Java tutorial
/* * 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 seconds. * <p> * <code>Seconds</code> is an immutable period that can only store seconds. * It does not store years, months or hours for example. As such it is a * type-safe way of representing a number of seconds in an application. * <p> * The number of seconds is set in the constructor, and may be queried using * <code>getSeconds()</code>. Basic mathematical operations are provided - * <code>plus()</code>, <code>minus()</code>, <code>multipliedBy()</code> and * <code>dividedBy()</code>. * <p> * <code>Seconds</code> is thread-safe and immutable. * * @author Stephen Colebourne * @since 1.4 */ public final class Seconds extends BaseSingleFieldPeriod { /** Constant representing zero seconds. */ public static final Seconds ZERO = new Seconds(0); /** Constant representing one second. */ public static final Seconds ONE = new Seconds(1); /** Constant representing two seconds. */ public static final Seconds TWO = new Seconds(2); /** Constant representing three seconds. */ public static final Seconds THREE = new Seconds(3); /** Constant representing the maximum number of seconds that can be stored in this object. */ public static final Seconds MAX_VALUE = new Seconds(Integer.MAX_VALUE); /** Constant representing the minimum number of seconds that can be stored in this object. */ public static final Seconds MIN_VALUE = new Seconds(Integer.MIN_VALUE); /** The parser to use for this class. */ private static final PeriodFormatter PARSER = ISOPeriodFormat.standard().withParseType(PeriodType.seconds()); /** Serialization version. */ private static final long serialVersionUID = 87525275727380862L; //----------------------------------------------------------------------- /** * Obtains an instance of <code>Seconds</code> that may be cached. * <code>Seconds</code> is immutable, so instances can be cached and shared. * This factory method provides access to shared instances. * * @param seconds the number of seconds to obtain an instance for * @return the instance of Seconds */ public static Seconds seconds(int seconds) { switch (seconds) { case 0: return ZERO; case 1: return ONE; case 2: return TWO; case 3: return THREE; case Integer.MAX_VALUE: return MAX_VALUE; case Integer.MIN_VALUE: return MIN_VALUE; default: return new Seconds(seconds); } } //----------------------------------------------------------------------- /** * Creates a <code>Seconds</code> representing the number of whole seconds * between the two specified datetimes. * * @param start the start instant, must not be null * @param end the end instant, must not be null * @return the period in seconds * @throws IllegalArgumentException if the instants are null or invalid */ public static Seconds secondsBetween(ReadableInstant start, ReadableInstant end) { int amount = BaseSingleFieldPeriod.between(start, end, DurationFieldType.seconds()); return Seconds.seconds(amount); } /** * Creates a <code>Seconds</code> representing the number of whole seconds * between the two specified partial datetimes. * <p> * The two partials must contain the same fields, for example you can specify * two <code>LocalTime</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 seconds * @throws IllegalArgumentException if the partials are null or invalid */ public static Seconds secondsBetween(ReadablePartial start, ReadablePartial end) { if (start instanceof LocalTime && end instanceof LocalTime) { Chronology chrono = DateTimeUtils.getChronology(start.getChronology()); int seconds = chrono.seconds().getDifference(((LocalTime) end).getLocalMillis(), ((LocalTime) start).getLocalMillis()); return Seconds.seconds(seconds); } int amount = BaseSingleFieldPeriod.between(start, end, ZERO); return Seconds.seconds(amount); } /** * Creates a <code>Seconds</code> representing the number of whole seconds * in the specified interval. * * @param interval the interval to extract seconds from, null returns zero * @return the period in seconds * @throws IllegalArgumentException if the partials are null or invalid */ public static Seconds secondsIn(ReadableInterval interval) { if (interval == null) { return Seconds.ZERO; } int amount = BaseSingleFieldPeriod.between(interval.getStart(), interval.getEnd(), DurationFieldType.seconds()); return Seconds.seconds(amount); } /** * Creates a new <code>Seconds</code> representing the number of complete * standard length seconds 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 seconds * @throws IllegalArgumentException if the period contains imprecise duration values */ public static Seconds standardSecondsIn(ReadablePeriod period) { int amount = BaseSingleFieldPeriod.standardPeriodIn(period, DateTimeConstants.MILLIS_PER_SECOND); return Seconds.seconds(amount); } /** * Creates a new <code>Seconds</code> by parsing a string in the ISO8601 format 'PTnS'. * <p> * The parse will accept the full ISO syntax of PnYnMnWnDTnHnMnS however only the * seconds 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 seconds * @throws IllegalArgumentException if the string format is invalid */ @FromString public static Seconds parseSeconds(String periodStr) { if (periodStr == null) { return Seconds.ZERO; } Period p = PARSER.parsePeriod(periodStr); return Seconds.seconds(p.getSeconds()); } //----------------------------------------------------------------------- /** * Creates a new instance representing a number of seconds. * You should consider using the factory method {@link #seconds(int)} * instead of the constructor. * * @param seconds the number of seconds to represent */ private Seconds(int seconds) { super(seconds); } /** * Resolves singletons. * * @return the singleton instance */ private Object readResolve() { return Seconds.seconds(getValue()); } //----------------------------------------------------------------------- /** * Gets the duration field type, which is <code>seconds</code>. * * @return the period type */ public DurationFieldType getFieldType() { return DurationFieldType.seconds(); } /** * Gets the period type, which is <code>seconds</code>. * * @return the period type */ public PeriodType getPeriodType() { return PeriodType.seconds(); } //----------------------------------------------------------------------- /** * Converts this period in seconds to a period in weeks assuming a * 7 day week, 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 weeks are 7 days * long, 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 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 period representing the number of whole weeks for this number of seconds */ public Weeks toStandardWeeks() { return Weeks.weeks(getValue() / DateTimeConstants.SECONDS_PER_WEEK); } /** * Converts this period in seconds to a period in days 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 days for this number of seconds */ public Days toStandardDays() { return Days.days(getValue() / DateTimeConstants.SECONDS_PER_DAY); } /** * Converts this period in seconds to a period in hours assuming a * 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 hours are * 60 minutes long and all minutes are 60 seconds 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 hours for this number of seconds */ public Hours toStandardHours() { return Hours.hours(getValue() / DateTimeConstants.SECONDS_PER_HOUR); } /** * Converts this period in seconds to a period in minutes assuming a * 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 minutes are * 60 seconds 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 minutes for this number of seconds */ public Minutes toStandardMinutes() { return Minutes.minutes(getValue() / DateTimeConstants.SECONDS_PER_MINUTE); } //----------------------------------------------------------------------- /** * Converts this period in seconds 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 seconds 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 seconds */ public Duration toStandardDuration() { long seconds = getValue(); // assign to a long return new Duration(seconds * DateTimeConstants.MILLIS_PER_SECOND); } //----------------------------------------------------------------------- /** * Gets the number of seconds that this period represents. * * @return the number of seconds in the period */ public int getSeconds() { return getValue(); } //----------------------------------------------------------------------- /** * Returns a new instance with the specified number of seconds added. * <p> * This instance is immutable and unaffected by this method call. * * @param seconds the amount of seconds to add, may be negative * @return the new period plus the specified number of seconds * @throws ArithmeticException if the result overflows an int */ public Seconds plus(int seconds) { if (seconds == 0) { return this; } return Seconds.seconds(FieldUtils.safeAdd(getValue(), seconds)); } /** * Returns a new instance with the specified number of seconds added. * <p> * This instance is immutable and unaffected by this method call. * * @param seconds the amount of seconds to add, may be negative, null means zero * @return the new period plus the specified number of seconds * @throws ArithmeticException if the result overflows an int */ public Seconds plus(Seconds seconds) { if (seconds == null) { return this; } return plus(seconds.getValue()); } //----------------------------------------------------------------------- /** * Returns a new instance with the specified number of seconds taken away. * <p> * This instance is immutable and unaffected by this method call. * * @param seconds the amount of seconds to take away, may be negative * @return the new period minus the specified number of seconds * @throws ArithmeticException if the result overflows an int */ public Seconds minus(int seconds) { return plus(FieldUtils.safeNegate(seconds)); } /** * Returns a new instance with the specified number of seconds taken away. * <p> * This instance is immutable and unaffected by this method call. * * @param seconds the amount of seconds to take away, may be negative, null means zero * @return the new period minus the specified number of seconds * @throws ArithmeticException if the result overflows an int */ public Seconds minus(Seconds seconds) { if (seconds == null) { return this; } return minus(seconds.getValue()); } //----------------------------------------------------------------------- /** * Returns a new instance with the seconds 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 Seconds multipliedBy(int scalar) { return Seconds.seconds(FieldUtils.safeMultiply(getValue(), scalar)); } /** * Returns a new instance with the seconds 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 Seconds dividedBy(int divisor) { if (divisor == 1) { return this; } return Seconds.seconds(getValue() / divisor); } //----------------------------------------------------------------------- /** * Returns a new instance with the seconds value negated. * * @return the new period with a negated value * @throws ArithmeticException if the result overflows an int */ public Seconds negated() { return Seconds.seconds(FieldUtils.safeNegate(getValue())); } //----------------------------------------------------------------------- /** * Is this seconds instance greater than the specified number of seconds. * * @param other the other period, null means zero * @return true if this seconds instance is greater than the specified one */ public boolean isGreaterThan(Seconds other) { if (other == null) { return getValue() > 0; } return getValue() > other.getValue(); } /** * Is this seconds instance less than the specified number of seconds. * * @param other the other period, null means zero * @return true if this seconds instance is less than the specified one */ public boolean isLessThan(Seconds 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, "PT4S" represents 4 seconds. * * @return the value as an ISO8601 string */ @ToString public String toString() { return "PT" + String.valueOf(getValue()) + "S"; } }