|
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.TimeZone;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
/**
* <p>A suite of utilities surrounding the use of the
* {@link java.util.Calendar} and {@link java.util.Date} object.</p>
*
* <p>DateUtils contains a lot of common methods considering manipulations
* of Dates or Calendars. Some methods require some extra explanation.
* The truncate and round methods could be considered the Math.floor(),
* Math.ceil() or Math.round versions for dates
* This way date-fields will be ignored in bottom-up order.
* As a complement to these methods we've introduced some fragment-methods.
* With these methods the Date-fields will be ignored in top-down order.
* Since a date without a year is not a valid date, you have to decide in what
* kind of date-field you want your result, for instance milliseconds or days.
* </p>
*
*
*
* @author <a href="mailto:sergek@lokitech.com">Serge Knystautas</a>
* @author Stephen Colebourne
* @author Janek Bogucki
* @author <a href="mailto:ggregory@seagullsw.com">Gary Gregory</a>
* @author Phil Steitz
* @author Robert Scholte
* @since 2.0
* @version $Id: DateUtils.java 634096 2008-03-06 00:58:11Z niallp $
*/
public class Main {
/**
* The UTC time zone (often referred to as GMT).
*/
public static final TimeZone UTC_TIME_ZONE = TimeZone.getTimeZone("GMT");
/**
* Number of milliseconds in a standard second.
* @since 2.1
*/
public static final long MILLIS_PER_SECOND = 1000;
/**
* Number of milliseconds in a standard minute.
* @since 2.1
*/
public static final long MILLIS_PER_MINUTE = 60 * MILLIS_PER_SECOND;
/**
* Number of milliseconds in a standard hour.
* @since 2.1
*/
public static final long MILLIS_PER_HOUR = 60 * MILLIS_PER_MINUTE;
/**
* Number of milliseconds in a standard day.
* @since 2.1
*/
public static final long MILLIS_PER_DAY = 24 * MILLIS_PER_HOUR;
/**
* This is half a month, so this represents whether a date is in the top
* or bottom half of the month.
*/
public final static int SEMI_MONTH = 1001;
private static final int[][] fields = {
{Calendar.MILLISECOND},
{Calendar.SECOND},
{Calendar.MINUTE},
{Calendar.HOUR_OF_DAY, Calendar.HOUR},
{Calendar.DATE, Calendar.DAY_OF_MONTH, Calendar.AM_PM
/* Calendar.DAY_OF_YEAR, Calendar.DAY_OF_WEEK, Calendar.DAY_OF_WEEK_IN_MONTH */
},
{Calendar.MONTH, DateUtils.SEMI_MONTH},
{Calendar.YEAR},
{Calendar.ERA}};
/**
* A week range, starting on Sunday.
*/
public final static int RANGE_WEEK_SUNDAY = 1;
/**
* A week range, starting on Monday.
*/
public final static int RANGE_WEEK_MONDAY = 2;
/**
* A week range, starting on the day focused.
*/
public final static int RANGE_WEEK_RELATIVE = 3;
/**
* A week range, centered around the day focused.
*/
public final static int RANGE_WEEK_CENTER = 4;
/**
* A month range, the week starting on Sunday.
*/
public final static int RANGE_MONTH_SUNDAY = 5;
/**
* A month range, the week starting on Monday.
*/
public final static int RANGE_MONTH_MONDAY = 6;
/**
* <p>Returns the number of days within the
* fragment. All datefields greater than the fragment will be ignored.</p>
*
* <p>Asking the days of any date will only return the number of days
* of the current month (resulting in a number between 1 and 31). This
* method will retrieve the number of days for any fragment.
* For example, if you want to calculate the number of days past this year,
* your fragment is Calendar.YEAR. The result will be all days of the
* past month(s).</p>
*
* <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
* Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
* Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
* A fragment less than or equal to a DAY field will return 0.</p>
*
* <p>
* <ul>
* <li>January 28, 2008 with Calendar.MONTH as fragment will return 28
* (equivalent to calendar.get(Calendar.DAY_OF_MONTH))</li>
* <li>February 28, 2008 with Calendar.MONTH as fragment will return 28
* (equivalent to calendar.get(Calendar.DAY_OF_MONTH))</li>
* <li>January 28, 2008 with Calendar.YEAR as fragment will return 28
* (equivalent to calendar.get(Calendar.DAY_OF_YEAR))</li>
* <li>February 28, 2008 with Calendar.YEAR as fragment will return 59
* (equivalent to calendar.get(Calendar.DAY_OF_YEAR))</li>
* <li>January 28, 2008 with Calendar.MILLISECOND as fragment will return 0
* (a millisecond cannot be split in days)</li>
* </ul>
* </p>
*
* @param calendar the calendar to work with, not null
* @param fragment the Calendar field part of calendar to calculate
* @return number of days within the fragment of date
* @throws IllegalArgumentException if the date is <code>null</code> or
* fragment is not supported
* @since 2.4
*/
public static long getFragmentInDays(Calendar calendar, int fragment) {
return getFragment(calendar, fragment, Calendar.DAY_OF_YEAR);
}
/**
* Date-version for fragment-calculation in any unit
*
* @param date the date to work with, not null
* @param fragment the Calendar field part of date to calculate
* @param unit Calendar field defining the unit
* @return number of units within the fragment of the date
* @throws IllegalArgumentException if the date is <code>null</code> or
* fragment is not supported
* @since 2.4
*/
private static long getFragment(Date date, int fragment, int unit) {
if(date == null) {
throw new IllegalArgumentException("The date must not be null");
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return getFragment(calendar, fragment, unit);
}
/**
* Calendar-version for fragment-calculation in any unit
*
* @param calendar the calendar to work with, not null
* @param fragment the Calendar field part of calendar to calculate
* @param unit Calendar field defining the unit
* @return number of units within the fragment of the calendar
* @throws IllegalArgumentException if the date is <code>null</code> or
* fragment is not supported
* @since 2.4
*/
private static long getFragment(Calendar calendar, int fragment, int unit) {
if(calendar == null) {
throw new IllegalArgumentException("The date must not be null");
}
long millisPerUnit = getMillisPerUnit(unit);
long result = 0;
// Fragments bigger than a day require a breakdown to days
switch (fragment) {
case Calendar.YEAR:
result += (calendar.get(Calendar.DAY_OF_YEAR) * MILLIS_PER_DAY) / millisPerUnit;
break;
case Calendar.MONTH:
result += (calendar.get(Calendar.DAY_OF_MONTH) * MILLIS_PER_DAY) / millisPerUnit;
break;
}
switch (fragment) {
// Number of days already calculated for these cases
case Calendar.YEAR:
case Calendar.MONTH:
// The rest of the valid cases
case Calendar.DAY_OF_YEAR:
case Calendar.DATE:
result += (calendar.get(Calendar.HOUR_OF_DAY) * MILLIS_PER_HOUR) / millisPerUnit;
case Calendar.HOUR_OF_DAY:
result += (calendar.get(Calendar.MINUTE) * MILLIS_PER_MINUTE) / millisPerUnit;
case Calendar.MINUTE:
result += (calendar.get(Calendar.SECOND) * MILLIS_PER_SECOND) / millisPerUnit;
case Calendar.SECOND:
result += (calendar.get(Calendar.MILLISECOND) * 1) / millisPerUnit;
break;
case Calendar.MILLISECOND: break;//never useful
default: throw new IllegalArgumentException("The fragment " + fragment + " is not supported");
}
return result;
}
/**
* Returns the number of millis of a datefield, if this is a constant value
*
* @param unit A Calendar field which is a valid unit for a fragment
* @return number of millis
* @throws IllegalArgumentException if date can't be represented in millisenconds
* @since 2.4
*/
private static long getMillisPerUnit(int unit) {
long result = Long.MAX_VALUE;
switch (unit) {
case Calendar.DAY_OF_YEAR:
case Calendar.DATE:
result = MILLIS_PER_DAY;
break;
case Calendar.HOUR_OF_DAY:
result = MILLIS_PER_HOUR;
break;
case Calendar.MINUTE:
result = MILLIS_PER_MINUTE;
break;
case Calendar.SECOND:
result = MILLIS_PER_SECOND;
break;
case Calendar.MILLISECOND:
result = 1;
break;
default: throw new IllegalArgumentException("The unit " + unit + " cannot be represented is milleseconds");
}
return result;
}
}
|