * @param unit the unit to check, null returns false 491 * @return true if the unit can be added/subtracted, false if not 492 */ 493 @Override 494 public boolean isSupported(TemporalUnit unit) { 495 if (unit instanceof ChronoUnit) { 496 return unit.isTimeBased() || unit == DAYS; 497 } 498 return unit != null && unit.isSupportedBy(this); 499 } 500 501 //----------------------------------------------------------------------- 502 /** 503 * Gets the range of valid values for the specified field. 504 * <p> 505 * The range object expresses the minimum and maximum valid values for a field. 506 * This instant is used to enhance the accuracy of the returned range. 507 * If it is not possible to return the range, because the field is not supported 508 * or for some other reason, an exception is thrown. 509 * <p> 510 * If the field is a {@link ChronoField} then the query is implemented here. 511 * The {@link #isSupported(TemporalField) supported fields} will return 512 * appropriate range instances. 513 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. 514 * <p> 515 * If the field is not a {@code ChronoField}, then the result of this method 516 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)} 517 * passing {@code this} as the argument. 518 * Whether the range can be obtained is determined by the field. 519 * 520 * @param field the field to query the range for, not null 521 * @return the range of valid values for the field, not null 522 * @throws DateTimeException if the range for the field cannot be obtained 523 * @throws UnsupportedTemporalTypeException if the field is not supported 524 */ 525 @Override // override for Javadoc 526 public ValueRange range(TemporalField field) { 527 return Temporal.super.range(field); 528 } 529 530 /** 531 * Gets the value of the specified field from this instant as an {@code int}. 532 * <p> 533 * This queries this instant for the value of the specified field. 534 * The returned value will always be within the valid range of values for the field. 535 * If it is not possible to return the value, because the field is not supported 536 * or for some other reason, an exception is thrown. 537 * <p> 538 * If the field is a {@link ChronoField} then the query is implemented here. 539 * The {@link #isSupported(TemporalField) supported fields} will return valid 540 * values based on this date-time, except {@code INSTANT_SECONDS} which is too 541 * large to fit in an {@code int} and throws a {@code DateTimeException}. 542 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. 543 * <p> 544 * If the field is not a {@code ChronoField}, then the result of this method 545 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)} 546 * passing {@code this} as the argument. Whether the value can be obtained, 547 * and what the value represents, is determined by the field. 548 * 549 * @param field the field to get, not null 550 * @return the value for the field 551 * @throws DateTimeException if a value for the field cannot be obtained or 552 * the value is outside the range of valid values for the field 553 * @throws UnsupportedTemporalTypeException if the field is not supported or 554 * the range of values exceeds an {@code int} 555 * @throws ArithmeticException if numeric overflow occurs 556 */ 557 @Override // override for Javadoc and performance 558 public int get(TemporalField field) { 559 if (field instanceof ChronoField) { 560 switch ((ChronoField) field) { 561 case NANO_OF_SECOND: return nanos; 562 case MICRO_OF_SECOND: return nanos / 1000; 563 case MILLI_OF_SECOND: return nanos / 1000_000; 564 } 565 throw new UnsupportedTemporalTypeException("Unsupported field: " + field); 566 } 567 return range(field).checkValidIntValue(field.getFrom(this), field); 568 } 569 570 /** 571 * Gets the value of the specified field from this instant as a {@code long}. 572 * <p> 573 * This queries this instant for the value of the specified field. 574 * If it is not possible to return the value, because the field is not supported 575 * or for some other reason, an exception is thrown. 576 * <p> 577 * If the field is a {@link ChronoField} then the query is implemented here. 578 * The {@link #isSupported(TemporalField) supported fields} will return valid 579 * values based on this date-time. 580 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. 581 * <p> 582 * If the field is not a {@code ChronoField}, then the result of this method 583 * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)} 584 * passing {@code this} as the argument. Whether the value can be obtained, 585 * and what the value represents, is determined by the field. 586 * 587 * @param field the field to get, not null 588 * @return the value for the field 589 * @throws DateTimeException if a value for the field cannot be obtained 590 * @throws UnsupportedTemporalTypeException if the field is not supported 591 * @throws ArithmeticException if numeric overflow occurs 592 */ 593 @Override 594 public long getLong(TemporalField field) { 595 if (field instanceof ChronoField) { 596 switch ((ChronoField) field) { 597 case NANO_OF_SECOND: return nanos; 598 case MICRO_OF_SECOND: return nanos / 1000; 599 case MILLI_OF_SECOND: return nanos / 1000_000; 600 case INSTANT_SECONDS: return seconds; 601 } 602 throw new UnsupportedTemporalTypeException("Unsupported field: " + field); 603 } 604 return field.getFrom(this); 605 } 606 607 //----------------------------------------------------------------------- 608 /** 609 * Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z. 610 * <p> 611 * The epoch second count is a simple incrementing count of seconds where 612 * second 0 is 1970-01-01T00:00:00Z. 613 * The nanosecond part is returned by {@link #getNano}. 614 * 615 * @return the seconds from the epoch of 1970-01-01T00:00:00Z 616 */ 617 public long getEpochSecond() { 618 return seconds; 619 } 620 621 /** 622 * Gets the number of nanoseconds, later along the time-line, from the start 623 * of the second. 624 * <p> 625 * The nanosecond-of-second value measures the total number of nanoseconds from 626 * the second returned by {@link #getEpochSecond}. 627 * 628 * @return the nanoseconds within the second, always positive, never exceeds 999,999,999 629 */ 630 public int getNano() { 631 return nanos; 632 } 633 634 //------------------------------------------------------------------------- 635 /** 636 * Returns an adjusted copy of this instant. 637 * <p> 638 * This returns an {@code Instant}, based on this one, with the instant adjusted. 639 * The adjustment takes place using the specified adjuster strategy object. 640 * Read the documentation of the adjuster to understand what adjustment will be made. 641 * <p> 642 * The result of this method is obtained by invoking the 643 * {@link TemporalAdjuster#adjustInto(Temporal)} method on the 644 * specified adjuster passing {@code this} as the argument. 645 * <p> 646 * This instance is immutable and unaffected by this method call. 647 * 648 * @param adjuster the adjuster to use, not null 649 * @return an {@code Instant} based on {@code this} with the adjustment made, not null 650 * @throws DateTimeException if the adjustment cannot be made 651 * @throws ArithmeticException if numeric overflow occurs 652 */ 653 @Override 654 public Instant with(TemporalAdjuster adjuster) { 655 return (Instant) adjuster.adjustInto(this); 656 } 657 658 /** 659 * Returns a copy of this instant with the specified field set to a new value. 660 * <p> 661 * This returns an {@code Instant}, based on this one, with the value 662 * for the specified field changed. 663 * If it is not possible to set the value, because the field is not supported or for 664 * some other reason, an exception is thrown. 665 * <p> 666 * If the field is a {@link ChronoField} then the adjustment is implemented here. 667 * The supported fields behave as follows: 668 * <ul> 669 * <li>{@code NANO_OF_SECOND} - 670 * Returns an {@code Instant} with the specified nano-of-second. 671 * The epoch-second will be unchanged. 672 * <li>{@code MICRO_OF_SECOND} - 673 * Returns an {@code Instant} with the nano-of-second replaced by the specified 674 * micro-of-second multiplied by 1,000. The epoch-second will be unchanged. 675 * <li>{@code MILLI_OF_SECOND} - 676 * Returns an {@code Instant} with the nano-of-second replaced by the specified 677 * milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged. 678 * <li>{@code INSTANT_SECONDS} - 679 * Returns an {@code Instant} with the specified epoch-second. 680 * The nano-of-second will be unchanged. 681 * </ul> 682 * <p> 683 * In all cases, if the new value is outside the valid range of values for the field 684 * then a {@code DateTimeException} will be thrown. 685 * <p> 686 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. 687 * <p> 688 * If the field is not a {@code ChronoField}, then the result of this method 689 * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)} 690 * passing {@code this} as the argument. In this case, the field determines 691 * whether and how to adjust the instant. 692 * <p> 693 * This instance is immutable and unaffected by this method call. 694 * 695 * @param field the field to set in the result, not null 696 * @param newValue the new value of the field in the result 697 * @return an {@code Instant} based on {@code this} with the specified field set, not null 698 * @throws DateTimeException if the field cannot be set 699 * @throws UnsupportedTemporalTypeException if the field is not supported 700 * @throws ArithmeticException if numeric overflow occurs 701 */ 702 @Override 703 public Instant with(TemporalField field, long newValue) { 704 if (field instanceof ChronoField) { 705 ChronoField f = (ChronoField) field; 706 f.checkValidValue(newValue); 707 switch (f) { 708 case MILLI_OF_SECOND: { 709 int nval = (int) newValue * 1000_000; 710 return (nval != nanos ? create(seconds, nval) : this); 711 } 712 case MICRO_OF_SECOND: { 713 int nval = (int) newValue * 1000; 714 return (nval != nanos ? create(seconds, nval) : this); 715 } 716 case NANO_OF_SECOND: return (newValue != nanos ? create(seconds, (int) newValue) : this); 717 case INSTANT_SECONDS: return (newValue != seconds ? create(newValue, nanos) : this); 718 } 719 throw new UnsupportedTemporalTypeException("Unsupported field: " + field); 720 } 721 return field.adjustInto(this, newValue); 722 } 723 724 //----------------------------------------------------------------------- 725 /** 726 * Returns a copy of this {@code Instant} truncated to the specified unit. 727 * <p> 728 * Truncating the instant returns a copy of the original with fields 729 * smaller than the specified unit set to zero. 730 * The fields are calculated on the basis of using a UTC offset as seen 731 * in {@code toString}. 732 * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will 733 * round down to the nearest minute, setting the seconds and nanoseconds to zero. 734 * <p> 735 * The unit must have a {@linkplain TemporalUnit#getDuration() duration} 736 * that divides into the length of a standard day without remainder. 737 * This includes all supplied time units on {@link ChronoUnit} and 738 * {@link ChronoUnit#DAYS DAYS}. Other units throw an exception. 739 * <p> 740 * This instance is immutable and unaffected by this method call. 741 * 742 * @param unit the unit to truncate to, not null 743 * @return an {@code Instant} based on this instant with the time truncated, not null 744 * @throws DateTimeException if the unit is invalid for truncation 745 * @throws UnsupportedTemporalTypeException if the unit is not supported 746 */ 747 public Instant truncatedTo(TemporalUnit unit) { 748 if (unit == ChronoUnit.NANOS) { 749 return this; 750 } 751 Duration unitDur = unit.getDuration(); 752 if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) { 753 throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation"); 754 } 755 long dur = unitDur.toNanos(); 756 if ((LocalTime.NANOS_PER_DAY % dur) != 0) { 757 throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder"); 758 } 759 long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos; 760 long result = Math.floorDiv(nod, dur) * dur; 761 return plusNanos(result - nod); 762 } 763 764 //----------------------------------------------------------------------- 765 /** 766 * Returns a copy of this instant with the specified amount added. 767 * <p> 768 * This returns an {@code Instant}, based on this one, with the specified amount added. 769 * The amount is typically {@link Duration} but may be any other type implementing 770 * the {@link TemporalAmount} interface. 771 * <p> 772 * The calculation is delegated to the amount object by calling 773 * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free 774 * to implement the addition in any way it wishes, however it typically 775 * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation 776 * of the amount implementation to determine if it can be successfully added. 777 * <p> 778 * This instance is immutable and unaffected by this method call. 779 * 780 * @param amountToAdd the amount to add, not null 781 * @return an {@code Instant} based on this instant with the addition made, not null 782 * @throws DateTimeException if the addition cannot be made 783 * @throws ArithmeticException if numeric overflow occurs 784 */ 785 @Override 786 public Instant plus(TemporalAmount amountToAdd) { 787 return (Instant) amountToAdd.addTo(this); 788 } 789 790 /** 791 * Returns a copy of this instant with the specified amount added. 792 * <p> 793 * This returns an {@code Instant}, based on this one, with the amount 794 * in terms of the unit added. If it is not possible to add the amount, because the 795 * unit is not supported or for some other reason, an exception is thrown. 796 * <p> 797 * If the field is a {@link ChronoUnit} then the addition is implemented here. 798 * The supported fields behave as follows: 799 * <ul> 800 * <li>{@code NANOS} - 801 * Returns an {@code Instant} with the specified number of nanoseconds added. 802 * This is equivalent to {@link #plusNanos(long)}. 803 * <li>{@code MICROS} - 804 * Returns an {@code Instant} with the specified number of microseconds added. 805 * This is equivalent to {@link #plusNanos(long)} with the amount 806 * multiplied by 1,000. 807 * <li>{@code MILLIS} - 808 * Returns an {@code Instant} with the specified number of milliseconds added. 809 * This is equivalent to {@link #plusNanos(long)} with the amount 810 * multiplied by 1,000,000. 811 * <li>{@code SECONDS} - 812 * Returns an {@code Instant} with the specified number of seconds added. 813 * This is equivalent to {@link #plusSeconds(long)}. 814 * <li>{@code MINUTES} - 815 * Returns an {@code Instant} with the specified number of minutes added. 816 * This is equivalent to {@link #plusSeconds(long)} with the amount 817 * multiplied by 60. 818 * <li>{@code HOURS} - 819 * Returns an {@code Instant} with the specified number of hours added. 820 * This is equivalent to {@link #plusSeconds(long)} with the amount 821 * multiplied by 3,600. 822 * <li>{@code HALF_DAYS} - 823 * Returns an {@code Instant} with the specified number of half-days added. 824 * This is equivalent to {@link #plusSeconds(long)} with the amount 825 * multiplied by 43,200 (12 hours). 826 * <li>{@code DAYS} - 827 * Returns an {@code Instant} with the specified number of days added. 828 * This is equivalent to {@link #plusSeconds(long)} with the amount 829 * multiplied by 86,400 (24 hours). 830 * </ul> 831 * <p> 832 * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}. 833 * <p> 834 * If the field is not a {@code ChronoUnit}, then the result of this method 835 * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)} 836 * passing {@code this} as the argument. In this case, the unit determines 837 * whether and how to perform the addition. 838 * <p> 839 * This instance is immutable and unaffected by this method call. 840 * 841 * @param amountToAdd the amount of the unit to add to the result, may be negative 842 * @param unit the unit of the amount to add, not null 843 * @return an {@code Instant} based on this instant with the specified amount added, not null 844 * @throws DateTimeException if the addition cannot be made 845 * @throws UnsupportedTemporalTypeException if the unit is not supported 846 * @throws ArithmeticException if numeric overflow occurs 847 */ 848 @Override 849 public Instant plus(long amountToAdd, TemporalUnit unit) { 850 if (unit instanceof ChronoUnit) { 851 switch ((ChronoUnit) unit) { 852 case NANOS: return plusNanos(amountToAdd); 853 case MICROS: return plus(amountToAdd / 1000_000, (amountToAdd % 1000_000) * 1000); 854 case MILLIS: return plusMillis(amountToAdd); 855 case SECONDS: return plusSeconds(amountToAdd); 856 case MINUTES: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_MINUTE)); 857 case HOURS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_HOUR)); 858 case HALF_DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2)); 859 case DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY)); 860 } 861 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); 862 } 863 return unit.addTo(this, amountToAdd); 864 } 865 866 //----------------------------------------------------------------------- 867 /** 868 * Returns a copy of this instant with the specified duration in seconds added. 869 * <p> 870 * This instance is immutable and unaffected by this method call. 871 * 872 * @param secondsToAdd the seconds to add, positive or negative 873 * @return an {@code Instant} based on this instant with the specified seconds added, not null 874 * @throws DateTimeException if the result exceeds the maximum or minimum instant 875 * @throws ArithmeticException if numeric overflow occurs 876 */ 877 public Instant plusSeconds(long secondsToAdd) { 878 return plus(secondsToAdd, 0); 879 } 880 881 /** 882 * Returns a copy of this instant with the specified duration in milliseconds added. 883 * <p> 884 * This instance is immutable and unaffected by this method call. 885 * 886 * @param millisToAdd the milliseconds to add, positive or negative 887 * @return an {@code Instant} based on this instant with the specified milliseconds added, not null 888 * @throws DateTimeException if the result exceeds the maximum or minimum instant 889 * @throws ArithmeticException if numeric overflow occurs 890 */ 891 public Instant plusMillis(long millisToAdd) { 892 return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000); 893 } 894 895 /** 896 * Returns a copy of this instant with the specified duration in nanoseconds added. 897 * <p> 898 * This instance is immutable and unaffected by this method call. 899 * 900 * @param nanosToAdd the nanoseconds to add, positive or negative 901 * @return an {@code Instant} based on this instant with the specified nanoseconds added, not null 902 * @throws DateTimeException if the result exceeds the maximum or minimum instant 903 * @throws ArithmeticException if numeric overflow occurs 904 */ 905 public Instant plusNanos(long nanosToAdd) { 906 return plus(0, nanosToAdd); 907 } 908 909 /** 910 * Returns a copy of this instant with the specified duration added. 911 * <p> 912 * This instance is immutable and unaffected by this method call. 913 * 914 * @param secondsToAdd the seconds to add, positive or negative 915 * @param nanosToAdd the nanos to add, positive or negative 916 * @return an {@code Instant} based on this instant with the specified seconds added, not null 917 * @throws DateTimeException if the result exceeds the maximum or minimum instant 918 * @throws ArithmeticException if numeric overflow occurs 919 */ 920 private Instant plus(long secondsToAdd, long nanosToAdd) { 921 if ((secondsToAdd | nanosToAdd) == 0) { 922 return this; 923 } 924 long epochSec = Math.addExact(seconds, secondsToAdd); 925 epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND); 926 nanosToAdd = nanosToAdd % NANOS_PER_SECOND; 927 long nanoAdjustment = nanos + nanosToAdd; // safe int+NANOS_PER_SECOND 928 return ofEpochSecond(epochSec, nanoAdjustment); 929 } 930 931 //----------------------------------------------------------------------- 932 /** 933 * Returns a copy of this instant with the specified amount subtracted. 934 * <p> 935 * This returns an {@code Instant}, based on this one, with the specified amount subtracted. 936 * The amount is typically {@link Duration} but may be any other type implementing 937 * the {@link TemporalAmount} interface. 938 * <p> 939 * The calculation is delegated to the amount object by calling 940 * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free 941 * to implement the subtraction in any way it wishes, however it typically 942 * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation 943 * of the amount implementation to determine if it can be successfully subtracted. 944 * <p> 945 * This instance is immutable and unaffected by this method call. 946 * 947 * @param amountToSubtract the amount to subtract, not null 948 * @return an {@code Instant} based on this instant with the subtraction made, not null 949 * @throws DateTimeException if the subtraction cannot be made 950 * @throws ArithmeticException if numeric overflow occurs 951 */ 952 @Override 953 public Instant minus(TemporalAmount amountToSubtract) { 954 return (Instant) amountToSubtract.subtractFrom(this); 955 } 956 957 /** 958 * Returns a copy of this instant with the specified amount subtracted. 959 * <p> 960 * This returns an {@code Instant}, based on this one, with the amount 961 * in terms of the unit subtracted. If it is not possible to subtract the amount, 962 * because the unit is not supported or for some other reason, an exception is thrown. 963 * <p> 964 * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated. 965 * See that method for a full description of how addition, and thus subtraction, works. 966 * <p> 967 * This instance is immutable and unaffected by this method call. 968 * 969 * @param amountToSubtract the amount of the unit to subtract from the result, may be negative 970 * @param unit the unit of the amount to subtract, not null 971 * @return an {@code Instant} based on this instant with the specified amount subtracted, not null 972 * @throws DateTimeException if the subtraction cannot be made 973 * @throws UnsupportedTemporalTypeException if the unit is not supported 974 * @throws ArithmeticException if numeric overflow occurs 975 */ 976 @Override 977 public Instant minus(long amountToSubtract, TemporalUnit unit) { 978 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit)); 979 } 980 981 //----------------------------------------------------------------------- 982 /** 983 * Returns a copy of this instant with the specified duration in seconds subtracted. 984 * <p> 985 * This instance is immutable and unaffected by this method call. 986 * 987 * @param secondsToSubtract the seconds to subtract, positive or negative 988 * @return an {@code Instant} based on this instant with the specified seconds subtracted, not null 989 * @throws DateTimeException if the result exceeds the maximum or minimum instant 990 * @throws ArithmeticException if numeric overflow occurs 991 */ 992 public Instant minusSeconds(long secondsToSubtract) { 993 if (secondsToSubtract == Long.MIN_VALUE) { 994 return plusSeconds(Long.MAX_VALUE).plusSeconds(1); 995 } 996 return plusSeconds(-secondsToSubtract); 997 } 998 999 /** 1000 * Returns a copy of this instant with the specified duration in milliseconds subtracted. 1001 * <p> 1002 * This instance is immutable and unaffected by this method call. 1003 * 1004 * @param millisToSubtract the milliseconds to subtract, positive or negative 1005 * @return an {@code Instant} based on this instant with the specified milliseconds subtracted, not null 1006 * @throws DateTimeException if the result exceeds the maximum or minimum instant 1007 * @throws ArithmeticException if numeric overflow occurs 1008 */ 1009 public Instant minusMillis(long millisToSubtract) { 1010 if (millisToSubtract == Long.MIN_VALUE) { 1011 return plusMillis(Long.MAX_VALUE).plusMillis(1); 1012 } 1013 return plusMillis(-millisToSubtract); 1014 } 1015 1016 /** 1017 * Returns a copy of this instant with the specified duration in nanoseconds subtracted. 1018 * <p> 1019 * This instance is immutable and unaffected by this method call. 1020 * 1021 * @param nanosToSubtract the nanoseconds to subtract, positive or negative 1022 * @return an {@code Instant} based on this instant with the specified nanoseconds subtracted, not null 1023 * @throws DateTimeException if the result exceeds the maximum or minimum instant 1024 * @throws ArithmeticException if numeric overflow occurs 1025 */ 1026 public Instant minusNanos(long nanosToSubtract) { 1027 if (nanosToSubtract == Long.MIN_VALUE) { 1028 return plusNanos(Long.MAX_VALUE).plusNanos(1); 1029 } 1030 return plusNanos(-nanosToSubtract); 1031 } 1032 1033 //------------------------------------------------------------------------- 1034 /** 1035 * Queries this instant using the specified query. 1036 * <p> 1037 * This queries this instant using the specified query strategy object. 1038 * The {@code TemporalQuery} object defines the logic to be used to 1039 * obtain the result. Read the documentation of the query to understand 1040 * what the result of this method will be. 1041 * <p> 1042 * The result of this method is obtained by invoking the 1043 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the 1044 * specified query passing {@code this} as the argument. 1045 * 1046 * @param <R> the type of the result 1047 * @param query the query to invoke, not null 1048 * @return the query result, null may be returned (defined by the query) 1049 * @throws DateTimeException if unable to query (defined by the query) 1050 * @throws ArithmeticException if numeric overflow occurs (defined by the query) 1051 */ 1052 @SuppressWarnings("unchecked") 1053 @Override 1054 public <R> R query(TemporalQuery<R> query) { 1055 if (query == TemporalQueries.precision()) { 1056 return (R) NANOS; 1057 } 1058 // inline TemporalAccessor.super.query(query) as an optimization 1059 if (query == TemporalQueries.chronology() || query == TemporalQueries.zoneId() || 1060 query == TemporalQueries.zone() || query == TemporalQueries.offset() || 1061 query == TemporalQueries.localDate() || query == TemporalQueries.localTime()) { 1062 return null; 1063 } 1064 return query.queryFrom(this); 1065 } 1066 1067 /** 1068 * Adjusts the specified temporal object to have this instant. 1069 * <p> 1070 * This returns a temporal object of the same observable type as the input 1071 * with the instant changed to be the same as this. 1072 * <p> 1073 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)} 1074 * twice, passing {@link ChronoField#INSTANT_SECONDS} and 1075 * {@link ChronoField#NANO_OF_SECOND} as the fields. 1076 * <p> 1077 * In most cases, it is clearer to reverse the calling pattern by using 1078 * {@link Temporal#with(TemporalAdjuster)}: 1079 * <pre> 1080 * // these two lines are equivalent, but the second approach is recommended 1081 * temporal = thisInstant.adjustInto(temporal); 1082 * temporal = temporal.with(thisInstant); 1083 * </pre> 1084 * <p> 1085 * This instance is immutable and unaffected by this method call. 1086 * 1087 * @param temporal the target object to be adjusted, not null 1088 * @return the adjusted object, not null 1089 * @throws DateTimeException if unable to make the adjustment 1090 * @throws ArithmeticException if numeric overflow occurs 1091 */ 1092 @Override 1093 public Temporal adjustInto(Temporal temporal) { 1094 return temporal.with(INSTANT_SECONDS, seconds).with(NANO_OF_SECOND, nanos); 1095 } 1096 1097 /** 1098 * Calculates the amount of time until another instant in terms of the specified unit. 1099 * <p> 1100 * This calculates the amount of time between two {@code Instant} 1101 * objects in terms of a single {@code TemporalUnit}. 1102 * The start and end points are {@code this} and the specified instant. 1103 * The result will be negative if the end is before the start. 1104 * The calculation returns a whole number, representing the number of 1105 * complete units between the two instants. 1106 * The {@code Temporal} passed to this method is converted to a 1107 * {@code Instant} using {@link #from(TemporalAccessor)}. 1108 * For example, the amount in seconds between two dates can be calculated 1109 * using {@code startInstant.until(endInstant, SECONDS)}. 1110 * <p> 1111 * There are two equivalent ways of using this method. 1112 * The first is to invoke this method. 1113 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}: 1114 * <pre> 1115 * // these two lines are equivalent 1116 * amount = start.until(end, SECONDS); 1117 * amount = SECONDS.between(start, end); 1118 * </pre> 1119 * The choice should be made based on which makes the code more readable. 1120 * <p> 1121 * The calculation is implemented in this method for {@link ChronoUnit}. 1122 * The units {@code NANOS}, {@code MICROS}, {@code MILLIS}, {@code SECONDS}, 1123 * {@code MINUTES}, {@code HOURS}, {@code HALF_DAYS} and {@code DAYS} 1124 * are supported. Other {@code ChronoUnit} values will throw an exception. 1125 * <p> 1126 * If the unit is not a {@code ChronoUnit}, then the result of this method 1127 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)} 1128 * passing {@code this} as the first argument and the converted input temporal 1129 * as the second argument. 1130 * <p> 1131 * This instance is immutable and unaffected by this method call. 1132 * 1133 * @param endExclusive the end date, exclusive, which is converted to an {@code Instant}, not null 1134 * @param unit the unit to measure the amount in, not null 1135 * @return the amount of time between this instant and the end instant 1136 * @throws DateTimeException if the amount cannot be calculated, or the end 1137 * temporal cannot be converted to an {@code Instant} 1138 * @throws UnsupportedTemporalTypeException if the unit is not supported 1139 * @throws ArithmeticException if numeric overflow occurs 1140 */ 1141 @Override 1142 public long until(Temporal endExclusive, TemporalUnit unit) { 1143 Instant end = Instant.from(endExclusive); 1144 if (unit instanceof ChronoUnit) { 1145 ChronoUnit f = (ChronoUnit) unit; 1146 switch (f) { 1147 case NANOS: return nanosUntil(end); 1148 case MICROS: return nanosUntil(end) / 1000; 1149 case MILLIS: return Math.subtractExact(end.toEpochMilli(), toEpochMilli()); 1150 case SECONDS: return secondsUntil(end); 1151 case MINUTES: return secondsUntil(end) / SECONDS_PER_MINUTE; 1152 case HOURS: return secondsUntil(end) / SECONDS_PER_HOUR; 1153 case HALF_DAYS: return secondsUntil(end) / (12 * SECONDS_PER_HOUR); 1154 case DAYS: return secondsUntil(end) / (SECONDS_PER_DAY); 1155 } 1156 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); 1157 } 1158 return unit.between(this, end); 1159 } 1160 1161 private long nanosUntil(Instant end) { 1162 long secsDiff = Math.subtractExact(end.seconds, seconds); 1163 long totalNanos = Math.multiplyExact(secsDiff, NANOS_PER_SECOND); 1164 return Math.addExact(totalNanos, end.nanos - nanos); 1165 } 1166 1167 private long secondsUntil(Instant end) { 1168 long secsDiff = Math.subtractExact(end.seconds, seconds); 1169 long nanosDiff = end.nanos - nanos; 1170 if (secsDiff > 0 && nanosDiff < 0) { 1171 secsDiff--; 1172 } else if (secsDiff < 0 && nanosDiff > 0) { 1173 secsDiff++; 1174 } 1175 return secsDiff; 1176 } 1177 1178 //----------------------------------------------------------------------- 1179 /** 1180 * Combines this instant with an offset to create an {@code OffsetDateTime}. 1181 * <p> 1182 * This returns an {@code OffsetDateTime} formed from this instant at the 1183 * specified offset from UTC/Greenwich. An exception will be thrown if the 1184 * instant is too large to fit into an offset date-time. 1185 * <p> 1186 * This method is equivalent to 1187 * {@link OffsetDateTime#ofInstant(Instant, ZoneId) OffsetDateTime.ofInstant(this, offset)}. 1188 * 1189 * @param offset the offset to combine with, not null 1190 * @return the offset date-time formed from this instant and the specified offset, not null 1191 * @throws DateTimeException if the result exceeds the supported range 1192 */ 1193 public OffsetDateTime atOffset(ZoneOffset offset) { 1194 return OffsetDateTime.ofInstant(this, offset); 1195 } 1196 1197 /** 1198 * Combines this instant with a time-zone to create a {@code ZonedDateTime}. 1199 * <p> 1200 * This returns an {@code ZonedDateTime} formed from this instant at the 1201 * specified time-zone. An exception will be thrown if the instant is too 1202 * large to fit into a zoned date-time. 1203 * <p> 1204 * This method is equivalent to 1205 * {@link ZonedDateTime#ofInstant(Instant, ZoneId) ZonedDateTime.ofInstant(this, zone)}. 1206 * 1207 * @param zone the zone to combine with, not null 1208 * @return the zoned date-time formed from this instant and the specified zone, not null 1209 * @throws DateTimeException if the result exceeds the supported range 1210 */ 1211 public ZonedDateTime atZone(ZoneId zone) { 1212 return ZonedDateTime.ofInstant(this, zone); 1213 } 1214 1215 //----------------------------------------------------------------------- 1216 /** 1217 * Converts this instant to the number of milliseconds from the epoch 1218 * of 1970-01-01T00:00:00Z. 1219 * <p> 1220 * If this instant represents a point on the time-line too far in the future 1221 * or past to fit in a {@code long} milliseconds, then an exception is thrown. 1222 * <p> 1223 * If this instant has greater than millisecond precision, then the conversion 1224 * will drop any excess precision information as though the amount in nanoseconds 1225 * was subject to integer division by one million. 1226 * 1227 * @return the number of milliseconds since the epoch of 1970-01-01T00:00:00Z 1228 * @throws ArithmeticException if numeric overflow occurs 1229 */ 1230 public long toEpochMilli() { 1231 if (seconds < 0 && nanos > 0) { 1232 long millis = Math.multiplyExact(seconds+1, 1000); 1233 long adjustment = nanos / 1000_000 - 1000; 1234 return Math.addExact(millis, adjustment); 1235 } else { 1236 long millis = Math.multiplyExact(seconds, 1000); 1237 return Math.addExact(millis, nanos / 1000_000); 1238 } 1239 } 1240 1241 //----------------------------------------------------------------------- 1242 /** 1243 * Compares this instant to the specified instant. 1244 * <p> 1245 * The comparison is based on the time-line position of the instants. 1246 * It is "consistent with equals", as defined by {@link Comparable}. 1247 * 1248 * @param otherInstant the other instant to compare to, not null 1249 * @return the comparator value, negative if less, positive if greater 1250 * @throws NullPointerException if otherInstant is null 1251 */ 1252 @Override 1253 public int compareTo(Instant otherInstant) { 1254 int cmp = Long.compare(seconds, otherInstant.seconds); 1255 if (cmp != 0) { 1256 return cmp; 1257 } 1258 return nanos - otherInstant.nanos; 1259 } 1260 1261 /** 1262 * Checks if this instant is after the specified instant. 1263 * <p> 1264 * The comparison is based on the time-line position of the instants. 1265 * 1266 * @param otherInstant the other instant to compare to, not null 1267 * @return true if this instant is after the specified instant 1268 * @throws NullPointerException if otherInstant is null 1269 */ 1270 public boolean isAfter(Instant otherInstant) { 1271 return compareTo(otherInstant) > 0; 1272 } 1273 1274 /** 1275 * Checks if this instant is before the specified instant. 1276 * <p> 1277 * The comparison is based on the time-line position of the instants. 1278 * 1279 * @param otherInstant the other instant to compare to, not null 1280 * @return true if this instant is before the specified instant 1281 * @throws NullPointerException if otherInstant is null 1282 */ 1283 public boolean isBefore(Instant otherInstant) { 1284 return compareTo(otherInstant) < 0; 1285 } 1286 1287 //----------------------------------------------------------------------- 1288 /** 1289 * Checks if this instant is equal to the specified instant. 1290 * <p> 1291 * The comparison is based on the time-line position of the instants. 1292 * 1293 * @param otherInstant the other instant, null returns false 1294 * @return true if the other instant is equal to this one 1295 */ 1296 @Override 1297 public boolean equals(Object otherInstant) { 1298 if (this == otherInstant) { 1299 return true; 1300 } 1301 if (otherInstant instanceof Instant) { 1302 Instant other = (Instant) otherInstant; 1303 return this.seconds == other.seconds && 1304 this.nanos == other.nanos; 1305 } 1306 return false; 1307 } 1308 1309 /** 1310 * Returns a hash code for this instant. 1311 * 1312 * @return a suitable hash code 1313 */ 1314 @Override 1315 public int hashCode() { 1316 return ((int) (seconds ^ (seconds >>> 32))) + 51 * nanos; 1317 } 1318 1319 //----------------------------------------------------------------------- 1320 /** 1321 * A string representation of this instant using ISO-8601 representation. 1322 * <p> 1323 * The format used is the same as {@link DateTimeFormatter#ISO_INSTANT}. 1324 * 1325 * @return an ISO-8601 representation of this instant, not null 1326 */ 1327 @Override 1328 public String toString() { 1329 return DateTimeFormatter.ISO_INSTANT.format(this); 1330 } 1331 1332 // ----------------------------------------------------------------------- 1333 /** 1334 * Writes the object using a 1335 * <a href="{@docRoot}/serialized-form.html#java.time.Ser">dedicated serialized form</a>. 1336 * @serialData 1337 * <pre> 1338 * out.writeByte(2); // identifies an Instant 1339 * out.writeLong(seconds); 1340 * out.writeInt(nanos); 1341 * </pre> 1342 * 1343 * @return the instance of {@code Ser}, not null 1344 */ 1345 private Object writeReplace() { 1346 return new Ser(Ser.INSTANT_TYPE, this); 1347 } 1348 1349 /** 1350 * Defend against malicious streams. 1351 * 1352 * @param s the stream to read 1353 * @throws InvalidObjectException always 1354 */ 1355 private void readObject(ObjectInputStream s) throws InvalidObjectException { 1356 throw new InvalidObjectException("Deserialization via serialization delegate"); 1357 } 1358 1359 void writeExternal(DataOutput out) throws IOException { 1360 out.writeLong(seconds); 1361 out.writeInt(nanos); 1362 } 1363 1364 static Instant readExternal(DataInput in) throws IOException { 1365 long seconds = in.readLong(); 1366 int nanos = in.readInt(); 1367 return Instant.ofEpochSecond(seconds, nanos); 1368 } 1369 1370 }