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Change-Id: I24cbf6ba6db262a1ae1445db1427a08fee35b3b4
diff --git a/java/time/Instant.java b/java/time/Instant.java
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+/*
+ * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * * Neither the name of JSR-310 nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package java.time;
+
+import static java.time.LocalTime.NANOS_PER_SECOND;
+import static java.time.LocalTime.SECONDS_PER_DAY;
+import static java.time.LocalTime.SECONDS_PER_HOUR;
+import static java.time.LocalTime.SECONDS_PER_MINUTE;
+import static java.time.temporal.ChronoField.INSTANT_SECONDS;
+import static java.time.temporal.ChronoField.MICRO_OF_SECOND;
+import static java.time.temporal.ChronoField.MILLI_OF_SECOND;
+import static java.time.temporal.ChronoField.NANO_OF_SECOND;
+import static java.time.temporal.ChronoUnit.DAYS;
+import static java.time.temporal.ChronoUnit.NANOS;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+import java.time.temporal.ChronoField;
+import java.time.temporal.ChronoUnit;
+import java.time.temporal.Temporal;
+import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalAdjuster;
+import java.time.temporal.TemporalAmount;
+import java.time.temporal.TemporalField;
+import java.time.temporal.TemporalQueries;
+import java.time.temporal.TemporalQuery;
+import java.time.temporal.TemporalUnit;
+import java.time.temporal.UnsupportedTemporalTypeException;
+import java.time.temporal.ValueRange;
+import java.util.Objects;
+
+// Android-changed: removed ValueBased paragraph.
+/**
+ * An instantaneous point on the time-line.
+ * <p>
+ * This class models a single instantaneous point on the time-line.
+ * This might be used to record event time-stamps in the application.
+ * <p>
+ * The range of an instant requires the storage of a number larger than a {@code long}.
+ * To achieve this, the class stores a {@code long} representing epoch-seconds and an
+ * {@code int} representing nanosecond-of-second, which will always be between 0 and 999,999,999.
+ * The epoch-seconds are measured from the standard Java epoch of {@code 1970-01-01T00:00:00Z}
+ * where instants after the epoch have positive values, and earlier instants have negative values.
+ * For both the epoch-second and nanosecond parts, a larger value is always later on the time-line
+ * than a smaller value.
+ *
+ * <h3>Time-scale</h3>
+ * <p>
+ * The length of the solar day is the standard way that humans measure time.
+ * This has traditionally been subdivided into 24 hours of 60 minutes of 60 seconds,
+ * forming a 86400 second day.
+ * <p>
+ * Modern timekeeping is based on atomic clocks which precisely define an SI second
+ * relative to the transitions of a Caesium atom. The length of an SI second was defined
+ * to be very close to the 86400th fraction of a day.
+ * <p>
+ * Unfortunately, as the Earth rotates the length of the day varies.
+ * In addition, over time the average length of the day is getting longer as the Earth slows.
+ * As a result, the length of a solar day in 2012 is slightly longer than 86400 SI seconds.
+ * The actual length of any given day and the amount by which the Earth is slowing
+ * are not predictable and can only be determined by measurement.
+ * The UT1 time-scale captures the accurate length of day, but is only available some
+ * time after the day has completed.
+ * <p>
+ * The UTC time-scale is a standard approach to bundle up all the additional fractions
+ * of a second from UT1 into whole seconds, known as <i>leap-seconds</i>.
+ * A leap-second may be added or removed depending on the Earth's rotational changes.
+ * As such, UTC permits a day to have 86399 SI seconds or 86401 SI seconds where
+ * necessary in order to keep the day aligned with the Sun.
+ * <p>
+ * The modern UTC time-scale was introduced in 1972, introducing the concept of whole leap-seconds.
+ * Between 1958 and 1972, the definition of UTC was complex, with minor sub-second leaps and
+ * alterations to the length of the notional second. As of 2012, discussions are underway
+ * to change the definition of UTC again, with the potential to remove leap seconds or
+ * introduce other changes.
+ * <p>
+ * Given the complexity of accurate timekeeping described above, this Java API defines
+ * its own time-scale, the <i>Java Time-Scale</i>.
+ * <p>
+ * The Java Time-Scale divides each calendar day into exactly 86400
+ * subdivisions, known as seconds. These seconds may differ from the
+ * SI second. It closely matches the de facto international civil time
+ * scale, the definition of which changes from time to time.
+ * <p>
+ * The Java Time-Scale has slightly different definitions for different
+ * segments of the time-line, each based on the consensus international
+ * time scale that is used as the basis for civil time. Whenever the
+ * internationally-agreed time scale is modified or replaced, a new
+ * segment of the Java Time-Scale must be defined for it. Each segment
+ * must meet these requirements:
+ * <ul>
+ * <li>the Java Time-Scale shall closely match the underlying international
+ * civil time scale;</li>
+ * <li>the Java Time-Scale shall exactly match the international civil
+ * time scale at noon each day;</li>
+ * <li>the Java Time-Scale shall have a precisely-defined relationship to
+ * the international civil time scale.</li>
+ * </ul>
+ * There are currently, as of 2013, two segments in the Java time-scale.
+ * <p>
+ * For the segment from 1972-11-03 (exact boundary discussed below) until
+ * further notice, the consensus international time scale is UTC (with
+ * leap seconds). In this segment, the Java Time-Scale is identical to
+ * <a href="http://www.cl.cam.ac.uk/~mgk25/time/utc-sls/">UTC-SLS</a>.
+ * This is identical to UTC on days that do not have a leap second.
+ * On days that do have a leap second, the leap second is spread equally
+ * over the last 1000 seconds of the day, maintaining the appearance of
+ * exactly 86400 seconds per day.
+ * <p>
+ * For the segment prior to 1972-11-03, extending back arbitrarily far,
+ * the consensus international time scale is defined to be UT1, applied
+ * proleptically, which is equivalent to the (mean) solar time on the
+ * prime meridian (Greenwich). In this segment, the Java Time-Scale is
+ * identical to the consensus international time scale. The exact
+ * boundary between the two segments is the instant where UT1 = UTC
+ * between 1972-11-03T00:00 and 1972-11-04T12:00.
+ * <p>
+ * Implementations of the Java time-scale using the JSR-310 API are not
+ * required to provide any clock that is sub-second accurate, or that
+ * progresses monotonically or smoothly. Implementations are therefore
+ * not required to actually perform the UTC-SLS slew or to otherwise be
+ * aware of leap seconds. JSR-310 does, however, require that
+ * implementations must document the approach they use when defining a
+ * clock representing the current instant.
+ * See {@link Clock} for details on the available clocks.
+ * <p>
+ * The Java time-scale is used for all date-time classes.
+ * This includes {@code Instant}, {@code LocalDate}, {@code LocalTime}, {@code OffsetDateTime},
+ * {@code ZonedDateTime} and {@code Duration}.
+ *
+ * @implSpec
+ * This class is immutable and thread-safe.
+ *
+ * @since 1.8
+ */
+public final class Instant
+ implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable {
+
+ /**
+ * Constant for the 1970-01-01T00:00:00Z epoch instant.
+ */
+ public static final Instant EPOCH = new Instant(0, 0);
+ /**
+ * The minimum supported epoch second.
+ */
+ private static final long MIN_SECOND = -31557014167219200L;
+ /**
+ * The maximum supported epoch second.
+ */
+ private static final long MAX_SECOND = 31556889864403199L;
+ /**
+ * The minimum supported {@code Instant}, '-1000000000-01-01T00:00Z'.
+ * This could be used by an application as a "far past" instant.
+ * <p>
+ * This is one year earlier than the minimum {@code LocalDateTime}.
+ * This provides sufficient values to handle the range of {@code ZoneOffset}
+ * which affect the instant in addition to the local date-time.
+ * The value is also chosen such that the value of the year fits in
+ * an {@code int}.
+ */
+ public static final Instant MIN = Instant.ofEpochSecond(MIN_SECOND, 0);
+ /**
+ * The maximum supported {@code Instant}, '1000000000-12-31T23:59:59.999999999Z'.
+ * This could be used by an application as a "far future" instant.
+ * <p>
+ * This is one year later than the maximum {@code LocalDateTime}.
+ * This provides sufficient values to handle the range of {@code ZoneOffset}
+ * which affect the instant in addition to the local date-time.
+ * The value is also chosen such that the value of the year fits in
+ * an {@code int}.
+ */
+ public static final Instant MAX = Instant.ofEpochSecond(MAX_SECOND, 999_999_999);
+
+ /**
+ * Serialization version.
+ */
+ private static final long serialVersionUID = -665713676816604388L;
+
+ /**
+ * The number of seconds from the epoch of 1970-01-01T00:00:00Z.
+ */
+ private final long seconds;
+ /**
+ * The number of nanoseconds, later along the time-line, from the seconds field.
+ * This is always positive, and never exceeds 999,999,999.
+ */
+ private final int nanos;
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains the current instant from the system clock.
+ * <p>
+ * This will query the {@link Clock#systemUTC() system UTC clock} to
+ * obtain the current instant.
+ * <p>
+ * Using this method will prevent the ability to use an alternate time-source for
+ * testing because the clock is effectively hard-coded.
+ *
+ * @return the current instant using the system clock, not null
+ */
+ public static Instant now() {
+ return Clock.systemUTC().instant();
+ }
+
+ /**
+ * Obtains the current instant from the specified clock.
+ * <p>
+ * This will query the specified clock to obtain the current time.
+ * <p>
+ * Using this method allows the use of an alternate clock for testing.
+ * The alternate clock may be introduced using {@link Clock dependency injection}.
+ *
+ * @param clock the clock to use, not null
+ * @return the current instant, not null
+ */
+ public static Instant now(Clock clock) {
+ Objects.requireNonNull(clock, "clock");
+ return clock.instant();
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code Instant} using seconds from the
+ * epoch of 1970-01-01T00:00:00Z.
+ * <p>
+ * The nanosecond field is set to zero.
+ *
+ * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
+ * @return an instant, not null
+ * @throws DateTimeException if the instant exceeds the maximum or minimum instant
+ */
+ public static Instant ofEpochSecond(long epochSecond) {
+ return create(epochSecond, 0);
+ }
+
+ /**
+ * Obtains an instance of {@code Instant} using seconds from the
+ * epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.
+ * <p>
+ * This method allows an arbitrary number of nanoseconds to be passed in.
+ * The factory will alter the values of the second and nanosecond in order
+ * to ensure that the stored nanosecond is in the range 0 to 999,999,999.
+ * For example, the following will result in the exactly the same instant:
+ * <pre>
+ * Instant.ofEpochSecond(3, 1);
+ * Instant.ofEpochSecond(4, -999_999_999);
+ * Instant.ofEpochSecond(2, 1000_000_001);
+ * </pre>
+ *
+ * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
+ * @param nanoAdjustment the nanosecond adjustment to the number of seconds, positive or negative
+ * @return an instant, not null
+ * @throws DateTimeException if the instant exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public static Instant ofEpochSecond(long epochSecond, long nanoAdjustment) {
+ long secs = Math.addExact(epochSecond, Math.floorDiv(nanoAdjustment, NANOS_PER_SECOND));
+ int nos = (int)Math.floorMod(nanoAdjustment, NANOS_PER_SECOND);
+ return create(secs, nos);
+ }
+
+ /**
+ * Obtains an instance of {@code Instant} using milliseconds from the
+ * epoch of 1970-01-01T00:00:00Z.
+ * <p>
+ * The seconds and nanoseconds are extracted from the specified milliseconds.
+ *
+ * @param epochMilli the number of milliseconds from 1970-01-01T00:00:00Z
+ * @return an instant, not null
+ * @throws DateTimeException if the instant exceeds the maximum or minimum instant
+ */
+ public static Instant ofEpochMilli(long epochMilli) {
+ long secs = Math.floorDiv(epochMilli, 1000);
+ int mos = (int)Math.floorMod(epochMilli, 1000);
+ return create(secs, mos * 1000_000);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code Instant} from a temporal object.
+ * <p>
+ * This obtains an instant based on the specified temporal.
+ * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
+ * which this factory converts to an instance of {@code Instant}.
+ * <p>
+ * The conversion extracts the {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS}
+ * and {@link ChronoField#NANO_OF_SECOND NANO_OF_SECOND} fields.
+ * <p>
+ * This method matches the signature of the functional interface {@link TemporalQuery}
+ * allowing it to be used as a query via method reference, {@code Instant::from}.
+ *
+ * @param temporal the temporal object to convert, not null
+ * @return the instant, not null
+ * @throws DateTimeException if unable to convert to an {@code Instant}
+ */
+ public static Instant from(TemporalAccessor temporal) {
+ if (temporal instanceof Instant) {
+ return (Instant) temporal;
+ }
+ Objects.requireNonNull(temporal, "temporal");
+ try {
+ long instantSecs = temporal.getLong(INSTANT_SECONDS);
+ int nanoOfSecond = temporal.get(NANO_OF_SECOND);
+ return Instant.ofEpochSecond(instantSecs, nanoOfSecond);
+ } catch (DateTimeException ex) {
+ throw new DateTimeException("Unable to obtain Instant from TemporalAccessor: " +
+ temporal + " of type " + temporal.getClass().getName(), ex);
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code Instant} from a text string such as
+ * {@code 2007-12-03T10:15:30.00Z}.
+ * <p>
+ * The string must represent a valid instant in UTC and is parsed using
+ * {@link DateTimeFormatter#ISO_INSTANT}.
+ *
+ * @param text the text to parse, not null
+ * @return the parsed instant, not null
+ * @throws DateTimeParseException if the text cannot be parsed
+ */
+ public static Instant parse(final CharSequence text) {
+ return DateTimeFormatter.ISO_INSTANT.parse(text, Instant::from);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code Instant} using seconds and nanoseconds.
+ *
+ * @param seconds the length of the duration in seconds
+ * @param nanoOfSecond the nano-of-second, from 0 to 999,999,999
+ * @throws DateTimeException if the instant exceeds the maximum or minimum instant
+ */
+ private static Instant create(long seconds, int nanoOfSecond) {
+ if ((seconds | nanoOfSecond) == 0) {
+ return EPOCH;
+ }
+ if (seconds < MIN_SECOND || seconds > MAX_SECOND) {
+ throw new DateTimeException("Instant exceeds minimum or maximum instant");
+ }
+ return new Instant(seconds, nanoOfSecond);
+ }
+
+ /**
+ * Constructs an instance of {@code Instant} using seconds from the epoch of
+ * 1970-01-01T00:00:00Z and nanosecond fraction of second.
+ *
+ * @param epochSecond the number of seconds from 1970-01-01T00:00:00Z
+ * @param nanos the nanoseconds within the second, must be positive
+ */
+ private Instant(long epochSecond, int nanos) {
+ super();
+ this.seconds = epochSecond;
+ this.nanos = nanos;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Checks if the specified field is supported.
+ * <p>
+ * This checks if this instant can be queried for the specified field.
+ * If false, then calling the {@link #range(TemporalField) range},
+ * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+ * methods will throw an exception.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The supported fields are:
+ * <ul>
+ * <li>{@code NANO_OF_SECOND}
+ * <li>{@code MICRO_OF_SECOND}
+ * <li>{@code MILLI_OF_SECOND}
+ * <li>{@code INSTANT_SECONDS}
+ * </ul>
+ * All other {@code ChronoField} instances will return false.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
+ * passing {@code this} as the argument.
+ * Whether the field is supported is determined by the field.
+ *
+ * @param field the field to check, null returns false
+ * @return true if the field is supported on this instant, false if not
+ */
+ @Override
+ public boolean isSupported(TemporalField field) {
+ if (field instanceof ChronoField) {
+ return field == INSTANT_SECONDS || field == NANO_OF_SECOND || field == MICRO_OF_SECOND || field == MILLI_OF_SECOND;
+ }
+ return field != null && field.isSupportedBy(this);
+ }
+
+ /**
+ * Checks if the specified unit is supported.
+ * <p>
+ * This checks if the specified unit can be added to, or subtracted from, this date-time.
+ * If false, then calling the {@link #plus(long, TemporalUnit)} and
+ * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+ * <p>
+ * If the unit is a {@link ChronoUnit} then the query is implemented here.
+ * The supported units are:
+ * <ul>
+ * <li>{@code NANOS}
+ * <li>{@code MICROS}
+ * <li>{@code MILLIS}
+ * <li>{@code SECONDS}
+ * <li>{@code MINUTES}
+ * <li>{@code HOURS}
+ * <li>{@code HALF_DAYS}
+ * <li>{@code DAYS}
+ * </ul>
+ * All other {@code ChronoUnit} instances will return false.
+ * <p>
+ * If the unit is not a {@code ChronoUnit}, then the result of this method
+ * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+ * passing {@code this} as the argument.
+ * Whether the unit is supported is determined by the unit.
+ *
+ * @param unit the unit to check, null returns false
+ * @return true if the unit can be added/subtracted, false if not
+ */
+ @Override
+ public boolean isSupported(TemporalUnit unit) {
+ if (unit instanceof ChronoUnit) {
+ return unit.isTimeBased() || unit == DAYS;
+ }
+ return unit != null && unit.isSupportedBy(this);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the range of valid values for the specified field.
+ * <p>
+ * The range object expresses the minimum and maximum valid values for a field.
+ * This instant is used to enhance the accuracy of the returned range.
+ * If it is not possible to return the range, because the field is not supported
+ * or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@link #isSupported(TemporalField) supported fields} will return
+ * appropriate range instances.
+ * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
+ * passing {@code this} as the argument.
+ * Whether the range can be obtained is determined by the field.
+ *
+ * @param field the field to query the range for, not null
+ * @return the range of valid values for the field, not null
+ * @throws DateTimeException if the range for the field cannot be obtained
+ * @throws UnsupportedTemporalTypeException if the field is not supported
+ */
+ @Override // override for Javadoc
+ public ValueRange range(TemporalField field) {
+ return Temporal.super.range(field);
+ }
+
+ /**
+ * Gets the value of the specified field from this instant as an {@code int}.
+ * <p>
+ * This queries this instant for the value of the specified field.
+ * The returned value will always be within the valid range of values for the field.
+ * If it is not possible to return the value, because the field is not supported
+ * or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@link #isSupported(TemporalField) supported fields} will return valid
+ * values based on this date-time, except {@code INSTANT_SECONDS} which is too
+ * large to fit in an {@code int} and throws a {@code DateTimeException}.
+ * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
+ * passing {@code this} as the argument. Whether the value can be obtained,
+ * and what the value represents, is determined by the field.
+ *
+ * @param field the field to get, not null
+ * @return the value for the field
+ * @throws DateTimeException if a value for the field cannot be obtained or
+ * the value is outside the range of valid values for the field
+ * @throws UnsupportedTemporalTypeException if the field is not supported or
+ * the range of values exceeds an {@code int}
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override // override for Javadoc and performance
+ public int get(TemporalField field) {
+ if (field instanceof ChronoField) {
+ switch ((ChronoField) field) {
+ case NANO_OF_SECOND: return nanos;
+ case MICRO_OF_SECOND: return nanos / 1000;
+ case MILLI_OF_SECOND: return nanos / 1000_000;
+ case INSTANT_SECONDS: INSTANT_SECONDS.checkValidIntValue(seconds);
+ }
+ throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
+ }
+ return range(field).checkValidIntValue(field.getFrom(this), field);
+ }
+
+ /**
+ * Gets the value of the specified field from this instant as a {@code long}.
+ * <p>
+ * This queries this instant for the value of the specified field.
+ * If it is not possible to return the value, because the field is not supported
+ * or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@link #isSupported(TemporalField) supported fields} will return valid
+ * values based on this date-time.
+ * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
+ * passing {@code this} as the argument. Whether the value can be obtained,
+ * and what the value represents, is determined by the field.
+ *
+ * @param field the field to get, not null
+ * @return the value for the field
+ * @throws DateTimeException if a value for the field cannot be obtained
+ * @throws UnsupportedTemporalTypeException if the field is not supported
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public long getLong(TemporalField field) {
+ if (field instanceof ChronoField) {
+ switch ((ChronoField) field) {
+ case NANO_OF_SECOND: return nanos;
+ case MICRO_OF_SECOND: return nanos / 1000;
+ case MILLI_OF_SECOND: return nanos / 1000_000;
+ case INSTANT_SECONDS: return seconds;
+ }
+ throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
+ }
+ return field.getFrom(this);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
+ * <p>
+ * The epoch second count is a simple incrementing count of seconds where
+ * second 0 is 1970-01-01T00:00:00Z.
+ * The nanosecond part of the day is returned by {@code getNanosOfSecond}.
+ *
+ * @return the seconds from the epoch of 1970-01-01T00:00:00Z
+ */
+ public long getEpochSecond() {
+ return seconds;
+ }
+
+ /**
+ * Gets the number of nanoseconds, later along the time-line, from the start
+ * of the second.
+ * <p>
+ * The nanosecond-of-second value measures the total number of nanoseconds from
+ * the second returned by {@code getEpochSecond}.
+ *
+ * @return the nanoseconds within the second, always positive, never exceeds 999,999,999
+ */
+ public int getNano() {
+ return nanos;
+ }
+
+ //-------------------------------------------------------------------------
+ /**
+ * Returns an adjusted copy of this instant.
+ * <p>
+ * This returns an {@code Instant}, based on this one, with the instant adjusted.
+ * The adjustment takes place using the specified adjuster strategy object.
+ * Read the documentation of the adjuster to understand what adjustment will be made.
+ * <p>
+ * The result of this method is obtained by invoking the
+ * {@link TemporalAdjuster#adjustInto(Temporal)} method on the
+ * specified adjuster passing {@code this} as the argument.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param adjuster the adjuster to use, not null
+ * @return an {@code Instant} based on {@code this} with the adjustment made, not null
+ * @throws DateTimeException if the adjustment cannot be made
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Instant with(TemporalAdjuster adjuster) {
+ return (Instant) adjuster.adjustInto(this);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified field set to a new value.
+ * <p>
+ * This returns an {@code Instant}, based on this one, with the value
+ * for the specified field changed.
+ * If it is not possible to set the value, because the field is not supported or for
+ * some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the adjustment is implemented here.
+ * The supported fields behave as follows:
+ * <ul>
+ * <li>{@code NANO_OF_SECOND} -
+ * Returns an {@code Instant} with the specified nano-of-second.
+ * The epoch-second will be unchanged.
+ * <li>{@code MICRO_OF_SECOND} -
+ * Returns an {@code Instant} with the nano-of-second replaced by the specified
+ * micro-of-second multiplied by 1,000. The epoch-second will be unchanged.
+ * <li>{@code MILLI_OF_SECOND} -
+ * Returns an {@code Instant} with the nano-of-second replaced by the specified
+ * milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged.
+ * <li>{@code INSTANT_SECONDS} -
+ * Returns an {@code Instant} with the specified epoch-second.
+ * The nano-of-second will be unchanged.
+ * </ul>
+ * <p>
+ * In all cases, if the new value is outside the valid range of values for the field
+ * then a {@code DateTimeException} will be thrown.
+ * <p>
+ * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
+ * passing {@code this} as the argument. In this case, the field determines
+ * whether and how to adjust the instant.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param field the field to set in the result, not null
+ * @param newValue the new value of the field in the result
+ * @return an {@code Instant} based on {@code this} with the specified field set, not null
+ * @throws DateTimeException if the field cannot be set
+ * @throws UnsupportedTemporalTypeException if the field is not supported
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Instant with(TemporalField field, long newValue) {
+ if (field instanceof ChronoField) {
+ ChronoField f = (ChronoField) field;
+ f.checkValidValue(newValue);
+ switch (f) {
+ case MILLI_OF_SECOND: {
+ int nval = (int) newValue * 1000_000;
+ return (nval != nanos ? create(seconds, nval) : this);
+ }
+ case MICRO_OF_SECOND: {
+ int nval = (int) newValue * 1000;
+ return (nval != nanos ? create(seconds, nval) : this);
+ }
+ case NANO_OF_SECOND: return (newValue != nanos ? create(seconds, (int) newValue) : this);
+ case INSTANT_SECONDS: return (newValue != seconds ? create(newValue, nanos) : this);
+ }
+ throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
+ }
+ return field.adjustInto(this, newValue);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Returns a copy of this {@code Instant} truncated to the specified unit.
+ * <p>
+ * Truncating the instant returns a copy of the original with fields
+ * smaller than the specified unit set to zero.
+ * The fields are calculated on the basis of using a UTC offset as seen
+ * in {@code toString}.
+ * For example, truncating with the {@link ChronoUnit#MINUTES MINUTES} unit will
+ * round down to the nearest minute, setting the seconds and nanoseconds to zero.
+ * <p>
+ * The unit must have a {@linkplain TemporalUnit#getDuration() duration}
+ * that divides into the length of a standard day without remainder.
+ * This includes all supplied time units on {@link ChronoUnit} and
+ * {@link ChronoUnit#DAYS DAYS}. Other units throw an exception.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param unit the unit to truncate to, not null
+ * @return an {@code Instant} based on this instant with the time truncated, not null
+ * @throws DateTimeException if the unit is invalid for truncation
+ * @throws UnsupportedTemporalTypeException if the unit is not supported
+ */
+ public Instant truncatedTo(TemporalUnit unit) {
+ if (unit == ChronoUnit.NANOS) {
+ return this;
+ }
+ Duration unitDur = unit.getDuration();
+ if (unitDur.getSeconds() > LocalTime.SECONDS_PER_DAY) {
+ throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
+ }
+ long dur = unitDur.toNanos();
+ if ((LocalTime.NANOS_PER_DAY % dur) != 0) {
+ throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
+ }
+ long nod = (seconds % LocalTime.SECONDS_PER_DAY) * LocalTime.NANOS_PER_SECOND + nanos;
+ long result = (nod / dur) * dur;
+ return plusNanos(result - nod);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Returns a copy of this instant with the specified amount added.
+ * <p>
+ * This returns an {@code Instant}, based on this one, with the specified amount added.
+ * The amount is typically {@link Duration} but may be any other type implementing
+ * the {@link TemporalAmount} interface.
+ * <p>
+ * The calculation is delegated to the amount object by calling
+ * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free
+ * to implement the addition in any way it wishes, however it typically
+ * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation
+ * of the amount implementation to determine if it can be successfully added.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param amountToAdd the amount to add, not null
+ * @return an {@code Instant} based on this instant with the addition made, not null
+ * @throws DateTimeException if the addition cannot be made
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Instant plus(TemporalAmount amountToAdd) {
+ return (Instant) amountToAdd.addTo(this);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified amount added.
+ * <p>
+ * This returns an {@code Instant}, based on this one, with the amount
+ * in terms of the unit added. If it is not possible to add the amount, because the
+ * unit is not supported or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoUnit} then the addition is implemented here.
+ * The supported fields behave as follows:
+ * <ul>
+ * <li>{@code NANOS} -
+ * Returns a {@code Instant} with the specified number of nanoseconds added.
+ * This is equivalent to {@link #plusNanos(long)}.
+ * <li>{@code MICROS} -
+ * Returns a {@code Instant} with the specified number of microseconds added.
+ * This is equivalent to {@link #plusNanos(long)} with the amount
+ * multiplied by 1,000.
+ * <li>{@code MILLIS} -
+ * Returns a {@code Instant} with the specified number of milliseconds added.
+ * This is equivalent to {@link #plusNanos(long)} with the amount
+ * multiplied by 1,000,000.
+ * <li>{@code SECONDS} -
+ * Returns a {@code Instant} with the specified number of seconds added.
+ * This is equivalent to {@link #plusSeconds(long)}.
+ * <li>{@code MINUTES} -
+ * Returns a {@code Instant} with the specified number of minutes added.
+ * This is equivalent to {@link #plusSeconds(long)} with the amount
+ * multiplied by 60.
+ * <li>{@code HOURS} -
+ * Returns a {@code Instant} with the specified number of hours added.
+ * This is equivalent to {@link #plusSeconds(long)} with the amount
+ * multiplied by 3,600.
+ * <li>{@code HALF_DAYS} -
+ * Returns a {@code Instant} with the specified number of half-days added.
+ * This is equivalent to {@link #plusSeconds(long)} with the amount
+ * multiplied by 43,200 (12 hours).
+ * <li>{@code DAYS} -
+ * Returns a {@code Instant} with the specified number of days added.
+ * This is equivalent to {@link #plusSeconds(long)} with the amount
+ * multiplied by 86,400 (24 hours).
+ * </ul>
+ * <p>
+ * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}.
+ * <p>
+ * If the field is not a {@code ChronoUnit}, then the result of this method
+ * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
+ * passing {@code this} as the argument. In this case, the unit determines
+ * whether and how to perform the addition.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param amountToAdd the amount of the unit to add to the result, may be negative
+ * @param unit the unit of the amount to add, not null
+ * @return an {@code Instant} based on this instant with the specified amount added, not null
+ * @throws DateTimeException if the addition cannot be made
+ * @throws UnsupportedTemporalTypeException if the unit is not supported
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Instant plus(long amountToAdd, TemporalUnit unit) {
+ if (unit instanceof ChronoUnit) {
+ switch ((ChronoUnit) unit) {
+ case NANOS: return plusNanos(amountToAdd);
+ case MICROS: return plus(amountToAdd / 1000_000, (amountToAdd % 1000_000) * 1000);
+ case MILLIS: return plusMillis(amountToAdd);
+ case SECONDS: return plusSeconds(amountToAdd);
+ case MINUTES: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_MINUTE));
+ case HOURS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_HOUR));
+ case HALF_DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2));
+ case DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY));
+ }
+ throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
+ }
+ return unit.addTo(this, amountToAdd);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Returns a copy of this instant with the specified duration in seconds added.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param secondsToAdd the seconds to add, positive or negative
+ * @return an {@code Instant} based on this instant with the specified seconds added, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public Instant plusSeconds(long secondsToAdd) {
+ return plus(secondsToAdd, 0);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified duration in milliseconds added.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param millisToAdd the milliseconds to add, positive or negative
+ * @return an {@code Instant} based on this instant with the specified milliseconds added, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public Instant plusMillis(long millisToAdd) {
+ return plus(millisToAdd / 1000, (millisToAdd % 1000) * 1000_000);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified duration in nanoseconds added.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param nanosToAdd the nanoseconds to add, positive or negative
+ * @return an {@code Instant} based on this instant with the specified nanoseconds added, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public Instant plusNanos(long nanosToAdd) {
+ return plus(0, nanosToAdd);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified duration added.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param secondsToAdd the seconds to add, positive or negative
+ * @param nanosToAdd the nanos to add, positive or negative
+ * @return an {@code Instant} based on this instant with the specified seconds added, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ private Instant plus(long secondsToAdd, long nanosToAdd) {
+ if ((secondsToAdd | nanosToAdd) == 0) {
+ return this;
+ }
+ long epochSec = Math.addExact(seconds, secondsToAdd);
+ epochSec = Math.addExact(epochSec, nanosToAdd / NANOS_PER_SECOND);
+ nanosToAdd = nanosToAdd % NANOS_PER_SECOND;
+ long nanoAdjustment = nanos + nanosToAdd; // safe int+NANOS_PER_SECOND
+ return ofEpochSecond(epochSec, nanoAdjustment);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Returns a copy of this instant with the specified amount subtracted.
+ * <p>
+ * This returns an {@code Instant}, based on this one, with the specified amount subtracted.
+ * The amount is typically {@link Duration} but may be any other type implementing
+ * the {@link TemporalAmount} interface.
+ * <p>
+ * The calculation is delegated to the amount object by calling
+ * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free
+ * to implement the subtraction in any way it wishes, however it typically
+ * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation
+ * of the amount implementation to determine if it can be successfully subtracted.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param amountToSubtract the amount to subtract, not null
+ * @return an {@code Instant} based on this instant with the subtraction made, not null
+ * @throws DateTimeException if the subtraction cannot be made
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Instant minus(TemporalAmount amountToSubtract) {
+ return (Instant) amountToSubtract.subtractFrom(this);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified amount subtracted.
+ * <p>
+ * This returns a {@code Instant}, based on this one, with the amount
+ * in terms of the unit subtracted. If it is not possible to subtract the amount,
+ * because the unit is not supported or for some other reason, an exception is thrown.
+ * <p>
+ * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated.
+ * See that method for a full description of how addition, and thus subtraction, works.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param amountToSubtract the amount of the unit to subtract from the result, may be negative
+ * @param unit the unit of the amount to subtract, not null
+ * @return an {@code Instant} based on this instant with the specified amount subtracted, not null
+ * @throws DateTimeException if the subtraction cannot be made
+ * @throws UnsupportedTemporalTypeException if the unit is not supported
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Instant minus(long amountToSubtract, TemporalUnit unit) {
+ return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Returns a copy of this instant with the specified duration in seconds subtracted.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param secondsToSubtract the seconds to subtract, positive or negative
+ * @return an {@code Instant} based on this instant with the specified seconds subtracted, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public Instant minusSeconds(long secondsToSubtract) {
+ if (secondsToSubtract == Long.MIN_VALUE) {
+ return plusSeconds(Long.MAX_VALUE).plusSeconds(1);
+ }
+ return plusSeconds(-secondsToSubtract);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified duration in milliseconds subtracted.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param millisToSubtract the milliseconds to subtract, positive or negative
+ * @return an {@code Instant} based on this instant with the specified milliseconds subtracted, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public Instant minusMillis(long millisToSubtract) {
+ if (millisToSubtract == Long.MIN_VALUE) {
+ return plusMillis(Long.MAX_VALUE).plusMillis(1);
+ }
+ return plusMillis(-millisToSubtract);
+ }
+
+ /**
+ * Returns a copy of this instant with the specified duration in nanoseconds subtracted.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param nanosToSubtract the nanoseconds to subtract, positive or negative
+ * @return an {@code Instant} based on this instant with the specified nanoseconds subtracted, not null
+ * @throws DateTimeException if the result exceeds the maximum or minimum instant
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public Instant minusNanos(long nanosToSubtract) {
+ if (nanosToSubtract == Long.MIN_VALUE) {
+ return plusNanos(Long.MAX_VALUE).plusNanos(1);
+ }
+ return plusNanos(-nanosToSubtract);
+ }
+
+ //-------------------------------------------------------------------------
+ /**
+ * Queries this instant using the specified query.
+ * <p>
+ * This queries this instant using the specified query strategy object.
+ * The {@code TemporalQuery} object defines the logic to be used to
+ * obtain the result. Read the documentation of the query to understand
+ * what the result of this method will be.
+ * <p>
+ * The result of this method is obtained by invoking the
+ * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
+ * specified query passing {@code this} as the argument.
+ *
+ * @param <R> the type of the result
+ * @param query the query to invoke, not null
+ * @return the query result, null may be returned (defined by the query)
+ * @throws DateTimeException if unable to query (defined by the query)
+ * @throws ArithmeticException if numeric overflow occurs (defined by the query)
+ */
+ @SuppressWarnings("unchecked")
+ @Override
+ public <R> R query(TemporalQuery<R> query) {
+ if (query == TemporalQueries.precision()) {
+ return (R) NANOS;
+ }
+ // inline TemporalAccessor.super.query(query) as an optimization
+ if (query == TemporalQueries.chronology() || query == TemporalQueries.zoneId() ||
+ query == TemporalQueries.zone() || query == TemporalQueries.offset() ||
+ query == TemporalQueries.localDate() || query == TemporalQueries.localTime()) {
+ return null;
+ }
+ return query.queryFrom(this);
+ }
+
+ /**
+ * Adjusts the specified temporal object to have this instant.
+ * <p>
+ * This returns a temporal object of the same observable type as the input
+ * with the instant changed to be the same as this.
+ * <p>
+ * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
+ * twice, passing {@link ChronoField#INSTANT_SECONDS} and
+ * {@link ChronoField#NANO_OF_SECOND} as the fields.
+ * <p>
+ * In most cases, it is clearer to reverse the calling pattern by using
+ * {@link Temporal#with(TemporalAdjuster)}:
+ * <pre>
+ * // these two lines are equivalent, but the second approach is recommended
+ * temporal = thisInstant.adjustInto(temporal);
+ * temporal = temporal.with(thisInstant);
+ * </pre>
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param temporal the target object to be adjusted, not null
+ * @return the adjusted object, not null
+ * @throws DateTimeException if unable to make the adjustment
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Temporal adjustInto(Temporal temporal) {
+ return temporal.with(INSTANT_SECONDS, seconds).with(NANO_OF_SECOND, nanos);
+ }
+
+ /**
+ * Calculates the amount of time until another instant in terms of the specified unit.
+ * <p>
+ * This calculates the amount of time between two {@code Instant}
+ * objects in terms of a single {@code TemporalUnit}.
+ * The start and end points are {@code this} and the specified instant.
+ * The result will be negative if the end is before the start.
+ * The calculation returns a whole number, representing the number of
+ * complete units between the two instants.
+ * The {@code Temporal} passed to this method is converted to a
+ * {@code Instant} using {@link #from(TemporalAccessor)}.
+ * For example, the amount in days between two dates can be calculated
+ * using {@code startInstant.until(endInstant, SECONDS)}.
+ * <p>
+ * There are two equivalent ways of using this method.
+ * The first is to invoke this method.
+ * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
+ * <pre>
+ * // these two lines are equivalent
+ * amount = start.until(end, SECONDS);
+ * amount = SECONDS.between(start, end);
+ * </pre>
+ * The choice should be made based on which makes the code more readable.
+ * <p>
+ * The calculation is implemented in this method for {@link ChronoUnit}.
+ * The units {@code NANOS}, {@code MICROS}, {@code MILLIS}, {@code SECONDS},
+ * {@code MINUTES}, {@code HOURS}, {@code HALF_DAYS} and {@code DAYS}
+ * are supported. Other {@code ChronoUnit} values will throw an exception.
+ * <p>
+ * If the unit is not a {@code ChronoUnit}, then the result of this method
+ * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
+ * passing {@code this} as the first argument and the converted input temporal
+ * as the second argument.
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param endExclusive the end date, exclusive, which is converted to an {@code Instant}, not null
+ * @param unit the unit to measure the amount in, not null
+ * @return the amount of time between this instant and the end instant
+ * @throws DateTimeException if the amount cannot be calculated, or the end
+ * temporal cannot be converted to an {@code Instant}
+ * @throws UnsupportedTemporalTypeException if the unit is not supported
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public long until(Temporal endExclusive, TemporalUnit unit) {
+ Instant end = Instant.from(endExclusive);
+ if (unit instanceof ChronoUnit) {
+ ChronoUnit f = (ChronoUnit) unit;
+ switch (f) {
+ case NANOS: return nanosUntil(end);
+ case MICROS: return nanosUntil(end) / 1000;
+ case MILLIS: return Math.subtractExact(end.toEpochMilli(), toEpochMilli());
+ case SECONDS: return secondsUntil(end);
+ case MINUTES: return secondsUntil(end) / SECONDS_PER_MINUTE;
+ case HOURS: return secondsUntil(end) / SECONDS_PER_HOUR;
+ case HALF_DAYS: return secondsUntil(end) / (12 * SECONDS_PER_HOUR);
+ case DAYS: return secondsUntil(end) / (SECONDS_PER_DAY);
+ }
+ throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
+ }
+ return unit.between(this, end);
+ }
+
+ private long nanosUntil(Instant end) {
+ long secsDiff = Math.subtractExact(end.seconds, seconds);
+ long totalNanos = Math.multiplyExact(secsDiff, NANOS_PER_SECOND);
+ return Math.addExact(totalNanos, end.nanos - nanos);
+ }
+
+ private long secondsUntil(Instant end) {
+ long secsDiff = Math.subtractExact(end.seconds, seconds);
+ long nanosDiff = end.nanos - nanos;
+ if (secsDiff > 0 && nanosDiff < 0) {
+ secsDiff--;
+ } else if (secsDiff < 0 && nanosDiff > 0) {
+ secsDiff++;
+ }
+ return secsDiff;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Combines this instant with an offset to create an {@code OffsetDateTime}.
+ * <p>
+ * This returns an {@code OffsetDateTime} formed from this instant at the
+ * specified offset from UTC/Greenwich. An exception will be thrown if the
+ * instant is too large to fit into an offset date-time.
+ * <p>
+ * This method is equivalent to
+ * {@link OffsetDateTime#ofInstant(Instant, ZoneId) OffsetDateTime.ofInstant(this, offset)}.
+ *
+ * @param offset the offset to combine with, not null
+ * @return the offset date-time formed from this instant and the specified offset, not null
+ * @throws DateTimeException if the result exceeds the supported range
+ */
+ public OffsetDateTime atOffset(ZoneOffset offset) {
+ return OffsetDateTime.ofInstant(this, offset);
+ }
+
+ /**
+ * Combines this instant with a time-zone to create a {@code ZonedDateTime}.
+ * <p>
+ * This returns an {@code ZonedDateTime} formed from this instant at the
+ * specified time-zone. An exception will be thrown if the instant is too
+ * large to fit into a zoned date-time.
+ * <p>
+ * This method is equivalent to
+ * {@link ZonedDateTime#ofInstant(Instant, ZoneId) ZonedDateTime.ofInstant(this, zone)}.
+ *
+ * @param zone the zone to combine with, not null
+ * @return the zoned date-time formed from this instant and the specified zone, not null
+ * @throws DateTimeException if the result exceeds the supported range
+ */
+ public ZonedDateTime atZone(ZoneId zone) {
+ return ZonedDateTime.ofInstant(this, zone);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Converts this instant to the number of milliseconds from the epoch
+ * of 1970-01-01T00:00:00Z.
+ * <p>
+ * If this instant represents a point on the time-line too far in the future
+ * or past to fit in a {@code long} milliseconds, then an exception is thrown.
+ * <p>
+ * If this instant has greater than millisecond precision, then the conversion
+ * will drop any excess precision information as though the amount in nanoseconds
+ * was subject to integer division by one million.
+ *
+ * @return the number of milliseconds since the epoch of 1970-01-01T00:00:00Z
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ public long toEpochMilli() {
+ if (seconds < 0 && nanos > 0) {
+ long millis = Math.multiplyExact(seconds+1, 1000);
+ long adjustment = nanos / 1000_000 - 1000;
+ return Math.addExact(millis, adjustment);
+ } else {
+ long millis = Math.multiplyExact(seconds, 1000);
+ return Math.addExact(millis, nanos / 1000_000);
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Compares this instant to the specified instant.
+ * <p>
+ * The comparison is based on the time-line position of the instants.
+ * It is "consistent with equals", as defined by {@link Comparable}.
+ *
+ * @param otherInstant the other instant to compare to, not null
+ * @return the comparator value, negative if less, positive if greater
+ * @throws NullPointerException if otherInstant is null
+ */
+ @Override
+ public int compareTo(Instant otherInstant) {
+ int cmp = Long.compare(seconds, otherInstant.seconds);
+ if (cmp != 0) {
+ return cmp;
+ }
+ return nanos - otherInstant.nanos;
+ }
+
+ /**
+ * Checks if this instant is after the specified instant.
+ * <p>
+ * The comparison is based on the time-line position of the instants.
+ *
+ * @param otherInstant the other instant to compare to, not null
+ * @return true if this instant is after the specified instant
+ * @throws NullPointerException if otherInstant is null
+ */
+ public boolean isAfter(Instant otherInstant) {
+ return compareTo(otherInstant) > 0;
+ }
+
+ /**
+ * Checks if this instant is before the specified instant.
+ * <p>
+ * The comparison is based on the time-line position of the instants.
+ *
+ * @param otherInstant the other instant to compare to, not null
+ * @return true if this instant is before the specified instant
+ * @throws NullPointerException if otherInstant is null
+ */
+ public boolean isBefore(Instant otherInstant) {
+ return compareTo(otherInstant) < 0;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Checks if this instant is equal to the specified instant.
+ * <p>
+ * The comparison is based on the time-line position of the instants.
+ *
+ * @param otherInstant the other instant, null returns false
+ * @return true if the other instant is equal to this one
+ */
+ @Override
+ public boolean equals(Object otherInstant) {
+ if (this == otherInstant) {
+ return true;
+ }
+ if (otherInstant instanceof Instant) {
+ Instant other = (Instant) otherInstant;
+ return this.seconds == other.seconds &&
+ this.nanos == other.nanos;
+ }
+ return false;
+ }
+
+ /**
+ * Returns a hash code for this instant.
+ *
+ * @return a suitable hash code
+ */
+ @Override
+ public int hashCode() {
+ return ((int) (seconds ^ (seconds >>> 32))) + 51 * nanos;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * A string representation of this instant using ISO-8601 representation.
+ * <p>
+ * The format used is the same as {@link DateTimeFormatter#ISO_INSTANT}.
+ *
+ * @return an ISO-8601 representation of this instant, not null
+ */
+ @Override
+ public String toString() {
+ return DateTimeFormatter.ISO_INSTANT.format(this);
+ }
+
+ // -----------------------------------------------------------------------
+ /**
+ * Writes the object using a
+ * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
+ * @serialData
+ * <pre>
+ * out.writeByte(2); // identifies an Instant
+ * out.writeLong(seconds);
+ * out.writeInt(nanos);
+ * </pre>
+ *
+ * @return the instance of {@code Ser}, not null
+ */
+ private Object writeReplace() {
+ return new Ser(Ser.INSTANT_TYPE, this);
+ }
+
+ /**
+ * Defend against malicious streams.
+ *
+ * @param s the stream to read
+ * @throws InvalidObjectException always
+ */
+ private void readObject(ObjectInputStream s) throws InvalidObjectException {
+ throw new InvalidObjectException("Deserialization via serialization delegate");
+ }
+
+ void writeExternal(DataOutput out) throws IOException {
+ out.writeLong(seconds);
+ out.writeInt(nanos);
+ }
+
+ static Instant readExternal(DataInput in) throws IOException {
+ long seconds = in.readLong();
+ int nanos = in.readInt();
+ return Instant.ofEpochSecond(seconds, nanos);
+ }
+
+}
