/*
*-------------------
* The DateUtils.java is part of ASH Viewer
*-------------------
*
* ASH Viewer is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* ASH Viewer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with ASH Viewer. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (c) 2009, Alex Kardapolov, All rights reserved.
*
*/
package org.ash.history.period;
import java.util.Calendar;
import java.util.Date;
/**
* @author Scott Violet
* @version $Revision: 1.4 $
*/
public class DateUtils {
private static Calendar CALENDAR = Calendar.getInstance();
/**
* Returns the last millisecond of the specified date.
*
* @param date Date to calculate end of day from
* @return Last millisecond of <code>date</code>
*/
public static Date endOfDay(Date date) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 23);
calendar.set(Calendar.MILLISECOND, 999);
calendar.set(Calendar.SECOND, 59);
calendar.set(Calendar.MINUTE, 59);
return calendar.getTime();
}
}
/**
* Returns a new Date with the hours, milliseconds, seconds and minutes
* set to 0.
*
* @param date Date used in calculating start of day
* @return Start of <code>date</code>
*/
public static Date startOfDay(Date date) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MILLISECOND, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MINUTE, 0);
return calendar.getTime();
}
}
/**
* Returns day in millis with the hours, milliseconds, seconds and minutes
* set to 0.
*
* @param date long used in calculating start of day
* @return Start of <code>date</code>
*/
public static long startOfDayInMillis(long date) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MILLISECOND, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MINUTE, 0);
return calendar.getTimeInMillis();
}
}
/**
* Returns the last millisecond of the specified date.
*
* @param date long to calculate end of day from
* @return Last millisecond of <code>date</code>
*/
public static long endOfDayInMillis(long date) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
calendar.set(Calendar.HOUR_OF_DAY, 23);
calendar.set(Calendar.MILLISECOND, 999);
calendar.set(Calendar.SECOND, 59);
calendar.set(Calendar.MINUTE, 59);
return calendar.getTimeInMillis();
}
}
/**
* Returns the day after <code>date</code>.
*
* @param date Date used in calculating next day
* @return Day after <code>date</code>.
*/
public static Date nextDay(Date date) {
return new Date(addDays(date.getTime(), 1));
}
/**
* Adds <code>amount</code> days to <code>time</code> and returns
* the resulting time.
*
* @param time Base time
* @param amount Amount of increment.
*
* @return the <var>time</var> + <var>amount</var> days
*/
public static long addDays(long time, int amount) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(time);
calendar.add(Calendar.DAY_OF_MONTH, amount);
return calendar.getTimeInMillis();
}
}
/**
* Returns the day after <code>date</code>.
*
* @param date Date used in calculating next day
* @return Day after <code>date</code>.
*/
public static long nextDay(long date) {
return addDays(date, 1);
}
/**
* Returns the week after <code>date</code>.
*
* @param date Date used in calculating next week
* @return week after <code>date</code>.
*/
public static long nextWeek(long date) {
return addDays(date, 7);
}
/**
* Returns the number of days difference between <code>t1</code> and
* <code>t2</code>.
*
* @param t1 Time 1
* @param t2 Time 2
* @param checkOverflow indicates whether to check for overflow
* @return Number of days between <code>start</code> and <code>end</code>
*/
public static int getDaysDiff(long t1, long t2, boolean checkOverflow) {
if (t1 > t2) {
long tmp = t1;
t1 = t2;
t2 = tmp;
}
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(t1);
int delta = 0;
while (calendar.getTimeInMillis() < t2) {
calendar.add(Calendar.DAY_OF_MONTH, 1);
delta++;
}
if (checkOverflow && (calendar.getTimeInMillis() > t2)) {
delta--;
}
return delta;
}
}
/**
* Returns the number of days difference between <code>t1</code> and
* <code>t2</code>.
*
* @param t1 Time 1
* @param t2 Time 2
* @return Number of days between <code>start</code> and <code>end</code>
*/
public static int getDaysDiff(long t1, long t2) {
return getDaysDiff(t1, t2, true);
}
/**
* Check, whether the date passed in is the first day of the year.
*
* @param date date to check in millis
* @return <code>true</code> if <var>date</var> corresponds to the first
* day of a year
* @see Date#getTime()
*/
public static boolean isFirstOfYear(long date) {
boolean ret = false;
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
int currentYear = calendar.get(Calendar.YEAR);
// Check yesterday
calendar.add(Calendar.DATE,-1);
int yesterdayYear = calendar.get(Calendar.YEAR);
ret = (currentYear != yesterdayYear);
}
return ret;
}
/**
* Check, whether the date passed in is the first day of the month.
*
* @param date date to check in millis
* @return <code>true</code> if <var>date</var> corresponds to the first
* day of a month
* @see Date#getTime()
*/
public static boolean isFirstOfMonth(long date) {
boolean ret = false;
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
int currentMonth = calendar.get(Calendar.MONTH);
// Check yesterday
calendar.add(Calendar.DATE,-1);
int yesterdayMonth = calendar.get(Calendar.MONTH);
ret = (currentMonth != yesterdayMonth);
}
return ret;
}
/**
* Returns the day before <code>date</code>.
*
* @param date Date used in calculating previous day
* @return Day before <code>date</code>.
*/
public static long previousDay(long date) {
return addDays(date, -1);
}
/**
* Returns the week before <code>date</code>.
*
* @param date Date used in calculating previous week
* @return week before <code>date</code>.
*/
public static long previousWeek(long date) {
return addDays(date, -7);
}
/**
* Returns the first day before <code>date</code> that has the
* day of week matching <code>startOfWeek</code>. For example, if you
* want to find the previous monday relative to <code>date</code> you
* would call <code>getPreviousDay(date, Calendar.MONDAY)</code>.
*
* @param date Base date
* @param startOfWeek Calendar constant correspoding to start of week.
* @return start of week, return value will have 0 hours, 0 minutes,
* 0 seconds and 0 ms.
*
*/
public static long getPreviousDay(long date, int startOfWeek) {
return getDay(date, startOfWeek, -1);
}
/**
* Returns the first day after <code>date</code> that has the
* day of week matching <code>startOfWeek</code>. For example, if you
* want to find the next monday relative to <code>date</code> you
* would call <code>getPreviousDay(date, Calendar.MONDAY)</code>.
*
* @param date Base date
* @param startOfWeek Calendar constant correspoding to start of week.
* @return start of week, return value will have 0 hours, 0 minutes,
* 0 seconds and 0 ms.
*
*/
public static long getNextDay(long date, int startOfWeek) {
return getDay(date, startOfWeek, 1);
}
private static long getDay(long date, int startOfWeek, int increment) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
int day = calendar.get(Calendar.DAY_OF_WEEK);
// Normalize the view starting date to a week starting day
while (day != startOfWeek) {
calendar.add(Calendar.DATE, increment);
day = calendar.get(Calendar.DAY_OF_WEEK);
}
return startOfDayInMillis(calendar.getTimeInMillis());
}
}
/**
* Returns the previous month.
*
* @param date Base date
* @return previous month
*/
public static long getPreviousMonth(long date) {
return incrementMonth(date, -1);
}
/**
* Returns the next month.
*
* @param date Base date
* @return next month
*/
public static long getNextMonth(long date) {
return incrementMonth(date, 1);
}
private static long incrementMonth(long date, int increment) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
calendar.add(Calendar.MONTH, increment);
return calendar.getTimeInMillis();
}
}
/**
* Returns the date corresponding to the start of the month.
*
* @param date Base date
* @return Start of month.
*/
public static long getStartOfMonth(long date) {
return getMonth(date, -1);
}
/**
* Returns the date corresponding to the end of the month.
*
* @param date Base date
* @return End of month.
*/
public static long getEndOfMonth(long date) {
return getMonth(date, 1);
}
private static long getMonth(long date, int increment) {
long result;
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
if (increment == -1) {
calendar.set(Calendar.DAY_OF_MONTH, 1);
result = startOfDayInMillis(calendar.getTimeInMillis());
} else {
calendar.add(Calendar.MONTH, 1);
calendar.set(Calendar.DAY_OF_MONTH, 1);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MILLISECOND, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.add(Calendar.MILLISECOND, -1);
result = calendar.getTimeInMillis();
}
}
return result;
}
/**
* Returns the day of the week.
*
* @param date date
* @return day of week.
*/
public static int getDayOfWeek(long date) {
Calendar calendar = CALENDAR;
synchronized(calendar) {
calendar.setTimeInMillis(date);
return (calendar.get(Calendar.DAY_OF_WEEK));
}
}
}