/*
* Copyright 2001-2010 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/LICENSE-2.0
*
* 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</code> is an immutable period that can only store days.
* It does not store years, months or hours for example. As such it is a
* type-safe 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()</code>. Basic mathematical operations are provided -
* <code>plus()</code>, <code>minus()</code>, <code>multipliedBy()</code> and
* <code>dividedBy()</code>.
* <p>
* <code>Days</code> is thread-safe 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 parser 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</code> that may be cached.
* <code>Days</code> 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</code> representing the number of whole days
* between the two specified datetimes. This method correctly 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</code> 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</code> 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</code> representing the number of whole days
* in the specified interval. This method correctly 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</code> 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</code> 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 non-zero. If any other component is non-zero, 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</code>.
*
* @return the period type
*/
public
DurationFieldType getFieldType() {
return
DurationFieldType.
days();
}
/**
* Gets the period type, which is <code>days</code>.
*
* @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";
}
}