/*license*\
XBN-Java: Copyright (C) 2014, Jeff Epstein (aliteralmind __DASH__ github __AT__ yahoo __DOT__ com)
This software is dual-licensed under the:
- Lesser General Public License (LGPL) version 3.0 or, at your option, any later version;
- Apache Software License (ASL) version 2.0.
Either license may be applied at your discretion. More information may be found at
- http://en.wikipedia.org/wiki/Multi-licensing.
The text of both licenses is available in the root directory of this project, under the names "LICENSE_lgpl-3.0.txt" and "LICENSE_asl-2.0.txt". The latest copies may be downloaded at:
- LGPL 3.0: https://www.gnu.org/licenses/lgpl-3.0.txt
- ASL 2.0: http://www.apache.org/licenses/LICENSE-2.0.txt
\*license*/
package com.github.xbn.util;
import java.util.Date;
/**
<p>Date arithmetic.</p>
* @since 0.1.0
* @author Copyright (C) 2014, Jeff Epstein ({@code aliteralmind __DASH__ github __AT__ yahoo __DOT__ com}), dual-licensed under the LGPL (version 3.0 or later) or the ASL (version 2.0). See source code for details. <a href="http://xbnjava.aliteralmind.com">{@code http://xbnjava.aliteralmind.com}</a>, <a href="https://github.com/aliteralmind/xbnjava">{@code https://github.com/aliteralmind/xbnjava}</a>
**/
public class DateUtil {
private DateUtil() {
throw new IllegalStateException("Do not instantiate");
}
/**
<p>Number of milliseconds in a second.</p>
<!-- MAIN VARIABLE -->
* <p>Equal to
<br/> {@code 1000}</p>
* @see #MILLS_IN_MINUTE
* @see #MILLS_IN_HOUR MILLS_IN_HOUR
* @see #MILLS_IN_DAY
* @see #MILLS_IN_WEEK
*/
public static final int MILLS_IN_SECOND = 1000;
/**
<p>Number of milliseconds in a minute.</p>
* <p>Equal to
<br/> <code>({@link #MILLS_IN_SECOND MILLS_IN_SECOND} * 60)</code></p>
*/
public static final int MILLS_IN_MINUTE = MILLS_IN_SECOND * 60;
/**
<p>Number of milliseconds in a hour.</p>
* <p>Equal to
<br/> <code>({@link #MILLS_IN_MINUTE MILLS_IN_MINUTE} * 60)</code></p>
*/
public static final int MILLS_IN_HOUR = MILLS_IN_MINUTE * 60;
/**
<p>Number of milliseconds in a day.</p>
* <p>Equal to
<br/> <code>({@link #MILLS_IN_HOUR MILLS_IN_HOUR} * 24)</code></p>
*/
public static final int MILLS_IN_DAY = MILLS_IN_HOUR * 24;
/**
<p>Number of milliseconds in a week.</p>
* <p>Equal to
<br/> <code>({@link #MILLS_IN_DAY MILLS_IN_DAY} * 7)</code></p>
*/
public static final int MILLS_IN_WEEK = MILLS_IN_DAY * 7;
/**
<p>Get a Date that is X units before the provided date.</p>
* @param multiplier The number used to translate a Date's milleseconds to some other unit. May not be zero.
* @param units_ago The number of "units ago" you want the returned date to be, in relation to from.
* @param from The date that you want to count back from. May not be {@code null}.
* @return {@code new Date(from.getTime() - (units_ago / multiplier))}
* @see
<li>{@link #getDateXBeforeNow(long, int) getDateXBeforeNow(l,i)}, {@link #getDateXBNSeconds(int) getDateXBNSeconds(i)}, {@link #getDateXBNMinutes(int) getDateXBNMinutes(i)}, {@link #getDateXBNHours(int) getDateXBNHours(i)}, {@link #getDateXBNDays(int) getDateXBNDays(i)}, {@link #getDateXBNWeeks(int) getDateXBNWeeks(i)}</li>
<li>{@link #getDateXSecondsAgo(int, Date) getDateXSecondsAgo(i,dt)}, {@link #getDateXMinutesAgo(int, Date) getDateXMinutesAgo(i,dt)}, {@link #getDateXHoursAgo(int, Date) getDateXHoursAgo(i,dt)}, {@link #getDateXDaysAgo(int, Date) getDateXDaysAgo(i,dt)}, {@link #getDateXAgoWeeks(int, Date) getDateXAgoWeeks(i,dt)}</li>
</ul>
*/
public final Date getDateXAgo(long multiplier, int units_ago, Date from) {
if(multiplier == 0) {
throw new IllegalArgumentException("multiplier is zero.");
}
long lTime = -1;
try {
lTime = from.getTime();
} catch(NullPointerException npx) {
throw new NullPointerException("from");
}
return new Date(lTime - (units_ago / multiplier));
}
/**
<p>How many units separate the provided dates?.</p>
* @return {@code (new Long(d_x, y_date, multiplier)).intValue()}
* @see
<li>{@link #getXMinusYSeconds(Date, Date) getXMinusYSeconds(dt,dt)}, {@link #getXMinusYMinutes(Date, Date) getXMinusYMinutes(dt,dt)}, {@link #getXMinusYHours(Date, Date) getXMinusYHours(dt,dt)}, {@link #getXMinusYDays(Date, Date) getXMinusYDays(dt,dt)}, {@link #getXMinusYWeeks(Date, Date) getXMinusYWeeks(dt,dt)}</li>
<li>{@link #getNowMinusYUnits(Date, long) getNowMinusYUnits(dt,l)}, {@link #getNowMinusYSeconds(Date) getNowMinusYSeconds(dt)}, {@link #getNowMinusYMinutes(Date) getNowMinusYMinutes(dt)}, {@link #getNowMinusYHours(Date) getNowMinusYHours(dt)}, {@link #getNowMinusYDays(Date) getNowMinusYDays(dt)}, {@link #getNowMinusYWeeks(Date) getNowMinusYWeeks(dt)}</li>
</ul>
*/
public final int getXMinusYUnits(Date d_x, Date y_date, long multiplier) {
return (new Long(((d_x.getTime() - y_date.getTime()) / multiplier))).intValue();
}
/**
<p>How many units, represented by a long, separate the provided dates?.</p>
* @param d_x The date on the left side of the minus equation. May not be {@code null}.
* @param y_date The date on the right side of the minus equation. May not be {@code null}.
* @param multiplier The number used to translate a Date's milleseconds to some other unit. May not be zero.
* @return {@code (d_x.getTime() - y_date.getTime()) / multiplier)}
*/
public final long getXMinusYUnitsLong(Date d_x, Date y_date, long multiplier) {
if(multiplier == 0) {
throw new IllegalArgumentException("multiplier is zero.");
}
long lXTime = -1;
try {
lXTime = d_x.getTime();
} catch(NullPointerException npx) {
throw new NullPointerException("d_x");
}
long lYTime = -1;
try {
lYTime = y_date.getTime();
} catch(NullPointerException npx) {
throw new NullPointerException("y_date");
}
return ((lXTime - lYTime) / multiplier);
}
}