Description
Date-version for fragment-calculation in any unit
License
Apache License
Parameter
| Parameter | Description |
|---|
| date | the date to work with, not null |
| fragment | the Calendar field part of date to calculate |
| unit | the Calendar field defining the unit |
Exception
| Parameter | Description |
|---|
| IllegalArgumentException | if the date is <code>null</code> or fragment is not supported |
Return
number of units within the fragment of the date
Declaration
private static long getFragment(Date date, int fragment, int unit)
Method Source Code
//package com.java2s;
/*//from w ww . j a va 2 s . c om
* 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.
*/
import java.util.Calendar;
import java.util.Date;
public class Main {
/**
* 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;
/**
* 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 the {@code 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 the {@code 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;
//$FALL-THROUGH$
case Calendar.HOUR_OF_DAY:
result += (calendar.get(Calendar.MINUTE) * MILLIS_PER_MINUTE)
/ millisPerUnit;
//$FALL-THROUGH$
case Calendar.MINUTE:
result += (calendar.get(Calendar.SECOND) * MILLIS_PER_SECOND)
/ millisPerUnit;
//$FALL-THROUGH$
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 milliseconds of a {@code Calendar} field, if this is a constant value.
* This handles millisecond, second, minute, hour and day (even though days can very in length).
*
* @param unit a {@code Calendar} field constant which is a valid unit for a fragment
* @return the number of milliseconds in the field
* @throws IllegalArgumentException if date can't be represented in milliseconds
* @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;
}
}
Related
- getDiffDays(String startDate, String endDate)
- getDiffDays(String startDate, String endDate)
- getDiffHour(String startTime, String endTime)
- getDiffHour(String startTime, String endTime)
- getFragment(Calendar calendar, int fragment, int unit)
- getFragmentInDays(Date date, int fragment)
- getFragmentInHours(Date date, int fragment)
- getInterval(String beginMonth, String endMonth)
- getIntervalDays(Date minDate, Date maxDate)