DayOfMonth.java
/*
* Copyright (c) 2007-present, 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 org.threeten.extra;
import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import java.io.Serializable;
import java.time.Clock;
import java.time.DateTimeException;
import java.time.LocalDate;
import java.time.Month;
import java.time.MonthDay;
import java.time.YearMonth;
import java.time.ZoneId;
import java.time.chrono.Chronology;
import java.time.chrono.IsoChronology;
import java.time.temporal.ChronoField;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalQueries;
import java.time.temporal.TemporalQuery;
import java.time.temporal.UnsupportedTemporalTypeException;
import java.time.temporal.ValueRange;
import java.util.Objects;
/**
* A day-of-month in the ISO-8601 calendar system.
* <p>
* {@code DayOfMonth} is an immutable date-time object that represents a day-of-month.
* It is a type-safe way of representing a day-of-month in an application.
* Any field that can be derived from a day-of-month can be obtained.
* <p>
* This class does not store or represent a year, month, time or time-zone.
* For example, the value "21" can be stored in a {@code DayOfMonth} and
* would represent the 21st day of any month.
*
* <h3>Implementation Requirements:</h3>
* This class is immutable and thread-safe.
* <p>
* This class must be treated as a value type. Do not synchronize, rely on the
* identity hash code or use the distinction between equals() and ==.
*/
public final class DayOfMonth
implements TemporalAccessor, TemporalAdjuster, Comparable<DayOfMonth>, Serializable {
/**
* Serialization version.
*/
private static final long serialVersionUID = -8840172642009917873L;
/**
* Cache of singleton instances.
*/
private static final DayOfMonth[] VALUES = new DayOfMonth[31];
static {
for (int i = 0; i < 31; i++) {
VALUES[i] = new DayOfMonth(i + 1);
}
}
/**
* The day-of-month being represented, from 1 to 31.
*/
private final int day;
//-----------------------------------------------------------------------
/**
* Obtains the current day-of-month from the system clock in the default time-zone.
* <p>
* This will query the {@link java.time.Clock#systemDefaultZone() system clock} in the default
* time-zone to obtain the current day-of-month.
* The zone and offset will be set based on the time-zone in the clock.
* <p>
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @return the current day-of-month using the system clock and default time-zone, not null
*/
public static DayOfMonth now() {
return now(Clock.systemDefaultZone());
}
/**
* Obtains the current day-of-month from the system clock in the specified time-zone.
* <p>
* This will query the {@link Clock#system(java.time.ZoneId) system clock} to obtain the current day-of-month.
* 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 day-of-month using the system clock, not null
*/
public static DayOfMonth now(ZoneId zone) {
return now(Clock.system(zone));
}
/**
* Obtains the current day-of-month from the specified clock.
* <p>
* This will query the specified clock to obtain the current day-of-month.
* 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 day-of-month, not null
*/
public static DayOfMonth now(Clock clock) {
final LocalDate now = LocalDate.now(clock); // called once
return DayOfMonth.of(now.getDayOfMonth());
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code DayOfMonth}.
* <p>
* A day-of-month object represents one of the 31 days of the month, from 1 to 31.
*
* @param dayOfMonth the day-of-month to represent, from 1 to 31
* @return the day-of-month, not null
* @throws DateTimeException if the day-of-month is invalid
*/
public static DayOfMonth of(int dayOfMonth) {
try {
return VALUES[dayOfMonth - 1];
} catch (IndexOutOfBoundsException ex) {
throw new DateTimeException("Invalid value for DayOfMonth: " + dayOfMonth);
}
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code DayOfMonth} from a date-time object.
* <p>
* This obtains a day-of-month 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 DayOfMonth}.
* <p>
* The conversion extracts the {@link ChronoField#DAY_OF_MONTH day-of-month} field.
* The extraction is only permitted if the temporal object has an ISO
* chronology, or can be converted to a {@code LocalDate}.
* <p>
* This method matches the signature of the functional interface {@link TemporalQuery}
* allowing it to be used in queries via method reference, {@code DayOfMonth::from}.
*
* @param temporal the temporal object to convert, not null
* @return the day-of-month, not null
* @throws DateTimeException if unable to convert to a {@code DayOfMonth}
*/
public static DayOfMonth from(TemporalAccessor temporal) {
if (temporal instanceof DayOfMonth) {
return (DayOfMonth) temporal;
}
Objects.requireNonNull(temporal, "temporal");
try {
if (IsoChronology.INSTANCE.equals(Chronology.from(temporal)) == false) {
temporal = LocalDate.from(temporal);
}
return of(temporal.get(DAY_OF_MONTH));
} catch (DateTimeException ex) {
throw new DateTimeException("Unable to obtain DayOfMonth from TemporalAccessor: " +
temporal + " of type " + temporal.getClass().getName(), ex);
}
}
//-----------------------------------------------------------------------
/**
* Constructor.
*
* @param dayOfMonth the day-of-month to represent
*/
private DayOfMonth(int dayOfMonth) {
this.day = dayOfMonth;
}
/**
* Validates the input.
*
* @return the valid object, not null
*/
private Object readResolve() {
return of(day);
}
//-----------------------------------------------------------------------
/**
* Gets the day-of-month value.
*
* @return the day-of-month, from 1 to 31
*/
public int getValue() {
return day;
}
//-----------------------------------------------------------------------
/**
* Checks if the specified field is supported.
* <p>
* This checks if this day-of-month can be queried for the specified field.
* If false, then calling the {@link #range(TemporalField) range},
* {@link #get(TemporalField) get} and {@link #getLong(TemporalField) getLong}
* 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 DAY_OF_MONTH}
* </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 day-of-month, false if not
*/
@Override
public boolean isSupported(TemporalField field) {
if (field instanceof ChronoField) {
return field == DAY_OF_MONTH;
}
return field != null && field.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 day-of-month 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
public ValueRange range(TemporalField field) {
return TemporalAccessor.super.range(field);
}
/**
* Gets the value of the specified field from this day-of-month as an {@code int}.
* <p>
* This queries this day-of-month 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 day-of-month.
* 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
public int get(TemporalField field) {
return TemporalAccessor.super.get(field);
}
/**
* Gets the value of the specified field from this day-of-month as a {@code long}.
* <p>
* This queries this day-of-month 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 day-of-month.
* 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 == DAY_OF_MONTH) {
return day;
} else if (field instanceof ChronoField) {
throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
}
return field.getFrom(this);
}
//-----------------------------------------------------------------------
/**
* Checks if the year-month is valid for this year.
* <p>
* This method checks whether this day and the input year and month form
* a valid date.
*
* @param yearMonth the year month to validate, null returns false
* @return true if the year and month are valid for this day
*/
public boolean isValidYearMonth(YearMonth yearMonth) {
return yearMonth != null && yearMonth.isValidDay(day);
}
//-----------------------------------------------------------------------
/**
* Queries this day-of-month using the specified query.
* <p>
* This queries this day-of-month 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<R> query) {
if (query == TemporalQueries.chronology()) {
return (R) IsoChronology.INSTANCE;
}
return TemporalAccessor.super.query(query);
}
/**
* Adjusts the specified temporal object to have this day-of-month.
* <p>
* This returns a temporal object of the same observable type as the input
* with the day-of-month changed to be the same as this.
* <p>
* The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
* passing {@link ChronoField#DAY_OF_MONTH} as the field.
* If the specified temporal object does not use the ISO calendar system then
* a {@code DateTimeException} is thrown.
* <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 = thisDay.adjustInto(temporal);
* temporal = temporal.with(thisDay);
* </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) {
if (Chronology.from(temporal).equals(IsoChronology.INSTANCE) == false) {
throw new DateTimeException("Adjustment only supported on ISO date-time");
}
return temporal.with(DAY_OF_MONTH, day);
}
//-----------------------------------------------------------------------
/**
* Combines this day-of-month with a month to create a {@code MonthDay}.
* <p>
* This returns a {@code MonthDay} formed from this day and the specified month.
* <p>
* This method can be used as part of a chain to produce a date:
* <pre>
* LocalDate date = day.atMonth(month).atYear(year);
* </pre>
* <p>
* If this day-of-month is invalid for the month then it will be changed
* to the last valid date for the month.
*
* @param month the month-of-year to use, not null
* @return the year-month formed from this year and the specified month, not null
*/
public MonthDay atMonth(Month month) {
return MonthDay.of(month, Math.min(day, month.maxLength()));
}
/**
* Combines this day-of-month with a month to create a {@code MonthDay}.
* <p>
* This returns a {@code MonthDay} formed from this day and the specified month.
* <p>
* This method can be used as part of a chain to produce a date:
* <pre>
* LocalDate date = day.atMonth(month).atYear(year);
* </pre>
* <p>
* If this day-of-month is invalid for the month then it will be changed
* to the last valid date for the month.
*
* @param month the month-of-year to use, from 1 (January) to 12 (December)
* @return the year-month formed from this year and the specified month, not null
* @throws DateTimeException if the month is invalid
*/
public MonthDay atMonth(int month) {
return atMonth(Month.of(month));
}
/**
* Combines this day-of-month with a year-month to create a {@code LocalDate}.
* <p>
* This returns a {@code LocalDate} formed from this year and the specified year-month.
* <p>
* If this day-of-month is invalid for the year-month then it will be changed
* to the last valid date for the month.
*
* @param yearMonth the year-month to use, not null
* @return the local date formed from this year and the specified year-month, not null
*/
public LocalDate atYearMonth(YearMonth yearMonth) {
return yearMonth.atDay(Math.min(day, yearMonth.lengthOfMonth()));
}
//-----------------------------------------------------------------------
/**
* Compares this day-of-month to another.
* <p>
* The comparison is based on the value of the day.
* It is "consistent with equals", as defined by {@link Comparable}.
*
* @param other the other day-of-month instance, not null
* @return the comparator value, negative if less, positive if greater
*/
@Override
public int compareTo(DayOfMonth other) {
return day - other.day;
}
//-----------------------------------------------------------------------
/**
* Checks if this day-of-month is equal to another day-of-month.
*
* @param obj the other day-of-month instance, null returns false
* @return true if the day-of-month is the same
*/
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj instanceof DayOfMonth) {
return day == ((DayOfMonth) obj).day;
}
return false;
}
/**
* A hash code for this day-of-month.
*
* @return a suitable hash code
*/
@Override
public int hashCode() {
return day;
}
//-----------------------------------------------------------------------
/**
* Outputs this day-of-month as a {@code String}.
*
* @return a string representation of this day-of-month, not null
*/
@Override
public String toString() {
return "DayOfMonth:" + day;
}
}