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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.MINUTES_PER_HOUR;
65 import static java.time.LocalTime.NANOS_PER_MILLI;
66 import static java.time.LocalTime.NANOS_PER_SECOND;
67 import static java.time.LocalTime.SECONDS_PER_DAY;
68 import static java.time.LocalTime.SECONDS_PER_HOUR;
69 import static java.time.LocalTime.SECONDS_PER_MINUTE;
70 import static java.time.temporal.ChronoField.NANO_OF_SECOND;
71 import static java.time.temporal.ChronoUnit.DAYS;
72 import static java.time.temporal.ChronoUnit.NANOS;
73 import static java.time.temporal.ChronoUnit.SECONDS;
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.math.BigDecimal;
82 import java.math.BigInteger;
83 import java.math.RoundingMode;
84 import java.time.format.DateTimeParseException;
85 import java.time.temporal.ChronoField;
86 import java.time.temporal.ChronoUnit;
87 import java.time.temporal.Temporal;
88 import java.time.temporal.TemporalAmount;
89 import java.time.temporal.TemporalUnit;
90 import java.time.temporal.UnsupportedTemporalTypeException;
91 import java.util.Arrays;
92 import java.util.Collections;
93 import java.util.List;
94 import java.util.Objects;
95 import java.util.regex.Matcher;
96 import java.util.regex.Pattern;
97 
98 // Android-changed: removed ValueBased paragraph.
99 /**
100  * A time-based amount of time, such as '34.5 seconds'.
101  * <p>
102  * This class models a quantity or amount of time in terms of seconds and nanoseconds.
103  * It can be accessed using other duration-based units, such as minutes and hours.
104  * In addition, the {@link ChronoUnit#DAYS DAYS} unit can be used and is treated as
105  * exactly equal to 24 hours, thus ignoring daylight savings effects.
106  * See {@link Period} for the date-based equivalent to this class.
107  * <p>
108  * A physical duration could be of infinite length.
109  * For practicality, the duration is stored with constraints similar to {@link Instant}.
110  * The duration uses nanosecond resolution with a maximum value of the seconds that can
111  * be held in a {@code long}. This is greater than the current estimated age of the universe.
112  * <p>
113  * The range of a duration requires the storage of a number larger than a {@code long}.
114  * To achieve this, the class stores a {@code long} representing seconds and an {@code int}
115  * representing nanosecond-of-second, which will always be between 0 and 999,999,999.
116  * The model is of a directed duration, meaning that the duration may be negative.
117  * <p>
118  * The duration is measured in "seconds", but these are not necessarily identical to
119  * the scientific "SI second" definition based on atomic clocks.
120  * This difference only impacts durations measured near a leap-second and should not affect
121  * most applications.
122  * See {@link Instant} for a discussion as to the meaning of the second and time-scales.
123  *
124  * @implSpec
125  * This class is immutable and thread-safe.
126  *
127  * @since 1.8
128  */
129 public final class Duration
130         implements TemporalAmount, Comparable<Duration>, Serializable {
131 
132     /**
133      * Constant for a duration of zero.
134      */
135     public static final Duration ZERO = new Duration(0, 0);
136     /**
137      * Serialization version.
138      */
139     @java.io.Serial
140     private static final long serialVersionUID = 3078945930695997490L;
141     /**
142      * Constant for nanos per second.
143      */
144     private static final BigInteger BI_NANOS_PER_SECOND = BigInteger.valueOf(NANOS_PER_SECOND);
145     /**
146      * The pattern for parsing.
147      */
148     private static final Pattern PATTERN =
149             Pattern.compile("([-+]?)P(?:([-+]?[0-9]+)D)?" +
150                     "(T(?:([-+]?[0-9]+)H)?(?:([-+]?[0-9]+)M)?(?:([-+]?[0-9]+)(?:[.,]([0-9]{0,9}))?S)?)?",
151                     Pattern.CASE_INSENSITIVE);
152 
153     /**
154      * The number of seconds in the duration.
155      */
156     private final long seconds;
157     /**
158      * The number of nanoseconds in the duration, expressed as a fraction of the
159      * number of seconds. This is always positive, and never exceeds 999,999,999.
160      */
161     private final int nanos;
162 
163     //-----------------------------------------------------------------------
164     /**
165      * Obtains a {@code Duration} representing a number of standard 24 hour days.
166      * <p>
167      * The seconds are calculated based on the standard definition of a day,
168      * where each day is 86400 seconds which implies a 24 hour day.
169      * The nanosecond in second field is set to zero.
170      *
171      * @param days  the number of days, positive or negative
172      * @return a {@code Duration}, not null
173      * @throws ArithmeticException if the input days exceeds the capacity of {@code Duration}
174      */
ofDays(long days)175     public static Duration ofDays(long days) {
176         return create(Math.multiplyExact(days, SECONDS_PER_DAY), 0);
177     }
178 
179     /**
180      * Obtains a {@code Duration} representing a number of standard hours.
181      * <p>
182      * The seconds are calculated based on the standard definition of an hour,
183      * where each hour is 3600 seconds.
184      * The nanosecond in second field is set to zero.
185      *
186      * @param hours  the number of hours, positive or negative
187      * @return a {@code Duration}, not null
188      * @throws ArithmeticException if the input hours exceeds the capacity of {@code Duration}
189      */
ofHours(long hours)190     public static Duration ofHours(long hours) {
191         return create(Math.multiplyExact(hours, SECONDS_PER_HOUR), 0);
192     }
193 
194     /**
195      * Obtains a {@code Duration} representing a number of standard minutes.
196      * <p>
197      * The seconds are calculated based on the standard definition of a minute,
198      * where each minute is 60 seconds.
199      * The nanosecond in second field is set to zero.
200      *
201      * @param minutes  the number of minutes, positive or negative
202      * @return a {@code Duration}, not null
203      * @throws ArithmeticException if the input minutes exceeds the capacity of {@code Duration}
204      */
ofMinutes(long minutes)205     public static Duration ofMinutes(long minutes) {
206         return create(Math.multiplyExact(minutes, SECONDS_PER_MINUTE), 0);
207     }
208 
209     //-----------------------------------------------------------------------
210     /**
211      * Obtains a {@code Duration} representing a number of seconds.
212      * <p>
213      * The nanosecond in second field is set to zero.
214      *
215      * @param seconds  the number of seconds, positive or negative
216      * @return a {@code Duration}, not null
217      */
ofSeconds(long seconds)218     public static Duration ofSeconds(long seconds) {
219         return create(seconds, 0);
220     }
221 
222     /**
223      * Obtains a {@code Duration} representing a number of seconds and an
224      * adjustment in nanoseconds.
225      * <p>
226      * This method allows an arbitrary number of nanoseconds to be passed in.
227      * The factory will alter the values of the second and nanosecond in order
228      * to ensure that the stored nanosecond is in the range 0 to 999,999,999.
229      * For example, the following will result in exactly the same duration:
230      * <pre>
231      *  Duration.ofSeconds(3, 1);
232      *  Duration.ofSeconds(4, -999_999_999);
233      *  Duration.ofSeconds(2, 1000_000_001);
234      * </pre>
235      *
236      * @param seconds  the number of seconds, positive or negative
237      * @param nanoAdjustment  the nanosecond adjustment to the number of seconds, positive or negative
238      * @return a {@code Duration}, not null
239      * @throws ArithmeticException if the adjustment causes the seconds to exceed the capacity of {@code Duration}
240      */
ofSeconds(long seconds, long nanoAdjustment)241     public static Duration ofSeconds(long seconds, long nanoAdjustment) {
242         long secs = Math.addExact(seconds, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND));
243         int nos = (int) Math.floorMod(nanoAdjustment, NANOS_PER_SECOND);
244         return create(secs, nos);
245     }
246 
247     //-----------------------------------------------------------------------
248     /**
249      * Obtains a {@code Duration} representing a number of milliseconds.
250      * <p>
251      * The seconds and nanoseconds are extracted from the specified milliseconds.
252      *
253      * @param millis  the number of milliseconds, positive or negative
254      * @return a {@code Duration}, not null
255      */
ofMillis(long millis)256     public static Duration ofMillis(long millis) {
257         long secs = millis / 1000;
258         int mos = (int) (millis % 1000);
259         if (mos < 0) {
260             mos += 1000;
261             secs--;
262         }
263         return create(secs, mos * 1000_000);
264     }
265 
266     //-----------------------------------------------------------------------
267     /**
268      * Obtains a {@code Duration} representing a number of nanoseconds.
269      * <p>
270      * The seconds and nanoseconds are extracted from the specified nanoseconds.
271      *
272      * @param nanos  the number of nanoseconds, positive or negative
273      * @return a {@code Duration}, not null
274      */
ofNanos(long nanos)275     public static Duration ofNanos(long nanos) {
276         long secs = nanos / NANOS_PER_SECOND;
277         int nos = (int) (nanos % NANOS_PER_SECOND);
278         if (nos < 0) {
279             nos += NANOS_PER_SECOND;
280             secs--;
281         }
282         return create(secs, nos);
283     }
284 
285     //-----------------------------------------------------------------------
286     /**
287      * Obtains a {@code Duration} representing an amount in the specified unit.
288      * <p>
289      * The parameters represent the two parts of a phrase like '6 Hours'. For example:
290      * <pre>
291      *  Duration.of(3, SECONDS);
292      *  Duration.of(465, HOURS);
293      * </pre>
294      * Only a subset of units are accepted by this method.
295      * The unit must either have an {@linkplain TemporalUnit#isDurationEstimated() exact duration} or
296      * be {@link ChronoUnit#DAYS} which is treated as 24 hours. Other units throw an exception.
297      *
298      * @param amount  the amount of the duration, measured in terms of the unit, positive or negative
299      * @param unit  the unit that the duration is measured in, must have an exact duration, not null
300      * @return a {@code Duration}, not null
301      * @throws DateTimeException if the period unit has an estimated duration
302      * @throws ArithmeticException if a numeric overflow occurs
303      */
of(long amount, TemporalUnit unit)304     public static Duration of(long amount, TemporalUnit unit) {
305         return ZERO.plus(amount, unit);
306     }
307 
308     //-----------------------------------------------------------------------
309     /**
310      * Obtains an instance of {@code Duration} from a temporal amount.
311      * <p>
312      * This obtains a duration based on the specified amount.
313      * A {@code TemporalAmount} represents an  amount of time, which may be
314      * date-based or time-based, which this factory extracts to a duration.
315      * <p>
316      * The conversion loops around the set of units from the amount and uses
317      * the {@linkplain TemporalUnit#getDuration() duration} of the unit to
318      * calculate the total {@code Duration}.
319      * Only a subset of units are accepted by this method. The unit must either
320      * have an {@linkplain TemporalUnit#isDurationEstimated() exact duration}
321      * or be {@link ChronoUnit#DAYS} which is treated as 24 hours.
322      * If any other units are found then an exception is thrown.
323      *
324      * @param amount  the temporal amount to convert, not null
325      * @return the equivalent duration, not null
326      * @throws DateTimeException if unable to convert to a {@code Duration}
327      * @throws ArithmeticException if numeric overflow occurs
328      */
from(TemporalAmount amount)329     public static Duration from(TemporalAmount amount) {
330         Objects.requireNonNull(amount, "amount");
331         Duration duration = ZERO;
332         for (TemporalUnit unit : amount.getUnits()) {
333             duration = duration.plus(amount.get(unit), unit);
334         }
335         return duration;
336     }
337 
338     //-----------------------------------------------------------------------
339     /**
340      * Obtains a {@code Duration} from a text string such as {@code PnDTnHnMn.nS}.
341      * <p>
342      * This will parse a textual representation of a duration, including the
343      * string produced by {@code toString()}. The formats accepted are based
344      * on the ISO-8601 duration format {@code PnDTnHnMn.nS} with days
345      * considered to be exactly 24 hours.
346      * <p>
347      * The string starts with an optional sign, denoted by the ASCII negative
348      * or positive symbol. If negative, the whole period is negated.
349      * The ASCII letter "P" is next in upper or lower case.
350      * There are then four sections, each consisting of a number and a suffix.
351      * The sections have suffixes in ASCII of "D", "H", "M" and "S" for
352      * days, hours, minutes and seconds, accepted in upper or lower case.
353      * The suffixes must occur in order. The ASCII letter "T" must occur before
354      * the first occurrence, if any, of an hour, minute or second section.
355      * At least one of the four sections must be present, and if "T" is present
356      * there must be at least one section after the "T".
357      * The number part of each section must consist of one or more ASCII digits.
358      * The number may be prefixed by the ASCII negative or positive symbol.
359      * The number of days, hours and minutes must parse to an {@code long}.
360      * The number of seconds must parse to an {@code long} with optional fraction.
361      * The decimal point may be either a dot or a comma.
362      * The fractional part may have from zero to 9 digits.
363      * <p>
364      * The leading plus/minus sign, and negative values for other units are
365      * not part of the ISO-8601 standard.
366      * <p>
367      * Examples:
368      * <pre>
369      *    "PT20.345S" -- parses as "20.345 seconds"
370      *    "PT15M"     -- parses as "15 minutes" (where a minute is 60 seconds)
371      *    "PT10H"     -- parses as "10 hours" (where an hour is 3600 seconds)
372      *    "P2D"       -- parses as "2 days" (where a day is 24 hours or 86400 seconds)
373      *    "P2DT3H4M"  -- parses as "2 days, 3 hours and 4 minutes"
374      *    "P-6H3M"    -- parses as "-6 hours and +3 minutes"
375      *    "-P6H3M"    -- parses as "-6 hours and -3 minutes"
376      *    "-P-6H+3M"  -- parses as "+6 hours and -3 minutes"
377      * </pre>
378      *
379      * @param text  the text to parse, not null
380      * @return the parsed duration, not null
381      * @throws DateTimeParseException if the text cannot be parsed to a duration
382      */
parse(CharSequence text)383     public static Duration parse(CharSequence text) {
384         Objects.requireNonNull(text, "text");
385         Matcher matcher = PATTERN.matcher(text);
386         if (matcher.matches()) {
387             // check for letter T but no time sections
388             if ("T".equals(matcher.group(3)) == false) {
389                 boolean negate = "-".equals(matcher.group(1));
390                 String dayMatch = matcher.group(2);
391                 String hourMatch = matcher.group(4);
392                 String minuteMatch = matcher.group(5);
393                 String secondMatch = matcher.group(6);
394                 String fractionMatch = matcher.group(7);
395                 if (dayMatch != null || hourMatch != null || minuteMatch != null || secondMatch != null) {
396                     long daysAsSecs = parseNumber(text, dayMatch, SECONDS_PER_DAY, "days");
397                     long hoursAsSecs = parseNumber(text, hourMatch, SECONDS_PER_HOUR, "hours");
398                     long minsAsSecs = parseNumber(text, minuteMatch, SECONDS_PER_MINUTE, "minutes");
399                     long seconds = parseNumber(text, secondMatch, 1, "seconds");
400                     int nanos = parseFraction(text,  fractionMatch, seconds < 0 ? -1 : 1);
401                     try {
402                         return create(negate, daysAsSecs, hoursAsSecs, minsAsSecs, seconds, nanos);
403                     } catch (ArithmeticException ex) {
404                         throw (DateTimeParseException) new DateTimeParseException("Text cannot be parsed to a Duration: overflow", text, 0).initCause(ex);
405                     }
406                 }
407             }
408         }
409         throw new DateTimeParseException("Text cannot be parsed to a Duration", text, 0);
410     }
411 
parseNumber(CharSequence text, String parsed, int multiplier, String errorText)412     private static long parseNumber(CharSequence text, String parsed, int multiplier, String errorText) {
413         // regex limits to [-+]?[0-9]+
414         if (parsed == null) {
415             return 0;
416         }
417         try {
418             long val = Long.parseLong(parsed);
419             return Math.multiplyExact(val, multiplier);
420         } catch (NumberFormatException | ArithmeticException ex) {
421             throw (DateTimeParseException) new DateTimeParseException("Text cannot be parsed to a Duration: " + errorText, text, 0).initCause(ex);
422         }
423     }
424 
parseFraction(CharSequence text, String parsed, int negate)425     private static int parseFraction(CharSequence text, String parsed, int negate) {
426         // regex limits to [0-9]{0,9}
427         if (parsed == null || parsed.length() == 0) {
428             return 0;
429         }
430         try {
431             parsed = (parsed + "000000000").substring(0, 9);
432             return Integer.parseInt(parsed) * negate;
433         } catch (NumberFormatException | ArithmeticException ex) {
434             throw (DateTimeParseException) new DateTimeParseException("Text cannot be parsed to a Duration: fraction", text, 0).initCause(ex);
435         }
436     }
437 
create(boolean negate, long daysAsSecs, long hoursAsSecs, long minsAsSecs, long secs, int nanos)438     private static Duration create(boolean negate, long daysAsSecs, long hoursAsSecs, long minsAsSecs, long secs, int nanos) {
439         long seconds = Math.addExact(daysAsSecs, Math.addExact(hoursAsSecs, Math.addExact(minsAsSecs, secs)));
440         if (negate) {
441             return ofSeconds(seconds, nanos).negated();
442         }
443         return ofSeconds(seconds, nanos);
444     }
445 
446     //-----------------------------------------------------------------------
447     /**
448      * Obtains a {@code Duration} representing the duration between two temporal objects.
449      * <p>
450      * This calculates the duration between two temporal objects. If the objects
451      * are of different types, then the duration is calculated based on the type
452      * of the first object. For example, if the first argument is a {@code LocalTime}
453      * then the second argument is converted to a {@code LocalTime}.
454      * <p>
455      * The specified temporal objects must support the {@link ChronoUnit#SECONDS SECONDS} unit.
456      * For full accuracy, either the {@link ChronoUnit#NANOS NANOS} unit or the
457      * {@link ChronoField#NANO_OF_SECOND NANO_OF_SECOND} field should be supported.
458      * <p>
459      * The result of this method can be a negative period if the end is before the start.
460      * To guarantee to obtain a positive duration call {@link #abs()} on the result.
461      *
462      * @param startInclusive  the start instant, inclusive, not null
463      * @param endExclusive  the end instant, exclusive, not null
464      * @return a {@code Duration}, not null
465      * @throws DateTimeException if the seconds between the temporals cannot be obtained
466      * @throws ArithmeticException if the calculation exceeds the capacity of {@code Duration}
467      */
between(Temporal startInclusive, Temporal endExclusive)468     public static Duration between(Temporal startInclusive, Temporal endExclusive) {
469         try {
470             return ofNanos(startInclusive.until(endExclusive, NANOS));
471         } catch (DateTimeException | ArithmeticException ex) {
472             long secs = startInclusive.until(endExclusive, SECONDS);
473             long nanos;
474             try {
475                 nanos = endExclusive.getLong(NANO_OF_SECOND) - startInclusive.getLong(NANO_OF_SECOND);
476                 if (secs > 0 && nanos < 0) {
477                     secs++;
478                 } else if (secs < 0 && nanos > 0) {
479                     secs--;
480                 }
481             } catch (DateTimeException ex2) {
482                 nanos = 0;
483             }
484             return ofSeconds(secs, nanos);
485         }
486     }
487 
488     //-----------------------------------------------------------------------
489     /**
490      * Obtains an instance of {@code Duration} using seconds and nanoseconds.
491      *
492      * @param seconds  the length of the duration in seconds, positive or negative
493      * @param nanoAdjustment  the nanosecond adjustment within the second, from 0 to 999,999,999
494      */
create(long seconds, int nanoAdjustment)495     private static Duration create(long seconds, int nanoAdjustment) {
496         if ((seconds | nanoAdjustment) == 0) {
497             return ZERO;
498         }
499         return new Duration(seconds, nanoAdjustment);
500     }
501 
502     /**
503      * Constructs an instance of {@code Duration} using seconds and nanoseconds.
504      *
505      * @param seconds  the length of the duration in seconds, positive or negative
506      * @param nanos  the nanoseconds within the second, from 0 to 999,999,999
507      */
Duration(long seconds, int nanos)508     private Duration(long seconds, int nanos) {
509         super();
510         this.seconds = seconds;
511         this.nanos = nanos;
512     }
513 
514     //-----------------------------------------------------------------------
515     /**
516      * Gets the value of the requested unit.
517      * <p>
518      * This returns a value for each of the two supported units,
519      * {@link ChronoUnit#SECONDS SECONDS} and {@link ChronoUnit#NANOS NANOS}.
520      * All other units throw an exception.
521      *
522      * @param unit the {@code TemporalUnit} for which to return the value
523      * @return the long value of the unit
524      * @throws DateTimeException if the unit is not supported
525      * @throws UnsupportedTemporalTypeException if the unit is not supported
526      */
527     @Override
get(TemporalUnit unit)528     public long get(TemporalUnit unit) {
529         if (unit == SECONDS) {
530             return seconds;
531         } else if (unit == NANOS) {
532             return nanos;
533         } else {
534             throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
535         }
536     }
537 
538     /**
539      * Gets the set of units supported by this duration.
540      * <p>
541      * The supported units are {@link ChronoUnit#SECONDS SECONDS},
542      * and {@link ChronoUnit#NANOS NANOS}.
543      * They are returned in the order seconds, nanos.
544      * <p>
545      * This set can be used in conjunction with {@link #get(TemporalUnit)}
546      * to access the entire state of the duration.
547      *
548      * @return a list containing the seconds and nanos units, not null
549      */
550     @Override
getUnits()551     public List<TemporalUnit> getUnits() {
552         return DurationUnits.UNITS;
553     }
554 
555     /**
556      * Private class to delay initialization of this list until needed.
557      * The circular dependency between Duration and ChronoUnit prevents
558      * the simple initialization in Duration.
559      */
560     private static class DurationUnits {
561         static final List<TemporalUnit> UNITS =
562                 Collections.unmodifiableList(Arrays.<TemporalUnit>asList(SECONDS, NANOS));
563     }
564 
565     //-----------------------------------------------------------------------
566     /**
567      * Checks if this duration is positive, excluding zero.
568      * <p>
569      * A {@code Duration} represents a directed distance between two points on
570      * the time-line and can therefore be positive, zero or negative.
571      * This method checks whether the length is greater than zero.
572      *
573      * @return true if this duration has a total length greater than zero
574      * @since 18
575      */
isPositive()576     public boolean isPositive() {
577         return (seconds | nanos) > 0;
578     }
579 
580     /**
581      * Checks if this duration is zero length.
582      * <p>
583      * A {@code Duration} represents a directed distance between two points on
584      * the time-line and can therefore be positive, zero or negative.
585      * This method checks whether the length is zero.
586      *
587      * @return true if this duration has a total length equal to zero
588      */
isZero()589     public boolean isZero() {
590         return (seconds | nanos) == 0;
591     }
592 
593     /**
594      * Checks if this duration is negative, excluding zero.
595      * <p>
596      * A {@code Duration} represents a directed distance between two points on
597      * the time-line and can therefore be positive, zero or negative.
598      * This method checks whether the length is less than zero.
599      *
600      * @return true if this duration has a total length less than zero
601      */
isNegative()602     public boolean isNegative() {
603         return seconds < 0;
604     }
605 
606     //-----------------------------------------------------------------------
607     /**
608      * Gets the number of seconds in this duration.
609      * <p>
610      * The length of the duration is stored using two fields - seconds and nanoseconds.
611      * The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to
612      * the length in seconds.
613      * The total duration is defined by calling this method and {@link #getNano()}.
614      * <p>
615      * A {@code Duration} represents a directed distance between two points on the time-line.
616      * A negative duration is expressed by the negative sign of the seconds part.
617      * A duration of -1 nanosecond is stored as -1 seconds plus 999,999,999 nanoseconds.
618      *
619      * @return the whole seconds part of the length of the duration, positive or negative
620      */
getSeconds()621     public long getSeconds() {
622         return seconds;
623     }
624 
625     /**
626      * Gets the number of nanoseconds within the second in this duration.
627      * <p>
628      * The length of the duration is stored using two fields - seconds and nanoseconds.
629      * The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to
630      * the length in seconds.
631      * The total duration is defined by calling this method and {@link #getSeconds()}.
632      * <p>
633      * A {@code Duration} represents a directed distance between two points on the time-line.
634      * A negative duration is expressed by the negative sign of the seconds part.
635      * A duration of -1 nanosecond is stored as -1 seconds plus 999,999,999 nanoseconds.
636      *
637      * @return the nanoseconds within the second part of the length of the duration, from 0 to 999,999,999
638      */
getNano()639     public int getNano() {
640         return nanos;
641     }
642 
643     //-----------------------------------------------------------------------
644     /**
645      * Returns a copy of this duration with the specified amount of seconds.
646      * <p>
647      * This returns a duration with the specified seconds, retaining the
648      * nano-of-second part of this duration.
649      * <p>
650      * This instance is immutable and unaffected by this method call.
651      *
652      * @param seconds  the seconds to represent, may be negative
653      * @return a {@code Duration} based on this period with the requested seconds, not null
654      */
withSeconds(long seconds)655     public Duration withSeconds(long seconds) {
656         return create(seconds, nanos);
657     }
658 
659     /**
660      * Returns a copy of this duration with the specified nano-of-second.
661      * <p>
662      * This returns a duration with the specified nano-of-second, retaining the
663      * seconds part of this duration.
664      * <p>
665      * This instance is immutable and unaffected by this method call.
666      *
667      * @param nanoOfSecond  the nano-of-second to represent, from 0 to 999,999,999
668      * @return a {@code Duration} based on this period with the requested nano-of-second, not null
669      * @throws DateTimeException if the nano-of-second is invalid
670      */
withNanos(int nanoOfSecond)671     public Duration withNanos(int nanoOfSecond) {
672         NANO_OF_SECOND.checkValidIntValue(nanoOfSecond);
673         return create(seconds, nanoOfSecond);
674     }
675 
676     //-----------------------------------------------------------------------
677     /**
678      * Returns a copy of this duration with the specified duration added.
679      * <p>
680      * This instance is immutable and unaffected by this method call.
681      *
682      * @param duration  the duration to add, positive or negative, not null
683      * @return a {@code Duration} based on this duration with the specified duration added, not null
684      * @throws ArithmeticException if numeric overflow occurs
685      */
plus(Duration duration)686     public Duration plus(Duration duration) {
687         return plus(duration.getSeconds(), duration.getNano());
688      }
689 
690     /**
691      * Returns a copy of this duration with the specified duration added.
692      * <p>
693      * The duration amount is measured in terms of the specified unit.
694      * Only a subset of units are accepted by this method.
695      * The unit must either have an {@linkplain TemporalUnit#isDurationEstimated() exact duration} or
696      * be {@link ChronoUnit#DAYS} which is treated as 24 hours. Other units throw an exception.
697      * <p>
698      * This instance is immutable and unaffected by this method call.
699      *
700      * @param amountToAdd  the amount to add, measured in terms of the unit, positive or negative
701      * @param unit  the unit that the amount is measured in, must have an exact duration, not null
702      * @return a {@code Duration} based on this duration with the specified duration added, not null
703      * @throws UnsupportedTemporalTypeException if the unit is not supported
704      * @throws ArithmeticException if numeric overflow occurs
705      */
plus(long amountToAdd, TemporalUnit unit)706     public Duration plus(long amountToAdd, TemporalUnit unit) {
707         Objects.requireNonNull(unit, "unit");
708         if (unit == DAYS) {
709             return plus(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY), 0);
710         }
711         if (unit.isDurationEstimated()) {
712             throw new UnsupportedTemporalTypeException("Unit must not have an estimated duration");
713         }
714         if (amountToAdd == 0) {
715             return this;
716         }
717         if (unit instanceof ChronoUnit chronoUnit) {
718             switch (chronoUnit) {
719                 case NANOS: return plusNanos(amountToAdd);
720                 case MICROS: return plusSeconds((amountToAdd / (1000_000L * 1000)) * 1000).plusNanos((amountToAdd % (1000_000L * 1000)) * 1000);
721                 case MILLIS: return plusMillis(amountToAdd);
722                 case SECONDS: return plusSeconds(amountToAdd);
723             }
724             return plusSeconds(Math.multiplyExact(unit.getDuration().seconds, amountToAdd));
725         }
726         Duration duration = unit.getDuration().multipliedBy(amountToAdd);
727         return plusSeconds(duration.getSeconds()).plusNanos(duration.getNano());
728     }
729 
730     //-----------------------------------------------------------------------
731     /**
732      * Returns a copy of this duration with the specified duration in standard 24 hour days added.
733      * <p>
734      * The number of days is multiplied by 86400 to obtain the number of seconds to add.
735      * This is based on the standard definition of a day as 24 hours.
736      * <p>
737      * This instance is immutable and unaffected by this method call.
738      *
739      * @param daysToAdd  the days to add, positive or negative
740      * @return a {@code Duration} based on this duration with the specified days added, not null
741      * @throws ArithmeticException if numeric overflow occurs
742      */
plusDays(long daysToAdd)743     public Duration plusDays(long daysToAdd) {
744         return plus(Math.multiplyExact(daysToAdd, SECONDS_PER_DAY), 0);
745     }
746 
747     /**
748      * Returns a copy of this duration with the specified duration in hours added.
749      * <p>
750      * This instance is immutable and unaffected by this method call.
751      *
752      * @param hoursToAdd  the hours to add, positive or negative
753      * @return a {@code Duration} based on this duration with the specified hours added, not null
754      * @throws ArithmeticException if numeric overflow occurs
755      */
plusHours(long hoursToAdd)756     public Duration plusHours(long hoursToAdd) {
757         return plus(Math.multiplyExact(hoursToAdd, SECONDS_PER_HOUR), 0);
758     }
759 
760     /**
761      * Returns a copy of this duration with the specified duration in minutes added.
762      * <p>
763      * This instance is immutable and unaffected by this method call.
764      *
765      * @param minutesToAdd  the minutes to add, positive or negative
766      * @return a {@code Duration} based on this duration with the specified minutes added, not null
767      * @throws ArithmeticException if numeric overflow occurs
768      */
plusMinutes(long minutesToAdd)769     public Duration plusMinutes(long minutesToAdd) {
770         return plus(Math.multiplyExact(minutesToAdd, SECONDS_PER_MINUTE), 0);
771     }
772 
773     /**
774      * Returns a copy of this duration with the specified duration in seconds added.
775      * <p>
776      * This instance is immutable and unaffected by this method call.
777      *
778      * @param secondsToAdd  the seconds to add, positive or negative
779      * @return a {@code Duration} based on this duration with the specified seconds added, not null
780      * @throws ArithmeticException if numeric overflow occurs
781      */
plusSeconds(long secondsToAdd)782     public Duration plusSeconds(long secondsToAdd) {
783         return plus(secondsToAdd, 0);
784     }
785 
786     /**
787      * Returns a copy of this duration with the specified duration in milliseconds added.
788      * <p>
789      * This instance is immutable and unaffected by this method call.
790      *
791      * @param millisToAdd  the milliseconds to add, positive or negative
792      * @return a {@code Duration} based on this duration with the specified milliseconds added, not null
793      * @throws ArithmeticException if numeric overflow occurs
794      */
plusMillis(long millisToAdd)795     public Duration plusMillis(long millisToAdd) {
796         return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000);
797     }
798 
799     /**
800      * Returns a copy of this duration with the specified duration in nanoseconds added.
801      * <p>
802      * This instance is immutable and unaffected by this method call.
803      *
804      * @param nanosToAdd  the nanoseconds to add, positive or negative
805      * @return a {@code Duration} based on this duration with the specified nanoseconds added, not null
806      * @throws ArithmeticException if numeric overflow occurs
807      */
plusNanos(long nanosToAdd)808     public Duration plusNanos(long nanosToAdd) {
809         return plus(0, nanosToAdd);
810     }
811 
812     /**
813      * Returns a copy of this duration with the specified duration added.
814      * <p>
815      * This instance is immutable and unaffected by this method call.
816      *
817      * @param secondsToAdd  the seconds to add, positive or negative
818      * @param nanosToAdd  the nanos to add, positive or negative
819      * @return a {@code Duration} based on this duration with the specified seconds added, not null
820      * @throws ArithmeticException if numeric overflow occurs
821      */
plus(long secondsToAdd, long nanosToAdd)822     private Duration plus(long secondsToAdd, long nanosToAdd) {
823         if ((secondsToAdd | nanosToAdd) == 0) {
824             return this;
825         }
826         long epochSec = Math.addExact(seconds, secondsToAdd);
827         epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND);
828         nanosToAdd = nanosToAdd % NANOS_PER_SECOND;
829         long nanoAdjustment = nanos + nanosToAdd;  // safe int+NANOS_PER_SECOND
830         return ofSeconds(epochSec, nanoAdjustment);
831     }
832 
833     //-----------------------------------------------------------------------
834     /**
835      * Returns a copy of this duration with the specified duration subtracted.
836      * <p>
837      * This instance is immutable and unaffected by this method call.
838      *
839      * @param duration  the duration to subtract, positive or negative, not null
840      * @return a {@code Duration} based on this duration with the specified duration subtracted, not null
841      * @throws ArithmeticException if numeric overflow occurs
842      */
minus(Duration duration)843     public Duration minus(Duration duration) {
844         long secsToSubtract = duration.getSeconds();
845         int nanosToSubtract = duration.getNano();
846         if (secsToSubtract == Long.MIN_VALUE) {
847             return plus(Long.MAX_VALUE, -nanosToSubtract).plus(1, 0);
848         }
849         return plus(-secsToSubtract, -nanosToSubtract);
850      }
851 
852     /**
853      * Returns a copy of this duration with the specified duration subtracted.
854      * <p>
855      * The duration amount is measured in terms of the specified unit.
856      * Only a subset of units are accepted by this method.
857      * The unit must either have an {@linkplain TemporalUnit#isDurationEstimated() exact duration} or
858      * be {@link ChronoUnit#DAYS} which is treated as 24 hours. Other units throw an exception.
859      * <p>
860      * This instance is immutable and unaffected by this method call.
861      *
862      * @param amountToSubtract  the amount to subtract, measured in terms of the unit, positive or negative
863      * @param unit  the unit that the amount is measured in, must have an exact duration, not null
864      * @return a {@code Duration} based on this duration with the specified duration subtracted, not null
865      * @throws ArithmeticException if numeric overflow occurs
866      */
minus(long amountToSubtract, TemporalUnit unit)867     public Duration minus(long amountToSubtract, TemporalUnit unit) {
868         return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
869     }
870 
871     //-----------------------------------------------------------------------
872     /**
873      * Returns a copy of this duration with the specified duration in standard 24 hour days subtracted.
874      * <p>
875      * The number of days is multiplied by 86400 to obtain the number of seconds to subtract.
876      * This is based on the standard definition of a day as 24 hours.
877      * <p>
878      * This instance is immutable and unaffected by this method call.
879      *
880      * @param daysToSubtract  the days to subtract, positive or negative
881      * @return a {@code Duration} based on this duration with the specified days subtracted, not null
882      * @throws ArithmeticException if numeric overflow occurs
883      */
minusDays(long daysToSubtract)884     public Duration minusDays(long daysToSubtract) {
885         return (daysToSubtract == Long.MIN_VALUE ? plusDays(Long.MAX_VALUE).plusDays(1) : plusDays(-daysToSubtract));
886     }
887 
888     /**
889      * Returns a copy of this duration with the specified duration in hours subtracted.
890      * <p>
891      * The number of hours is multiplied by 3600 to obtain the number of seconds to subtract.
892      * <p>
893      * This instance is immutable and unaffected by this method call.
894      *
895      * @param hoursToSubtract  the hours to subtract, positive or negative
896      * @return a {@code Duration} based on this duration with the specified hours subtracted, not null
897      * @throws ArithmeticException if numeric overflow occurs
898      */
minusHours(long hoursToSubtract)899     public Duration minusHours(long hoursToSubtract) {
900         return (hoursToSubtract == Long.MIN_VALUE ? plusHours(Long.MAX_VALUE).plusHours(1) : plusHours(-hoursToSubtract));
901     }
902 
903     /**
904      * Returns a copy of this duration with the specified duration in minutes subtracted.
905      * <p>
906      * The number of hours is multiplied by 60 to obtain the number of seconds to subtract.
907      * <p>
908      * This instance is immutable and unaffected by this method call.
909      *
910      * @param minutesToSubtract  the minutes to subtract, positive or negative
911      * @return a {@code Duration} based on this duration with the specified minutes subtracted, not null
912      * @throws ArithmeticException if numeric overflow occurs
913      */
minusMinutes(long minutesToSubtract)914     public Duration minusMinutes(long minutesToSubtract) {
915         return (minutesToSubtract == Long.MIN_VALUE ? plusMinutes(Long.MAX_VALUE).plusMinutes(1) : plusMinutes(-minutesToSubtract));
916     }
917 
918     /**
919      * Returns a copy of this duration 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 a {@code Duration} based on this duration with the specified seconds subtracted, not null
925      * @throws ArithmeticException if numeric overflow occurs
926      */
minusSeconds(long secondsToSubtract)927     public Duration minusSeconds(long secondsToSubtract) {
928         return (secondsToSubtract == Long.MIN_VALUE ? plusSeconds(Long.MAX_VALUE).plusSeconds(1) : plusSeconds(-secondsToSubtract));
929     }
930 
931     /**
932      * Returns a copy of this duration with the specified duration in milliseconds subtracted.
933      * <p>
934      * This instance is immutable and unaffected by this method call.
935      *
936      * @param millisToSubtract  the milliseconds to subtract, positive or negative
937      * @return a {@code Duration} based on this duration with the specified milliseconds subtracted, not null
938      * @throws ArithmeticException if numeric overflow occurs
939      */
minusMillis(long millisToSubtract)940     public Duration minusMillis(long millisToSubtract) {
941         return (millisToSubtract == Long.MIN_VALUE ? plusMillis(Long.MAX_VALUE).plusMillis(1) : plusMillis(-millisToSubtract));
942     }
943 
944     /**
945      * Returns a copy of this duration with the specified duration in nanoseconds subtracted.
946      * <p>
947      * This instance is immutable and unaffected by this method call.
948      *
949      * @param nanosToSubtract  the nanoseconds to subtract, positive or negative
950      * @return a {@code Duration} based on this duration with the specified nanoseconds subtracted, not null
951      * @throws ArithmeticException if numeric overflow occurs
952      */
minusNanos(long nanosToSubtract)953     public Duration minusNanos(long nanosToSubtract) {
954         return (nanosToSubtract == Long.MIN_VALUE ? plusNanos(Long.MAX_VALUE).plusNanos(1) : plusNanos(-nanosToSubtract));
955     }
956 
957     //-----------------------------------------------------------------------
958     /**
959      * Returns a copy of this duration multiplied by the scalar.
960      * <p>
961      * This instance is immutable and unaffected by this method call.
962      *
963      * @param multiplicand  the value to multiply the duration by, positive or negative
964      * @return a {@code Duration} based on this duration multiplied by the specified scalar, not null
965      * @throws ArithmeticException if numeric overflow occurs
966      */
multipliedBy(long multiplicand)967     public Duration multipliedBy(long multiplicand) {
968         if (multiplicand == 0) {
969             return ZERO;
970         }
971         if (multiplicand == 1) {
972             return this;
973         }
974         return create(toBigDecimalSeconds().multiply(BigDecimal.valueOf(multiplicand)));
975      }
976 
977     /**
978      * Returns a copy of this duration divided by the specified value.
979      * <p>
980      * This instance is immutable and unaffected by this method call.
981      *
982      * @param divisor  the value to divide the duration by, positive or negative, not zero
983      * @return a {@code Duration} based on this duration divided by the specified divisor, not null
984      * @throws ArithmeticException if the divisor is zero or if numeric overflow occurs
985      */
dividedBy(long divisor)986     public Duration dividedBy(long divisor) {
987         if (divisor == 0) {
988             throw new ArithmeticException("Cannot divide by zero");
989         }
990         if (divisor == 1) {
991             return this;
992         }
993         return create(toBigDecimalSeconds().divide(BigDecimal.valueOf(divisor), RoundingMode.DOWN));
994      }
995 
996     /**
997      * Returns number of whole times a specified Duration occurs within this Duration.
998      * <p>
999      * This instance is immutable and unaffected by this method call.
1000      *
1001      * @param divisor the value to divide the duration by, positive or negative, not null
1002      * @return number of whole times, rounded toward zero, a specified
1003      *         {@code Duration} occurs within this Duration, may be negative
1004      * @throws ArithmeticException if the divisor is zero, or if numeric overflow occurs
1005      * @since 9
1006      */
dividedBy(Duration divisor)1007     public long dividedBy(Duration divisor) {
1008         Objects.requireNonNull(divisor, "divisor");
1009         BigDecimal dividendBigD = toBigDecimalSeconds();
1010         BigDecimal divisorBigD = divisor.toBigDecimalSeconds();
1011         return dividendBigD.divideToIntegralValue(divisorBigD).longValueExact();
1012     }
1013 
1014     /**
1015      * Converts this duration to the total length in seconds and
1016      * fractional nanoseconds expressed as a {@code BigDecimal}.
1017      *
1018      * @return the total length of the duration in seconds, with a scale of 9, not null
1019      */
toBigDecimalSeconds()1020     private BigDecimal toBigDecimalSeconds() {
1021         return BigDecimal.valueOf(seconds).add(BigDecimal.valueOf(nanos, 9));
1022     }
1023 
1024     /**
1025      * Creates an instance of {@code Duration} from a number of seconds.
1026      *
1027      * @param seconds  the number of seconds, up to scale 9, positive or negative
1028      * @return a {@code Duration}, not null
1029      * @throws ArithmeticException if numeric overflow occurs
1030      */
create(BigDecimal seconds)1031     private static Duration create(BigDecimal seconds) {
1032         BigInteger nanos = seconds.movePointRight(9).toBigIntegerExact();
1033         BigInteger[] divRem = nanos.divideAndRemainder(BI_NANOS_PER_SECOND);
1034         if (divRem[0].bitLength() > 63) {
1035             throw new ArithmeticException("Exceeds capacity of Duration: " + nanos);
1036         }
1037         return ofSeconds(divRem[0].longValue(), divRem[1].intValue());
1038     }
1039 
1040     //-----------------------------------------------------------------------
1041     /**
1042      * Returns a copy of this duration with the length negated.
1043      * <p>
1044      * This method swaps the sign of the total length of this duration.
1045      * For example, {@code PT1.3S} will be returned as {@code PT-1.3S}.
1046      * <p>
1047      * This instance is immutable and unaffected by this method call.
1048      *
1049      * @return a {@code Duration} based on this duration with the amount negated, not null
1050      * @throws ArithmeticException if numeric overflow occurs
1051      */
negated()1052     public Duration negated() {
1053         return multipliedBy(-1);
1054     }
1055 
1056     /**
1057      * Returns a copy of this duration with a positive length.
1058      * <p>
1059      * This method returns a positive duration by effectively removing the sign from any negative total length.
1060      * For example, {@code PT-1.3S} will be returned as {@code PT1.3S}.
1061      * <p>
1062      * This instance is immutable and unaffected by this method call.
1063      *
1064      * @return a {@code Duration} based on this duration with an absolute length, not null
1065      * @throws ArithmeticException if numeric overflow occurs
1066      */
abs()1067     public Duration abs() {
1068         return isNegative() ? negated() : this;
1069     }
1070 
1071     //-------------------------------------------------------------------------
1072     /**
1073      * Adds this duration to the specified temporal object.
1074      * <p>
1075      * This returns a temporal object of the same observable type as the input
1076      * with this duration added.
1077      * <p>
1078      * In most cases, it is clearer to reverse the calling pattern by using
1079      * {@link Temporal#plus(TemporalAmount)}.
1080      * <pre>
1081      *   // these two lines are equivalent, but the second approach is recommended
1082      *   dateTime = thisDuration.addTo(dateTime);
1083      *   dateTime = dateTime.plus(thisDuration);
1084      * </pre>
1085      * <p>
1086      * The calculation will add the seconds, then nanos.
1087      * Only non-zero amounts will be added.
1088      * <p>
1089      * This instance is immutable and unaffected by this method call.
1090      *
1091      * @param temporal  the temporal object to adjust, not null
1092      * @return an object of the same type with the adjustment made, not null
1093      * @throws DateTimeException if unable to add
1094      * @throws ArithmeticException if numeric overflow occurs
1095      */
1096     @Override
addTo(Temporal temporal)1097     public Temporal addTo(Temporal temporal) {
1098         if (seconds != 0) {
1099             temporal = temporal.plus(seconds, SECONDS);
1100         }
1101         if (nanos != 0) {
1102             temporal = temporal.plus(nanos, NANOS);
1103         }
1104         return temporal;
1105     }
1106 
1107     /**
1108      * Subtracts this duration from the specified temporal object.
1109      * <p>
1110      * This returns a temporal object of the same observable type as the input
1111      * with this duration subtracted.
1112      * <p>
1113      * In most cases, it is clearer to reverse the calling pattern by using
1114      * {@link Temporal#minus(TemporalAmount)}.
1115      * <pre>
1116      *   // these two lines are equivalent, but the second approach is recommended
1117      *   dateTime = thisDuration.subtractFrom(dateTime);
1118      *   dateTime = dateTime.minus(thisDuration);
1119      * </pre>
1120      * <p>
1121      * The calculation will subtract the seconds, then nanos.
1122      * Only non-zero amounts will be added.
1123      * <p>
1124      * This instance is immutable and unaffected by this method call.
1125      *
1126      * @param temporal  the temporal object to adjust, not null
1127      * @return an object of the same type with the adjustment made, not null
1128      * @throws DateTimeException if unable to subtract
1129      * @throws ArithmeticException if numeric overflow occurs
1130      */
1131     @Override
subtractFrom(Temporal temporal)1132     public Temporal subtractFrom(Temporal temporal) {
1133         if (seconds != 0) {
1134             temporal = temporal.minus(seconds, SECONDS);
1135         }
1136         if (nanos != 0) {
1137             temporal = temporal.minus(nanos, NANOS);
1138         }
1139         return temporal;
1140     }
1141 
1142     //-----------------------------------------------------------------------
1143     /**
1144      * Gets the number of days in this duration.
1145      * <p>
1146      * This returns the total number of days in the duration by dividing the
1147      * number of seconds by 86400.
1148      * This is based on the standard definition of a day as 24 hours.
1149      * <p>
1150      * This instance is immutable and unaffected by this method call.
1151      *
1152      * @return the number of days in the duration, may be negative
1153      */
toDays()1154     public long toDays() {
1155         return seconds / SECONDS_PER_DAY;
1156     }
1157 
1158     /**
1159      * Gets the number of hours in this duration.
1160      * <p>
1161      * This returns the total number of hours in the duration by dividing the
1162      * number of seconds by 3600.
1163      * <p>
1164      * This instance is immutable and unaffected by this method call.
1165      *
1166      * @return the number of hours in the duration, may be negative
1167      */
toHours()1168     public long toHours() {
1169         return seconds / SECONDS_PER_HOUR;
1170     }
1171 
1172     /**
1173      * Gets the number of minutes in this duration.
1174      * <p>
1175      * This returns the total number of minutes in the duration by dividing the
1176      * number of seconds by 60.
1177      * <p>
1178      * This instance is immutable and unaffected by this method call.
1179      *
1180      * @return the number of minutes in the duration, may be negative
1181      */
toMinutes()1182     public long toMinutes() {
1183         return seconds / SECONDS_PER_MINUTE;
1184     }
1185 
1186     /**
1187      * Gets the number of seconds in this duration.
1188      * <p>
1189      * This returns the total number of whole seconds in the duration.
1190      * <p>
1191      * This instance is immutable and unaffected by this method call.
1192      *
1193      * @return the whole seconds part of the length of the duration, positive or negative
1194      * @since 9
1195      */
toSeconds()1196     public long toSeconds() {
1197         return seconds;
1198     }
1199 
1200     /**
1201      * Converts this duration to the total length in milliseconds.
1202      * <p>
1203      * If this duration is too large to fit in a {@code long} milliseconds, then an
1204      * exception is thrown.
1205      * <p>
1206      * If this duration has greater than millisecond precision, then the conversion
1207      * will drop any excess precision information as though the amount in nanoseconds
1208      * was subject to integer division by one million.
1209      *
1210      * @return the total length of the duration in milliseconds
1211      * @throws ArithmeticException if numeric overflow occurs
1212      */
toMillis()1213     public long toMillis() {
1214         long millis = Math.multiplyExact(seconds, 1000);
1215         millis = Math.addExact(millis, nanos / 1000_000);
1216         return millis;
1217     }
1218 
1219     /**
1220      * Converts this duration to the total length in nanoseconds expressed as a {@code long}.
1221      * <p>
1222      * If this duration is too large to fit in a {@code long} nanoseconds, then an
1223      * exception is thrown.
1224      *
1225      * @return the total length of the duration in nanoseconds
1226      * @throws ArithmeticException if numeric overflow occurs
1227      */
toNanos()1228     public long toNanos() {
1229         long totalNanos = Math.multiplyExact(seconds, NANOS_PER_SECOND);
1230         totalNanos = Math.addExact(totalNanos, nanos);
1231         return totalNanos;
1232     }
1233 
1234     /**
1235      * Extracts the number of days in the duration.
1236      * <p>
1237      * This returns the total number of days in the duration by dividing the
1238      * number of seconds by 86400.
1239      * This is based on the standard definition of a day as 24 hours.
1240      * <p>
1241      * This instance is immutable and unaffected by this method call.
1242      *
1243      * @return the number of days in the duration, may be negative
1244      * @since 9
1245      */
toDaysPart()1246     public long toDaysPart(){
1247         return seconds / SECONDS_PER_DAY;
1248     }
1249 
1250     /**
1251      * Extracts the number of hours part in the duration.
1252      * <p>
1253      * This returns the number of remaining hours when dividing {@link #toHours}
1254      * by hours in a day.
1255      * This is based on the standard definition of a day as 24 hours.
1256      * <p>
1257      * This instance is immutable and unaffected by this method call.
1258      *
1259      * @return the number of hours part in the duration, may be negative
1260      * @since 9
1261      */
toHoursPart()1262     public int toHoursPart(){
1263         return (int) (toHours() % 24);
1264     }
1265 
1266     /**
1267      * Extracts the number of minutes part in the duration.
1268      * <p>
1269      * This returns the number of remaining minutes when dividing {@link #toMinutes}
1270      * by minutes in an hour.
1271      * This is based on the standard definition of an hour as 60 minutes.
1272      * <p>
1273      * This instance is immutable and unaffected by this method call.
1274      *
1275      * @return the number of minutes parts in the duration, may be negative
1276      * @since 9
1277      */
toMinutesPart()1278     public int toMinutesPart(){
1279         return (int) (toMinutes() % MINUTES_PER_HOUR);
1280     }
1281 
1282     /**
1283      * Extracts the number of seconds part in the duration.
1284      * <p>
1285      * This returns the remaining seconds when dividing {@link #toSeconds}
1286      * by seconds in a minute.
1287      * This is based on the standard definition of a minute as 60 seconds.
1288      * <p>
1289      * This instance is immutable and unaffected by this method call.
1290      *
1291      * @return the number of seconds parts in the duration, may be negative
1292      * @since 9
1293      */
toSecondsPart()1294     public int toSecondsPart(){
1295         return (int) (seconds % SECONDS_PER_MINUTE);
1296     }
1297 
1298     /**
1299      * Extracts the number of milliseconds part of the duration.
1300      * <p>
1301      * This returns the milliseconds part by dividing the number of nanoseconds by 1,000,000.
1302      * The length of the duration is stored using two fields - seconds and nanoseconds.
1303      * The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to
1304      * the length in seconds.
1305      * The total duration is defined by calling {@link #getNano()} and {@link #getSeconds()}.
1306      * <p>
1307      * This instance is immutable and unaffected by this method call.
1308      *
1309      * @return the number of milliseconds part of the duration.
1310      * @since 9
1311      */
toMillisPart()1312     public int toMillisPart(){
1313         return nanos / 1000_000;
1314     }
1315 
1316     /**
1317      * Get the nanoseconds part within seconds of the duration.
1318      * <p>
1319      * The length of the duration is stored using two fields - seconds and nanoseconds.
1320      * The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to
1321      * the length in seconds.
1322      * The total duration is defined by calling {@link #getNano()} and {@link #getSeconds()}.
1323      * <p>
1324      * This instance is immutable and unaffected by this method call.
1325      *
1326      * @return the nanoseconds within the second part of the length of the duration, from 0 to 999,999,999
1327      * @since 9
1328      */
toNanosPart()1329     public int toNanosPart(){
1330         return nanos;
1331     }
1332 
1333 
1334     //-----------------------------------------------------------------------
1335     /**
1336      * Returns a copy of this {@code Duration} truncated to the specified unit.
1337      * <p>
1338      * Truncating the duration returns a copy of the original with conceptual fields
1339      * smaller than the specified unit set to zero.
1340      * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will
1341      * round down towards zero to the nearest minute, setting the seconds and
1342      * nanoseconds to zero.
1343      * <p>
1344      * The unit must have a {@linkplain TemporalUnit#getDuration() duration}
1345      * that divides into the length of a standard day without remainder.
1346      * This includes all
1347      * {@linkplain ChronoUnit#isTimeBased() time-based units on {@code ChronoUnit}}
1348      * and {@link ChronoUnit#DAYS DAYS}. Other ChronoUnits throw an exception.
1349      * <p>
1350      * This instance is immutable and unaffected by this method call.
1351      *
1352      * @param unit the unit to truncate to, not null
1353      * @return a {@code Duration} based on this duration with the time truncated, not null
1354      * @throws DateTimeException if the unit is invalid for truncation
1355      * @throws UnsupportedTemporalTypeException if the unit is not supported
1356      * @since 9
1357      */
truncatedTo(TemporalUnit unit)1358     public Duration truncatedTo(TemporalUnit unit) {
1359         Objects.requireNonNull(unit, "unit");
1360         if (unit == ChronoUnit.SECONDS && (seconds >= 0 || nanos == 0)) {
1361             return new Duration(seconds, 0);
1362         } else if (unit == ChronoUnit.NANOS) {
1363             return this;
1364         }
1365         Duration unitDur = unit.getDuration();
1366         if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) {
1367             throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
1368         }
1369         long dur = unitDur.toNanos();
1370         if ((LocalTime.NANOS_PER_DAY % dur) != 0) {
1371             throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
1372         }
1373         long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos;
1374         long result = (nod / dur) * dur;
1375         return plusNanos(result - nod);
1376     }
1377 
1378     //-----------------------------------------------------------------------
1379     /**
1380      * Compares this duration to the specified {@code Duration}.
1381      * <p>
1382      * The comparison is based on the total length of the durations.
1383      * It is "consistent with equals", as defined by {@link Comparable}.
1384      *
1385      * @param otherDuration the other duration to compare to, not null
1386      * @return the comparator value, negative if less, positive if greater
1387      */
1388     @Override
compareTo(Duration otherDuration)1389     public int compareTo(Duration otherDuration) {
1390         int cmp = Long.compare(seconds, otherDuration.seconds);
1391         if (cmp != 0) {
1392             return cmp;
1393         }
1394         return nanos - otherDuration.nanos;
1395     }
1396 
1397     //-----------------------------------------------------------------------
1398     /**
1399      * Checks if this duration is equal to the specified {@code Duration}.
1400      * <p>
1401      * The comparison is based on the total length of the durations.
1402      *
1403      * @param other the other duration, null returns false
1404      * @return true if the other duration is equal to this one
1405      */
1406     @Override
equals(Object other)1407     public boolean equals(Object other) {
1408         if (this == other) {
1409             return true;
1410         }
1411         return (other instanceof Duration otherDuration)
1412                 && this.seconds == otherDuration.seconds
1413                 && this.nanos == otherDuration.nanos;
1414     }
1415 
1416     /**
1417      * A hash code for this duration.
1418      *
1419      * @return a suitable hash code
1420      */
1421     @Override
hashCode()1422     public int hashCode() {
1423         return ((int) (seconds ^ (seconds >>> 32))) + (51 * nanos);
1424     }
1425 
1426     //-----------------------------------------------------------------------
1427     /**
1428      * A string representation of this duration using ISO-8601 seconds
1429      * based representation, such as {@code PT8H6M12.345S}.
1430      * <p>
1431      * The format of the returned string will be {@code PTnHnMnS}, where n is
1432      * the relevant hours, minutes or seconds part of the duration.
1433      * Any fractional seconds are placed after a decimal point in the seconds section.
1434      * If a section has a zero value, it is omitted.
1435      * The hours, minutes and seconds will all have the same sign.
1436      * <p>
1437      * Examples:
1438      * <pre>
1439      *    "20.345 seconds"                 -- "PT20.345S
1440      *    "15 minutes" (15 * 60 seconds)   -- "PT15M"
1441      *    "10 hours" (10 * 3600 seconds)   -- "PT10H"
1442      *    "2 days" (2 * 86400 seconds)     -- "PT48H"
1443      * </pre>
1444      * Note that multiples of 24 hours are not output as days to avoid confusion
1445      * with {@code Period}.
1446      *
1447      * @return an ISO-8601 representation of this duration, not null
1448      */
1449     @Override
toString()1450     public String toString() {
1451         if (this == ZERO) {
1452             return "PT0S";
1453         }
1454         long hours = seconds / SECONDS_PER_HOUR;
1455         int minutes = (int) ((seconds % SECONDS_PER_HOUR) / SECONDS_PER_MINUTE);
1456         int secs = (int) (seconds % SECONDS_PER_MINUTE);
1457         StringBuilder buf = new StringBuilder(24);
1458         buf.append("PT");
1459         if (hours != 0) {
1460             buf.append(hours).append('H');
1461         }
1462         if (minutes != 0) {
1463             buf.append(minutes).append('M');
1464         }
1465         if (secs == 0 && nanos == 0 && buf.length() > 2) {
1466             return buf.toString();
1467         }
1468         if (secs < 0 && nanos > 0) {
1469             if (secs == -1) {
1470                 buf.append("-0");
1471             } else {
1472                 buf.append(secs + 1);
1473             }
1474         } else {
1475             buf.append(secs);
1476         }
1477         if (nanos > 0) {
1478             int pos = buf.length();
1479             if (secs < 0) {
1480                 buf.append(2 * NANOS_PER_SECOND - nanos);
1481             } else {
1482                 buf.append(nanos + NANOS_PER_SECOND);
1483             }
1484             while (buf.charAt(buf.length() - 1) == '0') {
1485                 buf.setLength(buf.length() - 1);
1486             }
1487             buf.setCharAt(pos, '.');
1488         }
1489         buf.append('S');
1490         return buf.toString();
1491     }
1492 
1493     //-----------------------------------------------------------------------
1494     /**
1495      * Writes the object using a
1496      * <a href="{@docRoot}/serialized-form.html#java.time.Ser">dedicated serialized form</a>.
1497      * @serialData
1498      * <pre>
1499      *  out.writeByte(1);  // identifies a Duration
1500      *  out.writeLong(seconds);
1501      *  out.writeInt(nanos);
1502      * </pre>
1503      *
1504      * @return the instance of {@code Ser}, not null
1505      */
1506     @java.io.Serial
writeReplace()1507     private Object writeReplace() {
1508         return new Ser(Ser.DURATION_TYPE, this);
1509     }
1510 
1511     /**
1512      * Defend against malicious streams.
1513      *
1514      * @param s the stream to read
1515      * @throws InvalidObjectException always
1516      */
1517     @java.io.Serial
readObject(ObjectInputStream s)1518     private void readObject(ObjectInputStream s) throws InvalidObjectException {
1519         throw new InvalidObjectException("Deserialization via serialization delegate");
1520     }
1521 
writeExternal(DataOutput out)1522     void writeExternal(DataOutput out) throws IOException {
1523         out.writeLong(seconds);
1524         out.writeInt(nanos);
1525     }
1526 
readExternal(DataInput in)1527     static Duration readExternal(DataInput in) throws IOException {
1528         long seconds = in.readLong();
1529         int nanos = in.readInt();
1530         return Duration.ofSeconds(seconds, nanos);
1531     }
1532 
1533 }
1534