src.java.time.temporal.TemporalAdjuster Maven / Gradle / Ivy
Show all versions of android-all Show documentation
/*
* 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) 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.DateTimeException;
/**
* Strategy for adjusting a temporal object.
*
* Adjusters are a key tool for modifying temporal objects.
* They exist to externalize the process of adjustment, permitting different
* approaches, as per the strategy design pattern.
* Examples might be an adjuster that sets the date avoiding weekends, or one that
* sets the date to the last day of the month.
*
* There are two equivalent ways of using a {@code TemporalAdjuster}.
* The first is to invoke the method on this interface directly.
* The second is to use {@link Temporal#with(TemporalAdjuster)}:
*
* // these two lines are equivalent, but the second approach is recommended
* temporal = thisAdjuster.adjustInto(temporal);
* temporal = temporal.with(thisAdjuster);
*
* It is recommended to use the second approach, {@code with(TemporalAdjuster)},
* as it is a lot clearer to read in code.
*
* The {@link TemporalAdjusters} class contains a standard set of adjusters,
* available as static methods.
* These include:
*
* - finding the first or last day of the month
*
- finding the first day of next month
*
- finding the first or last day of the year
*
- finding the first day of next year
*
- finding the first or last day-of-week within a month, such as "first Wednesday in June"
*
- finding the next or previous day-of-week, such as "next Thursday"
*
*
* @implSpec
* This interface places no restrictions on the mutability of implementations,
* however immutability is strongly recommended.
*
* @see TemporalAdjusters
* @since 1.8
*/
@FunctionalInterface
public interface TemporalAdjuster {
/**
* Adjusts the specified temporal object.
*
* This adjusts the specified temporal object using the logic
* encapsulated in the implementing class.
* Examples might be an adjuster that sets the date avoiding weekends, or one that
* sets the date to the last day of the month.
*
* There are two equivalent ways of using this method.
* The first is to invoke this method directly.
* The second is to use {@link Temporal#with(TemporalAdjuster)}:
*
* // these two lines are equivalent, but the second approach is recommended
* temporal = thisAdjuster.adjustInto(temporal);
* temporal = temporal.with(thisAdjuster);
*
* It is recommended to use the second approach, {@code with(TemporalAdjuster)},
* as it is a lot clearer to read in code.
*
* @implSpec
* The implementation must take the input object and adjust it.
* The implementation defines the logic of the adjustment and is responsible for
* documenting that logic. It may use any method on {@code Temporal} to
* query the temporal object and perform the adjustment.
* The returned object must have the same observable type as the input object
*
* The input object must not be altered.
* Instead, an adjusted copy of the original must be returned.
* This provides equivalent, safe behavior for immutable and mutable temporal objects.
*
* The input temporal object may be in a calendar system other than ISO.
* Implementations may choose to document compatibility with other calendar systems,
* or reject non-ISO temporal objects by {@link TemporalQueries#chronology() querying the chronology}.
*
* This method may be called from multiple threads in parallel.
* It must be thread-safe when invoked.
*
* @param temporal the temporal object to adjust, not null
* @return an object of the same observable type with the adjustment made, not null
* @throws DateTimeException if unable to make the adjustment
* @throws ArithmeticException if numeric overflow occurs
*/
Temporal adjustInto(Temporal temporal);
}