| /* |
| * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file: |
| * |
| * Copyright (c) 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; |
| import java.time.chrono.Chronology; |
| import java.time.format.ResolverStyle; |
| import java.util.Locale; |
| import java.util.Map; |
| import java.util.Objects; |
| |
| /** |
| * A field of date-time, such as month-of-year or hour-of-minute. |
| * <p> |
| * Date and time is expressed using fields which partition the time-line into something |
| * meaningful for humans. Implementations of this interface represent those fields. |
| * <p> |
| * The most commonly used units are defined in {@link ChronoField}. |
| * Further fields are supplied in {@link IsoFields}, {@link WeekFields} and {@link JulianFields}. |
| * Fields can also be written by application code by implementing this interface. |
| * <p> |
| * The field works using double dispatch. Client code calls methods on a date-time like |
| * {@code LocalDateTime} which check if the field is a {@code ChronoField}. |
| * If it is, then the date-time must handle it. |
| * Otherwise, the method call is re-dispatched to the matching method in this interface. |
| * |
| * @implSpec |
| * This interface must be implemented with care to ensure other classes operate correctly. |
| * All implementations that can be instantiated must be final, immutable and thread-safe. |
| * Implementations should be {@code Serializable} where possible. |
| * An enum is as effective implementation choice. |
| * |
| * @since 1.8 |
| */ |
| public interface TemporalField { |
| |
| /** |
| * Gets the display name for the field in the requested locale. |
| * <p> |
| * If there is no display name for the locale then a suitable default must be returned. |
| * <p> |
| * The default implementation must check the locale is not null |
| * and return {@code toString()}. |
| * |
| * @param locale the locale to use, not null |
| * @return the display name for the locale or a suitable default, not null |
| */ |
| default String getDisplayName(Locale locale) { |
| Objects.requireNonNull(locale, "locale"); |
| return toString(); |
| } |
| |
| /** |
| * Gets the unit that the field is measured in. |
| * <p> |
| * The unit of the field is the period that varies within the range. |
| * For example, in the field 'MonthOfYear', the unit is 'Months'. |
| * See also {@link #getRangeUnit()}. |
| * |
| * @return the unit defining the base unit of the field, not null |
| */ |
| TemporalUnit getBaseUnit(); |
| |
| /** |
| * Gets the range that the field is bound by. |
| * <p> |
| * The range of the field is the period that the field varies within. |
| * For example, in the field 'MonthOfYear', the range is 'Years'. |
| * See also {@link #getBaseUnit()}. |
| * <p> |
| * The range is never null. For example, the 'Year' field is shorthand for |
| * 'YearOfForever'. It therefore has a unit of 'Years' and a range of 'Forever'. |
| * |
| * @return the unit defining the range of the field, not null |
| */ |
| TemporalUnit getRangeUnit(); |
| |
| /** |
| * Gets the range of valid values for the field. |
| * <p> |
| * All fields can be expressed as a {@code long} integer. |
| * This method returns an object that describes the valid range for that value. |
| * This method is generally only applicable to the ISO-8601 calendar system. |
| * <p> |
| * Note that the result only describes the minimum and maximum valid values |
| * and it is important not to read too much into them. For example, there |
| * could be values within the range that are invalid for the field. |
| * |
| * @return the range of valid values for the field, not null |
| */ |
| ValueRange range(); |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Checks if this field represents a component of a date. |
| * <p> |
| * A field is date-based if it can be derived from |
| * {@link ChronoField#EPOCH_DAY EPOCH_DAY}. |
| * Note that it is valid for both {@code isDateBased()} and {@code isTimeBased()} |
| * to return false, such as when representing a field like minute-of-week. |
| * |
| * @return true if this field is a component of a date |
| */ |
| boolean isDateBased(); |
| |
| /** |
| * Checks if this field represents a component of a time. |
| * <p> |
| * A field is time-based if it can be derived from |
| * {@link ChronoField#NANO_OF_DAY NANO_OF_DAY}. |
| * Note that it is valid for both {@code isDateBased()} and {@code isTimeBased()} |
| * to return false, such as when representing a field like minute-of-week. |
| * |
| * @return true if this field is a component of a time |
| */ |
| boolean isTimeBased(); |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Checks if this field is supported by the temporal object. |
| * <p> |
| * This determines whether the temporal accessor supports this field. |
| * If this returns false, then the temporal cannot be queried for this field. |
| * <p> |
| * There are two equivalent ways of using this method. |
| * The first is to invoke this method directly. |
| * The second is to use {@link TemporalAccessor#isSupported(TemporalField)}: |
| * <pre> |
| * // these two lines are equivalent, but the second approach is recommended |
| * temporal = thisField.isSupportedBy(temporal); |
| * temporal = temporal.isSupported(thisField); |
| * </pre> |
| * It is recommended to use the second approach, {@code isSupported(TemporalField)}, |
| * as it is a lot clearer to read in code. |
| * <p> |
| * Implementations should determine whether they are supported using the fields |
| * available in {@link ChronoField}. |
| * |
| * @param temporal the temporal object to query, not null |
| * @return true if the date-time can be queried for this field, false if not |
| */ |
| boolean isSupportedBy(TemporalAccessor temporal); |
| |
| /** |
| * Get the range of valid values for this field using the temporal object to |
| * refine the result. |
| * <p> |
| * This uses the temporal object to find the range of valid values for the field. |
| * This is similar to {@link #range()}, however this method refines the result |
| * using the temporal. For example, if the field is {@code DAY_OF_MONTH} the |
| * {@code range} method is not accurate as there are four possible month lengths, |
| * 28, 29, 30 and 31 days. Using this method with a date allows the range to be |
| * accurate, returning just one of those four options. |
| * <p> |
| * There are two equivalent ways of using this method. |
| * The first is to invoke this method directly. |
| * The second is to use {@link TemporalAccessor#range(TemporalField)}: |
| * <pre> |
| * // these two lines are equivalent, but the second approach is recommended |
| * temporal = thisField.rangeRefinedBy(temporal); |
| * temporal = temporal.range(thisField); |
| * </pre> |
| * It is recommended to use the second approach, {@code range(TemporalField)}, |
| * as it is a lot clearer to read in code. |
| * <p> |
| * Implementations should perform any queries or calculations using the fields |
| * available in {@link ChronoField}. |
| * If the field is not supported an {@code UnsupportedTemporalTypeException} must be thrown. |
| * |
| * @param temporal the temporal object used to refine the result, not null |
| * @return the range of valid values for this field, not null |
| * @throws DateTimeException if the range for the field cannot be obtained |
| * @throws UnsupportedTemporalTypeException if the field is not supported by the temporal |
| */ |
| ValueRange rangeRefinedBy(TemporalAccessor temporal); |
| |
| /** |
| * Gets the value of this field from the specified temporal object. |
| * <p> |
| * This queries the temporal object for the value of this field. |
| * <p> |
| * There are two equivalent ways of using this method. |
| * The first is to invoke this method directly. |
| * The second is to use {@link TemporalAccessor#getLong(TemporalField)} |
| * (or {@link TemporalAccessor#get(TemporalField)}): |
| * <pre> |
| * // these two lines are equivalent, but the second approach is recommended |
| * temporal = thisField.getFrom(temporal); |
| * temporal = temporal.getLong(thisField); |
| * </pre> |
| * It is recommended to use the second approach, {@code getLong(TemporalField)}, |
| * as it is a lot clearer to read in code. |
| * <p> |
| * Implementations should perform any queries or calculations using the fields |
| * available in {@link ChronoField}. |
| * If the field is not supported an {@code UnsupportedTemporalTypeException} must be thrown. |
| * |
| * @param temporal the temporal object to query, not null |
| * @return the value of this field, not null |
| * @throws DateTimeException if a value for the field cannot be obtained |
| * @throws UnsupportedTemporalTypeException if the field is not supported by the temporal |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| long getFrom(TemporalAccessor temporal); |
| |
| /** |
| * Returns a copy of the specified temporal object with the value of this field set. |
| * <p> |
| * This returns a new temporal object based on the specified one with the value for |
| * this field changed. For example, on a {@code LocalDate}, this could be used to |
| * set the year, month or day-of-month. |
| * The returned object has the same observable type as the specified object. |
| * <p> |
| * In some cases, changing a field is not fully defined. For example, if the target object is |
| * a date representing the 31st January, then changing the month to February would be unclear. |
| * In cases like this, the implementation is responsible for resolving the result. |
| * Typically it will choose the previous valid date, which would be the last valid |
| * day of February in this example. |
| * <p> |
| * 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(TemporalField, long)}: |
| * <pre> |
| * // these two lines are equivalent, but the second approach is recommended |
| * temporal = thisField.adjustInto(temporal); |
| * temporal = temporal.with(thisField); |
| * </pre> |
| * It is recommended to use the second approach, {@code with(TemporalField)}, |
| * as it is a lot clearer to read in code. |
| * <p> |
| * Implementations should perform any queries or calculations using the fields |
| * available in {@link ChronoField}. |
| * If the field is not supported an {@code UnsupportedTemporalTypeException} must be thrown. |
| * <p> |
| * Implementations must not alter the specified temporal object. |
| * Instead, an adjusted copy of the original must be returned. |
| * This provides equivalent, safe behavior for immutable and mutable implementations. |
| * |
| * @param <R> the type of the Temporal object |
| * @param temporal the temporal object to adjust, not null |
| * @param newValue the new value of the field |
| * @return the adjusted temporal object, not null |
| * @throws DateTimeException if the field cannot be set |
| * @throws UnsupportedTemporalTypeException if the field is not supported by the temporal |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| <R extends Temporal> R adjustInto(R temporal, long newValue); |
| |
| /** |
| * Resolves this field to provide a simpler alternative or a date. |
| * <p> |
| * This method is invoked during the resolve phase of parsing. |
| * It is designed to allow application defined fields to be simplified into |
| * more standard fields, such as those on {@code ChronoField}, or into a date. |
| * <p> |
| * Applications should not normally invoke this method directly. |
| * |
| * @implSpec |
| * If an implementation represents a field that can be simplified, or |
| * combined with others, then this method must be implemented. |
| * <p> |
| * The specified map contains the current state of the parse. |
| * The map is mutable and must be mutated to resolve the field and |
| * any related fields. This method will only be invoked during parsing |
| * if the map contains this field, and implementations should therefore |
| * assume this field is present. |
| * <p> |
| * Resolving a field will consist of looking at the value of this field, |
| * and potentially other fields, and either updating the map with a |
| * simpler value, such as a {@code ChronoField}, or returning a |
| * complete {@code ChronoLocalDate}. If a resolve is successful, |
| * the code must remove all the fields that were resolved from the map, |
| * including this field. |
| * <p> |
| * For example, the {@code IsoFields} class contains the quarter-of-year |
| * and day-of-quarter fields. The implementation of this method in that class |
| * resolves the two fields plus the {@link ChronoField#YEAR YEAR} into a |
| * complete {@code LocalDate}. The resolve method will remove all three |
| * fields from the map before returning the {@code LocalDate}. |
| * <p> |
| * A partially complete temporal is used to allow the chronology and zone |
| * to be queried. In general, only the chronology will be needed. |
| * Querying items other than the zone or chronology is undefined and |
| * must not be relied on. |
| * The behavior of other methods such as {@code get}, {@code getLong}, |
| * {@code range} and {@code isSupported} is unpredictable and the results undefined. |
| * <p> |
| * If resolution should be possible, but the data is invalid, the resolver |
| * style should be used to determine an appropriate level of leniency, which |
| * may require throwing a {@code DateTimeException} or {@code ArithmeticException}. |
| * If no resolution is possible, the resolve method must return null. |
| * <p> |
| * When resolving time fields, the map will be altered and null returned. |
| * When resolving date fields, the date is normally returned from the method, |
| * with the map altered to remove the resolved fields. However, it would also |
| * be acceptable for the date fields to be resolved into other {@code ChronoField} |
| * instances that can produce a date, such as {@code EPOCH_DAY}. |
| * <p> |
| * Not all {@code TemporalAccessor} implementations are accepted as return values. |
| * Implementations that call this method must accept {@code ChronoLocalDate}, |
| * {@code ChronoLocalDateTime}, {@code ChronoZonedDateTime} and {@code LocalTime}. |
| * <p> |
| * The default implementation must return null. |
| * |
| * @param fieldValues the map of fields to values, which can be updated, not null |
| * @param partialTemporal the partially complete temporal to query for zone and |
| * chronology; querying for other things is undefined and not recommended, not null |
| * @param resolverStyle the requested type of resolve, not null |
| * @return the resolved temporal object; null if resolving only |
| * changed the map, or no resolve occurred |
| * @throws ArithmeticException if numeric overflow occurs |
| * @throws DateTimeException if resolving results in an error. This must not be thrown |
| * by querying a field on the temporal without first checking if it is supported |
| */ |
| default TemporalAccessor resolve( |
| Map<TemporalField, Long> fieldValues, |
| TemporalAccessor partialTemporal, |
| ResolverStyle resolverStyle) { |
| return null; |
| } |
| |
| /** |
| * Gets a descriptive name for the field. |
| * <p> |
| * The should be of the format 'BaseOfRange', such as 'MonthOfYear', |
| * unless the field has a range of {@code FOREVER}, when only |
| * the base unit is mentioned, such as 'Year' or 'Era'. |
| * |
| * @return the name of the field, not null |
| */ |
| @Override |
| String toString(); |
| |
| |
| } |
