
The Days.java Java example source code
/*
* Copyright 20012010 Stephen Colebourne
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.joda.time;
import org.joda.convert.FromString;
import org.joda.convert.ToString;
import org.joda.time.base.BaseSingleFieldPeriod;
import org.joda.time.field.FieldUtils;
import org.joda.time.format.ISOPeriodFormat;
import org.joda.time.format.PeriodFormatter;
/**
* An immutable time period representing a number of days.
* <p>
* <code>Days is an immutable period that can only store days.
* It does not store years, months or hours for example. As such it is a
* typesafe way of representing a number of days in an application.
* <p>
* The number of days is set in the constructor, and may be queried using
* <code>getDays(). Basic mathematical operations are provided 
* <code>plus(), minus() , multipliedBy() and
* <code>dividedBy().
* <p>
* <code>Days is threadsafe and immutable.
*
* @author Stephen Colebourne
* @since 1.4
*/
public final class Days extends BaseSingleFieldPeriod {
/** Constant representing zero days. */
public static final Days ZERO = new Days(0);
/** Constant representing one day. */
public static final Days ONE = new Days(1);
/** Constant representing two days. */
public static final Days TWO = new Days(2);
/** Constant representing three days. */
public static final Days THREE = new Days(3);
/** Constant representing four days. */
public static final Days FOUR = new Days(4);
/** Constant representing five days. */
public static final Days FIVE = new Days(5);
/** Constant representing six days. */
public static final Days SIX = new Days(6);
/** Constant representing seven days. */
public static final Days SEVEN = new Days(7);
/** Constant representing the maximum number of days that can be stored in this object. */
public static final Days MAX_VALUE = new Days(Integer.MAX_VALUE);
/** Constant representing the minimum number of days that can be stored in this object. */
public static final Days MIN_VALUE = new Days(Integer.MIN_VALUE);
/** The paser to use for this class. */
private static final PeriodFormatter PARSER = ISOPeriodFormat.standard().withParseType(PeriodType.days());
/** Serialization version. */
private static final long serialVersionUID = 87525275727380865L;
//
/**
* Obtains an instance of <code>Days that may be cached.
* <code>Days is immutable, so instances can be cached and shared.
* This factory method provides access to shared instances.
*
* @param days the number of days to obtain an instance for
* @return the instance of Days
*/
public static Days days(int days) {
switch (days) {
case 0:
return ZERO;
case 1:
return ONE;
case 2:
return TWO;
case 3:
return THREE;
case 4:
return FOUR;
case 5:
return FIVE;
case 6:
return SIX;
case 7:
return SEVEN;
case Integer.MAX_VALUE:
return MAX_VALUE;
case Integer.MIN_VALUE:
return MIN_VALUE;
default:
return new Days(days);
}
}
//
/**
* Creates a <code>Days representing the number of whole days
* between the two specified datetimes. This method corectly handles
* any daylight savings time changes that may occur during the interval.
*
* @param start the start instant, must not be null
* @param end the end instant, must not be null
* @return the period in days
* @throws IllegalArgumentException if the instants are null or invalid
*/
public static Days daysBetween(ReadableInstant start, ReadableInstant end) {
int amount = BaseSingleFieldPeriod.between(start, end, DurationFieldType.days());
return Days.days(amount);
}
/**
* Creates a <code>Days representing the number of whole days
* between the two specified partial datetimes.
* <p>
* The two partials must contain the same fields, for example you can specify
* two <code>LocalDate objects.
*
* @param start the start partial date, must not be null
* @param end the end partial date, must not be null
* @return the period in days
* @throws IllegalArgumentException if the partials are null or invalid
*/
public static Days daysBetween(ReadablePartial start, ReadablePartial end) {
if (start instanceof LocalDate && end instanceof LocalDate) {
Chronology chrono = DateTimeUtils.getChronology(start.getChronology());
int days = chrono.days().getDifference(
((LocalDate) end).getLocalMillis(), ((LocalDate) start).getLocalMillis());
return Days.days(days);
}
int amount = BaseSingleFieldPeriod.between(start, end, ZERO);
return Days.days(amount);
}
/**
* Creates a <code>Days representing the number of whole days
* in the specified interval. This method corectly handles any daylight
* savings time changes that may occur during the interval.
*
* @param interval the interval to extract days from, null returns zero
* @return the period in days
* @throws IllegalArgumentException if the partials are null or invalid
*/
public static Days daysIn(ReadableInterval interval) {
if (interval == null) {
return Days.ZERO;
}
int amount = BaseSingleFieldPeriod.between(interval.getStart(), interval.getEnd(), DurationFieldType.days());
return Days.days(amount);
}
/**
* Creates a new <code>Days representing the number of complete
* standard length days in the specified period.
* <p>
* This factory method converts all fields from the period to hours using standardised
* durations for each field. Only those fields which have a precise duration in
* the ISO UTC chronology can be converted.
* <ul>
* <li>One week consists of 7 days.
* <li>One day consists of 24 hours.
* <li>One hour consists of 60 minutes.
* <li>One minute consists of 60 seconds.
* <li>One second consists of 1000 milliseconds.
* </ul>
* Months and Years are imprecise and periods containing these values cannot be converted.
*
* @param period the period to get the number of hours from, null returns zero
* @return the period in days
* @throws IllegalArgumentException if the period contains imprecise duration values
*/
public static Days standardDaysIn(ReadablePeriod period) {
int amount = BaseSingleFieldPeriod.standardPeriodIn(period, DateTimeConstants.MILLIS_PER_DAY);
return Days.days(amount);
}
/**
* Creates a new <code>Days by parsing a string in the ISO8601 format 'PnD'.
* <p>
* The parse will accept the full ISO syntax of PnYnMnWnDTnHnMnS however only the
* days component may be nonzero. If any other component is nonzero, an exception
* will be thrown.
*
* @param periodStr the period string, null returns zero
* @return the period in days
* @throws IllegalArgumentException if the string format is invalid
*/
@FromString
public static Days parseDays(String periodStr) {
if (periodStr == null) {
return Days.ZERO;
}
Period p = PARSER.parsePeriod(periodStr);
return Days.days(p.getDays());
}
//
/**
* Creates a new instance representing a number of days.
* You should consider using the factory method {@link #days(int)}
* instead of the constructor.
*
* @param days the number of days to represent
*/
private Days(int days) {
super(days);
}
/**
* Resolves singletons.
*
* @return the singleton instance
*/
private Object readResolve() {
return Days.days(getValue());
}
//
/**
* Gets the duration field type, which is <code>days.
*
* @return the period type
*/
public DurationFieldType getFieldType() {
return DurationFieldType.days();
}
/**
* Gets the period type, which is <code>days.
*
* @return the period type
*/
public PeriodType getPeriodType() {
return PeriodType.days();
}
//
/**
* Converts this period in days to a period in weeks assuming a
* 7 day week.
* <p>
* This method allows you to convert between different types of period.
* However to achieve this it makes the assumption that all weeks are
* 7 days long.
* This may not be true for some unusual chronologies. However, it is included
* as it is a useful operation for many applications and business rules.
*
* @return a period representing the number of weeks for this number of days
*/
public Weeks toStandardWeeks() {
return Weeks.weeks(getValue() / DateTimeConstants.DAYS_PER_WEEK);
}
/**
* Converts this period in days to a period in hours assuming a
* 24 hour day.
* <p>
* This method allows you to convert between different types of period.
* However to achieve this it makes the assumption that all days are 24 hours long.
* This is not true when daylight savings is considered and may also not
* be true for some unusual chronologies. However, it is included
* as it is a useful operation for many applications and business rules.
*
* @return a period representing the number of hours for this number of days
* @throws ArithmeticException if the number of hours is too large to be represented
*/
public Hours toStandardHours() {
return Hours.hours(FieldUtils.safeMultiply(getValue(), DateTimeConstants.HOURS_PER_DAY));
}
/**
* Converts this period in days to a period in minutes assuming a
* 24 hour day and 60 minute hour.
* <p>
* This method allows you to convert between different types of period.
* However to achieve this it makes the assumption that all days are 24 hours
* long and all hours are 60 minutes long.
* This is not true when daylight savings is considered and may also not
* be true for some unusual chronologies. However, it is included
* as it is a useful operation for many applications and business rules.
*
* @return a period representing the number of minutes for this number of days
* @throws ArithmeticException if the number of minutes is too large to be represented
*/
public Minutes toStandardMinutes() {
return Minutes.minutes(FieldUtils.safeMultiply(getValue(), DateTimeConstants.MINUTES_PER_DAY));
}
/**
* Converts this period in days to a period in seconds assuming a
* 24 hour day, 60 minute hour and 60 second minute.
* <p>
* This method allows you to convert between different types of period.
* However to achieve this it makes the assumption that all days are 24 hours
* long, all hours are 60 minutes long and all minutes are 60 seconds long.
* This is not true when daylight savings is considered and may also not
* be true for some unusual chronologies. However, it is included
* as it is a useful operation for many applications and business rules.
*
* @return a period representing the number of seconds for this number of days
* @throws ArithmeticException if the number of seconds is too large to be represented
*/
public Seconds toStandardSeconds() {
return Seconds.seconds(FieldUtils.safeMultiply(getValue(), DateTimeConstants.SECONDS_PER_DAY));
}
//
/**
* Converts this period in days to a duration in milliseconds assuming a
* 24 hour day, 60 minute hour and 60 second minute.
* <p>
* This method allows you to convert from a period to a duration.
* However to achieve this it makes the assumption that all days are 24 hours
* long, all hours are 60 minutes and all minutes are 60 seconds.
* This is not true when daylight savings time is considered, and may also
* not be true for some unusual chronologies. However, it is included as it
* is a useful operation for many applications and business rules.
*
* @return a duration equivalent to this number of days
*/
public Duration toStandardDuration() {
long days = getValue(); // assign to a long
return new Duration(days * DateTimeConstants.MILLIS_PER_DAY);
}
//
/**
* Gets the number of days that this period represents.
*
* @return the number of days in the period
*/
public int getDays() {
return getValue();
}
//
/**
* Returns a new instance with the specified number of days added.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param days the amount of days to add, may be negative
* @return the new period plus the specified number of days
* @throws ArithmeticException if the result overflows an int
*/
public Days plus(int days) {
if (days == 0) {
return this;
}
return Days.days(FieldUtils.safeAdd(getValue(), days));
}
/**
* Returns a new instance with the specified number of days added.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param days the amount of days to add, may be negative, null means zero
* @return the new period plus the specified number of days
* @throws ArithmeticException if the result overflows an int
*/
public Days plus(Days days) {
if (days == null) {
return this;
}
return plus(days.getValue());
}
//
/**
* Returns a new instance with the specified number of days taken away.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param days the amount of days to take away, may be negative
* @return the new period minus the specified number of days
* @throws ArithmeticException if the result overflows an int
*/
public Days minus(int days) {
return plus(FieldUtils.safeNegate(days));
}
/**
* Returns a new instance with the specified number of days taken away.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param days the amount of days to take away, may be negative, null means zero
* @return the new period minus the specified number of days
* @throws ArithmeticException if the result overflows an int
*/
public Days minus(Days days) {
if (days == null) {
return this;
}
return minus(days.getValue());
}
//
/**
* Returns a new instance with the days multiplied by the specified scalar.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param scalar the amount to multiply by, may be negative
* @return the new period multiplied by the specified scalar
* @throws ArithmeticException if the result overflows an int
*/
public Days multipliedBy(int scalar) {
return Days.days(FieldUtils.safeMultiply(getValue(), scalar));
}
/**
* Returns a new instance with the days divided by the specified divisor.
* The calculation uses integer division, thus 3 divided by 2 is 1.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param divisor the amount to divide by, may be negative
* @return the new period divided by the specified divisor
* @throws ArithmeticException if the divisor is zero
*/
public Days dividedBy(int divisor) {
if (divisor == 1) {
return this;
}
return Days.days(getValue() / divisor);
}
//
/**
* Returns a new instance with the days value negated.
*
* @return the new period with a negated value
* @throws ArithmeticException if the result overflows an int
*/
public Days negated() {
return Days.days(FieldUtils.safeNegate(getValue()));
}
//
/**
* Is this days instance greater than the specified number of days.
*
* @param other the other period, null means zero
* @return true if this days instance is greater than the specified one
*/
public boolean isGreaterThan(Days other) {
if (other == null) {
return getValue() > 0;
}
return getValue() > other.getValue();
}
/**
* Is this days instance less than the specified number of days.
*
* @param other the other period, null means zero
* @return true if this days instance is less than the specified one
*/
public boolean isLessThan(Days other) {
if (other == null) {
return getValue() < 0;
}
return getValue() < other.getValue();
}
//
/**
* Gets this instance as a String in the ISO8601 duration format.
* <p>
* For example, "P4D" represents 4 days.
*
* @return the value as an ISO8601 string
*/
@ToString
public String toString() {
return "P" + String.valueOf(getValue()) + "D";
}
}
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