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Java example source code file (LocalTime.java)

This example Java source code file (LocalTime.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

chronofield, hours, hours_per_day, localtime, minutes_per_hour, nanos_per_day, nanos_per_hour, nanos_per_minute, nanos_per_second, override, seconds_per_day, seconds_per_hour, seconds_per_minute, unsupportedtemporaltypeexception, util

The LocalTime.java Java example source code

/*
 * Copyright (c) 2012, 2013, 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.
 *
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/*
 * 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.
 *
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 *    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
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package java.time;

import static java.time.temporal.ChronoField.HOUR_OF_DAY;
import static java.time.temporal.ChronoField.MICRO_OF_DAY;
import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;
import static java.time.temporal.ChronoField.NANO_OF_DAY;
import static java.time.temporal.ChronoField.NANO_OF_SECOND;
import static java.time.temporal.ChronoField.SECOND_OF_DAY;
import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;
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;

/**
 * A time without time-zone in the ISO-8601 calendar system,
 * such as {@code 10:15:30}.
 * <p>
 * {@code LocalTime} is an immutable date-time object that represents a time,
 * often viewed as hour-minute-second.
 * Time is represented to nanosecond precision.
 * For example, the value "13:45.30.123456789" can be stored in a {@code LocalTime}.
 * <p>
 * It does not store or represent a date or time-zone.
 * Instead, it is a description of the local time as seen on a wall clock.
 * It cannot represent an instant on the time-line without additional information
 * such as an offset or time-zone.
 * <p>
 * The ISO-8601 calendar system is the modern civil calendar system used today
 * in most of the world. This API assumes that all calendar systems use the same
 * representation, this class, for time-of-day.
 *
 * <p>
 * This is a <a href="{@docRoot}/java/lang/doc-files/ValueBased.html">value-based
 * class; use of identity-sensitive operations (including reference equality
 * ({@code ==}), identity hash code, or synchronization) on instances of
 * {@code LocalTime} may have unpredictable results and should be avoided.
 * The {@code equals} method should be used for comparisons.
 *
 * @implSpec
 * This class is immutable and thread-safe.
 *
 * @since 1.8
 */
public final class LocalTime
        implements Temporal, TemporalAdjuster, Comparable<LocalTime>, Serializable {

    /**
     * The minimum supported {@code LocalTime}, '00:00'.
     * This is the time of midnight at the start of the day.
     */
    public static final LocalTime MIN;
    /**
     * The maximum supported {@code LocalTime}, '23:59:59.999999999'.
     * This is the time just before midnight at the end of the day.
     */
    public static final LocalTime MAX;
    /**
     * The time of midnight at the start of the day, '00:00'.
     */
    public static final LocalTime MIDNIGHT;
    /**
     * The time of noon in the middle of the day, '12:00'.
     */
    public static final LocalTime NOON;
    /**
     * Constants for the local time of each hour.
     */
    private static final LocalTime[] HOURS = new LocalTime[24];
    static {
        for (int i = 0; i < HOURS.length; i++) {
            HOURS[i] = new LocalTime(i, 0, 0, 0);
        }
        MIDNIGHT = HOURS[0];
        NOON = HOURS[12];
        MIN = HOURS[0];
        MAX = new LocalTime(23, 59, 59, 999_999_999);
    }

    /**
     * Hours per day.
     */
    static final int HOURS_PER_DAY = 24;
    /**
     * Minutes per hour.
     */
    static final int MINUTES_PER_HOUR = 60;
    /**
     * Minutes per day.
     */
    static final int MINUTES_PER_DAY = MINUTES_PER_HOUR * HOURS_PER_DAY;
    /**
     * Seconds per minute.
     */
    static final int SECONDS_PER_MINUTE = 60;
    /**
     * Seconds per hour.
     */
    static final int SECONDS_PER_HOUR = SECONDS_PER_MINUTE * MINUTES_PER_HOUR;
    /**
     * Seconds per day.
     */
    static final int SECONDS_PER_DAY = SECONDS_PER_HOUR * HOURS_PER_DAY;
    /**
     * Milliseconds per day.
     */
    static final long MILLIS_PER_DAY = SECONDS_PER_DAY * 1000L;
    /**
     * Microseconds per day.
     */
    static final long MICROS_PER_DAY = SECONDS_PER_DAY * 1000_000L;
    /**
     * Nanos per second.
     */
    static final long NANOS_PER_SECOND = 1000_000_000L;
    /**
     * Nanos per minute.
     */
    static final long NANOS_PER_MINUTE = NANOS_PER_SECOND * SECONDS_PER_MINUTE;
    /**
     * Nanos per hour.
     */
    static final long NANOS_PER_HOUR = NANOS_PER_MINUTE * MINUTES_PER_HOUR;
    /**
     * Nanos per day.
     */
    static final long NANOS_PER_DAY = NANOS_PER_HOUR * HOURS_PER_DAY;

    /**
     * Serialization version.
     */
    private static final long serialVersionUID = 6414437269572265201L;

    /**
     * The hour.
     */
    private final byte hour;
    /**
     * The minute.
     */
    private final byte minute;
    /**
     * The second.
     */
    private final byte second;
    /**
     * The nanosecond.
     */
    private final int nano;

    //-----------------------------------------------------------------------
    /**
     * Obtains the current time from the system clock in the default time-zone.
     * <p>
     * This will query the {@link Clock#systemDefaultZone() system clock} in the default
     * time-zone to obtain the current time.
     * <p>
     * Using this method will prevent the ability to use an alternate clock for testing
     * because the clock is hard-coded.
     *
     * @return the current time using the system clock and default time-zone, not null
     */
    public static LocalTime now() {
        return now(Clock.systemDefaultZone());
    }

    /**
     * Obtains the current time from the system clock in the specified time-zone.
     * <p>
     * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current time.
     * Specifying the time-zone avoids dependence on the default time-zone.
     * <p>
     * Using this method will prevent the ability to use an alternate clock for testing
     * because the clock is hard-coded.
     *
     * @param zone  the zone ID to use, not null
     * @return the current time using the system clock, not null
     */
    public static LocalTime now(ZoneId zone) {
        return now(Clock.system(zone));
    }

    /**
     * Obtains the current time from the specified clock.
     * <p>
     * This will query the specified clock to obtain the current time.
     * 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 time, not null
     */
    public static LocalTime now(Clock clock) {
        Objects.requireNonNull(clock, "clock");
        // inline OffsetTime factory to avoid creating object and InstantProvider checks
        final Instant now = clock.instant();  // called once
        ZoneOffset offset = clock.getZone().getRules().getOffset(now);
        long localSecond = now.getEpochSecond() + offset.getTotalSeconds();  // overflow caught later
        int secsOfDay = (int) Math.floorMod(localSecond, SECONDS_PER_DAY);
        return ofNanoOfDay(secsOfDay * NANOS_PER_SECOND + now.getNano());
    }

    //------------------------get-----------------------------------------------
    /**
     * Obtains an instance of {@code LocalTime} from an hour and minute.
     * <p>
     * This returns a {@code LocalTime} with the specified hour and minute.
     * The second and nanosecond fields will be set to zero.
     *
     * @param hour  the hour-of-day to represent, from 0 to 23
     * @param minute  the minute-of-hour to represent, from 0 to 59
     * @return the local time, not null
     * @throws DateTimeException if the value of any field is out of range
     */
    public static LocalTime of(int hour, int minute) {
        HOUR_OF_DAY.checkValidValue(hour);
        if (minute == 0) {
            return HOURS[hour];  // for performance
        }
        MINUTE_OF_HOUR.checkValidValue(minute);
        return new LocalTime(hour, minute, 0, 0);
    }

    /**
     * Obtains an instance of {@code LocalTime} from an hour, minute and second.
     * <p>
     * This returns a {@code LocalTime} with the specified hour, minute and second.
     * The nanosecond field will be set to zero.
     *
     * @param hour  the hour-of-day to represent, from 0 to 23
     * @param minute  the minute-of-hour to represent, from 0 to 59
     * @param second  the second-of-minute to represent, from 0 to 59
     * @return the local time, not null
     * @throws DateTimeException if the value of any field is out of range
     */
    public static LocalTime of(int hour, int minute, int second) {
        HOUR_OF_DAY.checkValidValue(hour);
        if ((minute | second) == 0) {
            return HOURS[hour];  // for performance
        }
        MINUTE_OF_HOUR.checkValidValue(minute);
        SECOND_OF_MINUTE.checkValidValue(second);
        return new LocalTime(hour, minute, second, 0);
    }

    /**
     * Obtains an instance of {@code LocalTime} from an hour, minute, second and nanosecond.
     * <p>
     * This returns a {@code LocalTime} with the specified hour, minute, second and nanosecond.
     *
     * @param hour  the hour-of-day to represent, from 0 to 23
     * @param minute  the minute-of-hour to represent, from 0 to 59
     * @param second  the second-of-minute to represent, from 0 to 59
     * @param nanoOfSecond  the nano-of-second to represent, from 0 to 999,999,999
     * @return the local time, not null
     * @throws DateTimeException if the value of any field is out of range
     */
    public static LocalTime of(int hour, int minute, int second, int nanoOfSecond) {
        HOUR_OF_DAY.checkValidValue(hour);
        MINUTE_OF_HOUR.checkValidValue(minute);
        SECOND_OF_MINUTE.checkValidValue(second);
        NANO_OF_SECOND.checkValidValue(nanoOfSecond);
        return create(hour, minute, second, nanoOfSecond);
    }

    //-----------------------------------------------------------------------
    /**
     * Obtains an instance of {@code LocalTime} from a second-of-day value.
     * <p>
     * This returns a {@code LocalTime} with the specified second-of-day.
     * The nanosecond field will be set to zero.
     *
     * @param secondOfDay  the second-of-day, from {@code 0} to {@code 24 * 60 * 60 - 1}
     * @return the local time, not null
     * @throws DateTimeException if the second-of-day value is invalid
     */
    public static LocalTime ofSecondOfDay(long secondOfDay) {
        SECOND_OF_DAY.checkValidValue(secondOfDay);
        int hours = (int) (secondOfDay / SECONDS_PER_HOUR);
        secondOfDay -= hours * SECONDS_PER_HOUR;
        int minutes = (int) (secondOfDay / SECONDS_PER_MINUTE);
        secondOfDay -= minutes * SECONDS_PER_MINUTE;
        return create(hours, minutes, (int) secondOfDay, 0);
    }

    /**
     * Obtains an instance of {@code LocalTime} from a nanos-of-day value.
     * <p>
     * This returns a {@code LocalTime} with the specified nanosecond-of-day.
     *
     * @param nanoOfDay  the nano of day, from {@code 0} to {@code 24 * 60 * 60 * 1,000,000,000 - 1}
     * @return the local time, not null
     * @throws DateTimeException if the nanos of day value is invalid
     */
    public static LocalTime ofNanoOfDay(long nanoOfDay) {
        NANO_OF_DAY.checkValidValue(nanoOfDay);
        int hours = (int) (nanoOfDay / NANOS_PER_HOUR);
        nanoOfDay -= hours * NANOS_PER_HOUR;
        int minutes = (int) (nanoOfDay / NANOS_PER_MINUTE);
        nanoOfDay -= minutes * NANOS_PER_MINUTE;
        int seconds = (int) (nanoOfDay / NANOS_PER_SECOND);
        nanoOfDay -= seconds * NANOS_PER_SECOND;
        return create(hours, minutes, seconds, (int) nanoOfDay);
    }

    //-----------------------------------------------------------------------
    /**
     * Obtains an instance of {@code LocalTime} from a temporal object.
     * <p>
     * This obtains a local time 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 LocalTime}.
     * <p>
     * The conversion uses the {@link TemporalQueries#localTime()} query, which relies
     * on extracting the {@link ChronoField#NANO_OF_DAY NANO_OF_DAY} field.
     * <p>
     * This method matches the signature of the functional interface {@link TemporalQuery}
     * allowing it to be used in queries via method reference, {@code LocalTime::from}.
     *
     * @param temporal  the temporal object to convert, not null
     * @return the local time, not null
     * @throws DateTimeException if unable to convert to a {@code LocalTime}
     */
    public static LocalTime from(TemporalAccessor temporal) {
        Objects.requireNonNull(temporal, "temporal");
        LocalTime time = temporal.query(TemporalQueries.localTime());
        if (time == null) {
            throw new DateTimeException("Unable to obtain LocalTime from TemporalAccessor: " +
                    temporal + " of type " + temporal.getClass().getName());
        }
        return time;
    }

    //-----------------------------------------------------------------------
    /**
     * Obtains an instance of {@code LocalTime} from a text string such as {@code 10:15}.
     * <p>
     * The string must represent a valid time and is parsed using
     * {@link java.time.format.DateTimeFormatter#ISO_LOCAL_TIME}.
     *
     * @param text the text to parse such as "10:15:30", not null
     * @return the parsed local time, not null
     * @throws DateTimeParseException if the text cannot be parsed
     */
    public static LocalTime parse(CharSequence text) {
        return parse(text, DateTimeFormatter.ISO_LOCAL_TIME);
    }

    /**
     * Obtains an instance of {@code LocalTime} from a text string using a specific formatter.
     * <p>
     * The text is parsed using the formatter, returning a time.
     *
     * @param text  the text to parse, not null
     * @param formatter  the formatter to use, not null
     * @return the parsed local time, not null
     * @throws DateTimeParseException if the text cannot be parsed
     */
    public static LocalTime parse(CharSequence text, DateTimeFormatter formatter) {
        Objects.requireNonNull(formatter, "formatter");
        return formatter.parse(text, LocalTime::from);
    }

    //-----------------------------------------------------------------------
    /**
     * Creates a local time from the hour, minute, second and nanosecond fields.
     * <p>
     * This factory may return a cached value, but applications must not rely on this.
     *
     * @param hour  the hour-of-day to represent, validated from 0 to 23
     * @param minute  the minute-of-hour to represent, validated from 0 to 59
     * @param second  the second-of-minute to represent, validated from 0 to 59
     * @param nanoOfSecond  the nano-of-second to represent, validated from 0 to 999,999,999
     * @return the local time, not null
     */
    private static LocalTime create(int hour, int minute, int second, int nanoOfSecond) {
        if ((minute | second | nanoOfSecond) == 0) {
            return HOURS[hour];
        }
        return new LocalTime(hour, minute, second, nanoOfSecond);
    }

    /**
     * Constructor, previously validated.
     *
     * @param hour  the hour-of-day to represent, validated from 0 to 23
     * @param minute  the minute-of-hour to represent, validated from 0 to 59
     * @param second  the second-of-minute to represent, validated from 0 to 59
     * @param nanoOfSecond  the nano-of-second to represent, validated from 0 to 999,999,999
     */
    private LocalTime(int hour, int minute, int second, int nanoOfSecond) {
        this.hour = (byte) hour;
        this.minute = (byte) minute;
        this.second = (byte) second;
        this.nano = nanoOfSecond;
    }

    //-----------------------------------------------------------------------
    /**
     * Checks if the specified field is supported.
     * <p>
     * This checks if this time 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 NANO_OF_DAY}
     * <li>{@code MICRO_OF_SECOND}
     * <li>{@code MICRO_OF_DAY}
     * <li>{@code MILLI_OF_SECOND}
     * <li>{@code MILLI_OF_DAY}
     * <li>{@code SECOND_OF_MINUTE}
     * <li>{@code SECOND_OF_DAY}
     * <li>{@code MINUTE_OF_HOUR}
     * <li>{@code MINUTE_OF_DAY}
     * <li>{@code HOUR_OF_AMPM}
     * <li>{@code CLOCK_HOUR_OF_AMPM}
     * <li>{@code HOUR_OF_DAY}
     * <li>{@code CLOCK_HOUR_OF_DAY}
     * <li>{@code AMPM_OF_DAY}
     * </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 time, false if not
     */
    @Override
    public boolean isSupported(TemporalField field) {
        if (field instanceof ChronoField) {
            return field.isTimeBased();
        }
        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}
     * </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  // override for Javadoc
    public boolean isSupported(TemporalUnit unit) {
        if (unit instanceof ChronoUnit) {
            return unit.isTimeBased();
        }
        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 time 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 time as an {@code int}.
     * <p>
     * This queries this time for the value for 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 time, except {@code NANO_OF_DAY} and {@code MICRO_OF_DAY}
     * which are too large to fit in an {@code int} and throw 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) {
            return get0(field);
        }
        return Temporal.super.get(field);
    }

    /**
     * Gets the value of the specified field from this time as a {@code long}.
     * <p>
     * This queries this time for the value for 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 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) {
            if (field == NANO_OF_DAY) {
                return toNanoOfDay();
            }
            if (field == MICRO_OF_DAY) {
                return toNanoOfDay() / 1000;
            }
            return get0(field);
        }
        return field.getFrom(this);
    }

    private int get0(TemporalField field) {
        switch ((ChronoField) field) {
            case NANO_OF_SECOND: return nano;
            case NANO_OF_DAY: throw new UnsupportedTemporalTypeException("Invalid field 'NanoOfDay' for get() method, use getLong() instead");
            case MICRO_OF_SECOND: return nano / 1000;
            case MICRO_OF_DAY: throw new UnsupportedTemporalTypeException("Invalid field 'MicroOfDay' for get() method, use getLong() instead");
            case MILLI_OF_SECOND: return nano / 1000_000;
            case MILLI_OF_DAY: return (int) (toNanoOfDay() / 1000_000);
            case SECOND_OF_MINUTE: return second;
            case SECOND_OF_DAY: return toSecondOfDay();
            case MINUTE_OF_HOUR: return minute;
            case MINUTE_OF_DAY: return hour * 60 + minute;
            case HOUR_OF_AMPM: return hour % 12;
            case CLOCK_HOUR_OF_AMPM: int ham = hour % 12; return (ham % 12 == 0 ? 12 : ham);
            case HOUR_OF_DAY: return hour;
            case CLOCK_HOUR_OF_DAY: return (hour == 0 ? 24 : hour);
            case AMPM_OF_DAY: return hour / 12;
        }
        throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
    }

    //-----------------------------------------------------------------------
    /**
     * Gets the hour-of-day field.
     *
     * @return the hour-of-day, from 0 to 23
     */
    public int getHour() {
        return hour;
    }

    /**
     * Gets the minute-of-hour field.
     *
     * @return the minute-of-hour, from 0 to 59
     */
    public int getMinute() {
        return minute;
    }

    /**
     * Gets the second-of-minute field.
     *
     * @return the second-of-minute, from 0 to 59
     */
    public int getSecond() {
        return second;
    }

    /**
     * Gets the nano-of-second field.
     *
     * @return the nano-of-second, from 0 to 999,999,999
     */
    public int getNano() {
        return nano;
    }

    //-----------------------------------------------------------------------
    /**
     * Returns an adjusted copy of this time.
     * <p>
     * This returns a {@code LocalTime}, based on this one, with the time 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>
     * A simple adjuster might simply set the one of the fields, such as the hour field.
     * A more complex adjuster might set the time to the last hour of the day.
     * <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 a {@code LocalTime} 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 LocalTime with(TemporalAdjuster adjuster) {
        // optimizations
        if (adjuster instanceof LocalTime) {
            return (LocalTime) adjuster;
        }
        return (LocalTime) adjuster.adjustInto(this);
    }

    /**
     * Returns a copy of this time with the specified field set to a new value.
     * <p>
     * This returns a {@code LocalTime}, based on this one, with the value
     * for the specified field changed.
     * This can be used to change any supported field, such as the hour, minute or second.
     * 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 a {@code LocalTime} with the specified nano-of-second.
     *  The hour, minute and second will be unchanged.
     * <li>{@code NANO_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified nano-of-day.
     *  This completely replaces the time and is equivalent to {@link #ofNanoOfDay(long)}.
     * <li>{@code MICRO_OF_SECOND} -
     *  Returns a {@code LocalTime} with the nano-of-second replaced by the specified
     *  micro-of-second multiplied by 1,000.
     *  The hour, minute and second will be unchanged.
     * <li>{@code MICRO_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified micro-of-day.
     *  This completely replaces the time and is equivalent to using {@link #ofNanoOfDay(long)}
     *  with the micro-of-day multiplied by 1,000.
     * <li>{@code MILLI_OF_SECOND} -
     *  Returns a {@code LocalTime} with the nano-of-second replaced by the specified
     *  milli-of-second multiplied by 1,000,000.
     *  The hour, minute and second will be unchanged.
     * <li>{@code MILLI_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified milli-of-day.
     *  This completely replaces the time and is equivalent to using {@link #ofNanoOfDay(long)}
     *  with the milli-of-day multiplied by 1,000,000.
     * <li>{@code SECOND_OF_MINUTE} -
     *  Returns a {@code LocalTime} with the specified second-of-minute.
     *  The hour, minute and nano-of-second will be unchanged.
     * <li>{@code SECOND_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified second-of-day.
     *  The nano-of-second will be unchanged.
     * <li>{@code MINUTE_OF_HOUR} -
     *  Returns a {@code LocalTime} with the specified minute-of-hour.
     *  The hour, second-of-minute and nano-of-second will be unchanged.
     * <li>{@code MINUTE_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified minute-of-day.
     *  The second-of-minute and nano-of-second will be unchanged.
     * <li>{@code HOUR_OF_AMPM} -
     *  Returns a {@code LocalTime} with the specified hour-of-am-pm.
     *  The AM/PM, minute-of-hour, second-of-minute and nano-of-second will be unchanged.
     * <li>{@code CLOCK_HOUR_OF_AMPM} -
     *  Returns a {@code LocalTime} with the specified clock-hour-of-am-pm.
     *  The AM/PM, minute-of-hour, second-of-minute and nano-of-second will be unchanged.
     * <li>{@code HOUR_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified hour-of-day.
     *  The minute-of-hour, second-of-minute and nano-of-second will be unchanged.
     * <li>{@code CLOCK_HOUR_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified clock-hour-of-day.
     *  The minute-of-hour, second-of-minute and nano-of-second will be unchanged.
     * <li>{@code AMPM_OF_DAY} -
     *  Returns a {@code LocalTime} with the specified AM/PM.
     *  The hour-of-am-pm, minute-of-hour, second-of-minute and 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 a {@code LocalTime} 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 LocalTime with(TemporalField field, long newValue) {
        if (field instanceof ChronoField) {
            ChronoField f = (ChronoField) field;
            f.checkValidValue(newValue);
            switch (f) {
                case NANO_OF_SECOND: return withNano((int) newValue);
                case NANO_OF_DAY: return LocalTime.ofNanoOfDay(newValue);
                case MICRO_OF_SECOND: return withNano((int) newValue * 1000);
                case MICRO_OF_DAY: return plusNanos((newValue - toNanoOfDay() / 1000) * 1000);
                case MILLI_OF_SECOND: return withNano((int) newValue * 1000_000);
                case MILLI_OF_DAY: return plusNanos((newValue - toNanoOfDay() / 1000_000) * 1000_000);
                case SECOND_OF_MINUTE: return withSecond((int) newValue);
                case SECOND_OF_DAY: return plusSeconds(newValue - toSecondOfDay());
                case MINUTE_OF_HOUR: return withMinute((int) newValue);
                case MINUTE_OF_DAY: return plusMinutes(newValue - (hour * 60 + minute));
                case HOUR_OF_AMPM: return plusHours(newValue - (hour % 12));
                case CLOCK_HOUR_OF_AMPM: return plusHours((newValue == 12 ? 0 : newValue) - (hour % 12));
                case HOUR_OF_DAY: return withHour((int) newValue);
                case CLOCK_HOUR_OF_DAY: return withHour((int) (newValue == 24 ? 0 : newValue));
                case AMPM_OF_DAY: return plusHours((newValue - (hour / 12)) * 12);
            }
            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
        }
        return field.adjustInto(this, newValue);
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a copy of this {@code LocalTime} with the hour-of-day value altered.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param hour  the hour-of-day to set in the result, from 0 to 23
     * @return a {@code LocalTime} based on this time with the requested hour, not null
     * @throws DateTimeException if the hour value is invalid
     */
    public LocalTime withHour(int hour) {
        if (this.hour == hour) {
            return this;
        }
        HOUR_OF_DAY.checkValidValue(hour);
        return create(hour, minute, second, nano);
    }

    /**
     * Returns a copy of this {@code LocalTime} with the minute-of-hour value altered.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param minute  the minute-of-hour to set in the result, from 0 to 59
     * @return a {@code LocalTime} based on this time with the requested minute, not null
     * @throws DateTimeException if the minute value is invalid
     */
    public LocalTime withMinute(int minute) {
        if (this.minute == minute) {
            return this;
        }
        MINUTE_OF_HOUR.checkValidValue(minute);
        return create(hour, minute, second, nano);
    }

    /**
     * Returns a copy of this {@code LocalTime} with the second-of-minute value altered.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param second  the second-of-minute to set in the result, from 0 to 59
     * @return a {@code LocalTime} based on this time with the requested second, not null
     * @throws DateTimeException if the second value is invalid
     */
    public LocalTime withSecond(int second) {
        if (this.second == second) {
            return this;
        }
        SECOND_OF_MINUTE.checkValidValue(second);
        return create(hour, minute, second, nano);
    }

    /**
     * Returns a copy of this {@code LocalTime} with the nano-of-second value altered.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param nanoOfSecond  the nano-of-second to set in the result, from 0 to 999,999,999
     * @return a {@code LocalTime} based on this time with the requested nanosecond, not null
     * @throws DateTimeException if the nanos value is invalid
     */
    public LocalTime withNano(int nanoOfSecond) {
        if (this.nano == nanoOfSecond) {
            return this;
        }
        NANO_OF_SECOND.checkValidValue(nanoOfSecond);
        return create(hour, minute, second, nanoOfSecond);
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a copy of this {@code LocalTime} with the time truncated.
     * <p>
     * Truncating the time returns a copy of the original time with fields
     * smaller than the specified unit set to zero.
     * For example, truncating with the {@link ChronoUnit#MINUTES minutes} unit
     * will set the second-of-minute and nano-of-second field 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 a {@code LocalTime} based on this time with the time truncated, not null
     * @throws DateTimeException if unable to truncate
     * @throws UnsupportedTemporalTypeException if the unit is not supported
     */
    public LocalTime truncatedTo(TemporalUnit unit) {
        if (unit == ChronoUnit.NANOS) {
            return this;
        }
        Duration unitDur = unit.getDuration();
        if (unitDur.getSeconds() > SECONDS_PER_DAY) {
            throw new UnsupportedTemporalTypeException("Unit is too large to be used for truncation");
        }
        long dur = unitDur.toNanos();
        if ((NANOS_PER_DAY % dur) != 0) {
            throw new UnsupportedTemporalTypeException("Unit must divide into a standard day without remainder");
        }
        long nod = toNanoOfDay();
        return ofNanoOfDay((nod / dur) * dur);
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a copy of this time with the specified amount added.
     * <p>
     * This returns a {@code LocalTime}, 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 a {@code LocalTime} based on this time with the addition made, not null
     * @throws DateTimeException if the addition cannot be made
     * @throws ArithmeticException if numeric overflow occurs
     */
    @Override
    public LocalTime plus(TemporalAmount amountToAdd) {
        return (LocalTime) amountToAdd.addTo(this);
    }

    /**
     * Returns a copy of this time with the specified amount added.
     * <p>
     * This returns a {@code LocalTime}, 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 LocalTime} with the specified number of nanoseconds added.
     *  This is equivalent to {@link #plusNanos(long)}.
     * <li>{@code MICROS} -
     *  Returns a {@code LocalTime} 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 LocalTime} 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 LocalTime} with the specified number of seconds added.
     *  This is equivalent to {@link #plusSeconds(long)}.
     * <li>{@code MINUTES} -
     *  Returns a {@code LocalTime} with the specified number of minutes added.
     *  This is equivalent to {@link #plusMinutes(long)}.
     * <li>{@code HOURS} -
     *  Returns a {@code LocalTime} with the specified number of hours added.
     *  This is equivalent to {@link #plusHours(long)}.
     * <li>{@code HALF_DAYS} -
     *  Returns a {@code LocalTime} with the specified number of half-days added.
     *  This is equivalent to {@link #plusHours(long)} with the amount
     *  multiplied by 12.
     * </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 a {@code LocalTime} based on this time 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 LocalTime plus(long amountToAdd, TemporalUnit unit) {
        if (unit instanceof ChronoUnit) {
            switch ((ChronoUnit) unit) {
                case NANOS: return plusNanos(amountToAdd);
                case MICROS: return plusNanos((amountToAdd % MICROS_PER_DAY) * 1000);
                case MILLIS: return plusNanos((amountToAdd % MILLIS_PER_DAY) * 1000_000);
                case SECONDS: return plusSeconds(amountToAdd);
                case MINUTES: return plusMinutes(amountToAdd);
                case HOURS: return plusHours(amountToAdd);
                case HALF_DAYS: return plusHours((amountToAdd % 2) * 12);
            }
            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
        }
        return unit.addTo(this, amountToAdd);
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a copy of this {@code LocalTime} with the specified period in hours added.
     * <p>
     * This adds the specified number of hours to this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param hoursToAdd  the hours to add, may be negative
     * @return a {@code LocalTime} based on this time with the hours added, not null
     */
    public LocalTime plusHours(long hoursToAdd) {
        if (hoursToAdd == 0) {
            return this;
        }
        int newHour = ((int) (hoursToAdd % HOURS_PER_DAY) + hour + HOURS_PER_DAY) % HOURS_PER_DAY;
        return create(newHour, minute, second, nano);
    }

    /**
     * Returns a copy of this {@code LocalTime} with the specified period in minutes added.
     * <p>
     * This adds the specified number of minutes to this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param minutesToAdd  the minutes to add, may be negative
     * @return a {@code LocalTime} based on this time with the minutes added, not null
     */
    public LocalTime plusMinutes(long minutesToAdd) {
        if (minutesToAdd == 0) {
            return this;
        }
        int mofd = hour * MINUTES_PER_HOUR + minute;
        int newMofd = ((int) (minutesToAdd % MINUTES_PER_DAY) + mofd + MINUTES_PER_DAY) % MINUTES_PER_DAY;
        if (mofd == newMofd) {
            return this;
        }
        int newHour = newMofd / MINUTES_PER_HOUR;
        int newMinute = newMofd % MINUTES_PER_HOUR;
        return create(newHour, newMinute, second, nano);
    }

    /**
     * Returns a copy of this {@code LocalTime} with the specified period in seconds added.
     * <p>
     * This adds the specified number of seconds to this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param secondstoAdd  the seconds to add, may be negative
     * @return a {@code LocalTime} based on this time with the seconds added, not null
     */
    public LocalTime plusSeconds(long secondstoAdd) {
        if (secondstoAdd == 0) {
            return this;
        }
        int sofd = hour * SECONDS_PER_HOUR +
                    minute * SECONDS_PER_MINUTE + second;
        int newSofd = ((int) (secondstoAdd % SECONDS_PER_DAY) + sofd + SECONDS_PER_DAY) % SECONDS_PER_DAY;
        if (sofd == newSofd) {
            return this;
        }
        int newHour = newSofd / SECONDS_PER_HOUR;
        int newMinute = (newSofd / SECONDS_PER_MINUTE) % MINUTES_PER_HOUR;
        int newSecond = newSofd % SECONDS_PER_MINUTE;
        return create(newHour, newMinute, newSecond, nano);
    }

    /**
     * Returns a copy of this {@code LocalTime} with the specified period in nanoseconds added.
     * <p>
     * This adds the specified number of nanoseconds to this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param nanosToAdd  the nanos to add, may be negative
     * @return a {@code LocalTime} based on this time with the nanoseconds added, not null
     */
    public LocalTime plusNanos(long nanosToAdd) {
        if (nanosToAdd == 0) {
            return this;
        }
        long nofd = toNanoOfDay();
        long newNofd = ((nanosToAdd % NANOS_PER_DAY) + nofd + NANOS_PER_DAY) % NANOS_PER_DAY;
        if (nofd == newNofd) {
            return this;
        }
        int newHour = (int) (newNofd / NANOS_PER_HOUR);
        int newMinute = (int) ((newNofd / NANOS_PER_MINUTE) % MINUTES_PER_HOUR);
        int newSecond = (int) ((newNofd / NANOS_PER_SECOND) % SECONDS_PER_MINUTE);
        int newNano = (int) (newNofd % NANOS_PER_SECOND);
        return create(newHour, newMinute, newSecond, newNano);
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a copy of this time with the specified amount subtracted.
     * <p>
     * This returns a {@code LocalTime}, 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 a {@code LocalTime} based on this time with the subtraction made, not null
     * @throws DateTimeException if the subtraction cannot be made
     * @throws ArithmeticException if numeric overflow occurs
     */
    @Override
    public LocalTime minus(TemporalAmount amountToSubtract) {
        return (LocalTime) amountToSubtract.subtractFrom(this);
    }

    /**
     * Returns a copy of this time with the specified amount subtracted.
     * <p>
     * This returns a {@code LocalTime}, 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 a {@code LocalTime} based on this time 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 LocalTime 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 {@code LocalTime} with the specified period in hours subtracted.
     * <p>
     * This subtracts the specified number of hours from this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param hoursToSubtract  the hours to subtract, may be negative
     * @return a {@code LocalTime} based on this time with the hours subtracted, not null
     */
    public LocalTime minusHours(long hoursToSubtract) {
        return plusHours(-(hoursToSubtract % HOURS_PER_DAY));
    }

    /**
     * Returns a copy of this {@code LocalTime} with the specified period in minutes subtracted.
     * <p>
     * This subtracts the specified number of minutes from this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param minutesToSubtract  the minutes to subtract, may be negative
     * @return a {@code LocalTime} based on this time with the minutes subtracted, not null
     */
    public LocalTime minusMinutes(long minutesToSubtract) {
        return plusMinutes(-(minutesToSubtract % MINUTES_PER_DAY));
    }

    /**
     * Returns a copy of this {@code LocalTime} with the specified period in seconds subtracted.
     * <p>
     * This subtracts the specified number of seconds from this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param secondsToSubtract  the seconds to subtract, may be negative
     * @return a {@code LocalTime} based on this time with the seconds subtracted, not null
     */
    public LocalTime minusSeconds(long secondsToSubtract) {
        return plusSeconds(-(secondsToSubtract % SECONDS_PER_DAY));
    }

    /**
     * Returns a copy of this {@code LocalTime} with the specified period in nanoseconds subtracted.
     * <p>
     * This subtracts the specified number of nanoseconds from this time, returning a new time.
     * The calculation wraps around midnight.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param nanosToSubtract  the nanos to subtract, may be negative
     * @return a {@code LocalTime} based on this time with the nanoseconds subtracted, not null
     */
    public LocalTime minusNanos(long nanosToSubtract) {
        return plusNanos(-(nanosToSubtract % NANOS_PER_DAY));
    }

    //-----------------------------------------------------------------------
    /**
     * Queries this time using the specified query.
     * <p>
     * This queries this time 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 query) {
        if (query == TemporalQueries.chronology() || query == TemporalQueries.zoneId() ||
                query == TemporalQueries.zone() || query == TemporalQueries.offset()) {
            return null;
        } else if (query == TemporalQueries.localTime()) {
            return (R) this;
        } else if (query == TemporalQueries.localDate()) {
            return null;
        } else if (query == TemporalQueries.precision()) {
            return (R) NANOS;
        }
        // inline TemporalAccessor.super.query(query) as an optimization
        // non-JDK classes are not permitted to make this optimization
        return query.queryFrom(this);
    }

    /**
     * Adjusts the specified temporal object to have the same time as this object.
     * <p>
     * This returns a temporal object of the same observable type as the input
     * with the time changed to be the same as this.
     * <p>
     * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
     * passing {@link ChronoField#NANO_OF_DAY} as the field.
     * <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 = thisLocalTime.adjustInto(temporal);
     *   temporal = temporal.with(thisLocalTime);
     * </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(NANO_OF_DAY, toNanoOfDay());
    }

    /**
     * Calculates the amount of time until another time in terms of the specified unit.
     * <p>
     * This calculates the amount of time between two {@code LocalTime}
     * objects in terms of a single {@code TemporalUnit}.
     * The start and end points are {@code this} and the specified time.
     * The result will be negative if the end is before the start.
     * The {@code Temporal} passed to this method is converted to a
     * {@code LocalTime} using {@link #from(TemporalAccessor)}.
     * For example, the amount in hours between two times can be calculated
     * using {@code startTime.until(endTime, HOURS)}.
     * <p>
     * The calculation returns a whole number, representing the number of
     * complete units between the two times.
     * For example, the amount in hours between 11:30 and 13:29 will only
     * be one hour as it is one minute short of two hours.
     * <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, MINUTES);
     *   amount = MINUTES.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} and {@code HALF_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 time, exclusive, which is converted to a {@code LocalTime}, not null
     * @param unit  the unit to measure the amount in, not null
     * @return the amount of time between this time and the end time
     * @throws DateTimeException if the amount cannot be calculated, or the end
     *  temporal cannot be converted to a {@code LocalTime}
     * @throws UnsupportedTemporalTypeException if the unit is not supported
     * @throws ArithmeticException if numeric overflow occurs
     */
    @Override
    public long until(Temporal endExclusive, TemporalUnit unit) {
        LocalTime end = LocalTime.from(endExclusive);
        if (unit instanceof ChronoUnit) {
            long nanosUntil = end.toNanoOfDay() - toNanoOfDay();  // no overflow
            switch ((ChronoUnit) unit) {
                case NANOS: return nanosUntil;
                case MICROS: return nanosUntil / 1000;
                case MILLIS: return nanosUntil / 1000_000;
                case SECONDS: return nanosUntil / NANOS_PER_SECOND;
                case MINUTES: return nanosUntil / NANOS_PER_MINUTE;
                case HOURS: return nanosUntil / NANOS_PER_HOUR;
                case HALF_DAYS: return nanosUntil / (12 * NANOS_PER_HOUR);
            }
            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
        }
        return unit.between(this, end);
    }

    /**
     * Formats this time using the specified formatter.
     * <p>
     * This time will be passed to the formatter to produce a string.
     *
     * @param formatter  the formatter to use, not null
     * @return the formatted time string, not null
     * @throws DateTimeException if an error occurs during printing
     */
    public String format(DateTimeFormatter formatter) {
        Objects.requireNonNull(formatter, "formatter");
        return formatter.format(this);
    }

    //-----------------------------------------------------------------------
    /**
     * Combines this time with a date to create a {@code LocalDateTime}.
     * <p>
     * This returns a {@code LocalDateTime} formed from this time at the specified date.
     * All possible combinations of date and time are valid.
     *
     * @param date  the date to combine with, not null
     * @return the local date-time formed from this time and the specified date, not null
     */
    public LocalDateTime atDate(LocalDate date) {
        return LocalDateTime.of(date, this);
    }

    /**
     * Combines this time with an offset to create an {@code OffsetTime}.
     * <p>
     * This returns an {@code OffsetTime} formed from this time at the specified offset.
     * All possible combinations of time and offset are valid.
     *
     * @param offset  the offset to combine with, not null
     * @return the offset time formed from this time and the specified offset, not null
     */
    public OffsetTime atOffset(ZoneOffset offset) {
        return OffsetTime.of(this, offset);
    }

    //-----------------------------------------------------------------------
    /**
     * Extracts the time as seconds of day,
     * from {@code 0} to {@code 24 * 60 * 60 - 1}.
     *
     * @return the second-of-day equivalent to this time
     */
    public int toSecondOfDay() {
        int total = hour * SECONDS_PER_HOUR;
        total += minute * SECONDS_PER_MINUTE;
        total += second;
        return total;
    }

    /**
     * Extracts the time as nanos of day,
     * from {@code 0} to {@code 24 * 60 * 60 * 1,000,000,000 - 1}.
     *
     * @return the nano of day equivalent to this time
     */
    public long toNanoOfDay() {
        long total = hour * NANOS_PER_HOUR;
        total += minute * NANOS_PER_MINUTE;
        total += second * NANOS_PER_SECOND;
        total += nano;
        return total;
    }

    //-----------------------------------------------------------------------
    /**
     * Compares this {@code LocalTime} to another time.
     * <p>
     * The comparison is based on the time-line position of the local times within a day.
     * It is "consistent with equals", as defined by {@link Comparable}.
     *
     * @param other  the other time to compare to, not null
     * @return the comparator value, negative if less, positive if greater
     * @throws NullPointerException if {@code other} is null
     */
    @Override
    public int compareTo(LocalTime other) {
        int cmp = Integer.compare(hour, other.hour);
        if (cmp == 0) {
            cmp = Integer.compare(minute, other.minute);
            if (cmp == 0) {
                cmp = Integer.compare(second, other.second);
                if (cmp == 0) {
                    cmp = Integer.compare(nano, other.nano);
                }
            }
        }
        return cmp;
    }

    /**
     * Checks if this {@code LocalTime} is after the specified time.
     * <p>
     * The comparison is based on the time-line position of the time within a day.
     *
     * @param other  the other time to compare to, not null
     * @return true if this is after the specified time
     * @throws NullPointerException if {@code other} is null
     */
    public boolean isAfter(LocalTime other) {
        return compareTo(other) > 0;
    }

    /**
     * Checks if this {@code LocalTime} is before the specified time.
     * <p>
     * The comparison is based on the time-line position of the time within a day.
     *
     * @param other  the other time to compare to, not null
     * @return true if this point is before the specified time
     * @throws NullPointerException if {@code other} is null
     */
    public boolean isBefore(LocalTime other) {
        return compareTo(other) < 0;
    }

    //-----------------------------------------------------------------------
    /**
     * Checks if this time is equal to another time.
     * <p>
     * The comparison is based on the time-line position of the time within a day.
     * <p>
     * Only objects of type {@code LocalTime} are compared, other types return false.
     * To compare the date of two {@code TemporalAccessor} instances, use
     * {@link ChronoField#NANO_OF_DAY} as a comparator.
     *
     * @param obj  the object to check, null returns false
     * @return true if this is equal to the other time
     */
    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof LocalTime) {
            LocalTime other = (LocalTime) obj;
            return hour == other.hour && minute == other.minute &&
                    second == other.second && nano == other.nano;
        }
        return false;
    }

    /**
     * A hash code for this time.
     *
     * @return a suitable hash code
     */
    @Override
    public int hashCode() {
        long nod = toNanoOfDay();
        return (int) (nod ^ (nod >>> 32));
    }

    //-----------------------------------------------------------------------
    /**
     * Outputs this time as a {@code String}, such as {@code 10:15}.
     * <p>
     * The output will be one of the following ISO-8601 formats:
     * <ul>
     * <li>{@code HH:mm}
     * <li>{@code HH:mm:ss}
     * <li>{@code HH:mm:ss.SSS}
     * <li>{@code HH:mm:ss.SSSSSS}
     * <li>{@code HH:mm:ss.SSSSSSSSS}
     * </ul>
     * The format used will be the shortest that outputs the full value of
     * the time where the omitted parts are implied to be zero.
     *
     * @return a string representation of this time, not null
     */
    @Override
    public String toString() {
        StringBuilder buf = new StringBuilder(18);
        int hourValue = hour;
        int minuteValue = minute;
        int secondValue = second;
        int nanoValue = nano;
        buf.append(hourValue < 10 ? "0" : "").append(hourValue)
            .append(minuteValue < 10 ? ":0" : ":").append(minuteValue);
        if (secondValue > 0 || nanoValue > 0) {
            buf.append(secondValue < 10 ? ":0" : ":").append(secondValue);
            if (nanoValue > 0) {
                buf.append('.');
                if (nanoValue % 1000_000 == 0) {
                    buf.append(Integer.toString((nanoValue / 1000_000) + 1000).substring(1));
                } else if (nanoValue % 1000 == 0) {
                    buf.append(Integer.toString((nanoValue / 1000) + 1000_000).substring(1));
                } else {
                    buf.append(Integer.toString((nanoValue) + 1000_000_000).substring(1));
                }
            }
        }
        return buf.toString();
    }

    //-----------------------------------------------------------------------
    /**
     * Writes the object using a
     * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form.
     * @serialData
     * A twos-complement value indicates the remaining values are not in the stream
     * and should be set to zero.
     * <pre>
     *  out.writeByte(4);  // identifies a LocalTime
     *  if (nano == 0) {
     *    if (second == 0) {
     *      if (minute == 0) {
     *        out.writeByte(~hour);
     *      } else {
     *        out.writeByte(hour);
     *        out.writeByte(~minute);
     *      }
     *    } else {
     *      out.writeByte(hour);
     *      out.writeByte(minute);
     *      out.writeByte(~second);
     *    }
     *  } else {
     *    out.writeByte(hour);
     *    out.writeByte(minute);
     *    out.writeByte(second);
     *    out.writeInt(nano);
     *  }
     * </pre>
     *
     * @return the instance of {@code Ser}, not null
     */
    private Object writeReplace() {
        return new Ser(Ser.LOCAL_TIME_TYPE, this);
    }

    /**
     * Defend against malicious streams.
     *
     * @throws InvalidObjectException always
     */
    private void readObject(ObjectInputStream s) throws InvalidObjectException {
        throw new InvalidObjectException("Deserialization via serialization delegate");
    }

    void writeExternal(DataOutput out) throws IOException {
        if (nano == 0) {
            if (second == 0) {
                if (minute == 0) {
                    out.writeByte(~hour);
                } else {
                    out.writeByte(hour);
                    out.writeByte(~minute);
                }
            } else {
                out.writeByte(hour);
                out.writeByte(minute);
                out.writeByte(~second);
            }
        } else {
            out.writeByte(hour);
            out.writeByte(minute);
            out.writeByte(second);
            out.writeInt(nano);
        }
    }

    static LocalTime readExternal(DataInput in) throws IOException {
        int hour = in.readByte();
        int minute = 0;
        int second = 0;
        int nano = 0;
        if (hour < 0) {
            hour = ~hour;
        } else {
            minute = in.readByte();
            if (minute < 0) {
                minute = ~minute;
            } else {
                second = in.readByte();
                if (second < 0) {
                    second = ~second;
                } else {
                    nano = in.readInt();
                }
            }
        }
        return LocalTime.of(hour, minute, second, nano);
    }

}

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