/*
* Copyright 2001-2009 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;
/**
* Defines an exact duration of time in milliseconds.
* <p>
* The implementation of this interface may be mutable or immutable. This
* interface only gives access to retrieve data, never to change it.
* <p>
* Methods that are passed a duration as a parameter will treat <code>null</code>
* as a zero length duration.
* <p>
* The {@code compareTo} method is no longer defined in this class in version 2.0.
* Instead, the definition is simply inherited from the {@code Comparable} interface.
* This approach is necessary to preserve binary compatibility.
* The definition of the comparison is ascending order by millisecond duration.
* Implementors are recommended to extend {@code AbstractInstant} instead of this interface.
*
* @see ReadableInterval
* @see ReadablePeriod
* @author Brian S O'Neill
* @author Stephen Colebourne
* @since 1.0
*/
public interface ReadableDuration extends Comparable<ReadableDuration> {
/**
* Gets the total length of this duration in milliseconds.
*
* @return the total length of the time duration in milliseconds.
*/
long getMillis();
//-----------------------------------------------------------------------
/**
* Get this duration as an immutable <code>Duration</code> object.
* <p>
* This will either typecast this instance, or create a new <code>Duration</code>.
*
* @return a Duration created using the millisecond duration from this instance
*/
Duration toDuration();
//-----------------------------------------------------------------------
/**
* Converts this duration to a Period instance using the standard period type
* and the ISO chronology.
* <p>
* Only precise fields in the period type will be used. Thus, only the hour,
* minute, second and millisecond fields on the period will be used.
* The year, month, week and day fields will not be populated.
* <p>
* If the duration is small, less than one day, then this method will perform
* as you might expect and split the fields evenly.
* If the duration is larger than one day then all the remaining duration will
* be stored in the largest available field, hours in this case.
* <p>
* For example, a duration effectively equal to (365 + 60 + 5) days will be
* converted to ((365 + 60 + 5) * 24) hours by this constructor.
* <p>
* For more control over the conversion process, you must pair the duration with
* an instant, see {@link Period#Period(ReadableInstant,ReadableDuration)}.
*
* @return a Period created using the millisecond duration from this instance
*/
Period toPeriod();
//-----------------------------------------------------------------------
// Method is no longer defined here as that would break generic backwards compatibility
// /**
// * Compares this duration with the specified duration based on length.
// *
// * @param obj a duration to check against
// * @return negative value if this is less, 0 if equal, or positive value if greater
// * @throws NullPointerException if the object is null
// * @throws ClassCastException if the given object is not supported
// */
// int compareTo(ReadableDuration obj);
/**
* Is the length of this duration equal to the duration passed in.
*
* @param duration another duration to compare to, null means zero milliseconds
* @return true if this duration is equal to the duration passed in
*/
boolean isEqual(ReadableDuration duration);
/**
* Is the length of this duration longer than the duration passed in.
*
* @param duration another duration to compare to, null means zero milliseconds
* @return true if this duration is greater than the duration passed in
*/
boolean isLongerThan(ReadableDuration duration);
/**
* Is the length of this duration shorter than the duration passed in.
*
* @param duration another duration to compare to, null means zero milliseconds
* @return true if this duration is less than the duration passed in
*/
boolean isShorterThan(ReadableDuration duration);
//-----------------------------------------------------------------------
/**
* Compares this object with the specified object for equality based
* on the millisecond length. All ReadableDuration instances are accepted.
*
* @param readableDuration a readable duration to check against
* @return true if the length of the duration is equal
*/
boolean equals(Object readableDuration);
/**
* Gets a hash code for the duration that is compatible with the
* equals method.
* The following formula must be used:
* <pre>
* long len = getMillis();
* return (int) (len ^ (len >>> 32));
* </pre>
*
* @return a hash code
*/
int hashCode();
//-----------------------------------------------------------------------
/**
* Gets the value as a String in the ISO8601 duration format using hours,
* minutes and seconds (including fractional milliseconds).
* <p>
* For example, "PT6H3M7S" represents 6 hours, 3 minutes, 7 seconds.
*
* @return the value as an ISO8601 string
*/
String toString();
}