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.chrono; 63 64 import static java.time.temporal.ChronoField.EPOCH_DAY; 65 import static java.time.temporal.ChronoField.NANO_OF_DAY; 66 import static java.time.temporal.ChronoUnit.FOREVER; 67 import static java.time.temporal.ChronoUnit.NANOS; 68 69 import java.io.Serializable; 70 import java.time.DateTimeException; 71 import java.time.Instant; 72 import java.time.LocalDateTime; 73 import java.time.LocalTime; 74 import java.time.ZoneId; 75 import java.time.ZoneOffset; 76 import java.time.format.DateTimeFormatter; 77 import java.time.temporal.ChronoField; 78 import java.time.temporal.ChronoUnit; 79 import java.time.temporal.Temporal; 80 import java.time.temporal.TemporalAccessor; 81 import java.time.temporal.TemporalAdjuster; 82 import java.time.temporal.TemporalAmount; 83 import java.time.temporal.TemporalField; 84 import java.time.temporal.TemporalQueries; 85 import java.time.temporal.TemporalQuery; 86 import java.time.temporal.TemporalUnit; 87 import java.time.zone.ZoneRules; 88 import java.util.Comparator; 89 import java.util.Objects; 90 91 /** 92 * A date-time without a time-zone in an arbitrary chronology, intended 93 * for advanced globalization use cases. 94 * <p> 95 * <b>Most applications should declare method signatures, fields and variables 96 * as {@link LocalDateTime}, not this interface.</b> 97 * <p> 98 * A {@code ChronoLocalDateTime} is the abstract representation of a local date-time 99 * where the {@code Chronology chronology}, or calendar system, is pluggable. 100 * The date-time is defined in terms of fields expressed by {@link TemporalField}, 101 * where most common implementations are defined in {@link ChronoField}. 102 * The chronology defines how the calendar system operates and the meaning of 103 * the standard fields. 104 * 105 * <h2>When to use this interface</h2> 106 * The design of the API encourages the use of {@code LocalDateTime} rather than this 107 * interface, even in the case where the application needs to deal with multiple 108 * calendar systems. The rationale for this is explored in detail in {@link ChronoLocalDate}. 109 * <p> 110 * Ensure that the discussion in {@code ChronoLocalDate} has been read and understood 111 * before using this interface. 112 * 113 * @implSpec 114 * This interface must be implemented with care to ensure other classes operate correctly. 115 * All implementations that can be instantiated must be final, immutable and thread-safe. 116 * Subclasses should be Serializable wherever possible. 117 * 118 * @param <D> the concrete type for the date of this date-time 119 * @since 1.8 120 */ 121 public interface ChronoLocalDateTime<D extends ChronoLocalDate> 122 extends Temporal, TemporalAdjuster, Comparable<ChronoLocalDateTime<?>> { 123 124 /** 125 * Gets a comparator that compares {@code ChronoLocalDateTime} in 126 * time-line order ignoring the chronology. 127 * <p> 128 * This comparator differs from the comparison in {@link #compareTo} in that it 129 * only compares the underlying date-time and not the chronology. 130 * This allows dates in different calendar systems to be compared based 131 * on the position of the date-time on the local time-line. 132 * The underlying comparison is equivalent to comparing the epoch-day and nano-of-day. 133 * 134 * @return a comparator that compares in time-line order ignoring the chronology 135 * @see #isAfter 136 * @see #isBefore 137 * @see #isEqual 138 */ timeLineOrder()139 static Comparator<ChronoLocalDateTime<?>> timeLineOrder() { 140 return (Comparator<ChronoLocalDateTime<? extends ChronoLocalDate>> & Serializable) (dateTime1, dateTime2) -> { 141 int cmp = Long.compare(dateTime1.toLocalDate().toEpochDay(), dateTime2.toLocalDate().toEpochDay()); 142 if (cmp == 0) { 143 cmp = Long.compare(dateTime1.toLocalTime().toNanoOfDay(), dateTime2.toLocalTime().toNanoOfDay()); 144 } 145 return cmp; 146 }; 147 } 148 149 //----------------------------------------------------------------------- 150 /** 151 * Obtains an instance of {@code ChronoLocalDateTime} from a temporal object. 152 * <p> 153 * This obtains a local date-time based on the specified temporal. 154 * A {@code TemporalAccessor} represents an arbitrary set of date and time information, 155 * which this factory converts to an instance of {@code ChronoLocalDateTime}. 156 * <p> 157 * The conversion extracts and combines the chronology and the date-time 158 * from the temporal object. The behavior is equivalent to using 159 * {@link Chronology#localDateTime(TemporalAccessor)} with the extracted chronology. 160 * Implementations are permitted to perform optimizations such as accessing 161 * those fields that are equivalent to the relevant objects. 162 * <p> 163 * This method matches the signature of the functional interface {@link TemporalQuery} 164 * allowing it to be used as a query via method reference, {@code ChronoLocalDateTime::from}. 165 * 166 * @param temporal the temporal object to convert, not null 167 * @return the date-time, not null 168 * @throws DateTimeException if unable to convert to a {@code ChronoLocalDateTime} 169 * @see Chronology#localDateTime(TemporalAccessor) 170 */ from(TemporalAccessor temporal)171 static ChronoLocalDateTime<?> from(TemporalAccessor temporal) { 172 if (temporal instanceof ChronoLocalDateTime) { 173 return (ChronoLocalDateTime<?>) temporal; 174 } 175 Objects.requireNonNull(temporal, "temporal"); 176 Chronology chrono = temporal.query(TemporalQueries.chronology()); 177 if (chrono == null) { 178 throw new DateTimeException("Unable to obtain ChronoLocalDateTime from TemporalAccessor: " + temporal.getClass()); 179 } 180 return chrono.localDateTime(temporal); 181 } 182 183 //----------------------------------------------------------------------- 184 /** 185 * Gets the chronology of this date-time. 186 * <p> 187 * The {@code Chronology} represents the calendar system in use. 188 * The era and other fields in {@link ChronoField} are defined by the chronology. 189 * 190 * @return the chronology, not null 191 */ getChronology()192 default Chronology getChronology() { 193 return toLocalDate().getChronology(); 194 } 195 196 /** 197 * Gets the local date part of this date-time. 198 * <p> 199 * This returns a local date with the same year, month and day 200 * as this date-time. 201 * 202 * @return the date part of this date-time, not null 203 */ toLocalDate()204 D toLocalDate(); 205 206 /** 207 * Gets the local time part of this date-time. 208 * <p> 209 * This returns a local time with the same hour, minute, second and 210 * nanosecond as this date-time. 211 * 212 * @return the time part of this date-time, not null 213 */ toLocalTime()214 LocalTime toLocalTime(); 215 216 /** 217 * Checks if the specified field is supported. 218 * <p> 219 * This checks if the specified field can be queried on this date-time. 220 * If false, then calling the {@link #range(TemporalField) range}, 221 * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)} 222 * methods will throw an exception. 223 * <p> 224 * The set of supported fields is defined by the chronology and normally includes 225 * all {@code ChronoField} date and time fields. 226 * <p> 227 * If the field is not a {@code ChronoField}, then the result of this method 228 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)} 229 * passing {@code this} as the argument. 230 * Whether the field is supported is determined by the field. 231 * 232 * @param field the field to check, null returns false 233 * @return true if the field can be queried, false if not 234 */ 235 @Override 236 boolean isSupported(TemporalField field); 237 238 /** 239 * Checks if the specified unit is supported. 240 * <p> 241 * This checks if the specified unit can be added to or subtracted from this date-time. 242 * If false, then calling the {@link #plus(long, TemporalUnit)} and 243 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception. 244 * <p> 245 * The set of supported units is defined by the chronology and normally includes 246 * all {@code ChronoUnit} units except {@code FOREVER}. 247 * <p> 248 * If the unit is not a {@code ChronoUnit}, then the result of this method 249 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)} 250 * passing {@code this} as the argument. 251 * Whether the unit is supported is determined by the unit. 252 * 253 * @param unit the unit to check, null returns false 254 * @return true if the unit can be added/subtracted, false if not 255 */ 256 @Override isSupported(TemporalUnit unit)257 default boolean isSupported(TemporalUnit unit) { 258 if (unit instanceof ChronoUnit) { 259 return unit != FOREVER; 260 } 261 return unit != null && unit.isSupportedBy(this); 262 } 263 264 //----------------------------------------------------------------------- 265 // override for covariant return type 266 /** 267 * {@inheritDoc} 268 * @throws DateTimeException {@inheritDoc} 269 * @throws ArithmeticException {@inheritDoc} 270 */ 271 @Override with(TemporalAdjuster adjuster)272 default ChronoLocalDateTime<D> with(TemporalAdjuster adjuster) { 273 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.with(adjuster)); 274 } 275 276 /** 277 * {@inheritDoc} 278 * @throws DateTimeException {@inheritDoc} 279 * @throws ArithmeticException {@inheritDoc} 280 */ 281 @Override with(TemporalField field, long newValue)282 ChronoLocalDateTime<D> with(TemporalField field, long newValue); 283 284 /** 285 * {@inheritDoc} 286 * @throws DateTimeException {@inheritDoc} 287 * @throws ArithmeticException {@inheritDoc} 288 */ 289 @Override plus(TemporalAmount amount)290 default ChronoLocalDateTime<D> plus(TemporalAmount amount) { 291 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.plus(amount)); 292 } 293 294 /** 295 * {@inheritDoc} 296 * @throws DateTimeException {@inheritDoc} 297 * @throws ArithmeticException {@inheritDoc} 298 */ 299 @Override plus(long amountToAdd, TemporalUnit unit)300 ChronoLocalDateTime<D> plus(long amountToAdd, TemporalUnit unit); 301 302 /** 303 * {@inheritDoc} 304 * @throws DateTimeException {@inheritDoc} 305 * @throws ArithmeticException {@inheritDoc} 306 */ 307 @Override minus(TemporalAmount amount)308 default ChronoLocalDateTime<D> minus(TemporalAmount amount) { 309 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amount)); 310 } 311 312 /** 313 * {@inheritDoc} 314 * @throws DateTimeException {@inheritDoc} 315 * @throws ArithmeticException {@inheritDoc} 316 */ 317 @Override minus(long amountToSubtract, TemporalUnit unit)318 default ChronoLocalDateTime<D> minus(long amountToSubtract, TemporalUnit unit) { 319 return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amountToSubtract, unit)); 320 } 321 322 //----------------------------------------------------------------------- 323 /** 324 * Queries this date-time using the specified query. 325 * <p> 326 * This queries this date-time using the specified query strategy object. 327 * The {@code TemporalQuery} object defines the logic to be used to 328 * obtain the result. Read the documentation of the query to understand 329 * what the result of this method will be. 330 * <p> 331 * The result of this method is obtained by invoking the 332 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the 333 * specified query passing {@code this} as the argument. 334 * 335 * @param <R> the type of the result 336 * @param query the query to invoke, not null 337 * @return the query result, null may be returned (defined by the query) 338 * @throws DateTimeException if unable to query (defined by the query) 339 * @throws ArithmeticException if numeric overflow occurs (defined by the query) 340 */ 341 @SuppressWarnings("unchecked") 342 @Override query(TemporalQuery<R> query)343 default <R> R query(TemporalQuery<R> query) { 344 if (query == TemporalQueries.zoneId() || query == TemporalQueries.zone() || query == TemporalQueries.offset()) { 345 return null; 346 } else if (query == TemporalQueries.localTime()) { 347 return (R) toLocalTime(); 348 } else if (query == TemporalQueries.chronology()) { 349 return (R) getChronology(); 350 } else if (query == TemporalQueries.precision()) { 351 return (R) NANOS; 352 } 353 // inline TemporalAccessor.super.query(query) as an optimization 354 // non-JDK classes are not permitted to make this optimization 355 return query.queryFrom(this); 356 } 357 358 /** 359 * Adjusts the specified temporal object to have the same date and time as this object. 360 * <p> 361 * This returns a temporal object of the same observable type as the input 362 * with the date and time changed to be the same as this. 363 * <p> 364 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)} 365 * twice, passing {@link ChronoField#EPOCH_DAY} and 366 * {@link ChronoField#NANO_OF_DAY} as the fields. 367 * <p> 368 * In most cases, it is clearer to reverse the calling pattern by using 369 * {@link Temporal#with(TemporalAdjuster)}: 370 * <pre> 371 * // these two lines are equivalent, but the second approach is recommended 372 * temporal = thisLocalDateTime.adjustInto(temporal); 373 * temporal = temporal.with(thisLocalDateTime); 374 * </pre> 375 * <p> 376 * This instance is immutable and unaffected by this method call. 377 * 378 * @param temporal the target object to be adjusted, not null 379 * @return the adjusted object, not null 380 * @throws DateTimeException if unable to make the adjustment 381 * @throws ArithmeticException if numeric overflow occurs 382 */ 383 @Override adjustInto(Temporal temporal)384 default Temporal adjustInto(Temporal temporal) { 385 return temporal 386 .with(EPOCH_DAY, toLocalDate().toEpochDay()) 387 .with(NANO_OF_DAY, toLocalTime().toNanoOfDay()); 388 } 389 390 /** 391 * Formats this date-time using the specified formatter. 392 * <p> 393 * This date-time will be passed to the formatter to produce a string. 394 * <p> 395 * The default implementation must behave as follows: 396 * <pre> 397 * return formatter.format(this); 398 * </pre> 399 * 400 * @param formatter the formatter to use, not null 401 * @return the formatted date-time string, not null 402 * @throws DateTimeException if an error occurs during printing 403 */ format(DateTimeFormatter formatter)404 default String format(DateTimeFormatter formatter) { 405 Objects.requireNonNull(formatter, "formatter"); 406 return formatter.format(this); 407 } 408 409 //----------------------------------------------------------------------- 410 /** 411 * Combines this time with a time-zone to create a {@code ChronoZonedDateTime}. 412 * <p> 413 * This returns a {@code ChronoZonedDateTime} formed from this date-time at the 414 * specified time-zone. The result will match this date-time as closely as possible. 415 * Time-zone rules, such as daylight savings, mean that not every local date-time 416 * is valid for the specified zone, thus the local date-time may be adjusted. 417 * <p> 418 * The local date-time is resolved to a single instant on the time-line. 419 * This is achieved by finding a valid offset from UTC/Greenwich for the local 420 * date-time as defined by the {@link ZoneRules rules} of the zone ID. 421 *<p> 422 * In most cases, there is only one valid offset for a local date-time. 423 * In the case of an overlap, where clocks are set back, there are two valid offsets. 424 * This method uses the earlier offset typically corresponding to "summer". 425 * <p> 426 * In the case of a gap, where clocks jump forward, there is no valid offset. 427 * Instead, the local date-time is adjusted to be later by the length of the gap. 428 * For a typical one hour daylight savings change, the local date-time will be 429 * moved one hour later into the offset typically corresponding to "summer". 430 * <p> 431 * To obtain the later offset during an overlap, call 432 * {@link ChronoZonedDateTime#withLaterOffsetAtOverlap()} on the result of this method. 433 * 434 * @param zone the time-zone to use, not null 435 * @return the zoned date-time formed from this date-time, not null 436 */ atZone(ZoneId zone)437 ChronoZonedDateTime<D> atZone(ZoneId zone); 438 439 //----------------------------------------------------------------------- 440 /** 441 * Converts this date-time to an {@code Instant}. 442 * <p> 443 * This combines this local date-time and the specified offset to form 444 * an {@code Instant}. 445 * <p> 446 * This default implementation calculates from the epoch-day of the date and the 447 * second-of-day of the time. 448 * 449 * @param offset the offset to use for the conversion, not null 450 * @return an {@code Instant} representing the same instant, not null 451 */ toInstant(ZoneOffset offset)452 default Instant toInstant(ZoneOffset offset) { 453 return Instant.ofEpochSecond(toEpochSecond(offset), toLocalTime().getNano()); 454 } 455 456 /** 457 * Converts this date-time to the number of seconds from the epoch 458 * of 1970-01-01T00:00:00Z. 459 * <p> 460 * This combines this local date-time and the specified offset to calculate the 461 * epoch-second value, which is the number of elapsed seconds from 1970-01-01T00:00:00Z. 462 * Instants on the time-line after the epoch are positive, earlier are negative. 463 * <p> 464 * This default implementation calculates from the epoch-day of the date and the 465 * second-of-day of the time. 466 * 467 * @param offset the offset to use for the conversion, not null 468 * @return the number of seconds from the epoch of 1970-01-01T00:00:00Z 469 */ toEpochSecond(ZoneOffset offset)470 default long toEpochSecond(ZoneOffset offset) { 471 Objects.requireNonNull(offset, "offset"); 472 long epochDay = toLocalDate().toEpochDay(); 473 long secs = epochDay * 86400 + toLocalTime().toSecondOfDay(); 474 secs -= offset.getTotalSeconds(); 475 return secs; 476 } 477 478 //----------------------------------------------------------------------- 479 /** 480 * Compares this date-time to another date-time, including the chronology. 481 * <p> 482 * The comparison is based first on the underlying time-line date-time, then 483 * on the chronology. 484 * It is "consistent with equals", as defined by {@link Comparable}. 485 * <p> 486 * For example, the following is the comparator order: 487 * <ol> 488 * <li>{@code 2012-12-03T12:00 (ISO)}</li> 489 * <li>{@code 2012-12-04T12:00 (ISO)}</li> 490 * <li>{@code 2555-12-04T12:00 (ThaiBuddhist)}</li> 491 * <li>{@code 2012-12-05T12:00 (ISO)}</li> 492 * </ol> 493 * Values #2 and #3 represent the same date-time on the time-line. 494 * When two values represent the same date-time, the chronology ID is compared to distinguish them. 495 * This step is needed to make the ordering "consistent with equals". 496 * <p> 497 * If all the date-time objects being compared are in the same chronology, then the 498 * additional chronology stage is not required and only the local date-time is used. 499 * <p> 500 * This default implementation performs the comparison defined above. 501 * 502 * @param other the other date-time to compare to, not null 503 * @return the comparator value, negative if less, positive if greater 504 */ 505 @Override compareTo(ChronoLocalDateTime<?> other)506 default int compareTo(ChronoLocalDateTime<?> other) { 507 int cmp = toLocalDate().compareTo(other.toLocalDate()); 508 if (cmp == 0) { 509 cmp = toLocalTime().compareTo(other.toLocalTime()); 510 if (cmp == 0) { 511 cmp = getChronology().compareTo(other.getChronology()); 512 } 513 } 514 return cmp; 515 } 516 517 /** 518 * Checks if this date-time is after the specified date-time ignoring the chronology. 519 * <p> 520 * This method differs from the comparison in {@link #compareTo} in that it 521 * only compares the underlying date-time and not the chronology. 522 * This allows dates in different calendar systems to be compared based 523 * on the time-line position. 524 * <p> 525 * This default implementation performs the comparison based on the epoch-day 526 * and nano-of-day. 527 * 528 * @param other the other date-time to compare to, not null 529 * @return true if this is after the specified date-time 530 */ isAfter(ChronoLocalDateTime<?> other)531 default boolean isAfter(ChronoLocalDateTime<?> other) { 532 long thisEpDay = this.toLocalDate().toEpochDay(); 533 long otherEpDay = other.toLocalDate().toEpochDay(); 534 return thisEpDay > otherEpDay || 535 (thisEpDay == otherEpDay && this.toLocalTime().toNanoOfDay() > other.toLocalTime().toNanoOfDay()); 536 } 537 538 /** 539 * Checks if this date-time is before the specified date-time ignoring the chronology. 540 * <p> 541 * This method differs from the comparison in {@link #compareTo} in that it 542 * only compares the underlying date-time and not the chronology. 543 * This allows dates in different calendar systems to be compared based 544 * on the time-line position. 545 * <p> 546 * This default implementation performs the comparison based on the epoch-day 547 * and nano-of-day. 548 * 549 * @param other the other date-time to compare to, not null 550 * @return true if this is before the specified date-time 551 */ isBefore(ChronoLocalDateTime<?> other)552 default boolean isBefore(ChronoLocalDateTime<?> other) { 553 long thisEpDay = this.toLocalDate().toEpochDay(); 554 long otherEpDay = other.toLocalDate().toEpochDay(); 555 return thisEpDay < otherEpDay || 556 (thisEpDay == otherEpDay && this.toLocalTime().toNanoOfDay() < other.toLocalTime().toNanoOfDay()); 557 } 558 559 /** 560 * Checks if this date-time is equal to the specified date-time ignoring the chronology. 561 * <p> 562 * This method differs from the comparison in {@link #compareTo} in that it 563 * only compares the underlying date and time and not the chronology. 564 * This allows date-times in different calendar systems to be compared based 565 * on the time-line position. 566 * <p> 567 * This default implementation performs the comparison based on the epoch-day 568 * and nano-of-day. 569 * 570 * @param other the other date-time to compare to, not null 571 * @return true if the underlying date-time is equal to the specified date-time on the timeline 572 */ isEqual(ChronoLocalDateTime<?> other)573 default boolean isEqual(ChronoLocalDateTime<?> other) { 574 // Do the time check first, it is cheaper than computing EPOCH day. 575 return this.toLocalTime().toNanoOfDay() == other.toLocalTime().toNanoOfDay() && 576 this.toLocalDate().toEpochDay() == other.toLocalDate().toEpochDay(); 577 } 578 579 /** 580 * Checks if this date-time is equal to another date-time, including the chronology. 581 * <p> 582 * Compares this date-time with another ensuring that the date-time and chronology are the same. 583 * 584 * @param obj the object to check, null returns false 585 * @return true if this is equal to the other date 586 */ 587 @Override 588 boolean equals(Object obj); 589 590 /** 591 * A hash code for this date-time. 592 * 593 * @return a suitable hash code 594 */ 595 @Override hashCode()596 int hashCode(); 597 598 //----------------------------------------------------------------------- 599 /** 600 * Outputs this date-time as a {@code String}. 601 * <p> 602 * The output will include the full local date-time. 603 * 604 * @return a string representation of this date-time, not null 605 */ 606 @Override toString()607 String toString(); 608 609 } 610