/* * 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. */ /* * 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.temporal; import static java.time.temporal.ChronoField.DAY_OF_MONTH; import static java.time.temporal.ChronoField.DAY_OF_WEEK; import static java.time.temporal.ChronoField.DAY_OF_YEAR; import static java.time.temporal.ChronoUnit.DAYS; import static java.time.temporal.ChronoUnit.MONTHS; import static java.time.temporal.ChronoUnit.YEARS; import java.time.DayOfWeek; import java.util.Objects; /** * Common implementations of {@code TemporalAdjuster}. *

* This class provides common implementations of {@link TemporalAdjuster}. * They are especially useful to document the intent of business logic and * often link well to requirements. * For example, these two pieces of code do the same thing, but the second * one is clearer (assuming that there is a static import of this class): * 

 *  // direct manipulation
 *  date.withDayOfMonth(1).plusMonths(1).minusDays(1);
 *  // use of an adjuster from this class
 *  date.with(lastDayOfMonth());
 *
* There are two equivalent ways of using a {@code TemporalAdjuster}. * The first is to invoke the method on the interface directly. * The second is to use {@link Temporal#with(TemporalAdjuster)}: * 
 *   // these two lines are equivalent, but the second approach is recommended
 *   dateTime = adjuster.adjustInto(dateTime);
 *   dateTime = dateTime.with(adjuster);
 *
* It is recommended to use the second approach, {@code with(TemporalAdjuster)}, * as it is a lot clearer to read in code. * *

Specification for implementors

* This is a thread-safe utility class. * All returned adjusters are immutable and thread-safe. * * @since 1.8 */ public final class Adjusters { /** * Private constructor since this is a utility class. */ private Adjusters() { } //----------------------------------------------------------------------- /** * Returns the "first day of month" adjuster, which returns a new date set to * the first day of the current month. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 will return 2011-01-01.
* The input 2011-02-15 will return 2011-02-01. *

* The behavior is suitable for use with most calendar systems. * It is equivalent to: * 

     *  temporal.with(DAY_OF_MONTH, 1);
     *
* * @return the first day-of-month adjuster, not null */ public static TemporalAdjuster firstDayOfMonth() { return Impl.FIRST_DAY_OF_MONTH; } /** * Returns the "last day of month" adjuster, which returns a new date set to * the last day of the current month. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 will return 2011-01-31.
* The input 2011-02-15 will return 2011-02-28.
* The input 2012-02-15 will return 2012-02-29 (leap year).
* The input 2011-04-15 will return 2011-04-30. *

* The behavior is suitable for use with most calendar systems. * It is equivalent to: * 

     *  long lastDay = temporal.range(DAY_OF_MONTH).getMaximum();
     *  temporal.with(DAY_OF_MONTH, lastDay);
     *
* * @return the last day-of-month adjuster, not null */ public static TemporalAdjuster lastDayOfMonth() { return Impl.LAST_DAY_OF_MONTH; } /** * Returns the "first day of next month" adjuster, which returns a new date set to * the first day of the next month. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 will return 2011-02-01.
* The input 2011-02-15 will return 2011-03-01. *

* The behavior is suitable for use with most calendar systems. * It is equivalent to: * 

     *  temporal.with(DAY_OF_MONTH, 1).plus(1, MONTHS);
     *
* * @return the first day of next month adjuster, not null */ public static TemporalAdjuster firstDayOfNextMonth() { return Impl.FIRST_DAY_OF_NEXT_MONTH; } //----------------------------------------------------------------------- /** * Returns the "first day of year" adjuster, which returns a new date set to * the first day of the current year. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 will return 2011-01-01.
* The input 2011-02-15 will return 2011-01-01.
*

* The behavior is suitable for use with most calendar systems. * It is equivalent to: * 

     *  temporal.with(DAY_OF_YEAR, 1);
     *
* * @return the first day-of-year adjuster, not null */ public static TemporalAdjuster firstDayOfYear() { return Impl.FIRST_DAY_OF_YEAR; } /** * Returns the "last day of year" adjuster, which returns a new date set to * the last day of the current year. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 will return 2011-12-31.
* The input 2011-02-15 will return 2011-12-31.
*

* The behavior is suitable for use with most calendar systems. * It is equivalent to: * 

     *  long lastDay = temporal.range(DAY_OF_YEAR).getMaximum();
     *  temporal.with(DAY_OF_YEAR, lastDay);
     *
* * @return the last day-of-year adjuster, not null */ public static TemporalAdjuster lastDayOfYear() { return Impl.LAST_DAY_OF_YEAR; } /** * Returns the "first day of next year" adjuster, which returns a new date set to * the first day of the next year. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 will return 2012-01-01. *

* The behavior is suitable for use with most calendar systems. * It is equivalent to: * 

     *  temporal.with(DAY_OF_YEAR, 1).plus(1, YEARS);
     *
* * @return the first day of next month adjuster, not null */ public static TemporalAdjuster firstDayOfNextYear() { return Impl.FIRST_DAY_OF_NEXT_YEAR; } //----------------------------------------------------------------------- /** * Enum implementing the adjusters. */ private static class Impl implements TemporalAdjuster { /** First day of month adjuster. */ private static final Impl FIRST_DAY_OF_MONTH = new Impl(0); /** Last day of month adjuster. */ private static final Impl LAST_DAY_OF_MONTH = new Impl(1); /** First day of next month adjuster. */ private static final Impl FIRST_DAY_OF_NEXT_MONTH = new Impl(2); /** First day of year adjuster. */ private static final Impl FIRST_DAY_OF_YEAR = new Impl(3); /** Last day of year adjuster. */ private static final Impl LAST_DAY_OF_YEAR = new Impl(4); /** First day of next month adjuster. */ private static final Impl FIRST_DAY_OF_NEXT_YEAR = new Impl(5); /** The ordinal. */ private final int ordinal; private Impl(int ordinal) { this.ordinal = ordinal; } @Override public Temporal adjustInto(Temporal temporal) { switch (ordinal) { case 0: return temporal.with(DAY_OF_MONTH, 1); case 1: return temporal.with(DAY_OF_MONTH, temporal.range(DAY_OF_MONTH).getMaximum()); case 2: return temporal.with(DAY_OF_MONTH, 1).plus(1, MONTHS); case 3: return temporal.with(DAY_OF_YEAR, 1); case 4: return temporal.with(DAY_OF_YEAR, temporal.range(DAY_OF_YEAR).getMaximum()); case 5: return temporal.with(DAY_OF_YEAR, 1).plus(1, YEARS); } throw new IllegalStateException("Unreachable"); } } //----------------------------------------------------------------------- /** * Returns the first in month adjuster, which returns a new date * in the same month with the first matching day-of-week. * This is used for expressions like 'first Tuesday in March'. *

* The ISO calendar system behaves as follows:
* The input 2011-12-15 for (MONDAY) will return 2011-12-05.
* The input 2011-12-15 for (FRIDAY) will return 2011-12-02.
*

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} and {@code DAY_OF_MONTH} fields * and the {@code DAYS} unit, and assumes a seven day week. * * @param dayOfWeek the day-of-week, not null * @return the first in month adjuster, not null */ public static TemporalAdjuster firstInMonth(DayOfWeek dayOfWeek) { Objects.requireNonNull(dayOfWeek, "dayOfWeek"); return new DayOfWeekInMonth(1, dayOfWeek); } /** * Returns the last in month adjuster, which returns a new date * in the same month with the last matching day-of-week. * This is used for expressions like 'last Tuesday in March'. *

* The ISO calendar system behaves as follows:
* The input 2011-12-15 for (MONDAY) will return 2011-12-26.
* The input 2011-12-15 for (FRIDAY) will return 2011-12-30.
*

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} and {@code DAY_OF_MONTH} fields * and the {@code DAYS} unit, and assumes a seven day week. * * @param dayOfWeek the day-of-week, not null * @return the first in month adjuster, not null */ public static TemporalAdjuster lastInMonth(DayOfWeek dayOfWeek) { Objects.requireNonNull(dayOfWeek, "dayOfWeek"); return new DayOfWeekInMonth(-1, dayOfWeek); } /** * Returns the day-of-week in month adjuster, which returns a new date * in the same month with the ordinal day-of-week. * This is used for expressions like the 'second Tuesday in March'. *

* The ISO calendar system behaves as follows:
* The input 2011-12-15 for (1,TUESDAY) will return 2011-12-06.
* The input 2011-12-15 for (2,TUESDAY) will return 2011-12-13.
* The input 2011-12-15 for (3,TUESDAY) will return 2011-12-20.
* The input 2011-12-15 for (4,TUESDAY) will return 2011-12-27.
* The input 2011-12-15 for (5,TUESDAY) will return 2012-01-03.
* The input 2011-12-15 for (-1,TUESDAY) will return 2011-12-27 (last in month).
* The input 2011-12-15 for (-4,TUESDAY) will return 2011-12-06 (3 weeks before last in month).
* The input 2011-12-15 for (-5,TUESDAY) will return 2011-11-29 (4 weeks before last in month).
* The input 2011-12-15 for (0,TUESDAY) will return 2011-11-29 (last in previous month).
*

* For a positive or zero ordinal, the algorithm is equivalent to finding the first * day-of-week that matches within the month and then adding a number of weeks to it. * For a negative ordinal, the algorithm is equivalent to finding the last * day-of-week that matches within the month and then subtracting a number of weeks to it. * The ordinal number of weeks is not validated and is interpreted leniently * according to this algorithm. This definition means that an ordinal of zero finds * the last matching day-of-week in the previous month. *

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} and {@code DAY_OF_MONTH} fields * and the {@code DAYS} unit, and assumes a seven day week. * * @param ordinal the week within the month, unbound but typically from -5 to 5 * @param dayOfWeek the day-of-week, not null * @return the day-of-week in month adjuster, not null * @throws IllegalArgumentException if the ordinal is invalid */ public static TemporalAdjuster dayOfWeekInMonth(int ordinal, DayOfWeek dayOfWeek) { Objects.requireNonNull(dayOfWeek, "dayOfWeek"); return new DayOfWeekInMonth(ordinal, dayOfWeek); } /** * Class implementing day-of-week in month adjuster. */ private static final class DayOfWeekInMonth implements TemporalAdjuster { /** The ordinal. */ private final int ordinal; /** The day-of-week value, from 1 to 7. */ private final int dowValue; private DayOfWeekInMonth(int ordinal, DayOfWeek dow) { super(); this.ordinal = ordinal; this.dowValue = dow.getValue(); } @Override public Temporal adjustInto(Temporal temporal) { if (ordinal >= 0) { Temporal temp = temporal.with(DAY_OF_MONTH, 1); int curDow = temp.get(DAY_OF_WEEK); int dowDiff = (dowValue - curDow + 7) % 7; dowDiff += (ordinal - 1L) * 7L; // safe from overflow return temp.plus(dowDiff, DAYS); } else { Temporal temp = temporal.with(DAY_OF_MONTH, temporal.range(DAY_OF_MONTH).getMaximum()); int curDow = temp.get(DAY_OF_WEEK); int daysDiff = dowValue - curDow; daysDiff = (daysDiff == 0 ? 0 : (daysDiff > 0 ? daysDiff - 7 : daysDiff)); daysDiff -= (-ordinal - 1L) * 7L; // safe from overflow return temp.plus(daysDiff, DAYS); } } } //----------------------------------------------------------------------- /** * Returns the next day-of-week adjuster, which adjusts the date to the * first occurrence of the specified day-of-week after the date being adjusted. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-17 (two days later).
* The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-19 (four days later).
* The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-22 (seven days later). *

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} field and the {@code DAYS} unit, * and assumes a seven day week. * * @param dayOfWeek the day-of-week to move the date to, not null * @return the next day-of-week adjuster, not null */ public static TemporalAdjuster next(DayOfWeek dayOfWeek) { return new RelativeDayOfWeek(2, dayOfWeek); } /** * Returns the next-or-same day-of-week adjuster, which adjusts the date to the * first occurrence of the specified day-of-week after the date being adjusted * unless it is already on that day in which case the same object is returned. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-17 (two days later).
* The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-19 (four days later).
* The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-15 (same as input). *

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} field and the {@code DAYS} unit, * and assumes a seven day week. * * @param dayOfWeek the day-of-week to check for or move the date to, not null * @return the next-or-same day-of-week adjuster, not null */ public static TemporalAdjuster nextOrSame(DayOfWeek dayOfWeek) { return new RelativeDayOfWeek(0, dayOfWeek); } /** * Returns the previous day-of-week adjuster, which adjusts the date to the * first occurrence of the specified day-of-week before the date being adjusted. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-10 (five days earlier).
* The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-12 (three days earlier).
* The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-08 (seven days earlier). *

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} field and the {@code DAYS} unit, * and assumes a seven day week. * * @param dayOfWeek the day-of-week to move the date to, not null * @return the previous day-of-week adjuster, not null */ public static TemporalAdjuster previous(DayOfWeek dayOfWeek) { return new RelativeDayOfWeek(3, dayOfWeek); } /** * Returns the previous-or-same day-of-week adjuster, which adjusts the date to the * first occurrence of the specified day-of-week before the date being adjusted * unless it is already on that day in which case the same object is returned. *

* The ISO calendar system behaves as follows:
* The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-10 (five days earlier).
* The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-12 (three days earlier).
* The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-15 (same as input). *

* The behavior is suitable for use with most calendar systems. * It uses the {@code DAY_OF_WEEK} field and the {@code DAYS} unit, * and assumes a seven day week. * * @param dayOfWeek the day-of-week to check for or move the date to, not null * @return the previous-or-same day-of-week adjuster, not null */ public static TemporalAdjuster previousOrSame(DayOfWeek dayOfWeek) { return new RelativeDayOfWeek(1, dayOfWeek); } /** * Implementation of next, previous or current day-of-week. */ private static final class RelativeDayOfWeek implements TemporalAdjuster { /** Whether the current date is a valid answer. */ private final int relative; /** The day-of-week value, from 1 to 7. */ private final int dowValue; private RelativeDayOfWeek(int relative, DayOfWeek dayOfWeek) { Objects.requireNonNull(dayOfWeek, "dayOfWeek"); this.relative = relative; this.dowValue = dayOfWeek.getValue(); } @Override public Temporal adjustInto(Temporal temporal) { int calDow = temporal.get(DAY_OF_WEEK); if (relative < 2 && calDow == dowValue) { return temporal; } if ((relative & 1) == 0) { int daysDiff = calDow - dowValue; return temporal.plus(daysDiff >= 0 ? 7 - daysDiff : -daysDiff, DAYS); } else { int daysDiff = dowValue - calDow; return temporal.minus(daysDiff >= 0 ? 7 - daysDiff : -daysDiff, DAYS); } } } }