Back to index...

	/*
	* 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.
	*
	* 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.
	*/

	/*
	* Copyright (c) 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.temporal;

	import java.time.Duration;

	/**
	* A standard set of date periods units.
	* <p>
	* This set of units provide unit-based access to manipulate a date, time or date-time.
	* The standard set of units can be extended by implementing {@link TemporalUnit}.
	* <p>
	* These units are intended to be applicable in multiple calendar systems.
	* For example, most non-ISO calendar systems define units of years, months and days,
	* just with slightly different rules.
	* The documentation of each unit explains how it operates.
	*
	* @implSpec
	* This is a final, immutable and thread-safe enum.
	*
	* @since 1.8
	*/
	public enum ChronoUnit implements TemporalUnit {

	/**
	* Unit that represents the concept of a nanosecond, the smallest supported unit of time.
	* For the ISO calendar system, it is equal to the 1,000,000,000th part of the second unit.
	*/
	NANOS("Nanos", Duration.ofNanos(1)),
	/**
	* Unit that represents the concept of a microsecond.
	* For the ISO calendar system, it is equal to the 1,000,000th part of the second unit.
	*/
	MICROS("Micros", Duration.ofNanos(1000)),
	/**
	* Unit that represents the concept of a millisecond.
	* For the ISO calendar system, it is equal to the 1000th part of the second unit.
	*/
	MILLIS("Millis", Duration.ofNanos(1000_000)),
	/**
	* Unit that represents the concept of a second.
	* For the ISO calendar system, it is equal to the second in the SI system
	* of units, except around a leap-second.
	*/
	SECONDS("Seconds", Duration.ofSeconds(1)),
	/**
	* Unit that represents the concept of a minute.
	* For the ISO calendar system, it is equal to 60 seconds.
	*/
	MINUTES("Minutes", Duration.ofSeconds(60)),
	/**
	* Unit that represents the concept of an hour.
	* For the ISO calendar system, it is equal to 60 minutes.
	*/
	HOURS("Hours", Duration.ofSeconds(3600)),
	/**
	* Unit that represents the concept of half a day, as used in AM/PM.
	* For the ISO calendar system, it is equal to 12 hours.
	*/
	HALF_DAYS("HalfDays", Duration.ofSeconds(43200)),
	/**
	* Unit that represents the concept of a day.
	* For the ISO calendar system, it is the standard day from midnight to midnight.
	* The estimated duration of a day is {@code 24 Hours}.
	* <p>
	* When used with other calendar systems it must correspond to the day defined by
	* the rising and setting of the Sun on Earth. It is not required that days begin
	* at midnight - when converting between calendar systems, the date should be
	* equivalent at midday.
	*/
	DAYS("Days", Duration.ofSeconds(86400)),
	/**
	* Unit that represents the concept of a week.
	* For the ISO calendar system, it is equal to 7 days.
	* <p>
	* When used with other calendar systems it must correspond to an integral number of days.
	*/
	WEEKS("Weeks", Duration.ofSeconds(7 * 86400L)),
	/**
	* Unit that represents the concept of a month.
	* For the ISO calendar system, the length of the month varies by month-of-year.
	* The estimated duration of a month is one twelfth of {@code 365.2425 Days}.
	* <p>
	* When used with other calendar systems it must correspond to an integral number of days.
	*/
	MONTHS("Months", Duration.ofSeconds(31556952L / 12)),
	/**
	* Unit that represents the concept of a year.
	* For the ISO calendar system, it is equal to 12 months.
	* The estimated duration of a year is {@code 365.2425 Days}.
	* <p>
	* When used with other calendar systems it must correspond to an integral number of days
	* or months roughly equal to a year defined by the passage of the Earth around the Sun.
	*/
	YEARS("Years", Duration.ofSeconds(31556952L)),
	/**
	* Unit that represents the concept of a decade.
	* For the ISO calendar system, it is equal to 10 years.
	* <p>
	* When used with other calendar systems it must correspond to an integral number of days
	* and is normally an integral number of years.
	*/
	DECADES("Decades", Duration.ofSeconds(31556952L * 10L)),
	/**
	* Unit that represents the concept of a century.
	* For the ISO calendar system, it is equal to 100 years.
	* <p>
	* When used with other calendar systems it must correspond to an integral number of days
	* and is normally an integral number of years.
	*/
	CENTURIES("Centuries", Duration.ofSeconds(31556952L * 100L)),
	/**
	* Unit that represents the concept of a millennium.
	* For the ISO calendar system, it is equal to 1000 years.
	* <p>
	* When used with other calendar systems it must correspond to an integral number of days
	* and is normally an integral number of years.
	*/
	MILLENNIA("Millennia", Duration.ofSeconds(31556952L * 1000L)),
	/**
	* Unit that represents the concept of an era.
	* The ISO calendar system doesn't have eras thus it is impossible to add
	* an era to a date or date-time.
	* The estimated duration of the era is artificially defined as {@code 1,000,000,000 Years}.
	* <p>
	* When used with other calendar systems there are no restrictions on the unit.
	*/
	ERAS("Eras", Duration.ofSeconds(31556952L * 1000_000_000L)),
	/**
	* Artificial unit that represents the concept of forever.
	* This is primarily used with {@link TemporalField} to represent unbounded fields
	* such as the year or era.
	* The estimated duration of this unit is artificially defined as the largest duration
	* supported by {@link Duration}.
	*/
	FOREVER("Forever", Duration.ofSeconds(Long.MAX_VALUE, 999_999_999));

	private final String name;
	private final Duration duration;

	private ChronoUnit(String name, Duration estimatedDuration) {
	this.name = name;
	this.duration = estimatedDuration;
	}

	//-----------------------------------------------------------------------
	/**
	* Gets the estimated duration of this unit in the ISO calendar system.
	* <p>
	* All of the units in this class have an estimated duration.
	* Days vary due to daylight saving time, while months have different lengths.
	*
	* @return the estimated duration of this unit, not null
	*/
	@Override
	public Duration getDuration() {
	return duration;
	}

	/**
	* Checks if the duration of the unit is an estimate.
	* <p>
	* All time units in this class are considered to be accurate, while all date
	* units in this class are considered to be estimated.
	* <p>
	* This definition ignores leap seconds, but considers that Days vary due to
	* daylight saving time and months have different lengths.
	*
	* @return true if the duration is estimated, false if accurate
	*/
	@Override
	public boolean isDurationEstimated() {
	return this.compareTo(DAYS) >= 0;
	}

	//-----------------------------------------------------------------------
	/**
	* Checks if this unit is a date unit.
	* <p>
	* All units from days to eras inclusive are date-based.
	* Time-based units and {@code FOREVER} return false.
	*
	* @return true if a date unit, false if a time unit
	*/
	@Override
	public boolean isDateBased() {
	return this.compareTo(DAYS) >= 0 && this != FOREVER;
	}

	/**
	* Checks if this unit is a time unit.
	* <p>
	* All units from nanos to half-days inclusive are time-based.
	* Date-based units and {@code FOREVER} return false.
	*
	* @return true if a time unit, false if a date unit
	*/
	@Override
	public boolean isTimeBased() {
	return this.compareTo(DAYS) < 0;
	}

	//-----------------------------------------------------------------------
	@Override
	public boolean isSupportedBy(Temporal temporal) {
	return temporal.isSupported(this);
	}

	@SuppressWarnings("unchecked")
	@Override
	public <R extends Temporal> R addTo(R temporal, long amount) {
	return (R) temporal.plus(amount, this);
	}

	//-----------------------------------------------------------------------
	@Override
	public long between(Temporal temporal1Inclusive, Temporal temporal2Exclusive) {
	return temporal1Inclusive.until(temporal2Exclusive, this);
	}

	//-----------------------------------------------------------------------
	@Override
	public String toString() {
	return name;
	}

	}

Back to index...